@article{sparks_woelfel_robertson_olby_2021, title={Association between filum terminale internum length and pain in Cavalier King Charles spaniels with and without syringomyelia}, volume={35}, ISSN={["1939-1676"]}, url={https://doi.org/10.1111/jvim.16023}, DOI={10.1111/jvim.16023}, abstractNote={AbstractBackgroundLumbar syringomyelia (SM), lumbosacral pain, and more caudal spinal cord termination are reported in Cavalier King Charles spaniels (CKCS). Data are lacking on the clinical relevance of alterations in their spinal cord terminal structures.ObjectivesTo compare spinal cord termination level and filum terminale internum length (FTIL) with presence of lumbar SM and clinical signs in CKCS.AnimalsForty‐eight CKCS.MethodsIn this prospective study, pain was quantified using owner and clinician assessments. Vertebral level of spinal cord and dural sac termination, presence of SM, and FTIL were determined from sagittal magnetic resonance imaging (MRI) sequences. Kappa and intraclass correlation (ICC) analyses determined interobserver reliability. The MRI findings were compared to owner and clinician‐reported pain quantification.ResultsInterobserver reliability was good for spinal cord and dural sac termination (kappa = 0.61 and 0.64, respectively) and excellent for FTIL (ICC: 92% agreement). The spinal cord terminated at 6th lumbar vertebra in 1, 7th lumbar vertebra in 31, and the sacrum in 15 dogs, and termination level was associated with lumbar SM (P = .002) but not clinical signs. Mean FTIL was 2.9 ± 1.08 mm; it was associated with owner‐reported pain (P = .033) and spinal palpation scores (P = .023). Painful CKCS without SM had shorter FTIL compared to normal CKCS and painful CKCS with SM (P = .02).ConclusionsPainful CKCS without SM have decreased distance between the termination of the spinal cord and dural sac, suggesting a shorter FTIL. More caudal spinal cord termination is associated with development of lumbar SM.}, number={1}, journal={JOURNAL OF VETERINARY INTERNAL MEDICINE}, author={Sparks, Courtney R. and Woelfel, Christian and Robertson, Ian and Olby, Natasha J.}, year={2021}, month={Jan}, pages={363–371} }
 @article{rivas_seiler_robertson_ryu_mathews_2019, title={Ability of positive and negative contrast computed tomographic peritoneography to delineate canine liver lobe fissures}, volume={48}, ISSN={["1532-950X"]}, DOI={10.1111/vsu.13318}, abstractNote={AbstractObjectiveTo determine the efficacy of contrast peritoneography in delineating liver lobe fissures by using computed tomography (CT).Study designProspective cross‐sectional study.AnimalsCanine cadavers (n = 10).MethodsAn abdominal CT image of each cadaver was obtained under three conditions: without peritoneal contrast (precontrast), after insufflation of the peritoneal cavity with CO2 (negative contrast), and after intraperitoneal administration of iohexol (positive contrast). Images were reconstructed in three planes. Three reviewers independently scored each plane/contrast combination. Observers measured the length of each fissure in each plane. The measurable length of fissures was compared between techniques but was not compared with the actual length on cadavers.ResultsWhen assessment of all fissures was combined, measurements were obtained in 96 to 108 of 120 (80%‐90%) positive contrast studies, 56 to 96 of 120 (47%‐80%) negative contrast studies, and 12 to 32 of 120 (10%‐27%) precontrast CT images. All observers measured fissures in all planes that were approximately two times longer on positive compared with negative contrast studies and two times longer on negative contrast studies compared with CT images without contrast. Measurable fissure lengths were greater on positive contrast CT images (P < .0001) than on other CT images.ConclusionPositive contrast CT peritoneography improved the delineation of hepatic interlobar fissures in normal canine cadavers.Clinical significanceThese results justify further studies to determine the ability to locate large hepatic masses in dogs with positive CT. Positive contrast CT peritoneography may assist treatment planning in dogs with large hepatic tumors.}, number={8}, journal={VETERINARY SURGERY}, author={Rivas, Luis R. and Seiler, Gabriela S. and Robertson, Ian D. and Ryu, Hongyu and Mathews, Kyle G.}, year={2019}, month={Nov}, pages={1444–1449} }
 @article{jones_adin_thompson_robertson_rivas_2019, title={Computed Tomography for the Diagnosis and Characterization of Dermoid Sinuses in Two Dogs}, volume={55}, ISSN={["1547-3317"]}, DOI={10.5326/JAAHA-MS-6891}, abstractNote={ABSTRACT
               A 6 mo old male castrated bloodhound–Rhodesian ridgeback mix (case 1) presented for a mass suspected to be a dermoid sinus in the thoracolumbar region, and a 2.5 yr old male castrated Rhodesian ridgeback (case 2) presented for a mass suspected to be a dorsal cervical dermoid sinus. Both dogs underwent single-phase contrast computed tomography (CT) to characterize the extent of the dermoid sinus prior to surgical excision. Soft tissue and bony abnormalities of the vertebral spine associated with the dermoid sinuses were confirmed in both dogs prior to surgery, demonstrating communication with the dura of the spinal cord. Surgical exploration and excision of the dermoid sinus was performed in each dog, including partial laminectomy. Both cases had resolution of the sinus and an uncomplicated recovery. These cases show that single-phase contrast CT was accurate in characterizing the extent of the dermoid sinus without adjunctive tests or more invasive diagnostics. Single-phase contrast CT should be considered as a preoperative method to characterize the extent of dermoid sinuses, avoiding the risks associated with myelography or fistulography and the expense of MRI. This is also the first report of a dermoid sinus in the thoracolumbar region and the first in a bloodhound and Rhodesian ridgeback mix.}, number={4}, journal={JOURNAL OF THE AMERICAN ANIMAL HOSPITAL ASSOCIATION}, author={Jones, Susan and Adin, Christopher and Thompson, Elizabeth and Robertson, Ian and Rivas, Rudy}, year={2019} }
 @article{sparks_robertson_olby_2019, title={Morphometric analysis of spinal cord termination in Cavalier King Charles Spaniels}, volume={33}, ISSN={0891-6640 1939-1676}, url={http://dx.doi.org/10.1111/jvim.15437}, DOI={10.1111/jvim.15437}, abstractNote={BackgroundThere is an association between Chiari malformations, syringomyelia (CMSM) and tethered cord syndrome (TCS) in people, suggesting Cavalier King Charles Spaniels (CKCS) with CMSM could also have TCS. Currently there are no data on the position of the caudal spinal cord structures in CKCS.ObjectiveTo describe and compare location of spinal cord termination in CKCS with weight‐matched controls and to examine the relationship between SM and spinal cord termination.AnimalsThirty‐nine CKCS and 33 controls with thoracolumbar MRIs; 34 of 39 CKCS also had cervical MRIs.MethodsBlinded retrospective study. Spinal cord and dural sac termination were determined from T2‐weighted sagittal and transverse images and half‐Fourier acquisition single‐shot turbo spin echo sequences. Intra‐observer reliability was determined using kappa analysis. Presence of SM was compared with location of spinal cord and dural sac termination.ResultsIntra‐observer reliability was moderate for identifying spinal cord termination (Kappa = 0.6) and good for dural sac termination (Kappa = 0.8). The spinal cord terminated at lumbar vertebra 6 (L6) in 1, 7 (L7) in 22, and sacrum in 16 CKCS versus 9 at L6, 23 at L7, 1 at sacrum in controls. Spinal cord (P < .001) and dural sac (P = .002) termination were significantly more caudal in CKCS compared to controls. The presence of thoracolumbar SM was associated with more caudal dural sac termination in CKCS (P = .03).Conclusions and Clinical ImportanceThe relationship between TL SM and possible spinal cord tethering because of a more caudal dural sac termination should be investigated.}, number={2}, journal={Journal of Veterinary Internal Medicine}, publisher={Wiley}, author={Sparks, Courtney R. and Robertson, Ian and Olby, Natasha J.}, year={2019}, month={Feb}, pages={717–725} }
 @article{jones_savage_naughton_singh_robertson_roe_marcellin-little_mathews_2018, title={Influence of Radiographic Positioning on Canine Sacroiliac and Lumbosacral Angle Measurements}, volume={31}, ISSN={["2567-6911"]}, DOI={10.3415/vcot-17-04-0052}, abstractNote={
            Objectives To evaluate the influence of radiographic malpositioning on canine sacroiliac and lumbosacral inclination angles.
            Methods Using canine cadavers, lateral pelvic radiographs were acquired with the radiographic beam in a neutral position and then rotated 5, 10 and 15° to mimic rotational malpositioning. The focal point of the beam was then focused over the abdomen and again over mid-diaphysis of the femur to mimic an abdominal or femoral radiographic study.
            Results Five degrees of rotational malpositioning did not influence measurements of sacroiliac or lumbosacral inclination, but malpositioning by more than 5° led to a significant decrease in both sacroiliac and lumbosacral angles. Moving the focal point to the femur significantly decreased the measured lumbosacral angle. Abdominally centred radiographs had no effect on lumbosacral and sacroiliac angle measurements.
            Clinical Significance When evaluating canine lumbosacral and sacroiliac angles radiographically, pelvic rotation of more than 5° should be avoided as should the use of lateral radiographs centred over the femur.}, number={1}, journal={VETERINARY AND COMPARATIVE ORTHOPAEDICS AND TRAUMATOLOGY}, author={Jones, Susan and Savage, Mason and Naughton, Brian and Singh, Susheela and Robertson, Ian and Roe, Simon C. and Marcellin-Little, Denis J. and Mathews, Kyle G.}, year={2018}, month={Jan}, pages={30–36} }
 @article{mariani_jennings_olby_borst_brown_robertson_seiler_mackillop_2015, title={Histiocytic Sarcoma with Central Nervous System Involvement in Dogs: 19 Cases (2006-2012)}, volume={29}, ISSN={0891-6640}, url={http://dx.doi.org/10.1111/jvim.12554}, DOI={10.1111/jvim.12554}, abstractNote={BackgroundReports of histiocytic sarcoma (HS) involving the central nervous system (CNS) are sparse and consist mainly of case reports describing 1–3 animals.ObjectiveThe objective of this study was to report the signalments, clinical signs, clinicopathologic and diagnostic imaging findings, treatment, and outcome of a series of dogs with HS and CNS involvement.AnimalsNineteen dogs with HS examined at veterinary referral hospitals.MethodsRetrospective case series. Medical records were reviewed and cases with a histopathological diagnosis of CNS HS were included in the study. Diagnostic imaging studies of the CNS were evaluated and histopathologic samples were reviewed to confirm the diagnosis.ResultsRetrievers and Pembroke Welsh Corgis were overrepresented in this cohort of dogs. Tumors involved the brain in 14 dogs and the spinal cord in 5. In 4 dogs, HS was part of a disseminated, multiorgan process whereas it appeared confined to the CNS in 15 dogs. Diagnostic imaging had variable appearances although extraaxial masses predominated in the brain. There was meningeal enhancement in all dogs that was often profound and remote from the primary mass lesion. Pleocytosis was present in all dogs with CSF evaluation. Median survival was 3 days.Conclusions and Clinical ImportanceBreed predispositions appear to vary from reports of HS in other organ systems. Some unique imaging and clinicopathologic characteristics, particularly brain herniation, profound meningeal enhancement, and pleocytosis in combination with 1 or more mass lesions, might help to differentiate this neoplasm from others involving the CNS, although this requires further study.}, number={2}, journal={Journal of Veterinary Internal Medicine}, publisher={Wiley}, author={Mariani, C.L. and Jennings, M.K. and Olby, N.J. and Borst, L.B. and Brown, J.C., Jr and Robertson, I.D. and Seiler, G.S. and MacKillop, E.}, year={2015}, month={Feb}, pages={607–613} }
 @article{oura_young_keene_robertson_jennings_thrall_2015, title={A VALENTINE-SHAPED CARDIAC SILHOUETTE IN FELINE THORACIC RADIOGRAPHS IS PRIMARILY DUE TO LEFT ATRIAL ENLARGEMENT}, volume={56}, ISSN={["1740-8261"]}, DOI={10.1111/vru.12221}, abstractNote={Conflicting information has been published regarding the cause of a valentine‐shaped cardiac silhouette in dorsoventral or ventrodorsal thoracic radiographs in cats. The purpose of this retrospective, cross‐sectional study was to test the hypothesis that the valentine shape is primarily due to left atrial enlargement. Images for cats with a radiographic valentine‐shaped cardiac silhouette and full echocardiography examination were retrieved and independently reviewed. A subjective scoring system was used to record severity of radiographic valentine shape. Subjective radiographic evidence of left atrial enlargement in a radiographic lateral projection and a final diagnosis based on medical records were also recorded. A total of 81 cats met inclusion criteria. There was a strong positive correlation (P < 0.001) between echocardiographic left atrial size and severity of radiographic valentine shape. There was no effect of echocardiographic right atrial size on the severity of valentine shape, except when concurrent with severe left atrial enlargement. In this situation, right atrial enlargement increased the likelihood of observing a severe valentine shape. There was no effect of right atrial enlargement on the shape of the cardiac silhouette when left atrial enlargement was absent or only mild to moderate. There was no correlation between the category of final diagnosis of cardiac disease and the severity of valentine shape. Findings from this study supported the hypothesis that a valentine‐shaped cardiac silhouette in radiographs is due primarily to left atrial enlargement in cats, with right atrial enlargement only impacting the shape if concurrent with severe left atrial enlargement.}, number={3}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Oura, Trisha J. and Young, Aisha N. and Keene, Bruce W. and Robertson, Ian D. and Jennings, Dennis E. and Thrall, Donald E.}, year={2015}, pages={245–250} }
 @article{fukuda_kobayashi_robertson_oshima_fukazawa_nakano_ono_thrall_2014, title={COMPUTED TOMOGRAPHIC FEATURES OF CANINE NONPARENCHYMAL HEMANGIOSARCOMA}, volume={55}, ISSN={["1740-8261"]}, DOI={10.1111/vru.12136}, abstractNote={The purpose of this retrospective study was to describe pre‐ and postcontrast computed tomographic (CT) characteristics of confirmed nonparenchymal hemangiosarcoma in a group of dogs. Medical records were searched during the period of July 2003 and October 2011 and dogs with histologically confirmed nonparenchymal hemangiosarcoma and pre‐ and postcontrast CT images were recruited. Two observers recorded a consensus opinion for the following CT characteristics for each dog: largest transverse tumor diameter, number of masses, general tumor shape, character of the tumor margin, precontrast appearance, presence of dystrophic calcification, presence of postcontrast enhancement, pattern of postcontrast enhancement, presence of regional lymphadenopathy, and presence of associated cavitary fluid. A total of 17 dogs met inclusion criteria. Tumors were located in the nasal cavity, muscle, mandible, mesentery, subcutaneous tissue, and retroperitoneal space. Computed tomographic features of nonparenchymal hemangiosarcoma were similar to those of other soft tissue sarcomas, with most tumors being heterogeneous in precontrast images, invasive into adjacent tissue, and heterogeneously contrast enhancing. One unexpected finding was the presence of intense foci of contrast enhancement in 13 of the 17 tumors (76%). This appearance, which is not typical of other soft tissue sarcomas, was consistent with contrast medium residing in vascular channels. Findings indicated that there were no unique distinguishing CT characteristics for nonparenchymal hemangiosarcoma in dogs; however, the presence of highly attenuating foci of contrast enhancement may warrant further investigation in prospective diagnostic sensitivity and treatment outcome studies.}, number={4}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Fukuda, Shoko and Kobayashi, Tetsuya and Robertson, Ian D. and Oshima, Fukiko and Fukazawa, Eri and Nakano, Yuko and Ono, Shin and Thrall, Donald E.}, year={2014}, pages={374–379} }
 @article{copple_robertson_thrall_samei_2013, title={EVALUATION OF TWO OBJECTIVE METHODS TO OPTIMIZE KVP AND PERSONNEL EXPOSURE USING A DIGITAL INDIRECT FLAT PANEL DETECTOR AND SIMULATED VETERINARY PATIENTS}, volume={54}, ISSN={["1740-8261"]}, DOI={10.1111/j.1740-8261.2012.01989.x}, abstractNote={It is important to optimize digital radiographic technique settings for small animal imaging in order to maximize image quality while minimizing radiation exposure to personnel. The purpose of this study was to evaluate two objective methods for determining optimal kVp values for an indirect flat panel digital detector. One method considered both image quality and personnel exposure as endpoints and one considered only image quality. Phantoms simulated veterinary patients of varying thicknesses with lesions of varying sizes. Phantoms were exposed to a range of kVp values (60, 81, 100, and 121), using different mAs settings for each phantom. Additionally, all phantoms were exposed to a standard test exposure of 100 kVp/2.5 mAs. Scattered radiation was recorded and used as a measure of personnel exposure. When personnel exposure was considered, a figure of merit was calculated as an endpoint of optimization. The optimal kVp value for each phantom was determined based on the highest signal difference‐to‐noise ratio with or without inclusion of the figure of merit. When personnel exposure was not considered, increasing kVp resulted in higher signal difference‐to‐noise ratios and personnel exposure increased when both patient thickness and kVp increased. Findings indicated that a single standard technique of 100 kVp/2.5 mAs was only optimal for most medium‐sized patients. Images of thinner patients should be made with a lower kVp. Very large patients require a higher kVp than 100 regardless of the optimization method used. Personnel exposure from optimized techniques was low and not expected to exceed annual occupational dose limits.}, number={1}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Copple, Christina and Robertson, Ian D. and Thrall, Donald E. and Samei, Ehsan}, year={2013}, pages={9–16} }
 @article{fields_robertson_osborne_brown_2012, title={COMPARISON OF ABDOMINAL COMPUTED TOMOGRAPHY AND ABDOMINAL ULTRASOUND IN SEDATED DOGS}, volume={53}, ISSN={["1740-8261"]}, DOI={10.1111/j.1740-8261.2012.01949.x}, abstractNote={Abdominal ultrasound (US) is used frequently as a first‐line screening tool for abdominal disease. Although computed tomography (CT) is superior to US in the diagnosis of some abdominal diseases, a major impediment is the requirement of general anesthesia to prevent motion and for safe restraint. With multidetector helical CT, faster examinations allow general anesthesia to be avoided, while producing diagnostic‐quality images. Abdominal US and CT were compared for lesion detection in 27 sedated dogs, divided into three even groups based on body weight. Lesions were categorized further as to subjective clinical relevance. In dogs less than 25 kg, there is no significant difference in lesion detection between CT and US. In dogs weighing greater than 25 kg, more lesions were detected with CT than with US (P = 0.0001), including clinically relevant lesions (P = 0.0277). From these results, it appears that CT has an advantage in lesion detection in dogs greater than 25 kg, making it a better screening test for abdominal disease in these patients.}, number={5}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Fields, Erica L. and Robertson, Ian D. and Osborne, Jason A. and Brown, James C., Jr.}, year={2012}, pages={513–517} }
 @article{fields_robertson_brown_2012, title={OPTIMIZATION OF CONTRAST-ENHANCED MULTIDETECTOR ABDOMINAL COMPUTED TOMOGRAPHY IN SEDATED CANINE PATIENTS}, volume={53}, ISSN={["1058-8183"]}, DOI={10.1111/j.1740-8261.2012.01950.x}, abstractNote={A major disadvantage of computed tomography for abdominal screening in dogs has been the need for general anesthesia to prevent motion artifacts. With multidetector helical CT, it is possible to decrease examination time, allowing patients to be scanned under sedation. It is also desirable to decrease tube loading to prolong x‐ray tube life. To develop a protocol that will allow for examination of sedated patients with minimal image artifacts, milliamperage (mA) and helical pitch were varied, providing 16 experimental scan protocols. A standard clinical protocol was also tested, providing 17 protocols for evaluation. These protocols were tested, using a standard CT phantom, canine tissues in a water bath, and a canine cadaver. The cadaver images were scored semiquantitatively by three reviewers to determine the protocol with the best combination of speed and minimal image artifact. The optimized protocol was then applied to 27 sedated canine patients of three body weight categories. The images obtained were compared to the standard protocol by two reviewers for presence of motion, streak, and quantum mottle artifacts. There was significantly more streak artifact noted by one observer using the optimized study protocol, but no significant difference in any other category. Scanning under sedation was well tolerated in all patients, and sedated CT examination is a promising tool for screening abdominal disease in dogs.}, number={5}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Fields, Erica L. and Robertson, Ian D. and Brown, James C., Jr.}, year={2012}, pages={507–512} }
 @article{seiler_robertson_mai_widmer_suran_nemanic_lamb_lang_johnson_thrall_2012, title={USEFULNESS OF A HALF-FOURIER ACQUISITION SINGLE-SHOT TURBO SPIN-ECHO PULSE SEQUENCE IN IDENTIFYING ARACHNOID DIVERTICULA IN DOGS}, volume={53}, ISSN={["1058-8183"]}, DOI={10.1111/j.1740-8261.2011.01893.x}, abstractNote={Single‐shot turbo spin‐echo sequences are heavily T2‐weighted sequences that are exceptionally well suited to evaluate the subarachnoid space. In the T2‐weighted fast spin‐echo sequences that are used routinely in spinal magnetic resonance (MR) imaging, the subarachnoid space is not well differentiated from the surrounding epidural fat, which could lead to decreased detection of lesions of the subarachnoid space such as arachnoid diverticula. Our purpose was to determine the added value of a single‐shot turbo spin‐echo sequence in identifying cystic lesions of the subarachnoid space in dogs. MR images of six dogs with a confirmed arachnoid diverticulum and 24 dogs with other spinal disease were included. Six observers were asked to interpret only T2‐weighted images initially, and in a second session, T2‐weighted and half‐Fourier acquisition single‐shot turbo spin‐echo (HASTE) sequences. The MR images were anonymized, and no signalment, history, or clinical information was provided. Without the HASTE sequences, 25% of arachnoid diverticula were identified. Adding the HASTE sequence increased the diagnosis of arachnoid diverticulum to 52.8%. The resulting difference, after adding the HASTE sequence, of 27.8% was statistically significant (P = 0.002). No false‐positive diagnoses of arachnoid diverticulum were made with either sequence. Although sensitivity in this study was likely artificially low, the significantly increased detection rate of arachnoid diverticula when using HASTE imaging indicates that this sequence is a valuable addition to MR imaging protocols for the canine spine.}, number={2}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Seiler, Gabriela S. and Robertson, Ian D. and Mai, Wilfried and Widmer, William R. and Suran, Jantra and Nemanic, Sarah and Lamb, Christopher R. and Lang, Johann and Johnson, Jeffrey L. and Thrall, Donald E.}, year={2012}, pages={157–161} }
 @article{boyle_hawkins_davis_robertson_2011, title={Failure of nebulized irritant, acidic, or hypotonic solutions or external mechanical stimulation of the trachea to consistently induce coughing in healthy, awake dogs}, volume={75}, number={3}, journal={Canadian Journal of Veterinary Research}, author={Boyle, T. E. and Hawkins, E. C. and Davis, J. L. and Robertson, I. D.}, year={2011}, pages={228–232} }
 @article{robertson_thrall_2011, title={IMAGING DOGS WITH SUSPECTED DISC HERNIATION: PROS AND CONS OF MYELOGRAPHY, COMPUTED TOMOGRAPHY, AND MAGNETIC RESONANCE}, volume={52}, ISSN={["1058-8183"]}, DOI={10.1111/j.1740-8261.2010.01788.x}, abstractNote={Myelography, computed tomography (CT), and magnetic resonance (MR) imaging are the diagnostic modalities currently used in the evaluation of dogs with suspected disc herniation. Where high‐field MR imaging is available, it is considered the optimal modality for any myelopathy in dogs, including those with disc disease. CT myelography may be the next best option, particularly in nonchondrodystrophoid dogs. In chondrodystrophoid dogs, in which extrusion of mineralized disc material is common, plain CT will enable diagnosis in most cases. Myelography is still considered adequate for diagnosis of disc herniation when MR and CT are unavailable.}, number={1}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Robertson, Ian and Thrall, Donald E.}, year={2011}, pages={S81–S84} }
 @article{tidwell_robertson_2011, title={MAGNETIC RESONANCE IMAGING OF NORMAL AND ABNORMAL BRAIN PERFUSION}, volume={52}, ISSN={["1740-8261"]}, DOI={10.1111/j.1740-8261.2010.01786.x}, abstractNote={The brain is highly susceptible to injury from any process that deprives its cells of oxygen, glucose, and other essential nutrients, and is therefore critically dependent on blood flow or perfusion. With hypoperfusion or ischemia, blood flow to the brain may be diminished to a level incompatible with normal function, eventually leading to acute ischemic stroke. Magnetic resonance (MR) imaging is one of several imaging methods used to evaluate brain perfusion and stroke. Using a multisequence approach comprised of conventional spin echo, inversion recovery, and heme‐sensitive gradient echo pulse sequences, MR angiography, and diffusion and perfusion sensitive techniques, MR imaging is capable of identifying vascular lesions, measuring abnormal blood flow, and depicting the metabolic and structural consequences of ischemia. MR imaging objectives and strategies for the diagnosis of acute ischemic stroke in humans and animals, terminology, pathophysiology, and normal vascular anatomy are reviewed.}, number={1}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Tidwell, Amy S. and Robertson, Ian D.}, year={2011}, pages={S62–S71} }
 @article{robertson_2011, title={OPTIMAL MAGNETIC RESONANCE IMAGING OF THE BRAIN}, volume={52}, ISSN={["1058-8183"]}, DOI={10.1111/j.1740-8261.2010.01781.x}, abstractNote={Quality magnetic resonance (MR) imaging is complex and requires optimization of many technical factors. The most important factors are: magnet field and gradient strengths, coil selection, receiver bandwidth, field of view and image matrix size, number of excitations, slice thickness, image weighting and contrast, imaging planes and the direction of the phase, and frequency gradients. The ability to augment a standard MR study with additional sequences, and the need to ensure the completed study is comprehensive and robust must be balanced against the time the patient spends under anesthesia in the magnet.}, number={1}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Robertson, Ian}, year={2011}, pages={S15–S22} }
 @article{freire_robertson_bondell_brown_hash_pease_lascelles_2011, title={RADIOGRAPHIC EVALUATION OF FELINE APPENDICULAR DEGENERATIVE JOINT DISEASE VS. MACROSCOPIC APPEARANCE OF ARTICULAR CARTILAGE}, volume={52}, ISSN={["1058-8183"]}, url={https://dx.doi.org/10.1111/j.1740-8261.2011.01803.x}, DOI={10.1111/j.1740-8261.2011.01803.x}, abstractNote={Degenerative joint disease (DJD) is common in domesticated cats. Our purpose was to describe how radiographic findings thought to indicate feline DJD relate to macroscopic cartilage degeneration in appendicular joints. Thirty adult cats euthanized for reasons unrelated to this study were evaluated. Orthogonal digital radiographs of the elbow, tarsus, stifle, and coxofemoral joints were evaluated for the presence of DJD. The same joints were dissected for visual inspection of changes indicative of DJD and macroscopic cartilage damage was graded using a Total Cartilage Damage Score. When considering all joints, there was statistically significant fair correlation between cartilage damage and the presence of osteophytes and joint‐associated mineralizations, and the subjective radiographic DJD score. Most correlations were statistically significant when looking at the different joints individually, but only the correlation between the presence of osteophytes and the subjective radiographic DJD score with the presence of cartilage damage in the elbow and coxofemoral joints had a value above 0.4 (moderate correlation). The joints most likely to have cartilage damage without radiographic evidence of DJD are the stifle (71% of radiographically normal joints) followed by the coxofemoral joint (57%), elbow (57%), and tarsal joint (46%). Our data support radiographic findings not relating well to cartilage degeneration, and that other modalities should be evaluated to aid in making a diagnosis of feline DJD.}, number={3}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Freire, Mila and Robertson, Ian and Bondell, Howard D. and Brown, James and Hash, Jon and Pease, Anthony P. and Lascelles, B. Duncan X.}, year={2011}, pages={239–247} }
 @article{labens_schramme_robertson_thrall_redding_2010, title={CLINICAL, MAGNETIC RESONANCE, AND SONOGRAPHIC IMAGING FINDINGS IN HORSES WITH PROXIMAL PLANTAR METATARSAL PAIN}, volume={51}, ISSN={["1740-8261"]}, DOI={10.1111/j.1740-8261.2009.01614.x}, abstractNote={Sonography is commonly used for diagnosis of desmopathy of the proximal part of the suspensory ligament in horses. However, magnetic resonance (MR) imaging has been stated to be superior for detecting disease and localizing lesions. In this retrospective study of 39 horses or 46 hind limbs with lameness due to proximal plantar metatarsal pain, the clinical and diagnostic findings are discussed and sonography and MR imaging compared for examination of the proximal part of the suspensory ligament. With MR imaging interpreted as the clinical gold standard, desmopathy of the proximal part of the suspensory ligament was diagnosed in 21 hind limbs, proximal plantar metatarsal pain of unknown cause in 12, an osseous injury at the origin of the suspensory ligament in four and a condition unrelated to the suspensory ligament in nine. Based on these findings, sonography had a sensitivity of 0.77 and 0.66 and specificity of 0.33 and 0.31 for diagnosing proximal suspensory desmopathy and for accurately localizing lesions, respectively. MR imaging changes consistent with proximal suspensory desmopathy were signal hyperintensities and an increase in cross‐sectional area compared with the contralateral limb. Anesthesia of the deep branch of the lateral plantar nerve is not specific neither for proximal suspensory desmopathy, as conditions unrelated to the suspensory ligament were diagnosed, nor for diagnosis of proximal plantar metatarsal pain, as conditions outside the proximal plantar metatarsal region were also diagnosed.}, number={1}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Labens, Raphael and Schramme, Michael C. and Robertson, Ian D. and Thrall, Donald E. and Redding, W. Rich}, year={2010}, pages={11–18} }
 @article{thames_robertson_flegel_henke_o'brien_coates_olby_2010, title={Development of a morphometric magnetic resonance image parameter suitable for distinguishing between normal dogs and dogs with cerebellar atrophy}, volume={51}, number={3}, journal={Veterinary Radiology & Ultrasound}, author={Thames, R. A. and Robertson, I. D. and Flegel, T. and Henke, D. and O'Brien, D. P. and Coates, J. R. and Olby, N. J.}, year={2010}, pages={246–253} }
 @article{seiler_robertson_mukundan_thrall_2011, title={IMAGING DIAGNOSIS-MAGNETIC RESONANCE IMAGING PULSATILITY ARTIFACT IN THE CANINE CERVICAL SPINE}, volume={52}, ISSN={["1740-8261"]}, DOI={10.1111/j.1740-8261.2010.01769.x}, abstractNote={Pulsatile venous flow in the internal vertebral venous plexus of the cervical spine can lead to vertical, linear T2‐hyperintensities in the spinal cord at the cranial aspect of C3 and C4 in transverse T2‐weighted images in large breed dogs that are not accompanied by ghosting. The artifact is more conspicuous in pre‐ and postcontrast transverse T1‐weighted images and is accompanied by ghosting in that sequence, typical of a pulsatility artifact. A flow‐related artifact was confirmed as the cause for this appearance by noting its absence after either exchange of phase and frequency encoding direction or by flow compensation. Care should be exercised to avoid misdiagnosing this pulsatility artifact seen in transverse T2‐weighted images of the midcervical spine in large dogs as an intramedullary lesion when T1‐images or phase‐swap images are not available to confirm its artifactual origin.}, number={3}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Seiler, Gabriela S. and Robertson, Ian D. and Mukundan, Srinivasan and Thrall, Donald E.}, year={2011}, pages={313–316} }
 @article{asakawa_mackillop_olby_robertson_cullen_2010, title={Imaging diagnosis-neuronal ceroid lipofuscinosis with a chronic subdural hematoma}, volume={51}, number={2}, journal={Veterinary Radiology & Ultrasound}, author={Asakawa, M. G. and Mackillop, E. and Olby, N. J. and Robertson, I. D. and Cullen, J. M.}, year={2010}, pages={155–158} }
 @article{gonzalez_schramme_robertson_thrall_redding_2010, title={MRI FEATURES OF METACARPO(TARSO)PHALANGEAL REGION LAMENESS IN 40 HORSES}, volume={51}, ISSN={1058-8183 1740-8261}, url={http://dx.doi.org/10.1111/j.1740-8261.2010.01676.x}, DOI={10.1111/j.1740-8261.2010.01676.x}, abstractNote={Lameness originating from the metacarpo(tarso)phalangeal (MP) joint has a significant effect on the use and athletic competitiveness of a horse. The identification of the cause of lameness originating from the MP joint can be challenging, given the limitations of radiography, ultrasonography, and nuclear scintigraphy. Our purpose was to describe the injury types and incidence in magnetic resonance imaging (MRI) studies from 40 horses with lameness attributable to the MP joint region where it was not possible to reach a clinically plausible diagnosis using other imaging modalities. Horses were examined in a 1.5 T magnet (Siemens Medical Solutions) under general anesthesia. The frequency of occurrence of MR lesions was subchondral bone injury (19), straight or oblique distal sesamoidean desmitis (13), articular cartilage injury and osteoarthritis (eight), suspensory branch desmitis (seven), osteochondral fragmentation (seven), proximal sesamoid bone injury (seven), inter-sesamoidean desmitis (four), deep digital flexor tendonitis (four), collateral desmitis (three), superficial digital flexor tendonitis (two), enostosis-like lesions of the proximal phalanx or MCIII (two), desmitis of the palmar annular ligament (one), desmitis of the proximal digital annular ligament (one), and dystrophic calcification of the lateral digital extensor tendon (one). Twenty-five horses had multiple MR abnormalities. MRI provided information that was complementary to radiography, ultrasonography, and nuclear scintigraphy and that allowed for a comprehensive evaluation of all structures in the MP joint region and a diagnosis in all 40 horses.}, number={4}, journal={Veterinary Radiology & Ultrasound}, publisher={Wiley}, author={Gonzalez, Liara M. and Schramme, Michael C. and Robertson, Ian D. and Thrall, Donald E. and Redding, Rich W.}, year={2010}, month={Apr}, pages={404–414} }
 @article{freire_brown_robertson_pease_hash_hunter_simpson_sumrell_lascelles_2010, title={Meniscal Mineralization in Domestic Cats}, volume={39}, ISSN={["0161-3499"]}, url={https://dx.doi.org/10.1111/j.1532-950x.2010.00648.x}, DOI={10.1111/j.1532-950x.2010.00648.x}, abstractNote={OBJECTIVE
To (1) determine prevalence of radiographically detectable meniscal mineralization in domestic cats and (2) to evaluate the association between meniscal mineralization and degenerative joint disease (DJD).


STUDY DESIGN
Prospective study.


ANIMALS
Client-owned cats (n=100) and 30 feline cadavers.


METHODS
Randomly selected client-owned cats were used to determine the prevalence of meniscal mineralization. Stifles from feline cadavers were used to evaluate the relationship between meniscal mineralization (using high-resolution X-ray), radiographic DJD, and cartilage damage. Menisci were evaluated histologically.


RESULTS
Forty-six percent of the client-owned cats had meniscal mineralization detected in 1 or both stifles. Pain scores were not significantly different between stifles with meniscal mineralization and those with no radiographic pathology (P=.38). Thirty-four of 57 cadaver stifles had meniscal mineralization, which was always located in the cranial horn of the medial meniscus. Percentage mineralization of the menisci was significantly correlated with the cartilage damage score of the medial femoral (r(2)=0.6; P<.0001) and tibial (r(2)=0.5; P<.0001) condyles as well as with the total joint cartilage damage (r(2)=0.36; P<.0001) score and DJD score (r(2)=0.8; P<.0001).


CONCLUSION
Meniscal mineralization is a common condition in domestic cats and seems to indicate medial compartment DJD.


CLINICAL RELEVANCE
Clinical significance of meniscal mineralization is uncertain. Further work is needed to determine if the meniscal mineralization is a cause, or a consequence of joint degeneration.}, number={5}, journal={VETERINARY SURGERY}, author={Freire, Mila and Brown, James and Robertson, Ian D. and Pease, Anthony P. and Hash, Jonathan and Hunter, Stuart and Simpson, Wendy and Sumrell, Andrea Thomson and Lascelles, B. Duncan X.}, year={2010}, month={Jul}, pages={545–552} }
 @article{levine_zhou_ghiloni_fields_birkenheuer_gookin_roberston_malloy_feldman_2009, title={Hereditary 1,25-Dihydroxyvitamin D-Resistant Rickets in a Pomeranian Dog Caused by a Novel Mutation in the Vitamin D Receptor Gene}, volume={23}, ISSN={["1939-1676"]}, DOI={10.1111/j.1939-1676.2009.0405.x}, abstractNote={Hypocalcemic rickets encompasses a group of disorders in which intestinal absorption of calcium is insufficient to meet the calcium demands of a growing skeleton. Causes include dietary calcium deficiency and insufficient intestinal absorption of calcium caused by vitamin D deficiency or decreased vitamin D activity. Hereditary disorders of vitamin D documented in humans include vitamin D-dependent rickets type I (VDDR-I), in which there is a deficiency of the renal enzyme (1α-hydroxylase) that converts 25-hydroxyvitamin D3 to the active hormone 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3 or calcitriol) and vitamin D-dependent rickets type II (VDDR-II) in which there is end-organ resistance to the active hormone. The latter is usually secondary to defects in the vitamin D receptor (VDR). VDDR-II is currently more commonly termed hereditary vitamin D-resistant rickets (HVDRR). We describe a case of rickets in a juvenile dog that led us to investigate potential hereditary vitamin D disorders and resulted in the documentation of HVDRR in a dog. The disease is characterized by hypocalcemia, secondary hyperparathyroidism, hypomineralization of bones, rickets, and in some cases, alopecia. An intact female Pomeranian dog was initially evaluated by one of the authors at 2 months of age for nonpruritic alopecia of the head and rear limbs. The remainder of the dog's physical examination at that time was unremarkable. A skin scraping was negative. The dog and her half-sibling (same sire, different dam) had been obtained from a breeder a few days before examination. The half-sibling was the same age as the affected dog, and was normal in appearance. Both dogs were eating a commercial puppy food. At 4 months of age, the affected dog appeared to tire easily when playing. On physical examination, there was lateral bowing of the antebrachium of both forelimbs and palpable thickening of the distal radii. The alopecia had become more generalized and remained nonpruritic (Fig 1). A serum biochemistry profile revealed marked hypocalcemia (total calcium 5.5 mg/dL; reference range 8.9–11.4 mg/dL) with a normal albumin concentration, hyperphosphatemia (phosphate 7.3 mg/dL; reference range 2.5–6 mg/dL), and increased alkaline phosphatase (ALP) (829 U/L; reference range 5–131 U/L). Blood urea nitrogen (BUN) and creatinine, complete blood count, and serum thyroxine (total thyroxine 2.7 μg/dL; reference range 1.0–4.0 μg/dL) were all within normal limits. Photograph of the affected dog at 3 months of age demonstrating the remarkable alopecia. The photograph shows partial alopecia on the ventral chest, in the perineal area, and on the caudo-medial aspect of thighs. In the areas where hair is present, it is thin, likely because of a decreased amount of secondary hairs. The normal half-sibling is pictured to the right for comparison. The dog was reevaluated at 5 months of age for intermittent lameness while playing. Although her alopecia was resolving, her abnormal forelimb conformation persisted. Radiographs showed widening and abnormal lucency (decreased mineralization) of the distal radial and ulnar physes, with sclerosis and widening of the adjacent epiphyses and metaphyses (Fig 2A and B). Persistent hypocalcemia (total calcium 5.7 mg/dL) and low-ionized calcium (0.66 mmol/L; reference range 1.24–1.43 mmol/L) were documented, along with hyperparathyroidism (intact parathyroid hormone [PTH] 739 pg/mL; reference range 27–155 pg/mL).a Pre- and postprandial serum concentrations of bile acids were within reference range. On the basis of hypocalcemia, hyperparathyroidism, and the skeletal abnormalities, a provisional diagnosis was a vitamin D-dependent form of rickets. Treatment with oral calcium supplementation (calcium carbonateb 29 mg/kg PO q24h) and 1,25(OH)2D3c (43 ng/kg PO q24h) was initiated. Lateral (A) and dorsopalmar (B) radiographs of the right carpus acquired at 5 months of age before initiation of treatment. There is widening and increased lucency of the distal radial and ulnar physes with irregular (frayed) metaphyseal margins and flaring of the adjacent epiphyses and metaphyses. Lateral (C) and dorsopalmar (D) radiographs of the right carpus acquired at 8.5 months of age, 3.5 months after initiation of treatment. The distal antebrachial physes appear more normal in width, opacity, and margination. Evidence of distal metaphyseal remodeling is present. Total serum calcium concentrations were persistently low (ranging from 4.9 to 6.2 mg/dL) despite consistent increases in oral calcium and 1,25(OH)2D3 supplementation to doses well above standard recommendations (25–50 mg/kg/d of calcium carbonate and 20–30 ng/kg/d 1,25(OH)2D3)1 (Table 1). At 7 months of age, the dog had a generalized seizure that was controlled by administration of diazepam. At the time of the seizure, total serum calcium concentration was 5.7 mg/dL (reference range 7.9–12 mg/dL).d The dog was referred to the Internal Medicine Service of North Carolina State University, College of Veterinary Medicine (NCSU CVM) for further evaluation. On examination, the dog was bright and alert and interactive. Her conformation was unusual, with the forelimbs being shorter than the hind limbs, and slightly bowed laterally. Despite prior resolution of the alopecia, the affected dog's coat was of poorer quality than that of her half-sibling. The remainder of the physical examination was unremarkable. A serum biochemistry profile confirmed persistent hypocalcemia (6.3 mg/dL; reference range 9.2–11.6 mg/dL), with normal serum phosphorous concentration (5.7 mg/dL; 2–6.7 mg/dL) and renal values (BUN and creatinine). There was high PTH (91 pmol/L; 3–17 pmol/L),e increased ALP (486 U/L; 14–120 U/L), low 25-hydroxyvitamin D (43 nmol/L; 60–215 nmol/L),e and low-ionized calcium (0.94 mmol/L; 1.25–1.45 mmol/L)e concentration in serum. Rickets due to vitamin D resistance was suspected because of the lack of response to high-dose therapy with 1,25(OH)2D3. Since the dog did not respond to oral calcium supplementation, calcium (12.5 mg/kg SQ q24h)f was administered parenterally. 1,25(OH)2D3 therapy (75 ng/kg PO q24h) was continued. At 8 months of age, while still receiving 1,25(OH)2D3, serum 1,25(OH)2D3 concentrationg was measured to definitively differentiate between vitamin D deficiency and the two types of vitamin D-dependent rickets, type-I and type-II (HVDRR). The dog's serum 1,25(OH)2D3 concentration was over 20-fold greater than the upper end of the reference range (1,017 pb/mL; 25–50 pg/mL) despite persistent hypocalcemia (total calcium 5.4 mg/dL; 8.9–11.4 mg/dL). The increased concentration of 1,25 (OH)2D3 was consistent with a diagnosis of HVDRR. In this case, even though the dog was being supplemented with 1,25(OH)2D3, HVDRR was considered likely because high-circulating concentrations of 1,25(OH)2D3 were ineffective in raising serum calcium concentrations, confirming 1,25(OH)2D3 resistance. Oral calcium carbonate therapy was reinitiated at this time (75 mg/kg PO q24h) in addition to the 1,25(OH)2D3 supplementation and daily SQ calcium injections. At 8.5 months of age, the dog became acutely paraplegic in the hind limbs and depressed. The dog was evaluated by her local veterinarian, where total calcium concentration was determined to be 4.0 mg/dL (reference range 7.9–12 mg/dL). The veterinarian administered calcium IM (25 mg/kg IM once)f and referred the dog to the Emergency Service at NCSU. On examination, the dog was opisthotonic and tetanic, stuporous, weak, and believed to be having frequent focal seizures. Ionized calcium was 0.61 mmol/L (reference range 1.11–1.40 mmol/L). Calcium gluconate (100 mg/kg IV once)h was administered slowly, followed by a continuous rate infusion of calcium (10 mg/kg/h IV).h The dog continued to have seizure-like activity and muscle tetany, despite normalization of serum-ionized calcium (0.91 mmol/L) and a normal ECG. Tetany and seizure activity were controlled with midazolami (0.5 mg/kg IV once, then 0.3 mg/kg/h IV). After initial stabilization, a neurologic examination revealed signs attributable to diffuse forebrain disease (variably obtunded to stuporous, intermittent lateral strabismus in both eyes, bilateral miotic pupils, and reduced nasal sensation bilaterally) and hind limb paresis (exaggerated pelvic limb segmental spinal reflexes, absent deep pain in both pelvic limbs and the tail). The forebrain signs were attributed to hypocalcemia exacerbated by potential cerebral edema. The pelvic limb paresis suggested a T3–L3 spinal lesion. Pain management was instituted with fentanyl (2 mcg/kg IV PRN).j Spinal radiographs were suggestive of a compression fracture of the vertebral body of T11, although a congenital deformity could not be ruled out (Fig 3A). Computed tomography confirmed the fracture of T11 and showed accompanying spinal cord compression. Flaring of the ribs at the costochondral junctions (so-called rachitic rosary in people) was also readily apparent on radiographs (Fig 3B). Radiographs of the distal radial and ulnar growth plates, however, showed progressive improvement in mineralization compared with the images taken at 5 months of age (Fig 2C and D). Radiographs at 8.5 months, 3.5 months after initiation of treatment. (A) Lateral radiograph of the spine at the thoracolumbar junction. There is generalized osteopenia, the T11 vertebral body is wedged shaped, and there is concavity of the ventral margin of the vertebral body. These changes are highly suggestive of a pathologic compression fracture, although a preexisting vertebral body anomaly could not be ruled out. (B) Lateral radiograph of the costochondral junctions. The junctions are "flared" and moderately sclerotic. This radiographic finding is frequently present in human patients with rickets, and is commonly called a rachitic rosary, because the lesions palpate like beads on a rosary. Given the severity of the dog's spinal injury (functionally complete), the chance of recovery was very low and would have been compromised by the difficulty in surgical repair of osteopenic bones. As a result, the dog was euthanized. Gross postmortem evaluation revealed signs of rickets with diffusely enlarged costochrondral junctions (beading), a fracture callus on the left eight rib, and displacement of the T11 vertebra. Microscopically, failure of endochondral ossification with retained cartilage cores was noted in several locations (ribs, radius, nasal turbinates). A compression fracture of T11 with subluxation was confirmed. In the region of T11, locally extensive, severe myelomalacia, and fibrinoid vasculitis of the spinal cord were seen. The brain was normal, suggesting that severe hypocalcemia was the cause for the dog's forebrain signs. The parathyroid was diffusely hyperplastic and hypertrophied, consistent with the persistently increased PTH levels. HVDRR in humans is almost always due to mutations in the VDR.2 For this reason, before euthanasia, blood samples were drawn from both the affected dog and the normal half-sibling for genomic sequence analysis of the VDR gene. With owner consent, immediately before euthanasia, the affected dog was anesthetized with propofolk to obtain skin biopsies from her ventral abdomen from which fibroblast cultures were derived. These cultures were subsequently used for analysis of VDR expression and as a source of RNA for VDR sequence analysis. The fibroblasts were grown in minimal essential media containing 10% calf seruml and maintained in an atmosphere of 95% air, 5% CO2 at 37°C. Genomic DNA was isolated from blood using a commercial kit.m Primers were designed based on the DNA sequence of Canis lupus familiaris VDR obtained from GenBank® (accession number NC_006609, Gene ID: 486588) (Table 2). Exons 2–9 of the VDR gene from the affected dog and half-sibling were amplified by PCR and directly sequenced at the Stanford University protein and nucleic acid facility. A unique single base deletion (guanine) was identified at the exon 4-intron junction (Fig 4A) in the affected dog's genomic DNA. The sequence of the exon 4-intron junction of the half-sibling was homozygous for the wild-type sequence (Fig 4B). DNA sequence of exon 4 of the VDR gene in the dog. (A) Genomic DNA sequence of the affected dog's VDR gene. A unique 1 bp (G) deletion was identified in the exon 4-intron junction (B) DNA sequence of the half-sibling's VDR gene. (C) Sequence of the affected dog's VDR cDNA. Deletion of a single guanine nucleotide base was identified in the dog's VDR cDNA resulting in a frameshift that introduced a downstream premature termination codon. The premature stop codon is predicted to be at codon 216, which is 232 amino acids upstream of the normal stop codon. The translated amino acid sequence is shown above the nucleotide sequence. The normal amino acid sequence and that of the affected dog diverge after amino acid R175. From the sequence in GenBank®, the normal VDR exon4-intron sequence is AGG|gtacgtggcc (exon 4 sequence in capitals and intron sequence in lower case with bolded letters indicating splicing recognition sequence). The deletion of a single guanine base in the GG|g triplet would generate the sequence AG|gtacgtggcc and leave the 5′-splice site intact. On the other hand, deletion of guanine in the coding sequence would cause a frameshift in exon 5. In order to document this frameshift, RNA was isolated from the dog's cultured fibroblasts. The RNA was reverse transcribedn and amplifiedo by PCR using gene specific primers (forward primer 5′-ctgcggcccaagctgtcgga and reverse primer 5′-ttggatgctgtaactgaccag). The VDR cDNA products were purifiedp and directly sequenced. As shown in Fig 4C, the single guanine nucleotide deletion in the VDR cDNA led to a frameshift that caused the amino acid sequence to diverge after R175. (It should be noted that the canine R175 corresponds to R154 in humans, because the canine VDR sequence is 21 amino acids longer at the N-terminus compared with the human sequence.) An additional 41 amino acids were in frame before a downstream termination signal occurred. The mutation deleted 273 amino acids of the VDR ligand-binding domain (LBD) and was expected to abolish 1,25(OH)2D3 binding. Although we were able to amplify the VDR cDNA from the dog's cells, the mutant VDR mRNA transcript may be subjected to nonsense-mediated mRNA decay and the affected dog may not express any VDR. To determine whether the mutation abolished 1,25(OH)2D3 binding, we examined [3H]1,25(OH)2D3 binding in the dog's fibroblasts compared with normal human fibroblasts. Cell extracts were incubated with 1 nM [3H]1,25(OH)2D3 (specific activity 158 Ci/mmol) with or without 250-fold excess of radioinert 1,25(OH)2D3 as described previously.3 Hydroxylapatite was used to separate bound and free hormone. Protein concentrations were determined by the Bradford method.4 No detectable binding was observed in extracts from the dog's cells. This report describes a VDR gene mutation resulting in HVDRR in a dog. The molecular basis for HVDRR was attributed to a 1 bp deletion in exon 4 that caused a frameshift and introduced a premature stop in exon 5. We expect that this mutation would lead to the affected dog's failure to respond to 1,25(OH)2D3 in one of 2 ways: either the mutation truncated a major portion of the LBD, leading to the inability of the dog's VDR to bind 1,25(OH)2D3, or the mRNA was subjected to nonsense-mediated degradation and this dog had a complete failure of VDR expression. The absence of 1,25(OH)2D3 binding in the dog fibroblast binding assay confirms that the affected dog's cells lack a VDR capable of responding to 1,25(OH)2D3, although it does not differentiate between these two causes of defective VDR binding. Over 100 human cases of HVDRR have been reported.2 In children, HVDRR is characterized by hypocalcemia, secondary hyperparathyroidism, and severe rickets.5,6 The disease is almost always because of mutations in the VDR, with many different mutations identified, including mutations in the LBD and in the DNA-binding domain.5,6 The VDR mutations result in end-organ resistance to 1,25(OH)2D3.2 Resistance leads to defective intestinal calcium absorption, hypocalcemia, and secondary hyperparathyroidism, which in turn causes failure of bone mineral deposition, especially failure of calcium deposition.5,7 As a result, metaphyseal cartilage accumulates, but cannot be properly mineralized and rickets results.7 A syndrome that is similar to HVDRR has been described in cats,7–9 although a genetic mutation in the VDR was not established in any of these animals. These case reports suggest that cats fare relatively well once they reach the end of their growth period, with the exception of one cat, which died suddenly at 13 months of age, and another that was euthanized at 9 years of age for hip pain from osteoarthritis.7–9 Inadequate dietary intake of vitamin D resulting in nutritional secondary hyperparathyroidism has been reported previously in dogs,10 but could be readily ruled out in this case because the dog failed to respond to high concentrations of calcitriol. VDDR-I has been reported in a Saint Bernard dog and a domestic short hair cat.11,12 In the dog reported here, clinical signs of early onset rickets, laboratory findings of hypocalcemia, secondary hyperparathyroidism, and markedly increased serum 1,25(OH)2D3 levels, and radiographic findings of abnormally wide growth plates are all consistent with those reported in people with HVDRR. The dog's poor response to therapy appears to be closely aligned with the human condition in how challenging it is to maintain normal calcium levels and adequate bone mineralization without functional VDRs. Most mutations in people result in a defective VDR that can no longer respond to even high doses of 1,25(OH)2D3. Some children can be treated by high doses of 1,25(OH)2D3 that overcome the defect in binding affinity for 1,25(OH)2D3, however, treatment usually requires high doses of IV calcium administered daily over many months to eventually correct the hypocalcemia, suppress the secondary hyperparathyroidism, and heal the rachitic bone abnormalities.13,14 IV calcium infusions bypass the intestinal calcium absorption defect caused by the disease. After the total body calcium deficit is restored to normal, some children can be transitioned to high doses of oral calcium to maintain their improved metabolic state and prevent rickets from recurring. It is possible that aggressive initial management of this dog with oral calcium therapy and injectable calcium supplementation may have improved the outcome in this case. Based on the VDR LBD mutation in this dog, she could not have responded to even high concentrations of calcitriol. Evidence that the calcium treatment regime used in this case had some efficacy was shown by the increase in bone mineralization seen in her appendicular skeletal radiographs from 5 to 8.5 months of age (Fig 2). Alternatively, an even more aggressive initial approach with vascular access port placement15 and daily IV calcium supplementation (with concurrent ECG monitoring) could have been undertaken as it is in human patients.16 This approach would be technically challenging, would likely be associated with port infections, and would require significant owner commitment. It is noteworthy that the alopecia observed in this dog is also present in many children with HVDDR.5,6 It is proposed that the product of the hairless gene (HR) acts as a corepressor of the VDR, and that the HR and the unliganded VDR are involved in regulation of the hair cycle.17–22 The details of the mechanism of alopecia in HVDDR remain unknown. Large cystic follicles filled with keratin were seen in this dog on postmortem evaluation along with thin epithelium, and reduced number and size of adnexal structures such as sebaceous and apocrine glands. The dog's secondary hair follicles were smaller than normal. In people with HVDRR, the hair follicles may appear normal on microscopic examination, but hair shafts are absent.5 It is interesting that the alopecia had resolved at the time of the dog's death, yet obvious dermal changes were still microscopically present. In contrast to this dog, alopecia persists in human patients with HVDRR that undergo successful therapy or that show spontaneous improvement in calcium homeostasis.5 In humans, all cases VDR mutations causing premature termination codons have life-long alopecia, even if medical treatment improves the hypocalcemia and rickets. We have no explanation for the improvement of the alopecia in this dog. Dogs may potentially have a compensatory mechanism in the hair cycle lacked by humans that can replace the absent VDR function. In humans, patients with alopecia generally have more severe resistance to 1,25(OH)2D3 than those without alopecia, which would correlate with the severity of this dog's disease.23 HVDRR is an autosomal recessive genetic disorder in humans.5 Unfortunately, the breeder of this dog was not interested in progenitor testing to help establish the pattern of heredity in this family. aAntech Diagnostics, Lake Success, NY bRoxane Laboratories Inc, Columbus, OH cCalcitriol, 100 ng/mL Fixed Oil Solution, compounded, Health Park Pharmacy, Raleigh, NC dIdexx VetTest 8008 Chemistry Analyzer, Idexx Laboratories, Westbrook, ME eDiagnostic Center for Population and Animal Health, Michigan State University, Lansing, MI fCalcium glycerophosphate and calcium lactate, Calphosan, Glenwood, Englewood, NJ gHeartland Assays, Ames, IA hCalcium gluconate 10%, AAP Pharmaceuticals LLC, Schaumburg, IL iMidazolam, Bedford Laboratories, Bedford, OH jFentanyl, Hospira, Lake Forest, IL kPropofol, Teva Pharmaceuticals, North Wales, PA lHyclone, Logan, UT mQIAamp DNA blood mini kit, Qiagen, Valencia, CA nSuperscript first strand CDNA synthesis kit, Invitrogen, Carlsbad, CA oTAQ DNA polymerase, New England Biolabs, Ipswich, MA pQIAquick PCR purification kit This work was supported by NIH grant DK42482 (to DF) and NCSU CVM teaching initiative funds (to DNL).}, number={6}, journal={JOURNAL OF VETERINARY INTERNAL MEDICINE}, author={LeVine, D. N. and Zhou, Y. and Ghiloni, R. J. and Fields, E. L. and Birkenheuer, A. J. and Gookin, J. L. and Roberston, I. D. and Malloy, P. J. and Feldman, D.}, year={2009}, pages={1278–1283} }
 @article{lo_hornof_zwingenberger_robertson_2009, title={MULTISCALE IMAGE PROCESSING AND ANTISCATTER GRIDS IN DIGITAL RADIOGRAPHY}, volume={50}, ISSN={["1740-8261"]}, DOI={10.1111/j.1740-8261.2009.01585.x}, abstractNote={Scatter radiation is a source of noise and results in decreased signal‐to‐noise ratio and thus decreased image quality in digital radiography. We determined subjectively whether a digitally processed image made without a grid would be of similar quality to an image made with a grid but without image processing. Additionally the effects of exposure dose and of a using a grid with digital radiography on overall image quality were studied. Thoracic and abdominal radiographs of five dogs of various sizes were made. Four acquisition techniques were included (1) with a grid, standard exposure dose, digital image processing; (2) without a grid, standard exposure dose, digital image processing; (3) without a grid, half the exposure dose, digital image processing; and (4) with a grid, standard exposure dose, no digital image processing (to mimic a film‐screen radiograph). Full‐size radiographs as well as magnified images of specific anatomic regions were generated. Nine reviewers rated the overall image quality subjectively using a five‐point scale. All digitally processed radiographs had higher overall scores than nondigitally processed radiographs regardless of patient size, exposure dose, or use of a grid. The images made at half the exposure dose had a slightly lower quality than those made at full dose, but this was only statistically significant in magnified images. Using a grid with digital image processing led to a slight but statistically significant increase in overall quality when compared with digitally processed images made without a grid but whether this increase in quality is clinically significant is unknown.}, number={6}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Lo, Winnie Y. and Hornof, William J. and Zwingenberger, Allison L. and Robertson, Ian D.}, year={2009}, pages={569–576} }
 @article{cruse_vaden_mathews_hill_robertson_2009, title={Use of Computed Tomography (CT) Scanning and Colorectal New Methylene Blue Infusion in Evaluation of an English Bulldog with a Rectourethral Fistula}, volume={23}, ISSN={["1939-1676"]}, DOI={10.1111/j.1939-1676.2009.0320.x}, abstractNote={Journal of Veterinary Internal MedicineVolume 23, Issue 4 p. 931-934 Open Access Use of Computed Tomography (CT) Scanning and Colorectal New Methylene Blue Infusion in Evaluation of an English Bulldog with a Rectourethral Fistula A.M. Cruse, A.M. Cruse Department of Clinical Sciences, North Carolina State University, Raleigh, NCSearch for more papers by this authorS.L. Vaden, S.L. Vaden Department of Clinical Sciences, North Carolina State University, Raleigh, NCSearch for more papers by this authorK.G. Mathews, K.G. Mathews Department of Clinical Sciences, North Carolina State University, Raleigh, NCSearch for more papers by this authorT.L. Hill, T.L. Hill Department of Clinical Sciences, North Carolina State University, Raleigh, NCSearch for more papers by this authorI.D. Robertson, I.D. Robertson Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NCSearch for more papers by this author A.M. Cruse, A.M. Cruse Department of Clinical Sciences, North Carolina State University, Raleigh, NCSearch for more papers by this authorS.L. Vaden, S.L. Vaden Department of Clinical Sciences, North Carolina State University, Raleigh, NCSearch for more papers by this authorK.G. Mathews, K.G. Mathews Department of Clinical Sciences, North Carolina State University, Raleigh, NCSearch for more papers by this authorT.L. Hill, T.L. Hill Department of Clinical Sciences, North Carolina State University, Raleigh, NCSearch for more papers by this authorI.D. Robertson, I.D. Robertson Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NCSearch for more papers by this author First published: 26 June 2009 https://doi.org/10.1111/j.1939-1676.2009.0320.xCitations: 3 Corresponding author: Shelly L. Vaden, DVM, PhD, DACVIM, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough Street, Raleigh, NC 27606; e-mail: shelly_vaden@ncsu.edu. This work was performed at North Carolina State University, College of Veterinary Medicine. AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abbreviations CT computed tomography NCSU-VTH North Carolina State University Veterinary Teaching Hospital Rectourethral fistulas are uncommonly reported in veterinary medicine having only been reported in 13 dogs.1-11 Seven were English Bulldogs and 3 were Miniature Poodles. The diagnosis of a rectourethral fistula is challenging. Survey radiography, double contrast cystography, pneumocystography, and colonoscopy are unreliable modalities for the diagnosis of a fistula.6-9 Four of the 13 previously reported dogs required more than 1 contrast imaging study to confirm the presence of a rectourethral fistula.2, 4, 7, 9 In 1 affected dog, 4 contrast cystourethrograms were performed over a 7-year period before identifying the fistula.4 To date, no case report in the veterinary literature has described use of computed tomography (CT) scanning or new methylene bluea as alternate methods for the diagnosis of rectourethral fistulas. Most rectourethral fistulas in people are acquired secondary to trauma, pelvic surgery, inflammatory bowel disease, or malignancy.12 The diagnosis can be made by witnessing fecaluria or by using advanced diagnostic procedures. Some physicians prefer the aid of contrast cystourethrography13, 14 whereas others have reported the usefulness of CT scanning for both establishing the diagnosis and for surgical planning.15 CT scanning for the detection of anorectal anomalies was first described in infants and has since become a valuable diagnostic tool.16, 17 To date, the most commonly utilized diagnostic techniques in people include cystourethroscopy, advanced imaging such as CT scanning or magnetic resonance imaging, and radiographic contrast imaging.13-19 This report describes the successful use of CT and cystourethrography to diagnose a rectourethral fistula in an English Bulldog. Whereas cystourethrography was used to determine that a fistula was present, the exact anatomic location could not be verified. In contrast, the CT scan was very useful in establishing an accurate anatomic localization of the fistula and surgical planning for repair. In addition, this report describes a technique of colorectal infusion of new methylene blue during cystourethroscopy, which may be a useful adjunctive procedure to verify the presence of an abnormal communication between the urinary and gastrointestinal tracts. A 1-year-old 26.1 kg male castrated English Bulldog was presented to the North Carolina State University Veterinary Teaching Hospital (NCSU-VTH) with a 4-month history of recurrent urinary tract infections. The owner reported pollakiuria, stranguria, and hematuria. Upon initial presentation to the referring veterinarian, gross hematuria, bacteriuria, and pyuria were detected in a voided urine sample. Clinical signs transiently abated after treatment with amoxicillin-clavulanic acidb (15 mg/kg PO q12h for 14 days). Approximately 21 days after initial presentation, a urine sample collected by cystocentesis grew Escherichia coli and Proteus mirabilis that were susceptible to amoxicillin-clavulanic acid. Although abdominal radiographs were unremarkable, small cystoliths, bilateral renal mineralization, and a thickened bladder wall were detected on abdominal ultrasonography. Urinary crystalline material analyzed by the Minnesota Urolith Centerc was identified as magnesium ammonium phosphate. Ninety days after initial presentation, urinalysis of a catheterized sample indicated hematuria and bacteriuria. Microbial culture of the same sample resulted in growth of Klebsiella pneumoniae and E. coli. Based on susceptibility test results, the dog was treated with amoxicillin-clavulanic acid (14 mg/kg PO q12h for 6 weeks) and marbofloxacin (8 mg/kg PO q24h for 6 weeks). At presentation to the NCSU-VTH, no abnormalities were detected during physical examination. Results of a CBC and biochemical profile were unremarkable. Urinalysis of a sample collected by cystocentesis indicated urine specific gravity of 1.014, urine pH of 8.0, trace bacteruria, and 0–5 white blood cells per high-power field. An aliquot of the same urine sample was submitted for microbial culture and resulted in light growth of a resistant strain of Enterococcus faecium. Abdominal ultrasonography identified a thickened irregular urinary bladder wall and small cystic calculi. A hyperemic bladder and urethral mucosa consistent with urinary tract inflammation, as well as particulate matter were identified during cystourethroscopy. Analysis of the particulate matter by the Minnesota Urolith Center identified a gelatinous material not consistent with urinary calculi, but rather a conglomerate of fungal hyphae, bacterial rods and cocci, and cellular material. A positive contrast retrograde urethrocystogram was performed after cystourethroscopy with fluoroscopic guidance. Approximately 20 mL of iohexold (240 mg/mL diluted with 0.9% saline to a concentration of 120 mg/mL) was infused over a 3–5-minute period through an 8-french Foley catheter placed into the urethra. The catheter balloon was positioned and inflated approximately 1 in. distal to the ischiatic tuberosity. At the level of the prostate gland, contrast medium exited the urethra within a tract that extended caudally and emptied into the rectum, indicating the presence of a rectourethral fistula. The dog represented 7 days later for surgical correction of the rectourethral fistula. Based on the owner's desire for a minimally invasive approach, initially laparoscopy was performed. Laparoscopic exploration of the area dorsal to the urethra failed to identify an obvious fistula, and the procedure was converted to a standard ventral midline laparotomy. A red rubber urinary catheter was placed to fill the bladder with saline. Pressure was applied to the urinary bladder while digitally obstructing the urethra in an attempt to force saline into the fistula as an aid to its identification. No abnormal tissue could be identified. Because of the potential risk to neurovascular structures associated with further dissection, and the potential morbidity associated with pelvic osteotomies, the decision was made to recover the animal from anesthesia and attempt to further characterize the anatomic location of the fistula with additional diagnostic techniques at a future date. The dog was discharged from the hospital the next day with instructions to be given amoxicillin-clavulanic acid (14 mg/kg PO q12h for 10 days). Thirty days after the initial surgery, colonoscopy was performed using a 1,680 mm length flexible Olympuse colonoscope with an outer diameter of 12.2 mm in an attempt to locate the fistula. Patient preparation consisted of a combination of a 24-hour fast, oral polyethylene glycol solution,f and warm water enemas. During colonoscopy, many small raised areas consistent with lymphoid follicles were noted, but a fistula was not visualized. After colonoscopy, cystourethroscopy was performed with a 600 mm length flexible Storzg cystoscope with an outer diameter of 3.8 mm. In another attempt to identify the location of the fistula, new methylene blue was instilled into the colon during urethroscopsy. A 24-french Foley catheter was advanced approximately 10 in. aborally into the descending colon. A 2nd 24-french Foley catheter was positioned in at the level of the rectum. The balloon of each catheter was filled with 30 mm 0.9% saline. Thirty milliliters of new methylene blue was diluted 1 : 1 with 0.9% saline to a total volume of 60 mm and instilled through the distal catheter, over a period of 10–15 seconds, into the space between the 2 catheter balloons where the fistula was believed to be located. The urine in the urethra became blue-tinged within minutes confirming translocation of the new methylene blue from the colon into the urethra. At the level of the prostatic urethra, several small depressions of the urethral mucosa were noted (Fig 1). Although the largest of these depressions was believed to be associated with the fistula, there was no definitive evidence of new methylene blue entering the urethra through these areas. Thus, the new methylene blue was useful in confirming the presence of the fistula but did not identify its location. Figure 1Open in figure viewerPowerPoint (A) Cystourethroscopy before new methylene blue infusion. There are several small depressions and one larger depression in the urethral mucosa. The larger depression is believed to be associated with the fistula. (B) Cystourethroscopy after new methylene blue infusion. The urine became blue-tinged consistent with passage of new methylene blue from the colon to the urethra. 101 × 76 mm (300 × 300 DPI). After cystourethroscopy, CTh scanning was performed in conjunction with a positive contrast retrograde urethrogram. Iohexol was diluted and administered at a concentration of 80 mg of iodine per milliliter through an 8-french Foley catheter placed in the urethra. Contrast medium was present within the urethra, urinary bladder, colon, and rectum. A fistulous tract oriented in a caudodorsal direction connecting the urethra to the rectum immediately caudal to the prostate was readily apparent (2, 3). Figure 2Open in figure viewerPowerPoint Retrograde urography. One millimeter transverse image of intrapelvic urethra and rectum immediately cranial to the coxofemoral joints. The white arrow is the urethra. The black arrow is the fistulous tract extending caudodorsally on the right. Contrast medium within the terminal colon is readily apparent. 101 × 76 mm (300 × 300 DPI). Figure 3Open in figure viewerPowerPoint Sagittal CT reconstruction. There is contrast medium within the tract between the urethra and rectum. White arrows are urethra. Black arrows are the fistulous tract. 101 × 76 mm (300 × 300 DPI). The CT scan allowed more accurate anatomic localization and the dog was returned to surgery in a 2nd attempt to ligate the fistula, this time using a perineal approach. A lumen was identified and catheterized with an 8-french red rubber catheter directed toward the urethra. Both the rectal end and urethral end of the fistula were ligated and oversewn. A total of 6 urine samples were obtained by cystocentesis and submitted for microbial culture over the next year while the dog was not receiving antibiotics. All were negative for bacterial growth. A 1-year follow-up conversation with the owner indicated that the dog no longer had any clinical signs related to the lower urinary tract. Rectourethral fistulas are persistent communications between the rectum and urethra. Of the 13 dogs reported with rectourethral fistulas, 11 were suspected to be congenital in nature.2-10 The exact embryologic formation of a rectourethral fistula is not known. During normal canine development, the urorectal fold contacts the cloacal membrane, which subsequently ruptures, resulting in separate urogenital and digestive orifices. The caudal portion of the urogenital orifice further differentiates into the urethra. Fistulas can occur either secondary to failure of the urorectal septum to separate the cloaca into ventral urethrovesical and dorsal rectal segments or due to rupture of the cloacal membrane before contacting the urorectal fold.3, 20 Additionally, infectious or inflammatory processes can occur in utero that could lead to perforation of the rectum and subsequent fistula formation.10 In both humans and dogs with rectourethral fistulas, the most common presenting clinical signs are caused by recurrent cystitis and include dysuria, hematuria, pollakiuria, or stranguria.3-10, 13, 21 Ten of the 13 canine rectourethral fistulas reports included aerobic urine culture results. Aerobic culture yielded growth of ≥ 2 bacterial species in 6 of these reports.2, 4, 6, 8-10 The most common bacterial organisms reported were E. coli and Proteus spp.1-10 Neither of the dogs with acquired fistulas had positive aerobic urine cultures.1, 11 In 1 study of dogs with recurrent or persistent urinary tract infections, approximately 25% of the urine specimens yielded the growth of ≥ 2 bacterial species by aerobic bacterial culture, as was noted in the dog of this report.12 The presence of multiple organisms on urine culture specimen may raise clinical suspicion of systemic immunocompromise, anatomic defects along the lower urinary tract, or external contamination of the urine sample. Rectourethral fistula is an uncommon anatomic defect that can lead to recurrent or persistent urinary tract infections. In this dog, the fistula was oriented in a cranioventral to caudodorsal direction running between the prostatic urethra and the caudoventral rectum. This orientation made identification of the fistula at surgery difficult because it was closely associated with the dorsal aspect of the urethra cranioventrally. After CT scan, a different surgical approach was used and resulted in successful repair of the fistula. To the authors' knowledge, this is the 1st report of CT scanning and colorectal infusion of new methylene blue during cystourethroscopy for the evaluation of rectourethral fistulas in a dog, although these techniques have been described in humans.18, 22 Since evaluating the dog of this case report, we have performed colorectal infusion of new methylene blue in 2 additional young dogs that were presented for evaluation of recurrent urinary tract infections. Neither of these dogs had any discoloration of the urine after infusion with new methylene blue nor did they have fistulas. The infusion is an easily performed technique that can be incorporated into cystourethroscopy to identify if there is an abnormal communication between the urethra and rectum or colon. Specific patient preparation for this technique includes enemas to evacuate the descending colon and the placement of 2 Foley catheters. Although the location of the fistula may not be readily identifiable, a color change of the urine indicates the presence of an abnormal communication between the urinary and gastrointestinal tracts. In the dog of this report, advanced imaging was needed for precise anatomical localization. CT scanning may be useful to accurately localize the fistula, which can aid surgical planning and successful repair. Footnotes aNew Methylene Blue 1% solution, Taylor Pharmaceuticals, Decatur, IL bClavamox; Pfizer Animal Health, Exton, PA cUniversity of Minnesota, St Paul, MN dOmnipaque 240 mg/mL, GE Healthcare, Princeton, NJ eOlympus America Inc, Center Valley, PA fGoLYTELY (PEG-3350 and electrolytes), Braintree Laboratories Inc, Braintree, MA gKarl Storz Endoscope, Roswell, GA hSiemens Sensation 16, Siemens Medical Solutions USA Inc, Malvern, PA Acknowledgment This study was not supported by a grant. References 1 Agut A, Lucas X, Castro A, et al. A urethrorectal fistula due to prostatic abscess associated with urolithiasis in a dog. Reprod Domest Anim 2006; 41: 247– 250 PubMed. Wiley Online LibraryCASPubMedWeb of Science®Google Scholar 2 Ralphs SC, Kramek BA. Novel perineal approach for repair of a urethrorectal fistula in a bulldog. Can Vet J 2003; 44: 822– 823. PubMedWeb of Science®Google Scholar 3 Chandler JC, MacPhail CM. Congenital urethrorectal fistulas. Comp Cont Ed Sm Anim Pract 2001; 23: 995– 1000. Web of Science®Google Scholar 4 Silverstone A, Adams WA. Radiographic diagnosis of a rectourethral fistula in a dog. J Am Anim Hosp Assoc 2001; 37: 573– 576 PubMed. CrossrefCASPubMedWeb of Science®Google Scholar 5 Tobias KS, Barbee D. Abnormal micturition and recurrent cystitis associated with multiple congenital anomalies of the lower urinary tract in a dog. J Am Vet Med Assoc 1995; 207: 191– 193 PubMed. CASPubMedWeb of Science®Google Scholar 6 Osuna DJ, Stone EA, Metcalf MR. A urethrorectal fistula with concurrent urolithiasis in a dog. J Am Anim Hosp Assoc 1989; 25: 35– 39 PubMed. Web of Science®Google Scholar 7 Whitney WO, Schrader LA. Urethrorectal fistulectomy in a dog, using a perineal approach. J Am Vet Med Assoc 1988; 193: 568– 569 PubMed. CASPubMedWeb of Science®Google Scholar 8 Miller CF. Urethrorectal fistula with concurrent urolithiasis in a dog. Vet Med Small Anim Clin 1980; 75: 73– 76. CASPubMedWeb of Science®Google Scholar 9 Osborne CA, Engen MH, Yano BL, et al. Congenital urethrorectal fistula in two dogs. J Am Vet Med Assoc 1975; 166: 999– 1002 PubMed. CASPubMedWeb of Science®Google Scholar 10 Goulden B, Bergman MM, Wyburn RS. Canine urethrorectal fistulae. J Small Anim Pract 1973; 14: 143– 150 PubMed. Wiley Online LibraryCASPubMedWeb of Science®Google Scholar 11 Rawlings CA. Extraperitoneal urinary bladder rupture and urinary fistula in a dog. J Am Vet Med Assoc 1969; 155: 123– 128 PubMed. CASPubMedWeb of Science®Google Scholar 12 Norris CR, Williams BJ, Ling GV, et al. Recurrent and persistent urinary tract infections in dogs: 383 cases. J Am Anim Hosp Assoc 2000; 36: 484– 492 PubMed. CASWeb of Science®Google Scholar 13 Crippa A, Dall'Oglio MF, Nesrallah LJ, et al. The York-Mason technique for rectourethral fistulas. Clinics 2007; 62: 699– 704 PubMed. CrossrefPubMedWeb of Science®Google Scholar 14 Hong AR, Croitoru DP, Nguyen LT, et al. Congenital urethral fistula with normal anus: A report of two cases. J Pediat Surg 1992; 27: 1278– 1280 PubMed. CASPubMedWeb of Science®Google Scholar 15 Nyam DC, Pemberton JH. Management of iatrogenic rectourethral fistula. Dis Colon Rectum 1999; 42: 994– 999 PubMed. CrossrefCASPubMedWeb of Science®Google Scholar 16 Kohda E, Fujioka M, Ikawa H, Yokoyama J. Congenital anorectal anomaly: CT evaluation. Radiology 1985; 157: 349– 352 PubMed. CASPubMedWeb of Science®Google Scholar 17 Berrocal T, Lamas M, Gutierrez J, et al. Congenital anomalies of the small intestine, colon, and rectum. Radiographics 1999; 19: 1219– 1236 PubMed. CrossrefCASPubMedWeb of Science®Google Scholar 18 Sotelo R, Mirandolino M, Trujillo G, et al. Laparoscopic repair of rectourethral fistulas after prostate surgery. Urology 2007; 70: 515– 518 PubMed. CrossrefPubMedWeb of Science®Google Scholar 19 Gupta AK, Guglani B. Imaging of congenital anomalies of the gastrointestinal tract. Indian J Pediatr 2005; 72: 403– 414 PubMed. CrossrefPubMedGoogle Scholar 20 Kruger JM, Osborne CA, Lulich JP. Inherited and congenital disease of the lower urinary tract. In: CA Osborne, DR Finco, eds. Canine and Feline Nephrology and Urology. Philadelphia, PA: Lea and Febiger; 1995: 688. Google Scholar 21 Culkin DJ, Ramsey CE. Urethrorectal fistula: Transanal, transsphincteric approach with locally based pedicle interposition flaps. J Urol 2003; 169: 2181– 2183. PubMedWeb of Science®Google Scholar 22 Miller BA. New diagnostic technics for an obscure vesicovaginal fistula. A case report. Obstet Gynecol 1971; 38: 436– 439 PubMed. CASPubMedWeb of Science®Google Scholar Citing Literature Volume23, Issue4July/August 2009Pages 931-934 FiguresReferencesRelatedInformation}, number={4}, journal={JOURNAL OF VETERINARY INTERNAL MEDICINE}, author={Cruse, A. M. and Vaden, S. L. and Mathews, K. G. and Hill, T. L. and Robertson, I. D.}, year={2009}, pages={931–934} }
 @article{leigh_mackillop_robertson_hudson_2008, title={Clinical anatomy of the canine brain using magnetic resonance imaging}, volume={49}, ISSN={["1740-8261"]}, DOI={10.1111/j.1740-8261.2008.00336.x}, abstractNote={The purpose of this study was to produce an magnetic resonsnce (MR) image atlas of clinically relevant brain anatomy and to relate this neuroanatomy to clinical signs. The brain of a large mixed breed dog was imaged in transverse, sagittal, and dorsal planes using a 1.5 T MR unit and the following pulse sequences: Turbo (fast) spin echo (TSE) T2, T1, and T2‐ weighted spatial and chemical shift‐encoded excitation sequence. Relevant neuroanatomic structures were identified using anatomic texts, sectioned cadaver heads, and previously published atlases. Major subdivisions of the brain were mapped and the neurologic signs of lesions in these divisions were described. TSE T2‐weighted images were found to be the most useful for identifying clinically relevant neuroanatomy. Relating clinical signs to morphology as seen on MR will assist veterinarians to better understand clinically relevant neuroanatomy in MR images.}, number={2}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Leigh, Edmund J. and Mackillop, Edward and Robertson, Ian D. and Hudson, Lola C.}, year={2008}, pages={113–121} }
 @article{blond_thrall_roe_chailleux_robertson_2008, title={Diagnostic accuracy of magnetic resonance imaging for meniscal tears in dogs affected with naturally occuring cranial cruciate ligament rupture}, volume={49}, ISSN={["1058-8183"]}, DOI={10.1111/j.1740-8261.2008.00401.x}, abstractNote={A stifle magnetic resonance (MR) imaging protocol was developed based on the appearance of the cruciate ligaments and menisci in normal dogs. Proton density images were subjectively considered to have the highest likelihood of detecting a meniscal lesion. Following this initial evaluation, the accuracy of high‐field MR imaging to detect meniscal tears in dogs was evaluated in 11 dogs suffering from naturally occurring cranial cruciate ligament rupture. Dogs underwent MR imaging of the affected stifle before surgery. MR imaging and surgical findings were assessed independently, and then compared. Five tears of the medial meniscus were correctly diagnosed with MR imaging and 19 normal menisci were accurately characterized as such, based on MR images. In one medial meniscus, changes consistent with meniscal degeneration were seen on MR images but this was not seen at surgery. With regard to the lateral meniscus, one false positive diagnosis of a tear was made and this likely represented a normal variation. One other lateral meniscus had changes consistent with meniscal degeneration but, as with the similar lesion seen in the medial meniscus, this was not confirmed surgically. The global sensitivity of MR imaging for the diagnosis of a meniscal tear was 100% and the specificity was 94%. High‐field MR imaging is a reliable method to diagnose meniscal tears preoperatively and this may be useful in selecting the surgical approach to clinically abnormal joints and may decrease the need for arthrotomy.}, number={5}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Blond, Laurent and Thrall, Donald E. and Roe, Simon C. and Chailleux, Nadege and Robertson, Ian D.}, year={2008}, pages={425–431} }
 @article{robertson_saveraid_2008, title={Hospital, radiology, and Picture Archiving and Communication Systems}, volume={49}, ISSN={["1740-8261"]}, DOI={10.1111/j.1740-8261.2007.00329.x}, abstractNote={Images generated during the course of patient evaluation and management are an integral part of the medical record and must be retained according to local regulations. Digital Imaging and Communications in Medicine (DICOM) makes it possible for images from many different imaging modalities to be distributed via a standard internet network to distant viewing workstations and a central archive in an almost seamless fashion. The DICOM standard is a truly universal standard for the dissemination of medical images. Picture Archive and Communication System (PACS) refers to the infrastructure that links modalities, workstations, the image archive, and the medical record information system into an integrated system, allowing for efficient electronic distribution and storage of medical images and access to medical record data. This paper discusses the important elements to a successful PACS implementation in a practice, including how it interacts with other practice computing systems.}, number={1}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Robertson, Ian D. and Saveraid, Travis}, year={2008}, pages={S19–S28} }
 @article{wright_ballance_robertson_poteet_2008, title={Introduction to dicom for the practicing veterinarian}, volume={49}, ISSN={["1740-8261"]}, DOI={10.1111/j.1740-8261.2007.00328.x}, abstractNote={Digital Imaging and Communication in Medicine (DICOM) is a communication protocol that imaging devices use to communicate. The universal acceptance of the DICOM standard by the major medical vendors means that the digital transition in veterinary medicine should be relatively smooth provided DICOM is used. DICOM service objects, roles, service classes, and conformance standards are discussed. The authors strongly encourage the use of image acquisition software and image archive systems that support the DICOM standard.}, number={1}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Wright, Matthew A. and Ballance, Dennis and Robertson, Ian D. and Poteet, Brian}, year={2008}, pages={S14–S18} }
 @article{robertson_2007, title={Image dissemination and archiving}, volume={22}, ISSN={["1096-2867"]}, DOI={10.1053/j.ctsap.2007.05.008}, abstractNote={Images generated as part of the sonographic examination are an integral part of the medical record and must be retained according to local regulations. The standard medical image format, known as DICOM (Digital Imaging and COmmunications in Medicine) makes it possible for images from many different imaging modalities, including ultrasound, to be distributed via a standard internet network to distant viewing workstations and a central archive in an almost seamless fashion. The DICOM standard is a truly universal standard for the dissemination of medical images. When purchasing an ultrasound unit, the consumer should research the unit's capacity to generate images in a DICOM format, especially if one wishes interconnectivity with viewing workstations and an image archive that stores other medical images. PACS, an acronym for Picture Archive and Communication System refers to the infrastructure that links modalities, workstations, the image archive, and the medical record information system into an integrated system, allowing for efficient electronic distribution and storage of medical images and access to medical record data.}, number={3}, journal={CLINICAL TECHNIQUES IN SMALL ANIMAL PRACTICE}, author={Robertson, Ian}, year={2007}, month={Aug}, pages={138–144} }
 @article{dorman_struve_wong_dye_robertson_2006, title={Correlation of brain magnetic resonance imaging changes with pallidal manganese concentrations in rhesus monkeys following subchronic manganese inhalation}, volume={92}, ISSN={["1096-0929"]}, DOI={10.1093/toxsci/kfj209}, abstractNote={High-dose manganese exposure is associated with parkinsonism. Because manganese is paramagnetic, its relative distribution within the brain can be examined using magnetic resonance imaging (MRI). Herein, we present the first comprehensive study to use MRI, pallidal index (PI), and T(1) relaxation rate (R1) in concert with chemical analysis to establish a direct association between MRI changes and pallidal manganese concentration in rhesus monkeys following subchronic inhalation of manganese sulfate (MnSO(4)). Monkeys exposed to MnSO(4) at > or = 0.06 mg Mn/m(3) developed increased manganese concentrations in the globus pallidus, putamen, olfactory epithelium, olfactory bulb, and cerebellum. Manganese concentrations within the olfactory system of the MnSO(4)-exposed monkeys demonstrated a decreasing rostral-caudal concentration gradient, a finding consistent with olfactory transport of inhaled manganese. Marked MRI signal hyperintensities were seen within the olfactory bulb and the globus pallidus; however, comparable changes could not be discerned in the intervening tissue. The R1 and PI were correlated with the pallidal manganese concentration. However, increases in white matter manganese concentrations in MnSO(4)-exposed monkeys confounded the PI measurement and may lead to underestimation of pallidal manganese accumulation. Our results indicate that the R1 can be used to estimate regional brain manganese concentrations and may be a reliable biomarker of occupational manganese exposure. To our knowledge, this study is the first to provide evidence of direct olfactory transport of an inhaled metal in a nonhuman primate. Pallidal delivery of manganese, however, likely arises primarily from systemic delivery and not directly from olfactory transport.}, number={1}, journal={TOXICOLOGICAL SCIENCES}, author={Dorman, David C. and Struve, Melanie F. and Wong, Brian A. and Dye, Janice A. and Robertson, Ian D.}, year={2006}, month={Jul}, pages={219–227} }
 @article{thompson_roe_robertson_2007, title={Effects of pelvic positioning and simulated dorsal acetabular rim remodeling on the radiographic shape of the dorsal acetabular edge}, volume={48}, ISSN={["1740-8261"]}, DOI={10.1111/j.1740-8261.2007.00196.x}, abstractNote={A radiographic study was conducted to evaluate the effect of pelvic rotation and of simulated dorsal acetabular rim (DAR) remodeling on the radiographic appearance of the dorsal acetabular edge (DAE). The DAE is the line connecting the cranial and caudal rims of the acetabulum when viewing a pelvic radiograph made with the dog in the ventrodorsal position with the hind limbs extended. In this study, it was hypothesized that the DAE would change with pelvic rotation and simulated DAR damage. Ventrodorsal radiographs of eight canine pelves were made at 0°, 5°, and 10° of left and right pelvic rotation over its longitudinal axis. These radiographs were repeated following removal of 2, 4, and then 6 mm of bone from the right DAR of each pelvis. The ratio of acetabular width to maximum depth of the DAE was calculated. The area between the DAE and a straight line connecting the cranial and caudal acetabular rims was measured digitally. The DAE depth and area changed with pelvic rotation, and with increasing simulated DAR damage. A linear relationship between the obturator foramina width ratio and pelvic rotation allowed estimation of the degree and direction of pelvic rotation. Equations were developed from the data to assist with the estimation of the amount of DAR remodeling on a clinical radiograph.}, number={1}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Thompson, Randall and Roe, Simon C. and Robertson, Ian D.}, year={2007}, pages={8–13} }
 @article{pease_sullivan_olby_galano_cerda-gonzalez_robertson_gavin_thrall_2006, title={Value of a single-shot turbo spin-echo pulse sequence for assessing the architecture of the subarachnoid space and the constitutive nature of cerebrospinal fluid}, volume={47}, ISSN={["1740-8261"]}, DOI={10.1111/j.1740-8261.2006.00136.x}, abstractNote={Three case history reports are presented to illustrate the value of the single‐shot turbo spin‐echo pulse sequence for assessment of the subarachnoid space. The use of the single‐shot turbo spin‐echo pulse sequence, which is a heavily T2‐weighted sequence, allows for a rapid, noninvasive evaluation of the subarachnoid space by using the high signal from cerebrospinal fluid. This sequence can be completed in seconds rather than the several minutes required for a T2‐fast spin‐echo sequence. Unlike the standard T2‐fast spin‐echo sequence, a single‐shot turbo spin‐echo pulse sequence also provides qualitative information about the protein and the cellular content of the cerebrospinal fluid, such as in patients with inflammatory debris or hemorrhage in the cerebrospinal fluid. Although the resolution of the single‐shot turbo spin‐echo pulse sequence images is relatively poor compared with more conventional sequences, the qualitative information about the subarachnoid space and cerebrospinal fluid and the rapid acquisition time, make it a useful sequence to include in standard protocols of spinal magnetic resonance imaging.}, number={3}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Pease, A and Sullivan, S and Olby, N and Galano, H and Cerda-Gonzalez, S and Robertson, ID and Gavin, P and Thrall, D}, year={2006}, pages={254–259} }
 @article{wang_mathews_robertson_stebbins_trumpatori_2005, title={The effects of patient positioning and slice selection on canine acetabular angle assessment with computed tomography}, volume={46}, ISSN={1058-8183 1740-8261}, url={http://dx.doi.org/10.1111/j.1740-8261.2005.00007.x}, DOI={10.1111/j.1740-8261.2005.00007.x}, abstractNote={Acetabular angles (AAs) and dorsal acetabular rim angles acquired by computed tomographic (CT) imaging have been used to assess patient response to juvenile pubic symphysiodesis surgery. The purpose of this study was to evaluate the effects of patient positioning and slice selection on these angles, and an attempt was made to devise a repeatable method of measuring these angles that would eliminate positioning effects. We found significant variation in AAs with small differences in pelvic tilt and slice selection. Dorsal acetabular rim angles were not affected. As a result of positioning differences from one CT study to the next, every attempt should be made to standardize pelvic tilt, or eliminate its effect on AAs by standardizing gantry angle in relation to an anatomic landmark that will not change over time. The floor of the sacral vertebral canal may be a reasonable landmark for this purpose and deserves further study.}, number={1}, journal={Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound}, publisher={Wiley}, author={Wang, Sandy I. and Mathews, Kyle G. and Robertson, Ian D. and Stebbins, Marty and Trumpatori, Brian J.}, year={2005}, month={Jan}, pages={39–43} }
 @article{pressler_mohammadian_li_vaden_levine_mathews_robertson_2004, title={In vitro prediction of canine urolith mineral composition using computed tomographic mean beam attenuation measurements}, volume={45}, ISSN={1058-8183 1740-8261}, url={http://dx.doi.org/10.1111/j.1740-8261.2004.04032.x}, DOI={10.1111/j.1740-8261.2004.04032.x}, abstractNote={Determination of urolith mineral composition is critical for management of urolithiasis in dogs and cats. Using computed tomography, urolith physical density, and hence chemical composition, can be quantified using mean beam attenuation measurements (Hounsfield units; HU). This study was designed to establish in vitro reference ranges for three types of compositionally pure uroliths retrieved from dogs. Sixty‐six canine uroliths (22 uric acid, 21 calcium oxalate, 14 struvite, nine mixed or compound) were placed in a phantom array. Uroliths were scanned at 120 kVp, 200 mA, and 80 kVp, 200 mA. The region of interest (ROI) for mean HU calculation was determined using two techniques, and reference ranges were calculated for each kVp using either ROI technique. HU for urolith types of pure composition were statistically different (Wilcoxon's two‐sample test, P<0.0083 [Bonferonni correction with six comparisons for total P<0.05]) using both ROI techniques at either kVp. Struvite uroliths were not statistically different from mixed or compound uroliths. The accuracy for determination of composition of pure uroliths ranged from 86% to 93%; the prediction accuracy for each urolith mineral type and for all uroliths in general was highest when the ROI was hand‐drawn just within the visible urolith border at 80 kVp. Technique of ROI determination and kVp that yielded the highest sensitivity, specificity, and positive and negative predictive values varied for each urolith type. Therefore, in this study, HU could be used to differentiate three types of uroliths of pure mineral composition in vitro. Further studies are needed to determine the predictive value of HU in vivo.}, number={3}, journal={Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound}, publisher={Wiley}, author={Pressler, Barrak M. and Mohammadian, Lenore A. and Li, Erning and Vaden, Shelly L. and Levine, Jay F. and Mathews, Kyle G. and Robertson, Ian D.}, year={2004}, month={May}, pages={189–197} }
 @article{trumpatori_mathews_roe_robertson_2003, title={Radiographic anatomy of the canine coxofemoral joint using the dorsal acetabular rim (DAR) view}, volume={44}, ISSN={1058-8183 1740-8261}, url={http://dx.doi.org/10.1111/j.1740-8261.2003.tb00501.x}, DOI={10.1111/j.1740-8261.2003.tb00501.x}, abstractNote={A radiographic study of the anatomy of the canine acetabulum was performed. The relationship between the area of dorsal acetabular rim that is subject to early damage in dogs with coxofemoral joint laxity, and the “DAR point” identified on dorsal acetabular rim (DAR) radiographic views was examined. Radiographs and digital photographs were made of the pelvis harvested from each of six skeletally mature dogs. Through analysis of these images, it was determined that in the standing animal, the DAR point is located 4–6 mm (or approximately 37°) caudal to the dorsal acetabular rim area that is prone to early damage in dogs with coxofemoral joint laxity. This study suggests that the DAR radiographic view may under‐represent changes to the dorsal acetabular rim in dogs with coxofemoral laxity.}, number={5}, journal={Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound}, publisher={Wiley}, author={Trumpatori, Brian J. and Mathews, Kyle G. and Roe, Simon R. and Robertson, Ian D.}, year={2003}, month={Sep}, pages={526–532} }
 @article{davis_gilger_spaulding_robertson_jones_2002, title={Nasal adenocarcinoma with diffuse metastases involving the orbit, cerebrum, and multiple cranial nerves in a horse}, volume={221}, ISSN={["0003-1488"]}, url={http://europepmc.org/abstract/med/12458617}, DOI={10.2460/javma.2002.221.1460}, abstractNote={A 9-year-old Trakehner gelding was examined because of right exophthalmus. Clinical findings included a lack of menace response in the right eye, reduced direct and consensual right pupillary light reflexes, ventrolateral strabismus of the right eye, mild right-sided facial asymmetry, a head tilt to the left, and increased extensor tone in the right limbs. Findings were suggestive of a multifocal lesion affecting the right forebrain; right optic, oculomotor, and facial nerves; and left vestibulocochlear nerve. Ultrasonographic examination of the right eye revealed a vascular retrobulbar mass. Computed tomographic imaging revealed a mass that filled the nasal cavity and invaded the forebrain. Necropsy revealed an undifferentiated nasal adenocarcinoma affecting the orbit with metastases to the right parotid gland, cranial cervical lymph nodes, fascial planes of the neck, and lungs. No evidence of direct involvement of the right facial and left vestibulocochlear nerves was found, suggesting the possibility of paraneoplastic peripheral neuropathy.}, number={10}, journal={JOURNAL OF THE AMERICAN VETERINARY MEDICAL ASSOCIATION}, author={Davis, JL and Gilger, BC and Spaulding, K and Robertson, ID and Jones, SL}, year={2002}, month={Nov}, pages={1460–1463} }
 @article{ramirez_douglass_robertson_2002, title={Ultrasonographic features of canine abdominal malignant histiocytosis}, volume={43}, ISSN={["1058-8183"]}, DOI={10.1111/j.1740-8261.2002.tb01664.x}, abstractNote={Ultrasonographic features of canine abdominal malignant histiocytosis (MH) of 16 dogs are reported. The most common finding was the presence of hypoechoic nodules in the spleen, some of which caused distortion of the splenic margin. The liver was the second‐most commonly affected organ. Hepatic ultrasonographic features were highly variable, including hypoechoic, hyperechoic, or mixed echogenic lesions. Other common ultrasonographic abnormalities included hypoechoic nodules in the kidneys and mesenteric and medial iliac lymphadenopathy. The results of this study suggest that the ultrasonographic appearance of canine abdominal MH is nonspecific, and definitive diagnosis requires cytologic or histologic examination.}, number={2}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Ramirez, S and Douglass, JP and Robertson, ID}, year={2002}, pages={167–170} }
 @article{thomas_pressler_robertson_2001, title={Radiographic diagnosis - Polyostotic lymphoma in a 5 month old dog}, volume={42}, ISSN={["1058-8183"]}, DOI={10.1111/j.1740-8261.2001.tb00980.x}, abstractNote={Veterinary Radiology & UltrasoundVolume 42, Issue 6 p. 521-523 RADIOGRAPHIC DIAGNOSIS—POLYOSTOTIC LYMPHOMA IN A 5 MONTH OLD DOG Helen L. Thomas BVMS, MSPVM, DVSc, Helen L. Thomas BVMS, MSPVM, DVSc Department of Anatomy, Physiological Sciences and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.Search for more papers by this authorBarrak M. Pressler DVM, Barrak M. Pressler DVM Department of Anatomy, Physiological Sciences and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.Search for more papers by this authorIan D. Robertson BVSc, Corresponding Author Ian D. Robertson BVSc Department of Anatomy, Physiological Sciences and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.Address correspondence and reprint requests to Dr. RobertsonSearch for more papers by this author Helen L. Thomas BVMS, MSPVM, DVSc, Helen L. Thomas BVMS, MSPVM, DVSc Department of Anatomy, Physiological Sciences and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.Search for more papers by this authorBarrak M. Pressler DVM, Barrak M. Pressler DVM Department of Anatomy, Physiological Sciences and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.Search for more papers by this authorIan D. Robertson BVSc, Corresponding Author Ian D. Robertson BVSc Department of Anatomy, Physiological Sciences and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606.Address correspondence and reprint requests to Dr. RobertsonSearch for more papers by this author First published: 19 May 2005 https://doi.org/10.1111/j.1740-8261.2001.tb00980.xCitations: 5AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume42, Issue6November 2001Pages 521-523 RelatedInformation}, number={6}, journal={VETERINARY RADIOLOGY & ULTRASOUND}, author={Thomas, HL and Pressler, BM and Robertson, ID}, year={2001}, pages={521–523} }