@article{alhmoud_walmer_kavanagh_chang_johnson_bikdash_2023, title={CLASSIFYING KIDNEY DISEASE IN A VERVET MODEL USING SPATIALLY ENCODED CONTRAST-ENHANCED ULTRASOUND PERFUSION PARAMETERS}, volume={49}, ISSN={["1879-291X"]}, DOI={10.1016/j.ultrasmedbio.2022.10.015}, abstractNote={Early stages of diabetic kidney disease (DKD) are difficult to diagnose in patients with type 2 diabetes. This work was aimed at identifying contrast-enhanced ultrasound (CEUS) perfusion parameters, a microcirculatory biomarker indicative of early DKD progression. CEUS kidney flash-replenishment data were acquired in control, insulin resistant and diabetic vervet monkeys (N = 16). By use of a mono-exponential model, time-intensity curve parameters related to blood volume (A), velocity (β) and flow rate (perfusion index [PI]) were extracted from 10 concentric kidney layers to study spatial perfusion patterns that could serve as strong indicators of disease. Mean squared error (MSE) was used to assess model performance. Features calculated from the perfusion parameters were inputs for the linear regression models to determine which features could distinguish between cohorts. The mono-exponential model performed well, with average MSEs (±standard deviation) of 0.0254 (±0.0210), 0.0321 (±0.0242) and 0.0287 (±0.0130) for the control, insulin resistant and diabetic cohorts, respectively. Perfusion index features, with blood pressure, were the best classifiers between cohorts (p < 0.05). CEUS has the potential to detect early microvascular changes, providing insight into disease-related structural changes in the kidney. The sensitivity of this technique should be explored further by assessing various stages of DKD.}, number={3}, journal={ULTRASOUND IN MEDICINE AND BIOLOGY}, author={Alhmoud, Issa W. and Walmer, Rachel W. and Kavanagh, Kylie and Chang, Emily H. and Johnson, Kennita A. and Bikdash, Marwan}, year={2023}, month={Mar}, pages={761–772} }
 @article{srivastava_sridharan_walmer_kasoji_burke_dayton_johnson_chang_2022, title={Association of Contrast-Enhanced Ultrasound-Derived Kidney Cortical Microvascular Perfusion with Kidney Function}, volume={3}, ISSN={["2641-7650"]}, DOI={10.34067/KID.0005452021}, abstractNote={
            Background
            Individuals with chronic kidney disease (CKD) have decreased kidney cortical microvascular perfusion, which may lead to worsening kidney function over time, but methods to quantify kidney cortical microvascular perfusion are not feasible to incorporate into clinical practice. Contrast-enhanced ultrasound (CEUS) may quantify kidney cortical microvascular perfusion, which requires further investigation in individuals across the spectrum of kidney function.
          }, number={4}, journal={KIDNEY360}, author={Srivastava, Anand and Sridharan, Anush and Walmer, Rachel W. and Kasoji, Sandeep K. and Burke, Lauren M. B. and Dayton, Paul A. and Johnson, Kennita A. and Chang, Emily H.}, year={2022}, month={Apr}, pages={647–656} }
 @article{yokoyama_hossain_caughey_fisher_detweiler_chang_gallippi_2022, title={in vivo VisR Measurements of Viscoelasticity and Viscoelastic Anisotropy in Human Allografted Kidneys Differentiate Interstitial Fibrosis and Graft Rejection}, ISSN={["1948-5719"]}, DOI={10.1109/IUS54386.2022.9958358}, abstractNote={Assessment of renal transplant failure typically in-volves nonspecific biomarkers or invasive biopsies, presenting a clinical need for noninvasive imaging modalities that can identify pathologic changes in renal allografts. One approach is Viscoelastic Response (VisR) ultrasound, an acoustic radiation force (ARF)-based imaging method that qualitatively evaluates, relative to the applied ARF amplitude, tissue elasticity (RE) and viscosity (RV). We hypothesize that, by measuring the RE and RV degree of anisotropy (DoA) along versus across nephrons in the cortex and the regional ratio (RR) of RE and RV in the outer versus inner cortex, VisR can discriminate transplanted kidneys with fibrosis and rejection in humans in vivo. VisR imaging was performed in renal transplant patients from 3 to 36 months after transplantation at 3 mo. (quarterly) intervals, coincident with routine clinic visits. RE and RV-based DoA in outer and inner cortices were significantly different between patients with and without biopsy-confirmed interstitial fibrosis up to 4 quarters before the time of clinically indicated biopsies. VisR RE-based RR had similar performance but also differentiated rejected from fibrotic kidney. These results suggest that noninvasive VisR imaging is relevant to early detection of transplant kidney fibrosis and rejection, which could enable timely interventions that extend graft life.}, journal={2022 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS)}, author={Yokoyama, Keita A. and Hossain, Md. Murad and Caughey, Melissa C. and Fisher, Melrose W. and Detweiler, Randal K. and Chang, Emily H. and Gallippi, Caterina M.}, year={2022} }
 @article{nyankima_kasoji_cianciolo_dayton_chang_2019, title={Histological and blood chemistry examination of the rodent kidney after exposure to flash-replenishment ultrasound contrast imaging}, volume={98}, ISSN={["1874-9968"]}, DOI={10.1016/j.ultras.2019.05.003}, abstractNote={The purpose of this work is to investigate whether imaging sequences of flash-replenishment contrast enhanced ultrasound (CEUS) of the kidney result in chronic or acute bioeffects. Kidneys of female Fischer 344 rats were imaged using the flash-replenishment technique. Animals were separated into four groups (N = 31). Imaging was conducted with a 4C1 probe, driven by an Acuson Sequoia system with Definity microbubbles as the ultrasound contrast agent. During the flash phase of the imaging sequence, one kidney in each animal was exposed to either a mechanical index (MI) of 1.0 or 1.9. For each MI, half of the animals were sacrificed shortly after imaging (4 h) or after 2 weeks. A blinded veterinary nephropathologist reviewed the histopathology of both the imaged and control (non-imaged) kidney. Blood urea nitrogen (BUN) was measured for each animal prior to imaging and at the time of necropsy. Histopathology assessments in both the 1.0 and 1.9 MI groups revealed no signs of hemorrhage at either the 4-h or 2-week time point. BUN showed minor but statistically significant elevations in both the 1.0 and 1.9 MI groups, but no significant difference was present at the 2-week time point in the 1.0 MI group. All BUN levels (at both time points) remained in the normal range. In conclusion, CEUS with flash-replenishment imaging sequences did not result in kidney bioeffects observable with histology at early or late time points. Increases in BUN levels were observed after imaging, but were minimized when using a moderate MI (1.0).}, journal={ULTRASONICS}, author={Nyankima, A. Gloria and Kasoji, Sandeep and Cianciolo, Rachel and Dayton, Paul A. and Chang, Emily H.}, year={2019}, month={Sep}, pages={1–6} }
 @article{nyankima_kasoji_cianciolo_dayton_chang_2019, title={The biological response of rodent kidneys to low frequency, full volume diagnostic contrast-enhanced ultrasound imaging: Pilot data}, volume={25}, ISSN={["2352-3409"]}, DOI={10.1016/j.dib.2019.104170}, abstractNote={With the growth of contrast-enhanced ultrasound (CEUS) clinically, there are concerns about histologic bioeffects in regards to the implementation of high mechanical index (MI) imaging, such as the imaging sequence used for a specific CEUS technique known as flash-replenishment. The data presented are results from a pilot study, which explored flash-replenishment with high and moderate MI imaging sequences at time points of 24 hours and 2 weeks post imaging. This pilot study was followed by a larger study, which can be found in a journal article entitled “Histological and Blood Chemistry Examination of the Rodent Kidney After Exposure to Flash-Replenishment Ultrasound Contrast Imaging” Nyankima et al., 2019.}, journal={DATA IN BRIEF}, author={Nyankima, A. Gloria and Kasoji, Sandeep and Cianciolo, Rachel and Dayton, Paul A. and Chang, Emily H.}, year={2019}, month={Aug} }