Comparison of Renal Blood Flow Using Maximum Slope-Based Computed Tomography Perfusion and Ultrasound Flow Probe in Healthy Dogs

Abstract

Computed tomography (CT) perfusion can analyze tissue perfusion and quantitative parameters, including blood flow, blood volume, and transit time. CT perfusion has been used for evaluating split renal function. However, its applicability in veterinary medicine was not validated. This study aimed to evaluate the correlation of renal blood flow (RBF) derived by maximum slope-based CT perfusion and an ultrasonic flow probe and assess the effect of the presence of a pre-existing contrast medium on CT perfusion in the kidneys. In five healthy purpose-bred beagles, CT perfusion was performed at the level of the left renal hila after injection of 1 mg/kg iohexol, during measuring RBF with an ultrasonic flow probe placed on the left renal artery. After post-contrast CT scan with injection of 2 mg/kg iohexol, CT perfusion scan was repeated with the same protocol used in the first perfusion study. The CT perfusion derived RBF was analyzed based on the maximum slope and was compared with the true RBF obtained using an ultrasonic flow probe. Results indicated that CT perfusion derived RBF was significantly correlated with true RBF, although CT perfusion derived RBF did not match the absolute value of the true RBF. It was correlated with the true RBF, even in the presence of a pre-existing contrast medium in the kidney. CT perfusion can estimate the change in individual renal perfusion non-invasively, and this method can be used supplementary to the conventional CT protocol in clinic.

Optimal injection rate and catheter size for brain perfusion computed tomography using non-ionic contrast medium in clinically normal Beagles

“…A nonionic iodinated contrast medium (Omnipaque, GE healthcare, 350 mg I/mL, 350 mg I/kg) was administered through an intravenous catheter using a power injector according to the different conditions mentioned earlier. 18 To prevent stagnation of the contrast medium in the cerebral blood vessels, a 5-minute interval was allowed between injections across all injection rates. 22 The same procedure was repeated in the second experiment using a 20-gauge catheter.…”

“…14,15 In veterinary medicine, PCT has been used in disease diagnoses that require perfusion evaluation. Several studies on variables affecting PCT have been conducted in abdominal organs such as the liver, 16 kidney, 17,18 , and pancreas. 19 In addition, studies on the diagnosis of cerebrovascular diseases that require perfusion evaluation, such as degenerative diseases 20 and brain tumors 21 have been performed.…”

Dynamic contrast‐enhanced computed tomography in dogs with nasal tumors

“…Dynamic contrast‐enhanced computed tomography has been used in dogs, and several proof‐of‐principle studies have assessed normal tissues and tumors, and compared DCECT to 18F‐fluorodeoxyglucose positron emission tomography‐computed tomography. 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 Two studies specifically reported DCECT in nasal tumors but did not find correlation with histogenesis or survival. 33 , 39 Our objectives were (a) to assess baseline perfusion parameters in dogs with nasal tumors based on histopathological type, (b) to characterize changes in perfusion parameters with changes in tumor volume after the start of RT, and (c) to evaluate if a correlation existed of either objective 1 or objective 2 with survival.…”

“…Dynamic contrast‐enhanced computed tomography has been used in dogs, and several proof‐of‐principle studies have assessed normal tissues and tumors, and compared DCECT to 18F‐fluorodeoxyglucose positron emission tomography‐computed tomography 26‐42 . Two studies specifically reported DCECT in nasal tumors but did not find correlation with histogenesis or survival 33,39 .…”