Objective—To determine computed tomography (CT) delay times by use of a sequential scan and identify the normal enhancement pattern in each phase of a triphasic CT scan of the kidneys in dogs.
Animals—14 healthy Beagles.
Procedures—A sequential CT scan was used for investigating delay time, and a triphasic helical CT scan was used for identifying the normal enhancement pattern and determining Hounsfield unit values in the kidneys of dogs.
Results—In the cine scan (single-slice dynamic scan), the optimal delay times were 10 seconds in the corticomedullary phase and 44 seconds in the nephrographic phase, after contrast medium injection. By use of triphasic CT images, Hounsfield unit values were acquired in each phase.
Conclusions and Clinical Relevance—Triphasic CT of the kidneys in clinically normal dogs was established by acquisition of delay times in a cine scan and may become an important imaging modality in the diagnosis of renal diseases and in treatment planning in dogs.
Objective—To evaluate the effects of thiopental, propofol, and etomidate on glomerular filtration rate (GFR) measured by the use of dynamic computed tomography in dogs.
Animals—17 healthy Beagles.
Procedures—Dogs were randomly assigned to receive 2 mg of etomidate/kg (n = 5), 6 mg of propofol/kg (7), or 15 mg of thiopental/kg (5) during induction of anesthesia; anesthesia was subsequently maintained by isoflurane evaporated in 100% oxygen. A 1 mL/kg dosage of a 300 mg/mL solution of iohexol was administered at a rate of 3 mL/s during GFR measurement. Regions of interest of the right kidney were manually drawn to exclude vessels and fatty tissues and highlight the abdominal portion of the aorta. Iohexol clearance per unit volume of the kidney was calculated by use of Patlak plot analysis.
Results—Mean ± SD weight-adjusted GFR of the right kidney after induction of anesthesia with thiopental, propofol, and etomidate was 2.04 ± 0.36 mL/min/kg, 2.06 ± 0.29 mL/min/kg, and 2.14 ± 0.43 mL/min/kg, respectively. However, no significant differences in weight-adjusted GFR were detected among the treatment groups.
Conclusions and Clinical Relevance—Results obtained for the measurement of GFR in anesthetized dogs after anesthetic induction with etomidate, propofol, or thiopental and maintenance with isoflurane did not differ significantly. Therefore, etomidate, propofol, or thiopental can be used in anesthesia-induction protocols that involve the use of isoflurane for maintenance of anesthesia without adversely affecting GFR measurements obtained by the use of dynamic computed tomography in dogs.
OBJECTIVE To determine serum cholecystokinin (CCK) concentrations in dogs with pituitary-dependent hyperadrenocorticism (PDH) and to evaluate associations among CCK concentration, PDH, and gallbladder mucocele (GBM).
ANIMALS 14 client-owned dogs with PDH and 14 healthy dogs.
PROCEDURES Dogs were separated into 4 groups: healthy dogs without gallbladder sludge (group A; n = 7), healthy dogs with gallbladder sludge (group B; 7), dogs with PDH and gallbladder sludge (group C; 8), and dogs with PDH and GBM (group D; 6). Serum CCK concentrations were then measured before and 1, 2, and 4 hours after consumption of a high-fat meal. Concentrations in dogs with PDH were also measured before and after trilostane treatment. Results were compared among groups and assessment points.
RESULTS Preprandial serum CCK concentrations in group C were significantly lower than those in groups A, B, and D, but no significant differences in postprandial CCK concentrations were identified among the groups 1, 2, or 4 hours after the meal. With respect to trilostane treatment of dogs with PDH, no significant differences were identified between pre- and post-trilostane serum CCK concentrations in group C or D. Median CCK concentration after trilostane treatment was higher in group D than in group C, but this difference was not significant.
CONCLUSIONS AND CLINICAL RELEVANCE The outcomes in this study did not support the hypothesis that a low circulating CCK concentration affects the development of GBM in dogs with PDH.
Objective—To obtain quantitative variables of the abdominal aorta and both kidneys on the basis of time-attenuation curves (TACs) and to measure glomerular filtration rate (GFR) for each kidney and the global GFR in clinically normal cats by use of dynamic computed tomography (CT) and Patlak analysis.
Animals—9 healthy cats.
Procedures—All the cats were anesthetized with propofol. Anesthesia was maintained by administration of isoflurane, and CT examination was performed in the anesthetized cats. The TACs and renal volume were measured by use of the baseline precontrast and single-slice dynamic scans. The CT-GFR of each kidney and the global CT-GFRs were calculated via Patlak plot analysis.
Results—CT-GFR results from 7 cats were valid. Peak aortic enhancement was detected between 9.0 and 14.0 seconds after iohexol injection, and the initial peak time of renal parenchymal enhancement was 15 to 24 seconds after iohexol injection. Mean ± SD global GFR was 2.06 ± 0.62 mL/min/kg. Mean ± SD CT-GFR of the right and left kidneys was 0.97 ± 0.32 mL/min/kg and 1.05 ± 0.31 mL/min/kg, respectively.
Conclusions and Clinical Relevance—The CT-GFR method can be rapidly and conveniently performed in clinically normal cats. This combined structural-functional approach provided physiologic and morphological information on the kidneys of cats.