Description and comparison of excretory urography performed during radiography and computed tomography for evaluation of the urinary system in healthy New Zealand White rabbits (Oryctolagus cuniculus).

Abstract

OBJECTIVE To evaluate the usefulness of excretory urography performed during radiography (REU) and CT (CTEU) in healthy rabbits, determine timings of urogram phases, and compare sensitivities of REU and CTEU for detection of these phases. ANIMALS 13 New Zealand White rabbits (Oryctolagus cuniculus). PROCEDURES Rabbits were screened for signs of systemic and urinary tract disease. An REU examination of each was performed, followed ≥ 5 days later by a CTEU examination. Contrast images from each modality were evaluated for quality of opacification and intervals between initiation of contrast medium administration and detection of various urogram phases. RESULTS Excretory urograms of excellent diagnostic quality were achieved with both imaging modalities. For all rabbits, the nephrographic phase of the urogram appeared in the first postcontrast REU image (obtained between 34 and 40 seconds after initiation of contrast medium administration) and at a median interval of 20 seconds in CTEU images. The pyelographic phase began at a median interval of 1.63 minutes with both imaging modalities. Contrast medium was visible within the urinary bladder at a median interval of 2.20 minutes. Median interval to the point at which the nephrogram and pyelogram were no longer visible in REU images was 8 hours and 2.67 hours, respectively. The CTEU technique was better than the REU technique for evaluating renal parenchyma. CONCLUSIONS AND CLINICAL RELEVANCE Findings suggested that REU and, particularly, CTEU may be valuable tools for the diagnosis of renal and urinary tract disease in rabbits; however, additional evaluation in diseased rabbits is required.