Ability of positive and negative contrast computed tomographic peritoneography to delineate canine liver lobe fissures.
To determine the efficacy of contrast peritoneography in delineating liver lobe fissures by using computed tomography (CT). Prospective cross-sectional study. Canine cadavers (n = 10). An 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. When 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. Positive contrast CT peritoneography improved the delineation of hepatic interlobar fissures in normal canine cadavers. These 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.