Gastrointestinal (GI) disease is a common clinical complaint in small animal patients; computed tomography (CT) examinations enable a global overview of the GI tract and associated structures. Previously, the GI wall has been reportedly identified from serosa to mucosa in 77% of standard postcontrast CT studies and wall layers seen in ultrasound have not been distinguished. Inconsistent strong contrast enhancement of the inner layer of the GI mucosal surface was noted on dual phase CT studies acquired in our institution, which increased the visibility of the GI tract and disease processes. The aim of this retrospective, observational, cross-sectional study was to determine the optimal portal vein attenuation for maximizing GI wall conspicuity using dual phase contrast-enhanced CT. Patients with abdominal CT for a non-GI related disease were included. In a pilot study, 175 GI segments from 35 CT studies were graded for presence of mucosal surface enhancement (MSE). The strongest mucosal surface enhancement grade correlated with portal vein attenuation of 43-150 HU; this value was used as inclusion criterion in the main study. A total of 441 GI segments were evaluated in 42 CT studies postcontrast for GI wall conspicuity. The GI wall was conspicuous in 56.7% precontrast, 84.5% at 30s, and 77.3% late postcontrast; 4.7% of segments were removed due to motion blur. At 30 s distinct mucosal surface enhancement was seen in the small intestine and gastric mucosal surface enhancement was poor. Findings supported the use of dual phase contrast-enhanced CT for improving conspicuity of the GI wall.

In dogs with non-perforated ulcers, survey radiography was usually negative whereas ultrasonography and CT frequently enabled detection of the site of the ulcer; in dogs with perforated ulcers, radiography was frequently positive for peritoneal gas and CT was a sensitive modality for both the ulcer and signs of perforation.

Objective: To investigate whether the donation of 1 unit of blood results in a significant decrease in the caudal vena cava diameter (CVCd) and the caudal vena cava diameter to aortic diameter (CVCd:Aod) ratio measured at the iliac location. Interventions:Eight healthy client-owned Greyhounds underwent ultrasound of their caudal vena cava and aorta before and after blood donation. The principal investigator obtained M-mode images of the blood vessels from all dogs and a secondary investigator measured the CVCd and aortic diameter in a blinded manner from stored images. The ratio of CVCd:Aod was then calculated. After assessing for normality, paired-sample t-tests were performed to compare mean values before and after donation.Main Results: The mean (±SD) CVCd before and after blood donation were 15.84 mm (±5.06 mm) and 15.82 mm (±5.42 mm) and the CVCd:Aod ratios were 0.93 (±0.23) and 1.00 (±0.27), respectively. There was no statistical difference between pre-and postdonation values for CVCd (P = 0.99) or CVCd:Aod (P = 0.34). Conclusion:The measurement of CVCd and CVCd:Aod ratio with ultrasound at the iliac location failed to detect mild-to-moderate blood loss produced by the donation of 1 unit of blood in Greyhounds. K E Y W O R D Scanine, blood loss, central venous pressure, vessel diameter, ultrasoundThe authors declare no conflict of interest.