Hyunyoung Park

Optimal scan delay depending on contrast material injection duration in abdominal multi-phase computed tomography of pancreas and liver in normal Beagle dogs

This study was conducted to establish the values for optimal fixed scan delays and diagnostic scan delays associated with the bolus-tracking technique using various contrast material injection durations in canine abdominal multi-phase computed tomography (CT). This study consisted of two experiments employing the crossover method. In experiment 1, three dynamic scans at the porta hepatis were performed using 5, 10 and 15 sec injection durations. In experiment 2, two CT scans consisting of five multi-phase series with different scan delays of 5 sec intervals for bolus-tracking were performed using 5, 10 and 15 sec injection duration. Mean arrival times to aortic enhancement peak (12.0, 15.6, and 18.6 sec for 5, 10, and 15 sec, respectively) and pancreatic parenchymal peak (17.8, 25.1, and 29.5 sec) differed among injection durations. The maximum mean attenuation values of aortas and pancreases were shown at the scan section with 0 and 5, 0 and 10 and 5 and 10 sec diagnostic scan delays during each injection duration, respectively. The optimal scan delays of the arterial and pancreatic parenchymal phase in multi-phase CT scan using fixed scan delay or bolus-tracking should be determined with consideration of the injection duration.

Evaluation of gallbladder and common bile duct size and appearance by computed tomography in dogs

The feasibility of using computed tomography (CT) to identify the common bile duct (CBD) and comparison with ultrasonography (US) results were evaluated in normal beagle dogs and dogs without hepatobiliary and pancreatic diseases. In addition, CBD diameters were obtained from CT at the level of the porta hepatis and the duodenal papilla level in dogs with underlying diseases that may cause cholestasis. US is a useful modality in the estimation of gallbladder volume because ejection fraction and CBD diameter from US were not significantly different from those of CT. The normal biliary tract was visible on CT images in 68% of the normal dog group. CBD diameter was not over 3 mm and 3.5 mm at the porta hepatis and duodenal papilla levels, respectively in normal dogs weighing less than 15 kg. Dogs suspected to have cholestasis associated with hepatobiliary or pancreatic diseases had significantly larger CBD than that in normal dogs.