The influence of body position on volume and x-ray attenuation of the lungs of three Beagles was investigated with computed tomography. In left and-right lateral recumbency, the dependent lung had decreased volume and increased x-ray attenuation compared with ventral recumbency. Volume and x-ray attenuation of the nondependent lung, however, were unchanged. In dorsal recumbency, there was a vertical gradient of x-ray attenuation being increased dorsally and decreased ventrally compared with ventral recumbency where regional differences in x-ray attenuation were not found. Result's indicate a risk of overlooking a mass in the dependent pulmonary parenchyma of dogs in lateral and dorsal recumbency. Regional differences in x-ray attenuation of the lungs of dogs can be avoided if the radiographs are obtained with the dog in ventral recumbency.

In a clinical series the accuracy of standard colloid scintigraphy and gray-scale ultrasonography in investigations for liver disease was evaluated. The results of 246 investigations in which both methods were utilized were reviewed and classified according to diagnosis and follow-up. In focal disease the sensitivity was 0.90 for scintigraphy, and 0.83 for ultrasonography; ultrasonography had the higher specificity, 0.94 compared with 0.77 for scintigraphy. In diffuse disease the sensitivity was found to be low for both methods, about 0.60, while specificity was high, 0.86 for scintigraphy and 0.92 for ultrasonography. Decreased liver function in diffuse liver disease as reflected by bone marrow uptake at scintigraphy was not found to have any influence on the degree of sensitivity of ultrasonography.

The utility of duplex Doppler ultrasonography (US) for monitoring was evaluated after 19 liver transplantations. The assessment of the resistive index (RI) of the hepatic arteries showed no significant difference in the RI measured in grafts with stable function compared with grafts with ischemic damage, acute rejection, chronic rejection, or cytomegalovirus hepatitis. Nor was there any correlation between the levels of RI and the severity of acute rejection. In 2 out of 5 liver transplants in which hepatic artery pulsations were not identified with US, hepatic artery thrombosis was found at angiography. Although high echogenicity of the parenchyma was often observed during acute rejection episodes, it was not diagnostic for rejection. Fluid collections observed around the grafts resolved spontaneously. Thus, duplex Doppler US for monitoring liver transplants is especially useful for the diagnosis of hepatic artery thrombosis. It was not helpful for the diagnosis of acute or chronic rejection.