Dynamic hepatobiliary SPECT: a method for tomography of a changing radioactivity distribution.

Dynamic single photon emission computed tomography (SPECT) of a changing radioactivity distribution can be performed with a rotating scintillation camera by acquiring several 360 degree studies and generating a new 360 degree study for which the acquisition time for every image is shifted to a single selected time. Following suppression of gallbladder filling with a fatty meal, dynamic SPECT of the hepatobiliary system was carried out by acquiring two successive studies with each head of a dual-headed camera within a 35-min period following injection of technetium-99m DISIDA. Each of the four acquired studies consisted of 60 images acquired at 6 degree intervals, spanning 360 degrees. Time-shifted studies, each consisting of 60 images over 360 degrees, were generated for times 9, 17, and 26 min postinjection. Transverse, sagittal, and coronal images were generated for each study. These images were artifact-free and demonstrated physiologic shifting of the radioactivity distribution over time. When gallbladder filling was not suppressed gross artifacts were obtained. This procedure permits examination of regional liver function and provides improved visualization of the biliary tree.