Liver-spleen studies with the rotating gamma camera. I: Utility of the rotating display

The clinical utility of a computer-generated dynamic cine display (rotating display) of the unprocessed projection images of the liver and spleen obtained with rotating gamma-camera tomography was prospectively compared with that of the standard multi-view static scintigram display. Two hundred cases were independently and blindly analyzed by three observers. Each study was coded from 1-5, indicating the certainty of normality or abnormality present. When abnormality was noted, the study was assessed for the presence of metastatic disease, inhomogeneous uptake, hepatosplenomegaly, and colloid distribution shift. ROC analysis was then performed on the initial coding for certainty of abnormality, and the causes for discrepancies were evaluated from the assessment of the type of abnormality present. No significant interdisplay differences could be demonstrated. In the small percentage of cases where interdisplay disagreement occurred, this was usually accompanied by marked interobserver variation and was most commonly due to differing assessment of organ size. It is concluded that the static and rotating display formats can be used interchangeably in the evaluation of technetium-99m-labeled sulfur colloid liver studies.