Correction of respiratory motion in hepatic scintigraphy

An analog device to correct for respiratory motion was used in 100 consecutive liver scans to determine its clinical utility. The sets of scan images generated were reviewed separately, then together, without knowledge of clinical presentation or imaging technique. When the images were reviewed separately, there was no clinical significant change in patient classification. When the images were reviewed together, 57% of the patients had detectable differences in image features, and in most instances this difference was limited to a clearer definition of organ outline or normal variants (e.g., gallbladder fossa). Of the 17 patients with focal hepatic disease, 14 had these defects better defined or additional lesions identified. Of the 18 patients with definite, diffuse, nonhomogeneous tracer distribution as seen in the uncorrected images, 12 had changes in scan appearance with motion correction. In eight patients the scan pattern became more normal, but in four the abnormal pattern was modified to that of focal defects.