Single-photon emission computed tomography/computed tomography as a problem-solving tool in patients with suspected...

The aim of this study was to evaluate our institutional experience with single-photon emission computed tomography/computed tomography (SPECT/CT) hepatobiliary imaging as a problem-solving tool in the workup of suspected acute cholecystitis.

We queried our radiology information system database for cases in which SPECT/CT had been performed as part of the routine hepatobiliary technetium Tc 99m iminodiacetic acid studies done for the evaluation of acute cholecystitis. Fifty-three consecutive patients who had SPECT/CT after planar imaging were included. This cohort represents cases that were considered problematic by the initial interpreting physician on the basis of planar images. The planar and SPECT/CT images were retrospectively reviewed independently and separately by 2 experienced nuclear medicine specialists who evaluated the planar images for visualization of the gallbladder on a binary scale (yes or no) and rated their level of confidence on an ordinal scale(unsure, somewhat sure, and sure).

Single-photon emission CT/CT would have led to change in the management for interpreter 1 in a total of 23 cases (41%), with change from normal to abnormal scan findings (28%) and from abnormal to normal scan findings (13%). Similarly, SPECT/CT would have led to change in the management for interpreter 2 in a total of 23 cases (43%), with change from normal to abnormal scan findings (13%) and from abnormal to normal scan findings (30%).

Although planar hepatobiliary scanning is usually sensitive and specific, there are occasionally problematic cases. In our experience, we found that the addition of SPECT/CT improved the interobserver agreement and may change management in patients with superimposed bowel activity and/or unusual gallbladder anatomy that can confound the planar interpretation.