Visualization of Noncalcified Gallstones on CT Due to Vicarious Excretion of Intravenous Contrast

We present a case where low attenuation gallstones are visible on CT only on delayed imaging secondary to gallbladder opacification from vicarious excretion of contrast. We discuss heterotopic accumulation of contrast in the gallbladder and its potential diagnostic utilization in the detection of occult pathology.