Gallium scintigraphy has a higher positive predictive value than CT in the detection of lymphoma;
gadolinium is more specific and sensitive for active lymphoma while CT may show more precise locations and sizes of lymph nodes
HIDA scan
for acute cholecystitis
Abnormal or positive test = lack of visualization of the gallbladder
PET scan
for detection of cancer
increased uptake of fluoro-deoxyglucose