Amyloidosis of heart and liver: comparison of Tc-99m pyrophosphate and Tc-99m methylene diphosphonate for detection.

Abstract
A prospective, comparative study was made of the efficacy of 99mTc pyrophosphate (Tc PYP) and 99mTc methylene diphosphonate (Tc MDP) in detecting soft tissue amyloidosis. Tc PYP and Tc MDP scans were obtained within 10-day intervals in 7 patients with histologically proven amyloidosis. Tc PYP was a better scanning agent for soft tissue amyloidosis in all patients. Cardiac and hepatic involvement were proved by autopsy in 1 patient. Involvement of the heart was confirmed by echocardiography in 5 patients. The potential use of Tc PYP scanning as a screening test for soft tissue amyloidosis is discussed.