TTR and cardiac amyloidosis: Indeed, asymptomatic cardiac ATTR deposits can be identified through 99mTc-DPD scintigraphy at an early stage when echocardiography, serum cardiac biomarkers, and perhaps even CMR remain normal.82 By contrast, uptake of 99mTc-DPD occurs in about one third of patients with cardiac AL amyloidosis, and 99mTc-DPD-SPECT-CT can help to distinguish the two types.82 The sensitivity of DPD scintigraphy for detecting cardiac amyloidosis of TTR type would appear to have considerable potential for diagnosis and screening.83