Abstract
Purpose
Scintigraphy using 99mTc-labeled bone-seeking tracers is a cornerstone in the non-invasive diagnosis of transthyretin amyloid cardiomyopathy (ATTR-CM). However, planar imaging alone, particularly in patients with Perugini score 1, often lacks diagnostic specificity. This study evaluates the incremental diagnostic value of quantitative SPECT/CT at 90 min post-injection (p.i.) when added to standard planar imaging at 60 and 180 min.
Methods
In this retrospective single-center study, 170 patients with suspected cardiac amyloidosis underwent 99mTc-PYP scintigraphy, including planar imaging and SPECT/CT. Quantitative myocardial uptake was assessed using myocardium-to-vertebra and myocardium-to-rib ratios across predefined left ventricular segments. Imaging findings were correlated with electrocardiographic, echocardiographic, cardiac magnetic resonance (CMR), biomarker, and histopathological data where available.