Kinetics of Technetium-Labeled Cardiac Amyloid Radionuclide Imaging

作者：Brett W. Sperry, Evan L. O’Keefe, Eric V. Burgett, Erika Hutt, Philip G. Jones, James A. Case, Timothy M. Bateman · 发表于：Circulation Cardiovascular Imaging · 年份：2026 · DOI：10.1161/circimaging.125.019371 · 被引用次数：2 · 研究领域：Amyloidosis: Diagnosis, Treatment, Outcomes、Medical Imaging Techniques and Applications、Parathyroid Disorders and Treatments

BACKGROUND: Technetium-labeled bone-avid tracers have been repurposed to diagnose transthyretin cardiac amyloidosis without rigorous kinetic studies. Supply shortages have necessitated the use of hydroxymethylene diphosphonate (HMDP) as an alternative to technetium-99m pyrophosphate, though comparative data remain limited. This study characterizes tracer kinetics using quantitative single-photon emission computed tomography with computed tomography. METHODS: Twenty-four subjects undergoing evaluation for transthyretin cardiac amyloidosis underwent serial single-photon emission computed tomography with computed tomography imaging with pyrophosphate (n=11) or HMDP (n=13) on a cadmium zinc telluride system (SpectrumDynamics Veriton). Single-photon emission computed tomography acquisitions were obtained at intervals from 5 minutes to 3 hours post-injection. Quantitative parameters included standardized uptake values (SUVs), target-to-background ratios, and total cardiac activity derived from 3-dimensional volumes of interest for myocardium, blood pool, and bone. Mixed-effects models with splines compared time-activity trends between tracers. RESULTS: All 16 subjects with positive imaging demonstrated visual myocardial uptake above the blood pool within 10 minutes post-injection. Myocardial SUVs were similar between tracers and decreased linearly over time, whereas blood pool SUVs declined biexponentially and bone SUVs increased exponentially. HMDP exhibited faster blood pool clea...