[Validation of Quantitative Evaluation Method Using a Cadmium Zinc Telluride Cardiac Camera in the Diagnosis of Cardiac Amyloidosis].

Purpose: The purpose of this study was to verify the clinical applicability of PYP accumulation rates obtained with a cadmium zinc telluride (CZT) cardiac camera in the diagnosis of cardiac amyloidosis.

Methods: We performed ^99mTc-PYP/²⁰¹Tl-Cl dual-isotope imaging in 84 patients with suspected cardiac amyloidosis using both a CZT cardiac camera and a conventional Anger camera. We obtained the PYP accumulation rate from CZT SPECT images and visual score and H/CL ratio from planar images. We evaluated PYP accumulation rates in 14 ATTR and 9 non-ATTR patients diagnosed by biopsy. We also evaluated the correlation between the PYP accumulation rate and both the visual assessment grade and H/CL ratio in 84 patients.

Results: The PYP accumulation rate was 18.5±10.6% in the non-ATTR group and 72.4±28.7% in the ATTR group, which was significantly higher in the ATTR group (p<0.01). The correlation coefficient between the PYP accumulation rate and visual score was 0.77, and that of the H/CL ratio was 0.76, both showing strong positive correlations.

Conclusion: The PYP accumulation rate obtained with a CZT cardiac camera showed significant differences between ATTR and non-ATTR groups and strong correlations with conventional assessment indices, suggesting its potential applicability in the diagnosis of cardiac amyloidosis.