Ultra-early phase scintigraphy detects ATTR cardiac amyloidosis

Tuesday, November 28 | 4:40 p.m.-4:50 p.m. | T8-SSNMMI04-2 | Room E353C

Bone scintigraphy can detect transthyretin protein accumulation associated with cardiac amyloidosis just five minutes after patients are injected with technetium-99m pyrophosphate (Tc-99m PYP) radiotracer, according to research to be presented in this session.

Presenter Shinichiro Kida noted that the imaging technique is less time-consuming and more beneficial, particularly for elderly patients, than the conventional protocol.

Tc-99m PYP scintigraphy is a noninvasive imaging modality used to diagnose transthyretin cardiac amyloidosis (ATTR-CA), a buildup of faulty proteins (fibrils) in the myocardium, with the heart-to-contralateral (H/CL) ratio an essential biomarker for radiotracer uptake. However, measuring the H/CL ratio requires planar imaging at one hour and/or three hours after injection, which is time-consuming and can cause physical exhaustion and discomfort for elderly patients.

In this study, the researchers analyzed imaging in four patients with ATTR-CA and four patients with hypertensive cardiomyopathy (non-CA) who underwent dynamic scintigraphic scanning. They reconstructed planar images every minute from three to 20 minutes and then every five minutes from 25 to 60 minutes after injection. The H/CL ratio was assessed on each planar image. The H/CL ratio on the planar images acquired at five minutes post-injection showed a significant difference between ATTR-CA and non-CA patients, according to the findings.

Ultra-early phase  Tc-99m PYP scintigraphy can detect ATTR-CA with 100% sensitivity at five minutes after tracer injection, the group suggests.

Attend this session on cardiovascular and pulmonary molecular imaging for all the details.