Pitfalls of 99mTc-pyrophosphate Scintigraphy for Detecting Transthyretin Cardiac Amyloidosis

• Published in: SHINZO KAKU IGAKU Vol. 27; no. 1; pp. 24 - 29
• Main Authors: Saitou, Toshinori, Aikawa, Tadao
• Format: Journal Article
• Language: Japanese
• Published: Japanese Society of Nuclear Cardiology 2025; 日本心臓核医学会
• Subjects: 99mTcピロリン酸シンチグラフィ; single-photon emission computed tomography（SPECT）; トランスサイレチン型心アミロイドーシス; プラナー像; 骨シンチグラフィ
• ISSN: 1346-2733; 2424-1733
• DOI: 10.14951/jsnc.27-002

Non-invasive diagnosis of cardiac amyloidosis using 99mTc-pyrophosphate (PYP) scintigraphy is valuable for differentiating between light chain and transthyretin cardiac amyloidosis. However, there are several pitfalls to be aware of when interpreting PYP planar imaging and single-photon emission computed tomography (SPECT) to assess myocardial PYP uptake. In visual and semi-quantitative assessments using PYP planar imaging, PYP uptake in the blood pool may produce false-positive results. SPECT imaging is essential for differentiating PYP tracer uptake in the myocardium from that in the blood pool, and attention should be paid to the timing of image acquisition and how to create fusion images with CT. This review aims to highlight pitfalls in interpreting PYP imaging and provide tips on how to avoid them.