Evaluation of washout rate using I-123 BMIPP for trigriceride deposit cardio myopathy

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K18414
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 90140:Medical technology assessment-related
• Research Institution: Osaka University
• Principal Investigator: Kamiya Takashi 大阪大学, 医学部附属病院, 診療放射線技師 (80550764)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 中性脂肪蓄積心筋血管症 / 脂肪酸代謝シンチ / 洗い出し率 / I-123 BMIPP

Outline of Final Research Achievements

Triglyceride deposit cardiomyovasculopathy (TGCV) was discovered in a Japanese cardiac transplant candidate in 2008, then characterized as the massive accumulation of triglyceride in cardiomyocytes and smooth muscle cells. TGCV is an intractable disease that causes severe heart failure, cardiomyopathy and coronary artery disease due to abnormal metabolism of long-chain fatty acids.
Washout rate (WR) of < 10% in myocardial fatty acid single-photon emission computed tomography (SPECT) using I-123 BMIPP is essential for a diagnosis of TGCV. We reported that the most important factor in the accuracy of WR is the reproducibility between early and delayed SPECT images for acquisition position, processing and analysis. In addition, it was found that WR was slightly overestimated for simultaneous acquisition of dual isotope, I-123 BMIPP and Tl-201 thallium chloride, due to the effect of crosstalk between 159 keV from I-123 and 167 keV from Tl-201.

Free Research Field

核医学技術

Academic Significance and Societal Importance of the Research Achievements

I-123 BMIPPを用いた心筋脂肪酸代謝シンチは中性脂肪蓄積心筋血管症(Trigriceride deposite cardiomyopathy: TGCV)の病態を表現する検査と考えられており洗い出し率が10%を下回ることが診断基準である。本研究では後期像の撮像による洗い出し率の算出によりTGCVが診断可能になり、洗い出し率の信頼性には早期像と後期像に対して収集から処理まで再現性が最も重要であることを報告した。また、多くの施設で行われている心筋脂肪酸代謝シンチと心筋血流シンチの2核種同時収集ではクロストークにより洗い出し率が過大評価されることを明らかにした。