Inflammation imaging of coronary plaque and perivascular adipose tissue by digital PET/CT

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K08052
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Ehime University
• Principal Investigator: Miyagawa Masao 愛媛大学, 医学部附属病院, 教授 (90346685)
• Co-Investigator(Kenkyū-buntansha): 川口 直人 愛媛大学, 医学部附属病院, 助教 (40837259)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: デジタル PET/CT / FDG

Outline of Final Research Achievements

Digital PET/CT with semiconductor detectors has excellent sensitivity and spacial resolution. We investigated its clinical usefulness in 150 patients with cardiovascular inflammatory diseases. For the evaluation of the activity of large vessel inflammation (outer diameter> 2-3 cm) such as Takayasu's arteritis and giant cell arteritis, the FDG accumulation in the vessel wall was a highly useful indicator by imaging analysis. The detection of periarteritis nodosa, which is inflammation of moderate vessels (outer diameter; 5-8 mm), was also improved.
On the other hand, detection of FDG accumulation in coronary arteries and surrounding fat tissue was difficult due to lack of enough spatial resolution. FDG accumulation in peri-coronary fat was detected in IgG4-related diseases and atrial fibrillation, but the detection rate was low in coronary artery lesions with severe calcification.

Free Research Field

放射線医学 (核医学)

Academic Significance and Societal Importance of the Research Achievements

原発性血管炎は,診断に難渋する症例が多く,その多くが難病に指定されている. 確定診断には血管から組織を採取し組織学的に活動性炎症を確認する. 代わりに動脈造影, CTおよびMR血管造影などが行われるが,活動性の評価は困難である. FDGは活動性炎症細胞浸潤部に集積するので活動性を評価でき, 免疫抑制剤等の治療適応の決定や効果判定の指標となる. 空間分解能に優れる半導体デジタルPET/CTを用いて高安動脈炎や巨細胞性動脈炎などの大血管炎, 中等度血管炎である結節性多発動脈炎について検出能の向上が確認され, IgG4関連疾患や心房細動などでは冠動脈周囲脂肪へのFDG集積が検出された.