Hosokawa Ryohei, Kambara Naoshige, Ohba Muneo, Mukai Takahiro, Ogawa Mikako, Motomura Hiroshi, Kume Noriaki, Saji Hideo, Kita Toru, Nohara Ryuji
Division of Cardiology, Kitano Hospital, Tadukekofukai Medical Research Institute, Osaka, Japan.
J Nucl Med. 2006 May;47(5):863-7.
Detection of vulnerable plaques before rupture is important in preventing acute coronary events such as myocardial infarction. Although therapeutic strategies such as percutaneous transluminal coronary angioplasty appear to prevent coronary occlusion and consequently may lead to improved prognosis in these patients, a method of detecting vulnerable plaques has not been established. A nuclear method that uses an intravascular radiation detector (IVRD) with the plaque-avid tracer (18)F-FDG is one of the most promising methods. The catheter-based IVRD consists of a catheter probe (a scintillator and flexible optic fibers), photomultipliers, a controller, and an automatic pullback unit and personal computer. A phantom study demonstrated that this detector was highly sensitive to (18)F and enabled the detection of (18)F point sources. However, details of the detection system in vivo remain unclear.
To evaluate vulnerable plaques in vivo, we investigated a canine femoral artery and coronary artery using this detector system. Our goal was to estimate the ability of this device to navigate through these arteries and to detect (18)F point sources fixed on their adventitia.
In the study using a canine femoral artery, the IVRD could detect the point sources with good repeatability. In the study using an open-chest canine model, the catheter probe could easily be advanced into the left descending coronary artery, and the IVRD could detect target sources attached externally to the coronary artery (7- to 15-mm intervals) with good resolution.
This newly developed catheter-based IVRD was able to detect, with good resolution, the slight radioactivity from (18)F point sources attached to the femoral artery and the coronary adventitia. These results show that catheter-based detection of coronary vulnerable plaques may be feasible.
在斑块破裂前检测易损斑块对于预防急性冠状动脉事件（如心肌梗死）很重要。尽管诸如经皮腔内冠状动脉成形术等治疗策略似乎可预防冠状动脉闭塞，从而可能改善这些患者的预后，但尚未建立检测易损斑块的方法。一种使用带有斑块亲和示踪剂（18）F-FDG的血管内辐射探测器（IVRD）的核方法是最有前景的方法之一。基于导管的IVRD由导管探头（闪烁体和柔性光纤）、光电倍增管、控制器、自动回撤单元和个人计算机组成。一项体模研究表明，该探测器对（18）F高度敏感，能够检测（18）F点源。然而，体内检测系统的细节仍不清楚。
为了在体内评估易损斑块，我们使用该探测器系统研究了犬的股动脉和冠状动脉。我们的目标是评估该设备在这些动脉中导航并检测固定在其外膜上的（18）F点源的能力。
在使用犬股动脉的研究中，IVRD能够以良好的重复性检测点源。在使用开胸犬模型的研究中，导管探头可以轻松推进到左冠状动脉前降支，IVRD能够以良好的分辨率检测附着在冠状动脉外部（间隔7至15毫米）的目标源。
这种新开发的基于导管的IVRD能够以良好的分辨率检测附着在股动脉和冠状动脉外膜上的（18）F点源的轻微放射性。这些结果表明基于导管检测冠状动脉易损斑块可能是可行的。
