Klein M A, Collier B D, Hellman R S, Bamrah V S
Department of Radiology, Medical College of Wisconsin, Milwaukee.
AJR Am J Roentgenol. 1993 Aug;161(2):257-63. doi: 10.2214/ajr.161.2.8333357.
The potential of MR imaging for evaluating myocardial perfusion and viability may make it the imaging procedure of choice for examining patients with ischemic heart disease. Accordingly, the purpose of this study is to determine the value of pharmacologically stressed, dynamically enhanced turbo-fast low-angle shot (FLASH) MR imaging in detecting chronic coronary artery disease.
Five patients who had coronary angiography within the past 6-12 months were included in the study. After injection of 0.56 mg/kg of dipyridamole over 4 min, a bolus of 0.05 mg/kg of gadopentetate dimeglumine and subsequently 10 mCi (370 MBq) of 99mTc-sestamibi were injected. Short-axis turbo-FLASH images were obtained before injection and immediately, 1 min, 3 min, and 5 min after the injection of contrast material. Stress single-photon emission computed tomography (SPECT) images of the heart were obtained 60 min after the 99mTc-sestamibi injection. One and a half hours after an additional 30 mCi (1110 MBq) of 99mTc-sestamibi was injected, SPECT images were obtained with patients at rest. Prospective MR imaging evaluation of these five patients was performed by radiologists who did not know any of the imaging data. The MR imaging studies were compared with the near simultaneous 99mTc-sestamibi SPECT studies and with recent coronary angiograms.
Thirteen myocardial segments were diagnosed as abnormal when 99mTc-sestamibi SPECT was used as the gold standard (12 reversible defects and one fixed defect). Twelve segments were normal on the 99mTc-sestamibi SPECT study. With SPECT as the gold standard, prospective MR imaging had a sensitivity of 77% and a specificity of 75%, whereas retrospectively it had a sensitivity of 92% and a specificity of 75%. With recent coronary angiography as the gold standard, prospective MR imaging had a sensitivity of 81% and a specificity of 100%. The quantitative data did not improve the accuracy of the qualitative analysis.
Our results suggest that accurate prospective identification of chronic coronary artery disease may be possible with dynamically enhanced, pharmacologically stressed, turbo-FLASH MR imaging. Studies of additional patients to confirm this initial impression are warranted.
磁共振成像（MR）在评估心肌灌注和存活能力方面的潜力，可能使其成为检查缺血性心脏病患者的首选成像方法。因此，本研究的目的是确定药物负荷、动态增强的快速低角度激发（FLASH）MR成像在检测慢性冠状动脉疾病中的价值。
研究纳入了5名在过去6至12个月内接受过冠状动脉造影的患者。在4分钟内静脉注射0.56mg/kg双嘧达莫后，静脉推注0.05mg/kg钆喷酸葡胺，随后注射10mCi（370MBq）的99m锝-甲氧基异丁基异腈（99mTc-sestamibi）。在注射对比剂前、注射后即刻、1分钟、3分钟和5分钟获取短轴FLASH图像。在注射99mTc-sestamibi后60分钟获取心脏的负荷单光子发射计算机断层扫描（SPECT）图像。在额外注射30mCi（1110MBq）的99mTc-sestamibi后1个半小时，让患者静息状态下获取SPECT图像。由对任何成像数据均不知情的放射科医生对这5名患者进行前瞻性MR成像评估。将MR成像研究结果与近乎同时进行的99mTc-sestamibi SPECT研究结果以及近期的冠状动脉造影结果进行比较。
以99mTc-sestamibi SPECT作为金标准时，13个心肌节段被诊断为异常（12个可逆性缺损和1个固定性缺损）。99mTc-sestamibi SPECT研究中有12个节段正常。以前瞻性SPECT作为金标准时，MR成像的敏感性为７７％，特异性为７５％；而回顾性分析时，敏感性为９２％，特异性为７５％。以近期冠状动脉造影作为金标准时，前瞻性MR成像的敏感性为８１％且特异性为１００％。定量数据并未提高定性分析的准确性。
我们的结果表明，通过动态增强、药物负荷的FLASH MR成像可能准确地前瞻性识别慢性冠状动脉疾病。有必要对更多患者进行研究以证实这一初步结论。
