Loubeyre P, Revel D, Douek P, Delignette A, Baldy C, Genin G, Amiel M
Département de Radiologie, Hôpital Cardiovasculaire et Pneumologique, Lyon Montchat, France.
AJR Am J Roentgenol. 1994 May;162(5):1035-9. doi: 10.2214/ajr.162.5.8165977.
Subsecond contrast-enhanced MR angiography, which is not a flow-based technique and does not require cardiac gating or breath-holding, provides multiplanar, rapid, dynamic visualization of the pulmonary arteries. Accordingly, we evaluated the use of this technique in the diagnosis of thrombi in both the proximal and peripheral portions of the pulmonary arteries. Digital subtraction angiography was used as the gold standard for the diagnosis.
Twenty-three consecutive patients with suspected pulmonary embolism were included in the study. All patients had intraarterial digital subtraction angiography, which showed emboli in 12 patients (13 proximal and six peripheral emboli). MR angiography was done within 24 hr of digital subtraction angiography. Subsecond contrast-enhanced MR angiograms were obtained in the long axis of each pulmonary artery after a unique injection of contrast medium (0.1 mmol/kg) in an antecubital vein. Fifteen dynamic frames of each pulmonary artery were alternately obtained in less than 1 min. MR angiograms were interpreted by two observers who had no knowledge of the findings on digital subtraction angiography. A diagnosis of pulmonary emboli was made when MR angiograms showed a constant intraluminal filling defect or an abrupt vascular cutoff.
All thrombi in the proximal branches of the pulmonary arteries were visualized on MR angiograms (n = 13), whereas none of the thrombi in the distal part of the pulmonary arteries were seen (n = 6). In the 11 patients in whom no pulmonary emboli were shown by digital subtraction angiography, findings on MR angiograms were normal (sensitivity, 0.7; specificity, 1.0).
Our results suggest that dynamic contrast-enhanced MR angiography is an accurate method for detecting emboli in the proximal portions of the pulmonary arteries but is of no value in detecting peripheral emboli.
亚秒级对比增强磁共振血管造影术不是基于血流的技术，不需要心脏门控或屏气，可对肺动脉进行多平面、快速、动态成像。因此，我们评估了该技术在诊断肺动脉近端和远端血栓中的应用。数字减影血管造影术用作诊断的金标准。
连续纳入23例疑似肺栓塞患者。所有患者均接受了动脉内数字减影血管造影，其中12例患者显示有栓子（13个近端栓子和6个远端栓子）。在数字减影血管造影术后24小时内进行磁共振血管造影。经肘前静脉单次注射造影剂（0.1 mmol/kg）后，在每条肺动脉的长轴上获取亚秒级对比增强磁共振血管造影图像。在不到1分钟的时间内交替获取每条肺动脉的15个动态图像帧。由两名对数字减影血管造影结果不知情的观察者解读磁共振血管造影图像。当磁共振血管造影图像显示管腔内持续充盈缺损或血管突然中断时，诊断为肺栓塞。
磁共振血管造影显示了所有肺动脉近端分支中的血栓（n = 13），而未发现肺动脉远端的血栓（n = 6）。在数字减影血管造影未显示肺栓塞的11例患者中，磁共振血管造影结果正常（敏感性为0.7；特异性为1.0）。
我们的结果表明，动态对比增强磁共振血管造影是检测肺动脉近端栓子的准确方法，但对检测远端栓子无价值。
