Laissy J P, Bancal C, Sekkal S, Chillon S, Berger J F, Limot O, Tebboune D, Henry-Feugeas M C, Falise B, Aubier M
Department of Radiology, Centre Hospitalier et Universitaire Bichat-Claude Bernard, Paris, France.
Eur J Radiol. 1995 May;20(1):9-15. doi: 10.1016/0720-048x(95)00626-2.
To evaluate the combined performance of two time-of-flight methods in imaging the pulmonary arteries.
This study was prospectively conducted in 28 patients suspected for pulmonary embolism (PE). Sixteen patients were free of pulmonary vascular disease, and 12 had pulmonary vascular disease as demonstrated by pulmonary angiography. To reduce artifacts caused by cardiac and respiratory motion, MR images were acquired in all subjects using bi-dimensional (2D), gradient-recalled echo (GRE), breath-hold techniques. Sagittal thin (6-mm) sections obtained with ECG gating, k-space segmentation and incremented flip-angles (TONE), and coronal thick (15-mm) sections obtained after a unique injection of Gadolinium chelate were used.
High quality images were obtained in all 16 (100%) subjects free of pulmonary disease with both techniques, and in 10 and 12 (87% and 100%) patients suspected for pulmonary artery disease with sagittal and coronal Gd-enhanced MRA, respectively. In patients free of pulmonary disease, TONE images exhibited distal pulmonary arteries with 2.1 subsegmental divisions on average, whereas Gd-enhanced TurboFLASH images were the most accurate to identify proximal pulmonary arteries within the mediastinum, even if only 0.8 subsegmental divisions were seen on average. A correct diagnosis of pulmonary embolism was obtained in all cases but one, with use of both MRA techniques, with an overall accuracy of 86%.
The association of segmented sagittal GRE images and coronal first-pass Gd-enhanced GRE images can provide information upon normal and diseased pulmonary arteries within the mediastinum until subsegmental pulmonary branches, even in patients with short-breathing. Further studies of patients with various pulmonary artery diseases will confirm whether this technique makes pulmonary MRA feasible in clinical routine situations.
评估两种飞行时间法在肺动脉成像中的联合性能。
本研究前瞻性纳入了28例疑似肺栓塞（PE）的患者。16例患者无肺血管疾病，12例经肺血管造影证实存在肺血管疾病。为减少心脏和呼吸运动引起的伪影，所有受试者均采用二维（2D）梯度回波（GRE）屏气技术采集磁共振图像。使用心电门控、k空间分段和递增翻转角（TONE）获得矢状位薄（6mm）层厚图像，以及在单次注射钆螯合物后获得冠状位厚（15mm）层厚图像。
两种技术在所有16例（100%）无肺部疾病的受试者中均获得了高质量图像，矢状位和冠状位钆增强磁共振血管造影（MRA）在疑似肺动脉疾病的患者中分别有10例（87%）和12例（100%）获得了高质量图像。在无肺部疾病的患者中，TONE图像平均显示远端肺动脉有2.1个亚段分支，而钆增强快速扰相梯度回波（TurboFLASH）图像在识别纵隔内近端肺动脉方面最为准确，即使平均仅见0.8个亚段分支。使用两种MRA技术，除1例病例外，所有病例均获得了肺栓塞的正确诊断，总体准确率为86%。
分段矢状位GRE图像与冠状位首次通过钆增强GRE图像相结合，即使在呼吸急促的患者中，也能提供纵隔内正常和病变肺动脉直至亚段肺分支的信息。对各种肺动脉疾病患者的进一步研究将证实该技术是否使肺部MRA在临床常规情况下可行。
