Nitatori T, Yokoyama K, Nakamura A, Haradome H, Hachiya J
Department of Radiology, Kyorin University School of Medicine, Tokyo, Japan.
Radiat Med. 1999 Sep-Oct;17(5):393-7.
We investigated the usefulness of single shot gradient echo type echo planar imaging (GRE-EPI) as magnetic resonance angiography (MRA) for the diagnosis of aortic aneurysm and dissection. This technique can detect blood flow signals in several tenths of a milliseconds without the need for contrast medium, breath-holding, or electrocardiographic (ECG) gating. By scanning approximately 20 frames in the coronal plane, three-dimensional (3D) imaging can be achieved by maximum intensity projection (MIP) at different angles. Three radiologists evaluated the ability of this single shot GRE-EPI as non-enhanced MRA (EPI-MRA) to diagnose aortic aneurysm and dissection. The examined lesions consisted of three cases of thoracic aortic aneurysm, seven of abdominal aortic aneurysm and eight of aortic dissection with a total of 15 involved aorta. In all patients with aortic aneurysm, EPI enabled detection and diagnosis of the aneurysm. However, the size of the lesion and relationship with major branches were determined only in the abdominal aorta, and could not be determined precisely in thoracic lesions. Similar results were obtained for patients with aortic dissection. The technique visualized the intimal flap and enabled determination of the extent of dissection in the abdominal aorta. In the thoracic aorta, serious magnetic susceptibility artifacts caused image distortion, and as a result only the dissection could be detected and diagnosed. No entry site was detected at either the abdominal or thoracic aorta. These results suggest that EPI-MRA may have a clinical potential for screening patients with acute aortic disease who cannot undergo physical restraint for scanning.
我们研究了单次激发梯度回波型回波平面成像（GRE-EPI）作为磁共振血管造影（MRA）用于诊断主动脉瘤和主动脉夹层的效用。该技术能够在几十毫秒内检测到血流信号，无需使用造影剂、屏气或心电图（ECG）门控。通过在冠状面扫描约20帧图像，可通过不同角度的最大强度投影（MIP）实现三维（3D）成像。三位放射科医生评估了这种单次激发GRE-EPI作为非增强MRA（EPI-MRA）诊断主动脉瘤和主动脉夹层的能力。检查的病变包括3例胸主动脉瘤、7例腹主动脉瘤和8例主动脉夹层，共累及15段主动脉。在所有主动脉瘤患者中，EPI能够检测并诊断出动脉瘤。然而，仅在腹主动脉中确定了病变大小及其与主要分支的关系，在胸段病变中无法精确确定。主动脉夹层患者也得到了类似结果。该技术可显示内膜瓣，并能确定腹主动脉夹层的范围。在胸主动脉中，严重的磁敏感性伪影导致图像失真，结果只能检测并诊断出夹层。在腹主动脉和胸主动脉均未检测到破口部位。这些结果表明，EPI-MRA对于筛查无法配合扫描的急性主动脉疾病患者可能具有临床应用潜力。
