Unlu Ercument, Temizoz Osman, Albayram Sait, Genchellac Hakan, Hamamcioglu M Kemal, Kurt Imran, Demir M Kemal
Department of Radiology, Trakya University Medicine School, Edirne, Turkey.
Eur J Radiol. 2006 Dec;60(3):367-78. doi: 10.1016/j.ejrad.2006.08.007. Epub 2006 Sep 11.
Digital subtraction angiography (DSA) is the current reference standard for the diagnosis, assessment, and management of brain arteriovenous malformations (AVMs). The purpose of this study was to compare the diagnostic utility of three-dimensional (3D) time-of-flight (TOF) magnetic resonance angiography (MRA) and contrast-enhanced 3D MRA in patients with intracranial arteriovenous malformations (AVMs) in different sizes and locations. The AVM diagnosis was proved via DSA and almost half of the patients had also hematoma.
Two radiologists, experienced on neurovascular imaging and independent from each other, retrospectively reviewed two MRA techniques and DSA with regard to the assessment of feeding arteries, AVM nidus, and venous drainage patterns on 20 patients with 23 examinations by scoring system. Disagreements were resolved by consensus.
An excellent agreement between contrast-enhanced MRA and DSA was found in order to assess the numbers of arterial feeders and draining veins (Spearman r=0.913, P<0.001). The average scores in contrast-enhanced MRA for feeders, nidi, and drainers were respectively 2.26, 2.69, and 2.48, while in TOF-MRA they are 1.96, 1.35, and 0.89, respectively.
Compared to TOF-MRA, 3D contrast-enhanced MRA is useful for visualization by subtraction technique of malformation components presented by hematoma or by haem product. On the other hand, for the cases presented by slow or complex flow that is especially in around or nidi or around the venous portion is also advantageous because of the independence from flow-related enhancement. Therapeutic effects were clearly demonstrated in three follow-up patients. A major limitation of this technique is the low spatial resolution. Since there is such a limitation, arterial feeder of a case with micro-AVM is not detected by contrast-enhanced MRA and nidus for the same case was observed retrospectively. In this respect, we believe that 3D contrast-enhanced MRA is a less invasive and inexpensive angiographic tool, but not a safe substitute for DSA. Yet, it can be a beneficial supplement to DSA in patients with cerebral AVMs at both initial diagnosis and at follow-up processes after therapy.
数字减影血管造影（DSA）是目前诊断、评估和治疗脑动静脉畸形（AVM）的参考标准。本研究的目的是比较三维（3D）时间飞跃（TOF）磁共振血管造影（MRA）和对比增强3D MRA对不同大小和位置的颅内动静脉畸形（AVM）患者的诊断效用。AVM诊断经DSA证实，几乎一半的患者还伴有血肿。
两名相互独立且有神经血管成像经验的放射科医生，采用评分系统对20例患者的23次检查回顾性分析了两种MRA技术和DSA的供血动脉、AVM病灶及静脉引流模式。分歧通过协商解决。
对比增强MRA与DSA在评估动脉供血支和引流静脉数量方面具有极好的一致性（Spearman相关系数r=0.913，P<0.001）。对比增强MRA中供血支、病灶及引流静脉的平均评分分别为2.26、2.69和2.48，而TOF-MRA中分别为1.96、1.35和0.89。
与TOF-MRA相比，3D对比增强MRA通过减影技术有助于显示由血肿或血液产物呈现的畸形成分。另一方面，对于血流缓慢或复杂的情况，特别是在病灶或静脉部分周围，由于不受血流相关强化的影响也具有优势。在3例随访患者中清楚地显示了治疗效果。该技术的一个主要局限性是空间分辨率低。由于存在这种局限性，对比增强MRA未检测到微AVM病例的动脉供血支，同一病例的病灶是回顾性观察到的。在这方面，我们认为3D对比增强MRA是一种侵入性较小且成本较低的血管造影工具，但并非DSA的安全替代方法。然而，它在脑AVM患者的初始诊断和治疗后的随访过程中可以是DSA的有益补充。
