Noncontrast dynamic MRA in intracranial arteriovenous malformation (AVM), comparison with time of flight (TOF) and digital subtraction angiography (DSA).

Digital subtraction angiography (DSA) remains the gold standard to diagnose intracranial arteriovenous malformations (AVMs) but is invasive. Existing magnetic resonance angiography (MRA) is suboptimal for assessing the hemodynamics of AVMs. The objective of this study was to evaluate the clinical utility of a novel noncontrast four-dimensional (4D) dynamic MRA (dMRA) in the evaluation of intracranial AVMs through comparison with DSA and time-of-flight (TOF) MRA. Nineteen patients (12 women, mean age 26.2±10.7 years) with intracranial AVMs were examined with 4D dMRA, TOF and DSA. Spetzler–Martin grading scale was evaluated using each of the above three methods independently by two raters. Diagnostic confidence scores for three components of AVMs (feeding artery, nidus and draining vein) were also rated. Kendall's coefficient of concordance was calculated to evaluate the reliability between two raters within each modality (dMRA, TOF, TOF plus dMRA). The Wilcoxon signed-rank test was applied to compare the diagnostic confidence scores between each pair of the three modalities dMRA was able to detect 16 out of 19 AVMs, and the ratings of AVM size and location matched those of DSA. The diagnostic confidence scores by dMRA were adequate for nidus (3.5/5), moderate for feeding arteries (2.5/5) and poor for draining veins (1.5/5). The hemodynamic information provided by dMRA improved diagnostic confidence scores by TOF MRA. As a completely noninvasive method, 4D dMRA offers hemodynamic information with a temporal resolution of 50–100 ms for the evaluation of AVMs and can complement existing methods such as DSA and TOF MRA.

数字减影血管造影（DSA）仍然是诊断颅内动静脉畸形（AVMs）的金标准，但具有侵入性。现有的磁共振血管造影（MRA）在评估AVMs的血流动力学方面欠佳。本研究的目的是通过与DSA和时间飞跃法（TOF）MRA进行比较，评估一种新型的无对比剂四维（4D）动态MRA（dMRA）在颅内AVMs评估中的临床应用价值。 19例颅内AVMs患者（12名女性，平均年龄26.2±10.7岁）接受了4D dMRA、TOF和DSA检查。由两名评估者分别使用上述三种方法独立评估Spetzler - Martin分级量表。还对AVMs的三个组成部分（供血动脉、畸形血管巢和引流静脉）的诊断置信度评分进行了评级。计算Kendall一致性系数以评估每种成像方式（dMRA、TOF、TOF加dMRA）内两名评估者之间的可靠性。采用Wilcoxon符号秩检验比较三种成像方式两两之间的诊断置信度评分。 dMRA能够检测出19个AVMs中的16个，并且AVM大小和位置的评级与DSA相符。dMRA的诊断置信度评分对于畸形血管巢为足够（3.5/5），对于供血动脉为中等（2.5/5），对于引流静脉为差（1.5/5）。dMRA提供的血流动力学信息提高了TOF MRA的诊断置信度评分。 作为一种完全无创的方法，4D dMRA为AVMs评估提供了时间分辨率为50 - 100 ms的血流动力学信息，并且可以补充现有的方法，如DSA和TOF MRA。