Dept of Radiology, The Sixth Affiliated People's Hospital; Medical school of Shanghai Jiaotong University, No, 600# Yishan Road, Shanghai, 200233, China.
BMC Neurol. 2012 Jul 6;12:50. doi: 10.1186/1471-2377-12-50.
A subarachnoid hemorrhage (SAH) due to the rupture of a cerebral aneurysm (CA) is a devastating event associated with high rates of mortality. Magnetic resonance angiography (MRA), as a noninvasive technique, is typically used initially. The object of our study is to evaluate the feasibility of 4D time-resolved MRA with keyhole (4D-TRAK) for the diagnostic accuracy and reliability of the detection and characterization of cerebral aneurysms (CAs), with a comparison of 3D time-of-flight MRA (3D-TOF-MRA) by using DSA as a reference.
3D-TOF-MRA, 4D-TRAK and 3D-DSA were performed sequentially in 52 patients with suspected CAs. 4D-TRAK was acquired using a combination of sensitivity encoding (SENSE) and CE timing robust angiography (CENTRA) k-space sampling techniques at a contrast dose of 10 ml at 3 T. Accuracy, sensitivity, specificity of 4D-TRAK and 3D-TOF-MRA were calculated and compared for the detection of CAs on patient-based and aneurysm-based evaluation using 3D-DSA as a reference.
The overall image quality of 4D-TRAK with a contrast dose of 10 ml was in the diagnostic range but still cannot be compared with that of 3D-TOF-MRA. In 52 patients with suspected CAs, fifty-eight CAs were confirmed on 3D-DSA finally. Fifty-one (with 2 false-positives and 9 false-negatives) and 58 (with 1 false-positive and 1 false-negative) CAs were visualized on 4D-TRAK and 3D-TOF-MRA, respectively. Accuracy, sensitivity and specificity on patient-based evaluation of 4D-TRAK and 3D-TOF-MRA were 92.31%, 93.33%, 85.71% and 98.08%, 100%, 85.71%, respectively, and 74.07%, 75.00%, 66.67% and 96.30%, 95.83%, 100% on aneurysm-based evaluation in patients with multiple CAs, respectively. Subgroup analysis revealed that for 19 very small CAs (maximal diameter <3 mm, measured on 3D-DSA), 9 were missed on 4D-TRAK and 1 on 3D-TOF-MRA (P = 0.008). However, for 39 CAs with maximal diameter ≥ 3 mm, the diagnostic accuracy is equally (39 on 4D-TRAK vs. 39 on 3D-TOF-MRA) (P = 1). In four larger CAs with maximal diameter ≥ 10 mm, 4D-TRAK provided a better characterization of morphology than 3D-TOF-MRA.
4D-TRAK at a lower contrast dose of 10 ml with a combination of SENSE and CENTRA at 3 T could provide similar diagnostic accuracy rate for CAs with maximal diameter ≥ 3 mm, and a better characterization of morphology for larger CAs with maximal diameter ≥ 10 mm compared to 3D-TOF-MRA. However, further study is still needed to improve the "vascular edge" artifact and the compromise in spatial resolution in depiction of CAs with maximal diameter<3 mm.
蛛网膜下腔出血（SAH）是由于脑动脉瘤（CA）破裂引起的，是一种死亡率很高的破坏性事件。磁共振血管造影（MRA）作为一种非侵入性技术，通常首先使用。我们的研究目的是评估使用 3T 时结合灵敏度编码（SENSE）和 CE 时间分辨血管造影（CENTRA）k 空间采样技术的 4D 时间分辨 MRA（4D-TRAK）对诊断脑动脉瘤（CA）的准确性和可靠性，并用 DSA 作为参考比较 3D 时间飞跃 MRA（3D-TOF-MRA）。
对 52 例疑似 CA 的患者依次进行 3D-TOF-MRA、4D-TRAK 和 3D-DSA 检查。4D-TRAK 使用灵敏度编码（SENSE）和 CE 时间分辨血管造影（CENTRA）k 空间采样技术组合，在 3T 时以 10ml 的对比剂量采集。在以患者为基础和以动脉瘤为基础的评估中，使用 3D-DSA 作为参考，计算并比较 4D-TRAK 和 3D-TOF-MRA 对 CA 的检测的准确性、灵敏度和特异性。
52 例疑似 CA 的患者中，最终有 58 例 CA 在 3D-DSA 上得到证实。4D-TRAK 上分别显示 51 个（2 个假阳性和 9 个假阴性）和 58 个（1 个假阳性和 1 个假阴性）CA，3D-TOF-MRA 上分别显示 51 个（1 个假阳性和 1 个假阴性）和 58 个（100%）CA。在以患者为基础的评估中，4D-TRAK 和 3D-TOF-MRA 的准确性、灵敏度和特异性分别为 92.31%、93.33%、85.71%和 98.08%、100%、85.71%，在有多个 CA 的患者中，以动脉瘤为基础的评估中分别为 74.07%、75.00%、66.67%和 96.30%、95.83%、100%。亚组分析显示，对于 19 个最大直径<3mm 的非常小的 CA（在 3D-DSA 上测量），4D-TRAK 漏诊了 9 个，3D-TOF-MRA 漏诊了 1 个（P=0.008）。然而，对于最大直径≥3mm 的 39 个 CA，诊断准确性相同（4D-TRAK 上为 39 个，3D-TOF-MRA 上为 39 个）（P=1）。在 4 个最大直径≥10mm 的较大 CA 中，4D-TRAK 比 3D-TOF-MRA 提供了更好的形态学特征描述。
在 3T 时结合 SENSE 和 CENTRA 的 10ml 低对比剂量的 4D-TRAK 可以为最大直径≥3mm 的 CA 提供相似的诊断准确率，并为最大直径≥10mm 的较大 CA 提供更好的形态学特征描述，而与 3D-TOF-MRA 相比，最大直径<3mm 的 CA 的“血管边缘”伪影和空间分辨率的折衷仍需要进一步研究。
