Yamada Naoaki, Hayashi Katsuhiko, Murao Kenichi, Higashi Masahiro, Iihara Koji
Department of Radiology and Nuclear Medicine, National Cardiovascular Center, Osaka, Japan.
AJNR Am J Neuroradiol. 2004 Aug;25(7):1154-7.
For intracranial aneurysms treated with Guglielmi detachable coils, long-term follow-up is mandatory because coil compaction may occur and aneurysms may recur. The purpose of this study was to establish a noninvasive technique to visualize residual flow in coiled aneurysms.
We designed a 3D time-of-flight (3D-TOF) MR angiography (MRA) technique targeted to depict coiled aneurysms that employed a very short TE (1.54-1.60 ms) and a high spatial resolution (0.3 x 0.3 x 0.3 mm3 with zero-filling) to diminish spin dephasing. To diminish spin saturation, image volume was carefully positioned so that the neck of the targeted aneurysm was within 2 cm of the inflow portion along the stream of blood. Fifty-one MRA images of 39 coiled aneurysms in 39 patients were compared with digital subtraction angiography (DSA) images. DSA and MRA findings were interpolated retrospectively for parent and branch arteries' patency, as well as residual flow in aneurysms. In the latest 11 MR studies, a dark-blood 3D turbo spin-echo sequence was added to MRA to negate the effect high-signal-intensity thrombus.
MRA visualized all parent and branch arteries with DSA confirmation. MRA visualized residual flow more frequently (38 studies) than did DSA (25 studies). Residual flow space visualized with MRA was always similar to or larger than that with DSA. The dark-blood sequence completely suppressed intraluminal high signal intensity on MRA images and confirmed that the high signal intensity was not due to thrombus.
TOF MRA targeted to depict coiled intracranial aneurysms is noninvasive and superior to DSA in visualization of residual flow and, hence, useful for follow-up of coiled aneurysms.
对于采用 Guglielmi 可脱卸弹簧圈治疗的颅内动脉瘤，必须进行长期随访，因为可能会发生弹簧圈压缩且动脉瘤可能复发。本研究的目的是建立一种无创技术来可视化弹簧圈栓塞动脉瘤内的残余血流。
我们设计了一种三维时间飞跃（3D-TOF）磁共振血管造影（MRA）技术，用于描绘弹簧圈栓塞的动脉瘤，该技术采用极短的回波时间（TE，1.54 - 1.60 毫秒）和高空间分辨率（零填充时为 0.3×0.3×0.3 立方毫米）以减少自旋去相位。为减少自旋饱和，仔细定位图像容积，使目标动脉瘤的颈部沿血流方向位于流入部分的 2 厘米范围内。对 39 例患者的 39 个弹簧圈栓塞动脉瘤的 51 张 MRA 图像与数字减影血管造影（DSA）图像进行比较。对 DSA 和 MRA 的结果进行回顾性插值分析，以评估载瘤动脉和分支动脉的通畅情况以及动脉瘤内的残余血流。在最近的 11 项磁共振研究中，在 MRA 中增加了黑血三维快速自旋回波序列以消除高信号强度血栓的影响。
MRA 在 DSA 证实下显示了所有载瘤动脉和分支动脉。MRA 比 DSA 更频繁地显示残余血流（38 项研究对 25 项研究）。MRA 显示的残余血流空间总是与 DSA 显示的相似或更大。黑血序列完全抑制了 MRA 图像上的管腔内高信号强度，并证实该高信号强度并非由血栓所致。
用于描绘颅内弹簧圈栓塞动脉瘤的 TOF MRA 是无创的，在显示残余血流方面优于 DSA，因此对弹簧圈栓塞动脉瘤的随访有用。
