Mamourian Alexander C, Pluta Daniel J, Eskey Clifford J, Merlis Anthony L
Department of Radiology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA.
J Neurosurg. 2007 Dec;107(6):1238-43. doi: 10.3171/JNS-07/12/1238.
At many institutions digital subtraction angiography remains the standard imaging procedure for the postoperative evaluation of patients following placement of a cerebral aneurysm clip largely because of the artifacts produced by the clip on computed tomography (CT). The authors evaluated the effect of various imaging parameters on the quality of 3D reconstructions from CT scans while imaging a phantom to optimize the CT angiograms.
Using multidetector CT scanners with submillimeter detector collimation (0.625 mm), the authors scanned a silicone phantom with attached commercial aneurysm clips. Slice thickness, reconstruction overlap, kilovolt level, milliampere level, and pitch were varied. Neuroradiologists, who were blinded to the scanning parameters, rated the reconstructions for image quality and artifact reduction.
Images of the titanium clip using 140 kV and 380 mA with 0.625-mm overlapping reconstructed slices provided excellent 3D visualization of both the clip and the aneurysm model, even when using two adjacent clips.
Overlapping reconstructions combined with thin-section acquisition can provide detailed images of titanium clips and surrounding tissues without the use of low-pitch values.
在许多机构中,数字减影血管造影术仍是脑动脉瘤夹置入术后患者进行术后评估的标准成像程序,这主要是因为夹子在计算机断层扫描(CT)上产生的伪影。作者在对一个模型进行成像时,评估了各种成像参数对CT扫描三维重建质量的影响,以优化CT血管造影。
作者使用具有亚毫米探测器准直(0.625毫米)的多排CT扫描仪,对附着有商用动脉瘤夹的硅胶模型进行扫描。改变层厚、重建重叠、千伏水平、毫安水平和螺距。对扫描参数不知情的神经放射科医生对重建图像的质量和伪影减少情况进行评分。
使用140 kV和380 mA,0.625毫米重叠重建层厚时,钛夹的图像即使在使用两个相邻夹子的情况下,也能对夹子和动脉瘤模型提供出色的三维可视化。
重叠重建结合薄层采集可以在不使用低螺距值的情况下,提供钛夹及其周围组织的详细图像。