Kubota Hisashi, Sanada Yasuhiro, Tasaki Takayuki, Miyauchi Masaharu, Tanikawa Rokuya, Ohtsuki Toshiho, Kato Amami
*Department of Neurosurgery, ‡Stroke Center, Kinki University, Faculty of Medicine, Osaka, Japan; §Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Sapporo, Japan.
Neurosurgery. 2015 May;76(5):633-6; discussion 636-7. doi: 10.1227/NEU.0000000000000664.
Magnetic resonance angiography (MRA) is helpful for preoperatively evaluating the degree of carotid stenosis, although it is not always useful for assessing surgical accessibility to the distal internal carotid artery (ICA) due to the lack of osteological information.
To demonstrate a method for evaluating the accessible distal portion of the ICA for carotid endarterectomy (CEA) using MRA.
As an indicator of the upper limit of the operating field, a line drawn from the C1 transverse process to the hyoid bone (C1-H line) was defined. The cross-point between the C1-H line and distal ICA was delineated on 3-dimensional (3-D) MRA and 3-D tomography angiography (CTA). The distance between the carotid bifurcation and C1-H line was measured in 11 patients. The exposed distal ICA was compared with the extent of intraoperative ICA exposure.
The mean vertical distance (27.5 mm) from the carotid bifurcation to the C1-H line measured using 3-D MRA was almost the same as the distance (28 mm) evaluated on 3-D CTA. The discrepancy in distance between the 2 modalities was 1.9 ± 1.7 mm. Furthermore, the point of the ICA across the C1-H line created on 3-D MRA was in accordance with the intraoperative measurement (28.7 mm) of the exposed ICA.
The C1-H line measured on 3-D MRA is a simple and useful indicator of the distal point of the accessible ICA during CEA, especially in patients with renal dysfunction and allergies to contrast medium.
磁共振血管造影（MRA）有助于术前评估颈动脉狭窄程度，不过由于缺乏骨学信息，它在评估颈内动脉（ICA）远端的手术可及性方面并不总是有用。
演示一种利用MRA评估颈动脉内膜切除术（CEA）中ICA可及远端部分的方法。
将从C1横突至舌骨绘制的线（C1-H线）定义为手术视野上限的指标。在三维（3-D）MRA和三维断层血管造影（CTA）上描绘C1-H线与ICA远端的交叉点。测量了11例患者颈动脉分叉与C1-H线之间的距离。将暴露的ICA远端与术中ICA暴露范围进行比较。
使用3-D MRA测量的从颈动脉分叉至C1-H线的平均垂直距离（27.5 mm）与在3-D CTA上评估的距离（28 mm）几乎相同。两种检查方式之间的距离差异为1.9±1.7 mm。此外，在3-D MRA上创建的ICA穿过C1-H线的点与暴露ICA的术中测量值（28.7 mm）一致。
在3-D MRA上测量的C1-H线是CEA期间ICA可及远端点的一个简单且有用的指标，尤其适用于肾功能不全和对造影剂过敏的患者。
