*Section of Neuroradiology; and ‡Department of Neurosurgery, Addenbrooke's Hospital, Cambridge, United Kingdom; §Department of Radiology, University of Cambridge, Cambridge, United Kingdom.
Neurosurgery. 2013 Dec;73(2 Suppl Operative):ons132-40; discussion ons140. doi: 10.1227/01.neu.0000430286.08552.ca.
The aqueduct of Sylvius (AqSylv) is a structure of increasing importance in neuroendoscopic procedures. However, there is currently no clear and adequate description of the normal anatomy of the AqSylv.
To study in detail hitherto unavailable normal magnetic resonance imaging morphometry and anatomic variants of the AqSylv.
We retrospectively studied normal midsagittal T1-weighted 3-T magnetic resonance images in 100 patients. We measured widths of the AqSylv pars anterior, ampulla, and pars posterior; its narrowest point; and its length. We recorded angulation of the AqSylv relative to the third ventricle as multiple deviations of the long axis of the AqSylv from the Talairach bicommissural line. We statistically determined age- and sex-related changes in AqSylv morphometry using the Pearson correlation coefficient. We measured angulation of the AqSylv relative to the fourth ventricle and correlated this to the cervicomedullary angle (a surrogate for head position).
Patients were 13 to 83 years of age (45% male, 55% female). Mean morphometrics were as follows: pars anterior width, 1.1 mm; ampulla width, 1.2 mm; pars posterior width, 1.4 mm; length, 14.1 mm; narrowest point, 0.9 mm; and angulation in relation to the third and fourth ventricles, 26° and 18°, respectively. Age correlated positively with width and negatively with length of the AqSylv. There was no correlation between AqSylv alignment relative to the foramen magnum and the cervicomedullary angle.
Normative dimensions of the AqSylv in vivo are at variance with published cadaveric morphometrics. The AqSylv widens and shortens with cerebral involution. Awareness of these normal morphometrics is highly useful when stent placement is an option during aqueductoplasty. Reported data are valuable in guiding neuroendoscopic management of hydrocephalus and aqueductal stenosis.
西尔维乌斯导水管（AqSylv）是神经内窥镜手术中越来越重要的结构。然而，目前对于 AqSylv 的正常解剖结构还没有明确和充分的描述。
详细研究迄今为止尚未报道的 AqSylv 的正常磁共振成像形态测量和解剖变异。
我们回顾性地研究了 100 例患者的正中矢状面 T1 加权 3T 磁共振图像。我们测量了 AqSylv 前部分、壶腹和后部分的宽度；最窄处；以及长度。我们记录了 AqSylv 相对于第三脑室的角度，即 AqSylv 长轴相对于 Talairach 双连合线的多个偏差。我们使用 Pearson 相关系数统计确定 AqSylv 形态测量值与年龄和性别相关的变化。我们测量了 AqSylv 相对于第四脑室的角度，并将其与颈髓角（头部位置的替代物）相关联。
患者年龄为 13 至 83 岁（45%为男性，55%为女性）。平均形态学数据如下：前部分宽度为 1.1mm；壶腹宽度为 1.2mm；后部分宽度为 1.4mm；长度为 14.1mm；最窄处为 0.9mm；相对于第三和第四脑室的角度分别为 26°和 18°。年龄与 AqSylv 的宽度呈正相关，与长度呈负相关。AqSylv 相对于枕骨大孔的对齐与颈髓角之间没有相关性。
活体 AqSylv 的正常尺寸与已发表的尸体形态学数据不同。AqSylv 随着脑萎缩而变宽和缩短。在选择支架放置作为 aqueductoplasty 方案时，了解这些正常形态学数据非常有用。所报道的数据对于指导脑积水和 aqueductal 狭窄的神经内镜管理具有重要价值。
