Fujiwara Masahiro, Watanabe Yoshiyuki, Kashiwagi Nobuo, Ohta Yumi, Sato Takashi, Nishigaki Megumi, Tomiyama Noriyuki
Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, Suita, Japan.
Department of Radiology, Shiga University of Medical Science, Otsu, Japan.
Acta Radiol Open. 2021 Nov 29;10(11):20584601211061444. doi: 10.1177/20584601211061444. eCollection 2021 Nov.
Recognition of the anatomical course of the chorda tympani nerve (CTN) is important for preventing iatrogenic injuries during middle-ear surgery.
This study aims to compare visualization of the CTN using two computed tomography (CT) methods: conventional high-resolution CT (C-HRCT) and ultra-high-resolution CT (U-HRCT).
We performed a retrospective visual assessment of 59 CTNs in normal temporal bones of 54 consecutive patients who underwent both C-HRCT and U-HRCT. After dividing CTN into three anatomical segments (posterior canaliculus, tympanic segment, and anterior canaliculus), two neuroradiologists scored the visualizations on a four-point scale.
On C-HRCT, the visual scores of the posterior canaliculus, tympanic segment, and anterior canaliculus were 3.5 ± 0.7, 1.6 ± 0.6, and 3.1 ± 0.7, respectively. The respective values were significantly higher in all segments on U-HRCT: 3.9 ± 0.2, 2.4 ± 0.6, 3.5 ± 0.6 ( < 0.01). Although the difference in scores between methods was greatest for the tympanic segment, the visual score on U-HRCT was lower for the tympanic segment than for the anterior and posterior segments ( < 0.01).
Ultra-high-resolution CT provides superior visualization of the CTN, especially the tympanic segment.
认识鼓索神经（CTN）的解剖走行对于预防中耳手术中的医源性损伤很重要。
本研究旨在比较使用两种计算机断层扫描（CT）方法观察CTN的情况：传统高分辨率CT（C-HRCT）和超高分辨率CT（U-HRCT）。
我们对54例连续患者正常颞骨中的59条CTN进行了回顾性视觉评估，这些患者均接受了C-HRCT和U-HRCT检查。将CTN分为三个解剖段（后小管、鼓室段和前小管）后，两名神经放射科医生采用四点量表对观察情况进行评分。
在C-HRCT上，后小管、鼓室段和前小管的视觉评分别为3.5±0.7、1.6±0.6和3.1±0.7。在U-HRCT上，所有段的相应值均显著更高：3.9±0.2、2.4±0.6、3.5±0.6（<0.01）。尽管两种方法在鼓室段的评分差异最大，但U-HRCT上鼓室段的视觉评分低于前、后段（<0.01）。
超高分辨率CT能更好地显示CTN，尤其是鼓室段。
