Department of Radiology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston MA, USA.
Department of Neurosurgery, Nuclear Industry 215 Hospital of Shaanxi Province, Xianyang, China.
Otol Neurotol. 2024 Oct 1;45(9):e647-e654. doi: 10.1097/MAO.0000000000004310. Epub 2024 Sep 5.
This study investigates the impact of different diffusion magnetic imaging (dMRI) acquisition settings and mathematical fiber models on tractography performance for depicting cranial nerve (CN) VII in healthy young adults.
The aim of this study is to optimize visualization of CN VII for preoperative assessment in surgeries near the nerve in the cerebellopontine angle, reducing surgery-associated complications. The study analyzes 100 CN VII in dMRI images from the Human Connectome Project, using three separate sets with different b values ( b = 1,000 s/mm 2 , b =2,000 s/mm 2 , b =3,000 s/mm 2 ) and four different tractography methods, resulting in 1,200 tractographies analyzed.
The results show that multifiber and free water (FW) compartment models produce significantly more streamlines than single-fiber tractography. The addition of an FW compartment significantly increases the mean streamline fractional anisotropy (FA). Expert quality ratings showed that the highest rated tractography was the 1 tensor (1T) method without FW at b values of 1,000 s/mm2.
In this young and healthy cohort, best tractography results are obtained by using a 1T model without a FW compartment in b =1,000 diffusion MR images. The FW compartment increased the contrast between streamlines and cerebrospinal fluid (higher mean streamline FA). This finding may help ongoing research to improve CN VII tractography results in tumor cases where the nerve is often stretched and thinned by the tumor.
本研究旨在探讨不同扩散磁共振成像（dMRI）采集设置和纤维模型对健康年轻成年人颅神经（CN）VII 示踪性能的影响。
本研究的目的是优化 CN VII 的可视化，以便在桥小脑角附近的神经手术中进行术前评估，减少手术相关并发症。该研究分析了来自人类连接组计划的 100 个 CN VII 的 dMRI 图像，使用了三种不同 b 值（b = 1000 s/mm 2 、b = 2000 s/mm 2 、b = 3000 s/mm 2 ）和四种不同的示踪方法，共分析了 1200 条示踪线。
结果表明，多纤维和自由水（FW）隔室模型产生的示踪线明显多于单纤维示踪法。加入 FW 隔室显著增加了平均示踪线各向异性分数（FA）。专家质量评分显示，在 b 值为 1000 s/mm 2 时，最高评分的示踪法是 1 张量（1T）法，不包含 FW。
在这个年轻健康的队列中，在 b = 1000 扩散磁共振成像中使用无 FW 隔室的 1T 模型可以获得最佳的示踪结果。FW 隔室增加了示踪线和脑脊液（更高的平均示踪线 FA）之间的对比度。这一发现可能有助于正在进行的研究，以改善肿瘤病例中 CN VII 示踪结果，因为在肿瘤情况下，神经经常被肿瘤拉伸和变薄。
