Al-Haj Husain Adib, Stadlinger Bernd, Winklhofer Sebastian, Müller Marcel, Piccirelli Marco, Valdec Silvio
Center of Dental Medicine, Clinic of Cranio-Maxillofacial and Oral Surgery, University of Zurich, 8032 Zurich, Switzerland.
Clinical Neuroscience Center, Department of Neuroradiology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland.
Diagnostics (Basel). 2021 Jul 12;11(7):1245. doi: 10.3390/diagnostics11071245.
The aim of this study was to evaluate the inferior alveolar nerve's (IAN) intraosseous position within the inferior alveolar canal (IAC) using a 3D double-echo steady-state MRI sequence (3D-DESS). The IAN position was prospectively evaluated in 19 patients undergoing mandibular third molar (MTM) surgery. In the coronal reference layer, the IAC was divided into six segments. These segments were checked for the presence of hyperintense tubular MRI signals representing the IAN's nervous tissue and assessed as visible/non-visible. Furthermore, the IAN in MRI and the IAC in MRI and CBCT were segmented at the third and second molar, determining the maximum diameter in all planes and a conversion factor between the imaging modalities. Regardless of the positional relationship at the third and second molar, the IAN showed the highest localization probability in the central segments (segment 2: 97.4% vs. 94.4%, segment 5: 100% vs. 91.6%). The conversion factors from IAC in CBCT and MRI to IAN in MRI, respectively, were the following: axial (2.04 ± 1.95, 2.37 ± 2.41), sagittal (1.86 ± 0.96, 1.76 ± 0.74), and coronal (1.26 ± 0.39, 1.37 ± 0.25). This radiation-free imaging modality, demonstrating good feasibility of accurate visualization of nervous tissue within the nerve canal's osseous boundaries, may benefit preoperative assessment before complex surgical procedures are performed near the IAC.
本研究的目的是使用三维双回波稳态磁共振成像序列（3D-DESS）评估下牙槽神经（IAN）在下牙槽管（IAC）内的骨内位置。对19例接受下颌第三磨牙（MTM）手术的患者进行前瞻性评估IAN位置。在冠状参考层面，将IAC分为六个节段。检查这些节段是否存在代表IAN神经组织的高强度管状MRI信号，并评估为可见/不可见。此外，在第三和第二磨牙处对MRI中的IAN以及MRI和CBCT中的IAC进行分割，确定所有平面中的最大直径以及成像模态之间的转换因子。无论在第三和第二磨牙处的位置关系如何，IAN在中央节段显示出最高的定位概率（节段2：97.4%对94.4%，节段5：100%对91.6%）。CBCT中的IAC和MRI中的IAC分别到MRI中的IAN的转换因子如下：轴向（2.04±1.95，2.37±2.41）、矢状（1.86±0.96，1.76±0.74）和冠状（1.26±0.39，1.37±0.25）。这种无辐射成像模态在神经管骨边界内准确显示神经组织方面显示出良好的可行性，可能有利于在IAC附近进行复杂手术前的术前评估。
