磁共振成像显示下牙槽神经几何的准确性

Geometric accuracy of magnetic resonance imaging displaying the inferior alveolar nerve

背景:MRI弥补了X射线及CT难以显示神经的软组织方面的不足,可以清晰直接显示下牙槽神经。目的:评价磁共振成像显示下牙槽神经的几何准确性。方法:新鲜尸体头颅1个去除软组织附丽,MRI、CT扫描获得数据,分别测量下颌两侧第2前磨牙与第1磨牙、第1磨牙与第2磨牙、第2磨牙与第3磨牙之间3个部位下牙槽神经与骨皮质之间距离,利用电锯切开两侧同样位置下颌骨体部,游标卡尺测量神经与骨皮质之间距离,将MRI、CT、游标卡尺测量3种方法所测得的数据进行t检验。结果与结论:通过3种方法测量18个点骨皮质距离,下牙槽神经距离平均值分别为(4.894±1.692),(4.906±1.715),(4.861±1.718)mm,三者间两两比较差异均无显著性意义(P>0.05)。提示MRI显示下牙槽神经具有良好的几何准确性,为进一步应用于种植等术前影像学检查提供依据。

BACKGROUND： MRI makes up for a deficiency of X-ray and CT images in nerve imaging and can display inferior alveolar nerve clearly and directly. OBJECTIVE： To assess the geometric accuracy of MRI displaying the inferior alveolar nerve. METHODS： One fresh human cadaver head was scanned by MRI and CT after removing the soft tissue. The distances were measured between the second premolar and the first molar, the first molar and the second molar, the second molar and the third molar. After cutting the bilateral mandible on the same sites with a saw, the distances between inferior alveolar nerve and cortex were measured with a caliper. The data measured by MRI, CT and caliper were statistically analyzed for the t-test. RESULTS AND CONCLUSION： The average distances measured by the three methods between inferior alveolar nerve and cortex were （4.894±1.692）, （4.906±1.715） and （4.861±1.718） mm, respectively. There was no significant difference in the average distance among the three methods （P 〉 0.05）. The geometric accuracy of MRI displaying the inferior alveolar nerve was good. It can provide experimental evidence for MRI application in preoperative imaging such as dental implant.