Keisuke Ohtani1, Toshihiro Mashiko2, Keiji Oguro2, Atsuhito Takemura3, Toru Hatayama4, Tatsuya Sasaki5, Eiju Watanabe2. 1. Department of Neurosurgery, Jichi Medical University, Tochigi, Japan. Electronic address: m01011ko@jichi.ac.jp. 2. Department of Neurosurgery, Jichi Medical University, Tochigi, Japan. 3. Department of Neurosurgery, Aomori City Hospital, Aomori, Japan. 4. Department of Neurosurgery, Mito Brain Heart Center, Ibaraki, Japan. 5. Department of Neurosurgery, Aomori Prefectural Central Hospital, Aomori, Japan.
Abstract
OBJECTIVE: Hemifacial spasm occurs when a blood vessel compresses against an area near the root exit zone of the facial nerve. Developments in diagnostic neuroimaging have allowed three-dimensional (3D) observation of artery and nerve locations, an effective aid for treatment selection. However, an accurate interpretation of the 3D data remains challenging because imaging representations of complex small vessels are drowned out by noise. We used a noise elimination method to analyze artery and nerve locations and to determine their 3D relationship. METHODS: Fifteen patients treated for hemifacial spasm were included. Images fused from 3 modalities of magnetic resonance imaging, 3D computed tomography, and angiography were used as source images. Using the images, models of the nerve and candidate vessels were created and shown in 3D to observe how the arteries were compressing the nerve and to identify the portions of the offending vessels that were closest to the nerve. These preoperative results were then compared with operative field observations during surgery. 3D models of the unaffected side were created and evaluated as controls. RESULTS: We confirmed that these models were accurate reconstructions of the source images as the tubular nerve and artery cross-sections showed good alignment onto magnetic resonance imaging axial slice images. The preoperative diagnoses of the compression sites and offending arteries all matched intraoperative findings. CONCLUSIONS: An accurate identification of the offending arteries and compression sites was possible, and this method is anticipated to offer effective means of preoperative simulation.
OBJECTIVE:Hemifacial spasm occurs when a blood vessel compresses against an area near the root exit zone of the facial nerve. Developments in diagnostic neuroimaging have allowed three-dimensional (3D) observation of artery and nerve locations, an effective aid for treatment selection. However, an accurate interpretation of the 3D data remains challenging because imaging representations of complex small vessels are drowned out by noise. We used a noise elimination method to analyze artery and nerve locations and to determine their 3D relationship. METHODS: Fifteen patients treated for hemifacial spasm were included. Images fused from 3 modalities of magnetic resonance imaging, 3D computed tomography, and angiography were used as source images. Using the images, models of the nerve and candidate vessels were created and shown in 3D to observe how the arteries were compressing the nerve and to identify the portions of the offending vessels that were closest to the nerve. These preoperative results were then compared with operative field observations during surgery. 3D models of the unaffected side were created and evaluated as controls. RESULTS: We confirmed that these models were accurate reconstructions of the source images as the tubular nerve and artery cross-sections showed good alignment onto magnetic resonance imaging axial slice images. The preoperative diagnoses of the compression sites and offending arteries all matched intraoperative findings. CONCLUSIONS: An accurate identification of the offending arteries and compression sites was possible, and this method is anticipated to offer effective means of preoperative simulation.