A trial study to make a MRI coil for gingiva

制作牙龈 MRI 线圈的试验研究

• 批准号: 13671990
• 负责人: YOTSUI Yoritaka
• 金额: $ 0.38万
• 依托单位: Osaka Dental University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13671990/
• 关键词: magnetic resonance imaging; intra oral coil; metallic artifact; phased array coil; periodontal disease; dental disease; 磁気共鳴画像; 撮像用コイル; 歯肉; 口腔

We tried to make a high-resolution intra-oral coil for the examination of dental-pulp diseases and periodontal diseases with MRI. Before making the new coil, we had two problems of setting angulations of the intra-oral coil and metallic artifact of dental material.About setting angulations, the coil gain will be decease by setting coil vertically toward the magnetic direction. We made experimental study to measure the coil-signal gain during the changing angulations of coil. When the coil set in 60 degree toward magnetic direction, we recognized that the signal gain became strongest.About the metallic artifacts, we made an experimental study with dental crowns. We confirmed that the influence by the metallic artifact would be extended widely. Before taking MRI, we should remove the metallic materials.We made some type of coils and measured the signal gain. From them, we selected two types of coils that were the flat type and the saddle type for the strength of signal gain and volume of the high signal area. We developed a phased array coil that was made with the intra-oral coil and the extra-oral surface coil. With this phased array coil, we could get high signal gain that was 16 times of usual extra-oral coil.We took MRI of volunteer' s oral cavity with two types of the phased array coils that were combined the surface coil with flat-type coil or saddle-type coil. With the phased array coil made with the surface coil and saddle-type coil, we could detect the structure of the gingival and the alveolar bone.We took MRI of periodontal disease patient's oral cavity with the phased array coils that were combined the surface coil with saddle-type coil. In the images, we could detect the infection in the gingival that was found in the pathological examination.

我们试图制造高分辨率的口腔内线圈，以检查使用MRI的牙髓疾病和牙周疾病。在制作新线圈之前，我们有两个问题，即设定牙科材料的口腔内线圈和金属伪像的角度。固定角度，线圈增益将通过垂直固定朝向磁性方向而脱落。我们进行了实验研究，以测量线圈变化角度的线圈信号增益。当线圈以60度朝着磁性方向设置时，我们认识到信号增益最强。金属伪像，我们用牙冠进行了一项实验性研究。我们证实，金属伪像的影响将被广泛扩展。在服用MRI之前，我们应该去除金属材料。我们制作了某种类型的线圈并测量了信号增益。从他们那里，我们选择了两种类型的线圈，这些线圈是扁平类型和鞍形类型，以使信号增益和高信号面积的体积的强度。我们开发了一个分阶段的阵列线圈，该线圈是用口内线圈和口外表面线圈制成的。借助该阶段阵列线圈，我们可以获得高信号增益，这是通常的口腔外线圈的16倍。我们将志愿者口腔的MRI带有两种类型的阶段阵列线圈，它们与表面线圈和平面型线圈或鞍形型线圈结合在一起。通过用表面线圈和马鞍型线圈制成的相位阵列线圈，我们可以检测牙龈和肺泡骨的结构。我们使用牙周疾病患者的口腔MRI与相位的阵列线圈与表面线圈与鞍型线圈组合在一起。在图像中，我们可以检测病理检查中发现的牙龈中的感染。