磁共振神经成像全景片：下颌骨和牙齿的超短回波时间成像，并辅以高分辨率形态学和功能性磁共振神经成像。

MR neurographic orthopantomogram: Ultrashort echo-time imaging of mandibular bone and teeth complemented with high-resolution morphological and functional MR neurography.

作者信息

Manoliu Andrei, Ho Michael, Nanz Daniel, Dappa Evelyn, Boss Andreas, Grodzki David M, Liu Wei, Chhabra Avneesh, Andreisek Gustav, Kuhn Felix P

机构信息

Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.

Siemens Healthcare, Erlangen, Germany.

出版信息

J Magn Reson Imaging. 2016 Aug;44(2):393-400. doi: 10.1002/jmri.25178. Epub 2016 Feb 8.

DOI:10.1002/jmri.25178

PMID:26854879

Abstract

PURPOSE

Panoramical radiographs or cone-beam computed tomography (CT) are the standard-of-care in dental imaging to assess teeth, mandible, and mandibular canal pathologies, but do not allow assessment of the inferior alveolar nerve itself nor of its branches. We propose a new technique for "MR neurographic orthopantomograms" exploiting ultrashort echo-time (UTE) imaging of bone and teeth complemented with high-resolution morphological and functional MR neurography.

MATERIALS AND METHODS

The Institutional Review Board approved the study in 10 healthy volunteers. Imaging of the subjects mandibles at 3.0T (Magnetom Skyra, Siemens-Healthcare) using a 64-channel head coil with isotropic spatial resolution for subsequent multiplanar reformatting, was performed. Bone images were acquired using a 3D PETRA sequence (TE, 0.07 msec). Morphological nerve imaging was performed using a dedicated 3D PSIF and 3D SPACE STIR sequence. Functional MR neurography was accomplished using a new accelerated diffusion-tensor-imaging (DTI) prototype sequence (2D SMS-accelerated RESOLVE). Qualitative and quantitative image analysis was performed and descriptive statistics are provided.

RESULTS

Image acquisition and subsequent postprocessing into the MR neurographic orthopantomogram by overlay of morphological and functional images were feasible in all 10 volunteers without artifacts. All mandibular bones and mandibular nerves were assessable and considered normal. Fiber tractography with quantitative evaluation of physiological diffusion properties of mandibular nerves yielded the following mean ± SD values: fractional anisotropy, 0.43 ± 0.07; mean diffusivity (mm(2) /s), 0.0014 ± 0.0002; axial diffusivity, 0.0020 ± 0.0002, and radial diffusivity, 0.0011 ± 0.0001.

CONCLUSION

The proposed technique of MR neurographic orthopantomogram exploiting UTE imaging complemented with high-resolution morphological and functional MR neurography was feasible and allowed comprehensive assessment of osseous texture and neural microarchitecture in a single examination. J. Magn. Reson. Imaging 2016;44:393-400.

摘要

目的

全景X线片或锥形束计算机断层扫描（CT）是牙科成像中评估牙齿、下颌骨及下颌管病变的标准方法，但无法对下牙槽神经本身及其分支进行评估。我们提出一种新的“磁共振神经成像全景体层摄影术”技术，利用骨与牙齿的超短回波时间（UTE）成像，并辅以高分辨率形态学和功能性磁共振神经成像。

材料与方法

机构审查委员会批准了对10名健康志愿者的研究。使用64通道头部线圈，在3.0T（Magnetom Skyra，西门子医疗）对受试者的下颌骨进行成像，具有各向同性空间分辨率以便后续进行多平面重组。使用3D PETRA序列（TE，0.07毫秒）采集骨图像。使用专用的3D PSIF和3D SPACE STIR序列进行形态学神经成像。使用新的加速扩散张量成像（DTI）原型序列（2D SMS加速RESOLVE）完成功能性磁共振神经成像。进行了定性和定量图像分析并提供了描述性统计数据。

结果

在所有10名志愿者中，通过叠加形态学和功能性图像将图像采集及后续后处理成磁共振神经成像全景体层摄影术是可行的，且无伪影。所有下颌骨和下颌神经均可评估且被认为正常。对下颌神经生理扩散特性进行定量评估的纤维束成像得出以下平均值±标准差：各向异性分数，0.43±0.07；平均扩散率（mm²/s），0.0014±0.0002；轴向扩散率，0.0020±0.0002，以及径向扩散率，0.0011±0.0001。