Kuhn Felix P, Spinner Georg, Del Grande Filippo, Wyss Michael, Piccirelli Marco, Erni Stefan, Pfister Pascal, Ho Michael, Sah Bert-Ram, Filli Lukas, Ettlin Dominik A, Gallo Luigi M, Andreisek Gustav, Manoliu Andrei
1 Institute for Diagnostic and Interventional Radiology, Department of Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
2 Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.
Dentomaxillofac Radiol. 2017 Jan;46(1):20160280. doi: 10.1259/dmfr.20160280. Epub 2016 Dec 18.
To qualitatively and quantitatively compare MRI of the temporomandibular joint (TMJ) at 7.0 T using high-permittivity dielectric pads and 3.0 T using a clinical high-resolution protocol.
Institutional review board-approved study with written informed consent. 12 asymptomatic volunteers were imaged at 7.0 and 3.0 T using 32-channel head coils. High-permittivity dielectric pads consisting of barium titanate in deuterated suspension were used for imaging at 7.0 T. Imaging protocol consisted of oblique sagittal proton density weighted turbo spin echo sequences. For quantitative analysis, pixelwise signal-to-noise ratio maps of the TMJ were calculated. For qualitative analysis, images were evaluated by two independent readers using 5-point Likert scales. Quantitative and qualitative results were compared using t-tests and Wilcoxon signed-rank tests, respectively.
TMJ imaging at 7.0 T using high-permittivity dielectric pads was feasible in all volunteers. Quantitative analysis showed similar signal-to-noise ratio for both field strengths (mean ± SD; 7.0 T, 13.02 ± 3.92; 3.0 T, 14.02 ± 3.41; two-sample t-tests, p = 0.188). At 7.0 T, qualitative analysis yielded better visibility of all anatomical subregions of the temporomandibular disc (anterior band, intermediate zone and posterior band) than 3.0 T (Wilcoxon signed-rank tests, p < 0.05, corrected for multiple comparisons).
MRI of the TMJ at 7.0 T using high-permittivity dielectric pads yields superior visibility of the temporomandibular disc compared with 3.0 T.
对使用高介电常数介质垫在7.0 T场强下和使用临床高分辨率方案在3.0 T场强下的颞下颌关节（TMJ）MRI进行定性和定量比较。
经机构审查委员会批准的研究，并获得书面知情同意。12名无症状志愿者使用32通道头部线圈分别在7.0 T和3.0 T场强下进行成像。由钛酸钡氘代悬浮液组成的高介电常数介质垫用于7.0 T场强下的成像。成像方案包括斜矢状面质子密度加权快速自旋回波序列。进行定量分析时，计算颞下颌关节的逐像素信噪比图。进行定性分析时，由两名独立的阅片者使用5分制李克特量表对图像进行评估。分别使用t检验和Wilcoxon符号秩检验对定量和定性结果进行比较。
所有志愿者使用高介电常数介质垫在7.0 T场强下进行颞下颌关节成像均可行。定量分析显示，两种场强下的信噪比相似（均值±标准差；7.0 T，13.02±3.92；3.0 T，14.02±3.41；两样本t检验，p = 0.188）。在7.0 T场强下，定性分析显示颞下颌盘所有解剖亚区域（前带、中间区和后带）的可视性均优于3.0 T场强（Wilcoxon符号秩检验，p < 0.05，经多重比较校正）。
与3.0 T场强相比，使用高介电常数介质垫在7.0 T场强下进行颞下颌关节MRI可获得更好的颞下颌盘可视性。
