Manoliu Andrei, Spinner Georg, Wyss Michael, Filli Lukas, Erni Stefan, Ettlin Dominik A, Ulbrich Erika J, Kuhn Felix P, Gallo Luigi M, Andreisek Gustav
1 Department of Radiology, Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Switzerland.
2 Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Switzerland.
Dentomaxillofac Radiol. 2016;45(4):20150420. doi: 10.1259/dmfr.20150420. Epub 2016 Feb 3.
To quantitatively and qualitatively compare MRI of the temporomandibular joint (TMJ) using a standard TMJ surface coil and a head coil at 3.0 T.
22 asymptomatic volunteers were MR imaged using a 2-channel surface coil (standard TMJ coil) and a 32-channel head coil at 3.0 T (Philips Ingenia; Philips Healthcare, Netherlands). Imaging protocol consisted of an oblique sagittal proton density weighted turbo spin echo sequence (repetition time/echo time, 2700/26 ms). For quantitative assessment, a spherical phantom was imaged using the same sequence including a noise scan and a B1+ scan. Signal-to-noise ratio (SNR) maps and B1+ maps were calculated on a voxelwise basis. For qualitative evaluation, all volunteers underwent MRI of both TMJs with the jaw in the closed position. Two independent blinded readers assessed accuracy of TMJ anatomical representation and overall image quality on a 5-point scale. Quantitative and qualitative measurements were compared between coils using t-tests and Wilcoxon signed-rank test, respectively.
Quantitative analysis showed similar B1+ and significantly higher SNR for the head coil than the TMJ surface coil. Qualitative analysis showed significantly better visibility and delineation of clinically relevant anatomical structures of the TMJ, including the articular disc, bilaminar zone and lateral pterygoid muscle. Furthermore, better overall image quality was observed for the head coil than for the TMJ surface coil.
A 32-channel head coil is preferable to a standard 2-channel TMJ surface coil when imaging the TMJ at 3.0 T, because it yields higher SNR, thus increasing accuracy of the anatomical representation of the TMJ.
在3.0 T场强下，使用标准颞下颌关节（TMJ）表面线圈和头部线圈对颞下颌关节进行定量和定性比较。
22名无症状志愿者在3.0 T（飞利浦Ingenia；飞利浦医疗保健公司，荷兰）场强下，使用2通道表面线圈（标准TMJ线圈）和32通道头部线圈进行磁共振成像。成像方案包括斜矢状面质子密度加权快速自旋回波序列（重复时间/回波时间，2700/26 ms）。为进行定量评估，使用相同序列对球形体模进行成像，包括噪声扫描和B1 +扫描。在体素基础上计算信噪比（SNR）图和B1 +图。为进行定性评估，所有志愿者在闭口位时对双侧TMJ进行磁共振成像。两名独立的盲法阅片者以5分制评估TMJ解剖结构显示的准确性和整体图像质量。分别使用t检验和Wilcoxon符号秩检验比较线圈之间的定量和定性测量结果。
定量分析显示，头部线圈的B1 +与TMJ表面线圈相似，但SNR显著更高。定性分析显示，TMJ临床相关解剖结构（包括关节盘、双板区和翼外肌）的可见性和轮廓清晰度明显更好。此外，观察到头部线圈的整体图像质量优于TMJ表面线圈。
在3.0 T场强下对TMJ进行成像时，32通道头部线圈优于标准2通道TMJ表面线圈，因为它能产生更高的SNR，从而提高TMJ解剖结构显示的准确性。
