Ngamsom Supak, Nakamura Shin, Sakamoto Junichiro, Kotaki Shinya, Tetsumura Akemi, Kurabayashi Tohru
1 Oral and Maxillofacial Radiology Department, Graduate School, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
2 Oral and Maxillofacial Radiology Department, Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
Dentomaxillofac Radiol. 2017 Jul;46(5):20160424. doi: 10.1259/dmfr.20160424. Epub 2017 Mar 23.
To quantitatively evaluate diffusion and perfusion status of lateral pterygoid muscle (LPM) in patients with temporomandibular joint disorder (TMD) by intravoxel incoherent motion (IVIM) imaging and to correlate with findings on temporomandibular joints (TMJs) by conventional MRI.
42 patients with TMD underwent MRI. To assess IVIM parameters, diffusion-weighted imaging was obtained by spin-echo-based single-shot echoplanar imaging. Regions of interest were created on all diffusion-weighted images of the superior belly of the lateral pterygoid (SLP) and inferior belly of the lateral pterygoid (ILP) at b-values 0-500 s mm. Then, IVIM parameters, diffusion (D) and perfusion (f) were calculated using biexponential fittings. The correlation of these values with conventional MRI findings on TMJs was investigated.
For SLP, the f parameter in TMJs with anterior disc displacement without reduction was significantly higher than that in normal ones (p = 0.015). It was also significantly higher in TMJs with joint effusion than in those without (p = 0.016). On the other hand, for both SLP and ILP, the D parameter significantly increased in TMJs with osteoarthritis compared with those without (p = 0.015 and p = 0.022, respectively).
Pathological changes of LPM in patients with TMD may be quantitatively evaluated by IVIM parameters.
通过体素内不相干运动（IVIM）成像定量评估颞下颌关节紊乱病（TMD）患者翼外肌（LPM）的扩散和灌注状态，并将其与颞下颌关节（TMJ）的传统MRI表现相关联。
42例TMD患者接受了MRI检查。为评估IVIM参数，通过基于自旋回波的单次激发平面回波成像获得扩散加权成像。在b值为0 - 500 s/mm²的翼外肌上半部分（SLP）和翼外肌下半部分（ILP）的所有扩散加权图像上绘制感兴趣区。然后，使用双指数拟合计算IVIM参数、扩散系数（D）和灌注分数（f）。研究这些值与TMJ传统MRI表现的相关性。
对于SLP，不可复性盘前移位的TMJ中的f参数显著高于正常TMJ（p = 0.015）。有关节积液的TMJ中的f参数也显著高于无积液的TMJ（p = 0.016）。另一方面，对于SLP和ILP，骨关节炎的TMJ中的D参数均显著高于无骨关节炎的TMJ（分别为p = 0.015和p = 0.022）。
IVIM参数可定量评估TMD患者LPM的病理变化。
