Kakimoto N, Shimamoto H, Chindasombatjaroen J, Tsujimoto T, Tomita S, Hasegawa Y, Murakami S, Furukawa S
From the Department of Oral and Maxillofacial Radiology (N.K., H.S., T.T., S.T., S.M., S.F.), Osaka University Graduate School of Dentistry, Osaka, Japan
From the Department of Oral and Maxillofacial Radiology (N.K., H.S., T.T., S.T., S.M., S.F.), Osaka University Graduate School of Dentistry, Osaka, Japan.
AJNR Am J Neuroradiol. 2014 Jul;35(7):1412-7. doi: 10.3174/ajnr.A3880. Epub 2014 Apr 17.
T2 relaxation time is a quantitative MR imaging parameter used to detect degenerated cartilage in the knee and lumbar intervertebral disks. We measured the T2 relaxation time of the articular disk of the temporomandibular joint in patients with temporomandibular disorders and asymptomatic volunteers to demonstrate an association between T2 relaxation time and temporomandibular disorder MR imaging findings.
One hundred forty-four patients with temporomandibular disorders and 17 volunteers were enrolled in this study. An 8-echo spin-echo sequence for measuring the T2 relaxation times was performed in the closed mouth position, and the T2 relaxation time of the entire articular disk was measured. Patients were classified according to the articular disk location and function, articular disk configuration, presence of joint effusion, osteoarthritis, and bone marrow abnormalities.
The T2 relaxation time of the entire articular disk was 29.3 ± 3.8 ms in the volunteer group and 30.7 ± 5.1 ms in the patient group (P = .177). When subgroups were analyzed, however, the T2 relaxation times of the entire articular disk in the anterior disk displacement without reduction group, the marked or extensive joint effusion group, the osteoarthritis-positive group, and the bone marrow abnormality-positive group were significantly longer than those in the volunteer group (P < .05).
The T2 relaxation times of the articular disk of the temporomandibular joint in patients with progressive temporomandibular disorders were longer than those of healthy volunteers.
T2弛豫时间是一种定量磁共振成像参数，用于检测膝关节和腰椎间盘退变的软骨。我们测量了颞下颌关节紊乱患者和无症状志愿者颞下颌关节盘的T2弛豫时间，以证明T2弛豫时间与颞下颌关节紊乱磁共振成像表现之间的关联。
本研究纳入了144例颞下颌关节紊乱患者和17名志愿者。在闭口位进行用于测量T2弛豫时间的8回波自旋回波序列扫描，并测量整个关节盘的T2弛豫时间。根据关节盘的位置和功能、关节盘形态、关节积液、骨关节炎及骨髓异常情况对患者进行分类。
志愿者组整个关节盘的T2弛豫时间为29.3±3.8毫秒，患者组为30.7±5.1毫秒（P = 0.177）。然而，在对亚组进行分析时，不可复性盘前移位组、明显或广泛关节积液组、骨关节炎阳性组及骨髓异常阳性组的整个关节盘T2弛豫时间显著长于志愿者组（P < 0.05）。
进展性颞下颌关节紊乱患者颞下颌关节盘的T2弛豫时间长于健康志愿者。
