MR FIESTA技术在TMJ动态成像中的应用

Application of the Fast Imaging Employing Steady-state Acquisition Technique in Dynamic Temporomandibular Joint MR Imaging

目的:探讨磁共振FIESTA技术在颞下颌关节(TMJ)动态成像中的应用。方法:连续对40例受检者的80侧TMJ行斜矢状位FIESTA动态磁共振成像。根据各TMJ在成像过程中完成的运动周期数分其为2组:运动周期≤3者(1组)和>3者(2组)。分别对每侧TMJ的关节盘和髁突的运动状况进行评估。结果:80侧TMJ中,关节盘位置、形态和运动范围清晰显示者分别为76侧(95%)、75侧(93.75%)和77侧(96.25%);关节盘运动过程中出现伪影和"跳跃"征象者分别为27侧(33.75%)和28侧(35%),两者具有相关性(P<0.01)。髁突位置、形态和运动范围清晰显示者分别为78侧(97.5%)、76侧(95%)和79侧(98.75%);髁突出现运动伪影和"跳跃"征象者分别为30侧(37.5%)和28侧(35%),两者亦具有相关性(P<0.01)。1组关节盘和髁突位置、形态的清晰显示率高于2组(P<0.05),而运动伪影和"跳跃"征象显现率低于2组(P<0.05)。结论:FIESTA技术能对自然状态下缓慢运动的TMJ进行动态成像,并为TMJ运动状况的显示提供有益信息。

Purpose：The study aimed to evaluate the T MJ movement by using serial dynamic fast imaging employing steady - state acquisition（FIESTA） MR technique. Methods：Eighty TMJs from 40 patients were consecutively performed a dynamic FIESTA MR sequence on oblique sagittal position. All the TMJs were classified into 2 groups based on the times of TMJ movement during the process of FIESTA imaging： times less than or equal 3 （group 1） and over 3 （group 2）. The position, shape, range of the motion, motion artifact of meniscus and mandibular condyle in each TMJ were assessed. Results： The position, shape and range of motion of the discs were clearly identified in 76 （95%）, 75 （93.75%） and 77（96.25%） out of 80 TMJs, respectively. There was a significant correlation between motion artifact （27 TMJs, 33.75%） and ＂Jumping＂ sign （28 TMJs, 35%） （P〈 0.01）. Of 80 TMJs, the position, shape and range of motion of the mandibular condyle were clearly demonstrated in 78 （97.5%）, 76 （95%） and 79 （98.75%）, respectively. Also, a significant correlation between motion artifact （ 30 TMJs, 37.5%） and ＂Jumping＂ sign （ 28 TMJs, 35%） was found （P 〈 0.01）. Compared between both groups, the position and shape of meniscus and condyle were better shown in group 1 than in group 2 （P 〈 0.05） ; but the motion artifact and ＂ Jumping＂ sign were more infrequently seen in group 1 than in group 2（P 〈 0.05） . Conclusion： Most TMJs with slow open - closed mouth movement could be successfully performed by a dynamic FIESTA MR imaging. The FIESTA sequence might provide valuable information for assessing the dynamic TMJ movement.