Comparison of T2 Weighted, Fat-Suppressed T2 Weighted, and Three-Dimensional (3D) Fast Imaging Employing Steady-State Acquisition (FIESTA-C) Sequences in the Temporomandibular Joint (TMJ) Evaluation

Abstract

Aim. Osteonecrosis can affect the mandibular condyle, and bone marrow edema may be a precursor in osteonecrosis development in temporomandibular disorder (TMD) patients. Early detection of bone marrow changes is crucial for occurring osteonecrosis. The purpose of this study was to compare the diagnostic value of fast spin-echo T2 weighted (FSE-T2W), fat-suppressed T2W (FS-T2W), and three-dimensional (3D) fast imaging employing steady-state acquisition (FIESTA-C) MR sequences for early detection of bone marrow changes as well as TMJ soft tissue alterations. Methods. A total of 60 joints with TMD were included in this study using a 1.5T MR machine (Signa HDxt, GE, Milwaukee, USA) using a dual surface TMJ coil. Qualitatively, the images were interpreted by two observers for disk configuration, disk position, joint fluid, and bone marrow changes. Quantitatively, signal intensity ratios (SIR) in the TMJ condyle, retrodiscal tissue, disk, and muscle were also measured using all tested sequences. Kappa coefficients were calculated to assess both intra- and interobserver agreements for each image set. The SIR of each sequence was compared using a one-way ANOVA Bonferroni-Dunn test. Results. Overall intraobserver kappa coefficients ranged between 0.35 and 0.88 for joint fluid and between 0.22 and 0.82 for bone marrow changes diagnosis, suggesting high intraobserver agreement for FS-T2W and 3D FIESTA-C sequences than FSE T2W sequence ( $p<0.05$ ). 3D FIESTA-C showed higher agreement values for disk configuration and position detection than other sequences. Conclusions. 3D FIESTA-C sequences can be used and incorporated into routine MRI protocols for obtaining high-resolution TMJ MR images due to the short acquisition time and 3D nature of the sequence. Additional studies should be done for dynamic TMJ imaging with this sequence.