||Magnetic Resonance Imaging Signal Intensities of the Temporomandibular Joint Articular Disc and Cortical Bone: Are These Measurements Valid for the Diagnosis of Temporomandibular Joint Disease?
FUJIKURA Mamiko :筆頭著者:責任著者 ,
NISHIKAWA KeiichiARAKI Kazuyuki
423 , 2017-12 , Showa University Society
The purpose of this study was to clarify the validity of measuring the signal intensities of cortical bone (CB) and temporomandibular joint (TMJ) discs on magnetic resonance (MR) images for the diagnosis of TMJ disease. Two investigations were performed. In the first investigation, MR images of 13 TMJs of volunteers were obtained using a multi spin-echo sequence. Echo time (TE) was increased from 10msec to 200msec in steps of 10msec. The signal intensities of the CB of the condylar head, and the anterior (AD) and posterior (PD) bands of the TMJ disc were measured, and their attenuation patterns were compared. In the second investigation, clinical MR images of 30 TMJs from patients with suspected TMJ disorders were selected. Proton density-weighted images (PDWIs) and T2-weighted images (T2WIs) were obtained at TEs of 14 and 85msec, respectively, using a double-echo fast spin-echo sequence. The signal intensities of CB, AD, and PD were measured and compared with that of the external auditory meatus (air) using a Bonferroni test. AD and PD showed nearly identical signal intensity attenuation patterns. The signal intensities of AD and PD were lower than CB at TEs longer than 20msec although they were higher at TEs shorter than 20msec. Clinical PDWIs and T2WIs showed similar results. The signal intensities of CB, AD, and PD were significantly higher than the external auditory meatus (air) in both PDWIs and T2WIs. CB and TMJ discs show characteristic signal intensities, suggesting that the signal intensity measurement of these structures is valid.