Abstract:

Objective To explore the magnetic resonance imaging（MRI） characteristics of temporomandibular joint （TMJ） disc including sequence and parameters of the film imaging modalities by means of 3T MRI. To provide morphological and functional reference images for clinical study of temporomandibular joint disc lesions. Methods Fifteen normal volunteers and seven patients with TMJ soft tissue injuries after condylar fractures were imaged by using GE Signa HD 3T MRI system and bilateral TMJ surface coils with oblique sagittal and oblique coronal section. Oblique sagittal and oblique coronal images of mouth close were performed with FSE-XL/T1WI, FLAIR/T1WI, FSEXL/ PDWI, FSE/PDWI+FS, FRFSE-XL/T2WI, FRFSE/T2WI+FS, and oblique sagittal images of mouth open with FSEXL/ T1WI, FSE-XL/PDWI. All MRI findings were analyzed by three senior radiologists and three senior surgeons respectively. Results PDWI showed the best effect in showing articular disc and surrounding structures clearly. T2WI showed articular disc lesions best, including articular disc injury, split, perforation, fluidify of articular capsule. For the displace of articular disc, PDWI showed the best effect. Conclusion 3T MRI can clearly show changes of articular disc during exercise and disease involvement, and play an important role in diagnosis of soft tissue injuries of TMJ in condylar fractures. T1WI, PDWI and T2WI should be routine scan method.

Key words: temporomandibular joint, 3T magnetic resonance imaging, joint disc