Real-time MRI of the temporomandibular joint at 15 frames per second—A feasibility study. Issue 12 (December 2016)

• Record Type: Journal Article
• Authors: Krohn, Sebastian; Gersdorff, Nikolaus; Wassmann, Torsten; Merboldt, Klaus-Dietmar; Joseph, Arun A.; Buergers, Ralf; Frahm, Jens
• Is Part Of: European journal of radiology. Volume 85:Issue 12(2016)
• Page Start: 2225
• Page End: 2230
• Publication Date: 2016-12
• Subjects: Articular disk -- Condyle -- Temporomandibular joint -- MR imaging/diagnosis -- Real-time imaging; Medical radiology -- Periodicals; Radiology -- Periodicals; Radiologie médicale -- Périodiques; Medical radiology; Periodicals; 616.075705
• DOI: 10.1016/j.ejrad.2016.10.020
• Languages: English
• ISSNs: 0720-048X

Abstract

Abstract: The purpose of this study was to develop and evaluate a novel method for real-time MRI of TMJ function at high temporal resolution and with two different contrasts. Real-time MRI was based on undersampled radial fast low angle shot (FLASH) acquisitions with iterative image reconstruction by regularized nonlinear inversion. Real-time MRI movies with T1 contrast were obtained with use of a radiofrequency-spoiled FLASH sequence, while movies with T2/T1 contrast employed a gradient-refocused FLASH version. TMJ function was characterized in 40 randomly selected volunteers by sequential 20 s acquisitions of both the right and left joint during voluntary opening and closing of the mouth (in a medial, central and lateral oblique sagittal section perpendicular to the long axis of the condylar head). All studies were performed on a commercial MRI system at 3 T using the standard head coil, while online reconstruction was achieved with a bypass computer fully integrated into the MRI system. As a first result, real-time MRI studies of the right and left TMJ were successfully performed in all 40 subjects (80 joints) within a total examination time per subject of only 15 min. Secondly, at an in-plane resolution of 0.75 mm and 5 mm section thickness, the achieved temporal resolution was 66.7 ms per image or 15 frames per second. Thirdly, both T1-weighted and T2/T1-weighted real-time MRI movies provided information about TMJ function such as disc position, condyle mobility and disc-condyle relationship. While T1 contrast offers a better delineation of structures during rapid jaw movements, T2/T1 contrast was rated superior for characterizing the articular disc. In conclusion, the proposed real-time MRI method may become a robust and efficient tool for the clinical assessment of TMJ function.