Pseudodynamic imaging of the temporomandibular joint: SE versus GE sequences

Pseudodynamic MR imaging of the temporomandibular joints (TMJs) has been used for the evaluation of the functional aspects of the TMJs. To evaluate the value of T1-weighted spin-echo (SE) and gradient-echo (GE) techniques, both techniques were performed in 9 asymptomatic (mean 25.7 years, 22-23 years), and 25 symptomatic (mean 44.9 years, 20-71 years) subjects with signs and symptoms of internal derangement or osteoarthrosis of the TMJs. The imaging time for the SE (180 ms/15 ms/110 degrees; repetition time/echo time/flip angle) and GE (fast low angle shot; FLASH, 90 ms/12 ms/40 degrees) sequences was 27 and 28 s, respectively. In asymptomatic and symptomatic subjects, the confidence of the identification of the meniscal position was better on SE than GE images (3.6 +/- 0.6 vs. 2.9 +/- 0.9, p < 0.01, 3.2 +/- 0.8 vs. 2.8 +/- 0.8, p < 0.05), respectively and the sizes of the menisci were bigger on SE than GE images. The delineation of the condylar cortex was better on GE than SE images. For pseudodynamic imaging display of the TMJs, the SE images might be better than GE images to provide the stable recognition of the menisci.