抄録
Objective: To optimize the concentration of contrast media and to compare the ability of cone beam CT
(CBCT) and multidetector CT (MDCT) in detecting the adhesion of the TMJ disk by CT- arthrography.
Materials and Method: The square shape phantom made by nylon thread, which was simulated for adhesive
change in TMJ space was used. The eight types of threads (diameter: 0.128, 0.148, 0.165, 0.205, 0.235, 0.330, 0.405,
and 0.500 mm) were joined inside the phantom in parallel at 1 mm interval. The contrast media (Omnipaque
350mg I /ml) was diluted with water, and seven types of the media with diff erent concentration, 5%, 10%,
20%, 30%, 40%, 50%, and 100%, were examined. A thread phantom was kept in the rubber balloon, which fi lled
with contrast media and then placed in the TMJ space of the cadaver, so that all of the threads paralleled
the F-H plane as possible. The phantom in the TMJ space was investigated using cone beam CT (CBCT) and
multi-detector CT (MDCT). The voxel size was approximately 0.125×0.125×0.125 mm and 0.1×0.1×0.6 mm,
respectively. Four observers independently assessed, whether the defect of contrast media by thread was
present or not in 12 consecutive slices in the middle of the thread. MDCT images were examined by printed
on fi lm and CBCT in computer display.
Results: The detected threads in the TMJ disk space in the contrast media that CBCT was superior to MDCT.
Statistically signifi cant diff erences (p 0.01) were found almost all detected threads.
Conclusion: MDCT and CBCT are similar detectability, when adequate concentration of contrast media is
used. However, CBCT can be used for the arthrography of TMJ with less concentration of contrast media, low
radiation dose, lowest price and narrow space than MDCT.
