The purpose of this study is to evaluate the possibility of dynamic knee MRI and what is the optimal pulse sequences, and to study new findings in this dynamic images which cannot be found is static knee MRI, Five patients with clincally
suspected
posterior cruciate ligament injury and other 5 normal controls were studied. In all groups, the knee was moved from flexion to extension state according to scan time of each pulse sequences in the prone position. In control group, 1) FSPGR, 2)
FGR.
3)
EPI, 4) conventional SE technique were operated to evaluate the optimal pulse sequence and in patients group, we studied FSPGR technique which changed
flip angle 30°, 45°, 60°, 90°. Successful dynamic images could bema de by FSPGR and FGR techniques, and the whole length and width of posterior cruciate ligaments and patellar tendon were well visualized but SNR and contrast resolution were
poor in
these images than conventional SE technique. On FGR images, general SNR and contrast resolution were better than FSPGR images especially in themuscles and bone marrow fats but those of the posterior cruciate ligaments were worse than FSPGR
images.
In
patients group, flip angle 60 was best in SNR on FSPGR images and irregular thickening and loss of normal even thickness of posterior cruciate ligaments dient technique and optimal pulse sequences was FSPGR with flip angle 60 in evaluation of
posterior
cruciate ligament. The changes in the shape of postrior cruciate ligament could be found in dynmic images and we expect the greater importance of dynamic images with increasing SNR in the near future.
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