VALUE OF DIFFERENT MR-TECHNIQUES IN DIAGN OSIS OF DEGENERATIVE-DISORDERS OF THE HYALINE CARTILAGE - IN-VITRO STUDY ON 50 JOINT SPECIMENS OFTHE KNEE WITH 1.5-T

Purpose: An experimental study was performed on joint specimens of the knee to assess the advantages and disadvantages of 14 generally avail able sequences in cartilage imaging. Methods: Each of the 50 surgicall y exposed cadaveric joints of the knee was examined by the following s equences: T-1, proton- and T-2 weighted spin echo(SE) sequences, proto n- and T-2 weighted Turbo-SE, T-1 weighted SE with fat suppression, MT C combined with T-1-weighted SE and T-2 weighted FLASH-2 D, STIR, FISP -3 D, FLASH-3 D (with fat suppression), and MR arthrography. We assess ed the image quality by a scale, signal to noise-ratio of cartilage an d joint fluid, and the accuracy in detection of cartilage lesions. Pat hology and arthroscopy were reference methods to MRI, and demonstrated grade 1 - 4 lesions on 186 of 300 joint facettes. Results: Advanced s tages of cartilage lesions (65 grade 3 and 4 lesions) were detected by standard SE sequences in 67-94%. Application of volume techniques (FI SP-3 D, FLASH-3 D), high definition matrix (512 pixel), MTC with FLASH -2 D and MR-arthrography improved the sensitivity up to 82-100%. Super ficial lesions (65 grade 2 lesions) were demonstrated in 3 - 38%, and on MR arthrography in 45%. Structural changes (56 Grade 1 lesions) wer e recorded on MRI in only 10%. Conclusions: With regard to standard SE sequences, the detectability of cartilage lesions can be improved by techniques that use 512 matrices, selective cartilage imaging, and vol ume acquisition.