ABNORMALITIES OF ARTICULAR-CARTILAGE IN THE KNEE - ANALYSIS OF AVAILABLE MR TECHNIQUES

In an attempt to improve the detection of chondral abnormalities with magnetic resonance imaging, a fat-suppressed three-dimensional gradien t-recalled acquisition in the steady state (GRASS) and spoiled GRASS ( SPGR) sequence was optimized by study of five cadaveric knee specimens . Results with this optimized sequence then were compared with results with three spin-echo (T1-, proton-density-, and T2-weighted) and two three-dimensional gradient-recalled echo sequences (GRASS and non-fat- suppressed SPGR) in the assessment of naturally occurring abnormalitie s of the patellofemoral compartment in 10 cadaveric knees. Results wit h the optimized fat-suppressed SPGR sequence were significantly better (P < .02) than results with the other five sequences and had a sensit ivity of 96%, a specificity of 95%, and an accuracy of 95%. In additio n, normal cartilage consistently appeared as a trilaminar structure wi th the fat-suppressed SPGR sequence, a feature that appeared to help i n identification of chondral lesions.