| PrefaceHyaline cartilage is vital in maintaining normal joint function. Hyaline cartilage will be destroyed in almost every articular disease. It is very important to detect the cartilage defects. Because they may produce symptoms confused clinically with meniscal tears, meniscal tears can be repaired easily, but hyaline cartilage cannot regeneration. The integrity of cartilage plays an important role in the prognostic of meniscal operation. The recent development of surgical and patho-physiologic methods for the treatment of articular cartilage abnormalities has created a need for the accurate, noninvasive evaluation of chondral lesions.Magnetic resonance imaging appears to be the most promising noninvasive modality for this purpose, but the result of the standard spin - echo sequence used to assess cartilage abnormalities is inaccurate. Recently fat - suppressed three - dimensional gradient - echo sequence have been reported to be the most useful for evaluate cartilage defect. However the optical sequence is still uncertain. But with the development of the image equipment and progressing of the technique, the ability of MR sequences in detecting hyaline cartilage defects need to be determined furthermore. The purpose of this study is to compare the MR imaging sequence for detecting hyaline cartilage defects.Materials and methods10 animal models of cartilage defect were established in 5 pig knees. 5 knees were examined with nine different MR sequences. MR imaging study consisted of 2D sagittal Tl - weighted spin - echo ( SE 500/20 ) , dual - echo T2 - weighted/proton density - weighted fast spin - echo ( FSE - PD/T2 3000/20/120), FSE - PD/T2 with fat saturation ( FS - FSE - PD/T2 3000/20/120) , 3D fast spoiled gradient echo with fat saturation ( FS - 3D - FSPGR 32.1/8. 1/40) , fluid attenuation inversion recovery (FLAIR 9000/160/2200) , short Tl inversion recovery (STIR 2000/20/120) and Tl weighted inversion recovery (IR -TT700 2000/20/700). The parameter; FOV 14cm; Pixel 256 x 256; NEX 2; Slice thickness 3mm; Slice gap 1. 5mm( two -dimensional) ; 1.2mm(three -dimensional). The cartilage and adjacent tissue signal intensity were measured. The signal noise ratio and contrast noise ratio were calculated and compared between cartilage and adjacent tissue. Measure of the defect depth and width in the imaging were correlated with the actual measure before imaging.From 2001. 6 to 2002. 12, we evaluated 23 patients for hyaline cartilage defects of the knee with MR imaging. All these patients underwent subsequent arthroscopy because of meniscal or anterior cruciate ligament tears or because of persistent symptoms of knee pain or locking. MR imaging protocol included a fat - suppressed three - dimensional fast spoiled gradient - echo sequence, Inversion Recovery sequence and dual - echo fast spin - echo with fat saturation sequence at least which is the selecting sequence in experimental study. All images were obtained with a 1. 5 T super - conducting magnet ( Advan-tage; General Electric Medical Systems) and a transmit - receive extremity coil. The imaging parameter is the same as the experimental study.The system used to grade the articular cartilage on both the MR imaging and at arthroscopy was a modification of the Noyes classification scheme. Cartilage surface was graded as intact ( grade I ) ; damaged but present ( grade II ) ; absent with subchondral bone exposed with an intact bone surface and a normal bone contour ( grade HI) ; absent with exposed subchondral bone with signal abnormal ( Grade IV). With this modification of the Noyes classification, the MR images were graded by consensus by two musculo - skeletal radiologists for every sequence image. All the arthroscopies were graded by one arthroscopist who were blinded to the MR imaging grading of the cartilage. The sensitivity and specificity for detecting hyaline cartilage defects for each sequence were calculated. The u - test was used to test the diagnostic reliability coefficients - Kappa.ResultsCompared with FSE - PD/T2,...
|
PDF Full Text Request