Traumatic Knee Evaluated With Multiple MR Sequences Imaging

The knee is a common site of trauma .especial meniscus and ligament, which contributes to pain of knee joint and internal derangement .In the past few years , with development of MRI techniques , MR image becomes the most frequent diagnostic modality in traumatic knee . MR image has several advantages when compared with other modalities in evaluating traumatic knee . MRI is a noninvasive , high resolution of soft-tissues and multi-orientation method . Currently , a few pulse sequences were used , but the diagnostic accuracies are not unanimous in those. Four MRI pulse sequences were used to evaluate the value of different sequences.then determined the routine MR image sequence for the assessment of knee injury .The MR image of 116 patients who had different trauma were studied from December in 2001 to September in 2002 . The patients were 11-64 years old, average 28.9 ; 60 were men and 56 were women; left knee were 58 , right knee were 61 ; three patients were imaged for two knee . Image sequences include fast low angle shot (FLASH, TR/TE = 540/18 ,flip angle 20 ) gradient echo sequence T2WI , Turbo spin double-echo with fat saturation (FS-TSE-PDWI-T2WI, TR/TE= 2500/16, 98ms) sequence PDWI-fs, T2WI-fs, Turbo spin double-echo (TSE-PDWI-T2WI, TR/TE = 2500/16, 98ms) sequence PDWI, T2WI ; spin echo (SE, TR/TE = 440/12ms) sequence T1WI. Sagittal images were obtained with all sequences . All images have the same following parameters : 3-mm-thick slices with a 0.6-mm interslice gap , 158mm 210mm field of view ,173 256 matrix , two excitations . According to the same diagnostic criteria , the MR unages were interpreted independently by three experienced radiologists . If there are discrepancies in cases , the MR images were jointly analysed to attain consensus . All images were confirmed by arthroscopy or operation . x2 analysis was used to evaluate the accuracies of different sequences.Using the results of arthroscopy or operation as gold criterion , in medial menisciinjuries , the accuracies in T2WI (FLASH) , PDWI-fs and T2WI-fs (Turbo spin doubl-echo with fat saturation), PDWI , T2WI (Turbo spin double-echo), T1WI (spin echo) were respectively 92.44%, 92.38%, 78.15%, 84.03%, 82.35%, 83.09%, T2WI (FLASH) and PDWI-fs (FS-TSE-PDWI-T2WI) were superior to other sequences and weighted images (p<0.05); in lateral menisci injuries , the accuracies were respectively 91.60%, 91.60%, 75.63%, 82.35%, 78.99%, 79.83%, T2WI (FLASH) and PDWI-fs (FS-TSE-PDWI-T2WI) were superior to other sequences weighted images (p<0.05), In anterior cruciate ligament injuries ,the accuracies were respectively 87.39%,96.64%, 97.48% , 95.80% , 96.64% , 89.08% , FS-TSE-PDWI-T2WI sequence and TSE-PDWI-T2WI sequence were superior to other sequences (p<0.05) ; in posterior cruciate ligament injuries , the accuracies were respectively 92.43%, 100%, 100%, 100%, 100%, 94.96% , FS-TSE-PDWI-T2WI sequence and TSE-PDWI-T2WI sequence were superior to other sequences (p<0.05).Based on this paper we concluded : 1 In menisci injuries , T2WI (FLASH) and PDWI-fs (FS-TSE-PDWI-T2WI) were superior to other sequences and weighted images; 2 In cruciate ligamentiou injuries , FS-TSE-PDWI-T2WI sequence and TSE-PDWI-T2WI sequence were superior to other sequences ; 3 In many cases , an injury is often associated with other injuries, FS-TSE-PDWI-T2WI sequence could be an ideal and routine sequence for its high accuracy of meniscus and cruciate ligament.