Semiquantitative assessment of focal cartilage damage at 3T MRI: A comparative study of dual echo at steady state (DESS) and intermediate-weighted (IW) fat suppressed fast spin echo sequences

Abstract

The aim of the study was to compare semiquantitative assessment of focal cartilage damage using the dual echo at steady state (DESS)- and intermediate-weighted (IW) fat suppressed (fs) sequences at 3T MRI. Included were 201 subjects aged 35-65 with frequent knee pain. MRI was performed with the same sequence protocol as in the Osteoarthritis Initiative (OAI): sagittal IW fs, triplanar DESS and coronal IW sequences. Cartilage status was scored according to the WORMS system using all five sequences. A total of 243 focal defects were detected. In an additional consensus reading, the lesions were evaluated side-by-side using only the sagittal DESS and IW fs sequences. Lesion conspicuity was graded from 0 to 3, intrachondral signal changes adjacent to the defect were recorded and the sequence that depicted the lesion with larger diameter was noted. Wilcoxon signed-rank tests, controlled for clustering by person, were used to examine differences between the sequences. 37 (17.5%) of the scorable lesions were located in the medial tibio-femoral (TF), 48 (22.7%) in the lateral TF and 126 (59.7%) in the patello-femoral compartment. 82.5% were superficial and 17.5% full-thickness defects. Conspicuity was superior for the IW sequence (p<0.001). The DESS sequence showed more associated intrachondral signal changes (p<0.001). In 103 (48.8%) cases, the IW fs sequence depicted the lesions as being larger (p<0.001). The IW fs sequence detected more and larger focal cartilage defects than the DESS. More intrachondral signal changes were observed with the DESS.