Comparing Relative Contrast in Three-dimensional Double-echo Steady State With Routine Sequences for a Better Diagnosis of Knee Cartilage Anomalies

This study compared relative contrast values in three-dimensional Double Echo Steady State (DESS) sequences with two flip angles of 40 and 90 degrees and other routine sequences. The obtained data could help to prove the effects of this sequence, compared to the other routine sequences; accordingly, it could be applied for better detection of lesions resulting from cartilage abnormalities.

 Total, 15 patients, including 9 men (14-56 y) and 6 women (36-65 y) with knee pain symptoms were referred to us by an orthopedic physician. All of the investigated patients underwent Magnetic Resonance Imaging (MRI) using DESS sequences with two flip angles of 40 and 90 degrees, as well as STIR , PD, T2, and 3D FLASH. We analyzed the acquired images using the Radiant DICOM Viewer4.6.9 software. We calculated relative contrast values for the selected SAGITAL images per sequence for each patient. The obtained data were analyzed using SPSS.

Friedman and Wilcoxon statistical tests data revealed significant P values (<0.05) for all the sequences examined in this study. The DESS sequence with a flip angle of 90° presented the most relative contrast value with the average score of 77.2667. The FLASH sequence provided the worst result of 3.733 for the relative contrast value.

 The DESS sequence with 90° flip angle indicated the best relative contrast values and provided the best possible signal from the synovial fluid and the cartilage; therefore, it leads to the better examination of articular cartilage in terms of lesion. Accordingly, the DESS sequence with a flip angle of 90° was the optimal sequence to evaluate cartilage abnormalities among the examined sequences in this study.