Diagnostic value of Zero Echo Time (ZTE) MRI pulse sequence in evaluation of osseous and cartilage changes in osteoarthritis of the knee joint, Is it significant?

Abstract Background Accurate evaluation of cartilage and bony changes in knee joints increases the diagnostic accuracy of osteoarthritis, the new CT-like image Zero Echo Time (ZTE) MRI pulse sequence can depict both cartilage and osseous abnormalities in addition to cartilage–bone interface changes, our study aimed to compare the diagnostic performance of the new MRI sequence ZTE with the widely used proton density with fat suppression (PD-FS) sequence in depiction and evaluation of cartilage and osseous osteoarthritic changes in the knee joint by using arthroscopy as reference standard. Methods Fifty-five adult patients were enrolled in this study. They did MRI examination for knee joints and then underwent knee arthroscopy within 3–7 days later, MRI was done using ZTE sequence and other routinely used MRI sequences including PD-FS sequence, and MR images were evaluated by two radiologists separately for detection and evaluation of cartilage and bony changes in the knee joint, then comparison between of (PD-FS) and (ZTE) sequences was done using arthroscopy as a reference standard. Both readers calculated sensitivity, specificity, and accuracy for each sequence. Results Sensitivity, specificity, and accuracy of ZTE sequence were higher than those of PD-FS sequence for the depiction and characterization of bony abnormalities, for reader 1 (sensitivity: 91.5% vs. 87.2%; specificity: 89.4% vs. 86.2%; and accuracy 92.2% vs. 88.6%) and reader 2 (sensitivity: 92.3% vs. 85.9%; specificity: 90.7% vs. 87.2%; and accuracy 93.8% vs. 86.1%). While sensitivity, specificity, and accuracy of ZTE sequence were lower than those of PD-FS sequence for the depiction and characterization of cartilage changes, for reader 1 (sensitivity: 91.2% vs. 93.5%; specificity: 89.3% vs. 91.2%; and accuracy 88.2% vs. 90.3%) and reader 2 (sensitivity: 90.3% vs. 92.9%; specificity: 91.7% vs. 93.2%; and accuracy 87.8% vs. 89.1%). Conclusion Using arthroscopy as the reference standard, the ZTE MRI pulse sequence of the knee joint, with its CT-like image, showed better diagnostic performance than the routine PD-FS sequence in depicting and evaluating osseous abnormalities in knee osteoarthritis.