Non-contrast MRI of synovitis in the knee using quantitative DESS

• Published in: European radiology 2021-12, Vol.31 (12), p.9369-9379
• Main Authors: Thoenen, Jacob, Stevens, Kathryn J., Turmezei, Tom D., Chaudhari, Akshay, Watkins, Lauren E., McWalter, Emily J., Hargreaves, Brian A., Gold, Garry E., MacKay, James W., Kogan, Feliks
• Format: Article
• Language: English
• Subjects: Accuracy; Biomedical materials; Contrast agents; Contrast Media; Diagnostic Radiology; Diagnostic systems; Diffusion; Gadolinium; Humans; Image contrast; Imaging; Internal Medicine; Interventional Radiology; Knee; Knee Joint - diagnostic imaging; Magnetic Resonance Imaging; Medicine; Medicine & Public Health; Musculoskeletal; Neuroradiology; Osteoarthritis; Osteoarthritis, Knee - diagnostic imaging; Radiology; Recesses; Steady state; Synovial Membrane; Synovitis; Synovitis - diagnostic imaging; Ultrasound; Weighting
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-021-08025-2

Objectives To determine whether synovitis graded by radiologists using hybrid quantitative double-echo in steady-state (qDESS) images can be utilized as a non-contrast approach to assess synovitis in the knee, compared against the reference standard of contrast-enhanced MRI (CE-MRI). Methods Twenty-two knees (11 subjects) with moderate to severe osteoarthritis (OA) were scanned using CE-MRI, qDESS with a high diffusion weighting (qDESS High ), and qDESS with a low diffusion weighting (qDESS Low ). Four radiologists graded the overall impression of synovitis, their diagnostic confidence, and regional grading of synovitis severity at four sites (suprapatellar pouch, intercondylar notch, and medial and lateral peripatellar recesses) in the knee using a 4-point scale. Agreement between CE-MRI and qDESS, inter-rater agreement, and intra-rater agreement were assessed using a linearly weighted Gwet’s AC2. Results Good agreement was seen between CE-MRI and both qDESS Low (AC2 = 0.74) and qDESS High (AC2 = 0.66) for the overall impression of synovitis, but both qDESS sequences tended to underestimate the severity of synovitis compared to CE-MRI. Good inter-rater agreement was seen for both qDESS sequences (AC2 = 0.74 for qDESS Low , AC2 = 0.64 for qDESS High ), and good intra-rater agreement was seen for both sequences as well (qDESS Low AC2 = 0.78, qDESS High AC2 = 0.80). Diagnostic confidence was moderate to high for qDESS Low (mean = 2.36) and slightly less than moderate for qDESS High (mean = 1.86), compared to mostly high confidence for CE-MRI (mean = 2.73). Conclusions qDESS shows potential as an alternative MRI technique for assessing the severity of synovitis without the use of a gadolinium-based contrast agent. Key Points The use of the quantitative double-echo in steady-state (qDESS) sequence for synovitis assessment does not require the use of a gadolinium-based contrast agent. Preliminary results found that low diffusion-weighted qDESS (qDESS Low ) shows good agreement to contrast-enhanced MRI for characterization of the severity of synovitis, with a relative bias towards underestimation of severity. Preliminary results also found that qDESS Low shows good inter- and intra-rater agreement for the depiction of synovitis, particularly for readers experienced with the sequence.