Comparison of accelerated MRI protocol approaches for clinical assessment of the knee

To evaluate the diagnostic performance and image quality of four accelerated knee MRI protocols (~ 6 minutes) compared with a conventional 2D fast spin echo (FSE) protocol (12-15 minutes).

In this prospective single-center study, 32 adults with knee pain and/or self-reported osteoarthritis underwent 3T MRI using five protocols: conventional 2D FSE, 2D FSE with deep learning (DL) reconstruction, 3D Cube, 3D quantitative double-echo steady-state (qDESS), and thin-slice 2D FSE. Five radiologists independently evaluated joint pathologies. Interreader and intermethod agreement (Gwet's AC1), positive and negative percent agreement (PPA and NPA), and diagnostic image quality (Likert scale; Friedman test, p < 0.05) were assessed.

Overall, 12/160 protocol scans were excluded due to motion artifacts. Interreader agreement was similar across protocols but varied by tissues. Intermethod agreement between accelerated protocols and the conventional protocol approached the repeatability of the conventional protocol. NPA remained consistently high across tissues and protocols. PPA was more variable, particularly for synovitis and effusion, whereas for bone marrow, cartilage, and meniscus, PPA for the DL, Cube, and qDESS protocols approached the repeatability of the reference protocol. For all accelerated protocols except the thin-slice approach, diagnostic image quality was diagnostically acceptable or better in > 94% of examinations.

Accelerated 2D DL, 3D Cube, and 3D qDESS protocols demonstrated diagnostic agreement and diagnostic image quality comparable to the conventional knee MRI protocol while reducing scan time to ~ 6 min. These approaches may serve as practical alternatives to conventional protocols, with potential benefits for clinical workflow and patient experience.