Imaging of cartilage, meniscus, and beyond: Role of Magnetic Resonance Imaging (MRI) and Computed Tomography (CT).

Magnetic Resonance Imaging (MRI) remains the reference standard for imaging cartilage and meniscus, offering superior soft tissue contrast essential for comprehensive joint assessment in osteoarthritis (OA). However, recent technological advancements in Computed Tomography (CT)-spectral imaging, and weight-bearing scanners-have sparked renewed interest in utilizing CT, and CT arthrography in the evaluation of OA. This narrative mini-review explores the strengths and limitations of both MRI and CT in imaging cartilage and meniscus, and presents some trends in the research setting. MRI remains the modality of choice for joint imaging, offering excellent soft tissue contrast and comprehensive articular assessment. CT is the reference for the assessment of mineralized tissue imaging, and in association with arthrography (CT arthrography, CTA), provides high performance in the diagnosis of surface lesions. In the research setting, efforts have focused on the acceleration of MRI acquisitions, with deep learning reconstructions disrupting the traditional trade-off between acquisition speed and image quality. Efforts are undertaken to standardize compositional MRI techniques, which probe early-stage biochemical tissular changes. Emerging techniques such as synthetic imaging may offer the ability to provide information on bone and soft tissues in a single acquisition. Weight-bearing acquisitions have allowed the assessment of joint structures, in particular menisci, in a loaded position. Photon-counting CT promises higher resolution, improved material separation without increasing radiation exposure. Finally, post-processing tools are being developed to leverage large quantities of data and integrate both modalities in a complementary framework that could provide a robust toolset for the assessment of OA.