Saleh Ahmed Alammari , Moath Ibrahim Alzapni , Zaid Awad Alshammari , Rashed Raja Alshammari , Mohammad Abdulaziz Altraifi , Abdulrahman Fahad Alluhaybi , Abdulaziz Sorour Sorour
To assess human articular cartilage tissue functionality by serial multi parametric quantitative MRI (qMRI) mapping as a function of histological degeneration. Forty-nine cartilage samples obtained during total knee replacement surgeries were placed in a standardized artificial knee joint within an MRI-compatible compressive loading device and imaged in situ and at three loading positions, i.e. unloaded, at 2.5 mm displacement (20% body weight [BW]) and at 5 mm displacement (110% BW). Using a clinical 3.0 T MRI system serial T1, T1ρ, T2 and T2* maps were generated for each sample and loading position. Histology (Mankin scoring) and biomechanics (Young’s modulus) served as references. Samples were dichotomized as intact (int, n = 27) or early degenerative (deg, n = 22) based on histology and analyzed using repeated-measures ANOVA and unpaired Student’s t-tests after log-transformation. For T1ρ, T2 and T2*, significant loading-induced differences were found in deg (in contrast to int) samples, while for T1 significant decreases in all zones were observed, irrespective of degeneration. In conclusion, cartilage functionality may be visualized using serial qMRI parameter mapping and the response-to-loading patterns are associated with histological degeneration. Hence, loading-induced changes in qMRI parameter maps provide promising surrogate parameters of tissue functionality and status in health and disease. Synthetic MRI is able to simultaneously acquire conventional images and quantitative maps, and has the potential to reduce the overall examination time. It provides comparable image quality to conventional MRI for the knee joint, with the exception of the bone marrow. With further optimization, it will be possible to take advantage of the image quality of musculoskeletal tissue with synthetic imaging. Synthetic MRI produces images of good contrast and is also a time-saving technique. Thus, it may be useful for assessing osteoarthritis in the knee joint in the early stages.Advantages of using 3.0 T: 3.0 T imaging is of interest to the system thanks to the inflated man signal and better SNR. SNR and Relaxation Time Considerations: While it seems that 3.0 T imaging ought to give double the intrinsic SNR of imaging at 1.5 T, changes in each T1 associate degreed T2 relaxation times together with the dearth of optimized coils ends up in an SNR improvement of slightly but double. Technical Considerations: Technical concerns should be accounted for so as to optimize 3.0 T imaging. Protocols: Protocols are developed at 3.0 T tomography that show promising results for assessment of the knee. Future direction: (1) Isotropic Imaging: Isotropic or 3-dimensional (3D) imaging techniques leave the acquisition of identical voxels as opposition the usually non-heritable eolotropic voxels with 2-dimensional (2D) imaging. (2) UTE imaging: Human tissues contain many elements that have a large vary of T2 values. (3) T2 Mapping: T2 relaxation times for a precise tissue square measure usually constant, tissue pathology may end up in changes in these relaxation times. (4) T1rho Imaging: T1rho imaging, or spin lattice relaxation within the rotating frame, is feasible once the magnetization is “spin-locked” by a continuing RF field once being tipped into the crosswise plane. (5) Sodium: Sodium imaging, like T1rho imaging, has shown promise in mensuration proteoglycan content as a marker of early, symptomless OA. Keywords: MRI, SNR, Bone Marrow, Directions, Diagnostic Tool, QMRI, Osteoarthritis Initiative.