Cartilage imaging: motivation, techniques, current and future significance

Abstract

Cartilage repair techniques and pharmacological therapies are currently areas of major clinical interest and research, in particular to prevent and treat osteoarthritis. MR imaging-based techniques to visualize cartilage are prerequisites to guide and monitor these therapies. In this review article, standard MR imaging sequences are described, including proton density-weighted fast spin echo, spoiled gradient echo and dual echo steady state sequences. In addition, new sequences that have been developed and are currently being investigated are presented, including driven equilibrium Fourier transform and steady-state free precession-based imaging. Using high-field MR imaging at 3.0-T, visualization of cartilage and the related pathology has been improved. Volumetric quantitative cartilage MR imaging was developed as a tool to monitor the progression of osteoarthritis and to evaluate new pharmacological cartilage protective therapies. The most exciting developments, however, are in the field of cartilage matrix assessment with quantitative dGEMRIC, T2 and T1rho mapping techniques. These techniques aim at detecting cartilage damage at a stage when changes are potentially still reversible, before cartilage tissue is lost. There is currently substantial interest in these techniques from rheumatologists and orthopedists; radiologists therefore need to keep up with these developments.

Diagnostic performance of in vivo 3-T MRI for articular cartilage abnormalities in human osteoarthritic knees using histology as standard of reference

“…In SPGR images, cartilage is only bright, and signal abnormalities are generally not observed, whereas iw FSE sequences do demonstrate changes in cartilage signal, believed to be caused by increased intracartilaginous water content as a result of loss of proteoglycans in OA [36], which, however, is not supported by the findings of our study. Further, SPGR imaging does not provide cartilagefluid contrast, lowering its ability to delineate small cartilage defects and surface lesions as compared to FSE imaging; in a study by McGibbon et al [27], for example, SPGR imaging at 1.5 T significantly under-predicted the actual depth of defects in cartilage, when compared to histology.…”

Direct magnetic resonance arthrography of the wrist with axial traction: A feasibility study to assess joint cartilage

“…This is particularly true at the wrist, where, even at 3 T, conventional MRI inaccurately evaluates the articular cartilage, partly due to the thinness of these surfaces (6). The advent of new therapeutic modalities generates growing interest in cartilage imaging (15). However, although some dedicated MR sequences are currently available, cartilage matrix changes depicted by dGEMRIC, T1-rho, and T2 relaxation time mapping are not yet feasible in daily routine.…”

Noninvasive Quantification of Human Nucleus Pulposus Pressure with Use of T1ρ-Weighted Magnetic Resonance Imaging

“…Other techniques, including delayed gadoliniumenhanced and sodium magnetic resonance imaging, may have sufficient sensitivity but there are also substantial limitations with regard to implementation of these methods [9][10][11] . T1r-weighted imaging is a spin-lock magnetic resonance imaging technique that shows promise as a noninvasive biomarker, as several in vivo studies have demonstrated the clinical feasibility of evaluating both intervertebral disc and articular cartilage with this modality [12][13][14][15] . The spin-lock technique was first employed by Redfield in 1955 and allows for a lower Larmor frequency 16 .…”