Quantitative MRI Musculoskeletal Techniques: An Update.

OBJECTIVE. For many years, MRI of the musculoskeletal system has relied mostly on conventional sequences with qualitative analysis. More recently, using quantitative MRI applications to complement qualitative imaging has gained increasing interest in the MRI community, providing more detailed physiologic or anatomic information. CONCLUSION. In this article, we review the current state of quantitative MRI, technical and software advances, and the most relevant clinical and research musculoskeletal applications of quantitative MRI

A unique anisotropic R2 of collagen degeneration (ARCADE) mapping as an efficient alternative to composite relaxation metric (R2â R1Ï ) in human knee cartilage study

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148373/1/mrm27621.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148373/2/mrm27621_am.pd

An order parameter without magic angle effect (OPTIMA) derived from R1ρ dispersion in ordered tissue

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153626/1/mrm28045.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153626/2/mrm28045_am.pd

The effect of glucosamine, chondroitin and harpagophytum procumbens on femoral hyaline cartilage thickness in patients with knee osteoarthritis– An MRI versus ultrasonography study

Background: the evaluation of cartilage thickness has become possible with new techniques such as musculoskeletal ultrasonography (US) and magnetic resonance imagining (MRI), making the evaluation of the treatment response and the progression of the disease more accurate. Objective: to evaluate the efficacy of a Symptomatic Slow Acting Drug for Osteoarthritis using both US and MRI for measuring cartilage thickness at baseline and after 1 year. Methods: The study included the clinical evaluation of 20 patients at baseline, at 6 and 12 months as well as imaging exams (US and MRI) at baseline and after 1 year. Measurements were performed in both knees, in lateral and medial condyles, and in the intercondylar area. After the baseline visit, patients underwent a SYSADOA treatment which included Harpagophytum procumbens (HPc) administered on a daily basis, in a specific regimen. Results and discussions: The US examination permitted the detailed evaluation of the femoral hyaline cartilage thickness, with statistically significant differences before and after treatment at the level of the medial compartment, both in the dominant (1.59±0.49 vs. 1.68±0.49, p=0.0013) and non-dominant knee (1.73±0.53 vs. 1.79±0.52, p=0.0106). The US and the MRI correlated well (r=0.63) and showed no radiographic progression in knee osteoarthritis after one year of treatment with specific SYSADOA. Moreover, the US showed improvement in the cartilage thickness of the medial compartment. Conclusions: The combination with HPc could increase the delay in the radiographic progression of the knee osteoarthritis, with improvement of femoral hyaline cartilage thickness in the medial and lateral compartment. The US might be an important tool in OA evaluation and monitoring

Low-field and variable-field NMR relaxation studies of H2O and D2O molecular dynamics in articular cartilage

Osteoarthritis (OA) as the main degenerative disease of articular cartilage in joints is accompanied by structural and compositional changes in the tissue. Degeneration is a consequence of a reduction of the amount of macromolecules, the so-called proteoglycans, and of a corresponding increase in water content, both leading to structural weakening of cartilage. NMR investigations of cartilage generally address only the relaxation properties of water. In this study, two-dimensional (T1-T2) measurements of bovine articular cartilage samples were carried out for different stages of hydration, complemented by molecular exchange with D2O and treatment by trypsin which simulates degeneration by OA. Two signal components were identified in all measurements, characterized by very different T2 which suggests liquid-like and solid-like dynamics. These measurements allow the quantification of separate hydrogen components and their assignment to defined physical pools which had been discussed repeatedly in the literature, i.e. bulk-like water and a combination of protein hydrogens and strongly bound water. The first determination of 2H relaxation dispersion in comparison to 1H dispersion suggests intramolecular interactions as the dominating source for the pronounced magnetic field dependence of the longitudinal relaxation time T1

Fourier-transform infrared anisotropy in cross and parallel sections of tendon and articular cartilage

<p>Abstract</p> <p>Background</p> <p>Fourier Transform Infrared Imaging (FTIRI) is used to investigate the amide anisotropies at different surfaces of a three-dimensional cartilage or tendon block. With the change in the polarization state of the incident infrared light, the resulting anisotropic behavior of the tissue structure is described here.</p> <p>Methods</p> <p>Thin sections (6 μm thick) were obtained from three different surfaces of the canine tissue blocks and imaged at 6.25 μm pixel resolution. For each section, infrared imaging experiments were repeated thirteen times with the identical parameters except a 15° increment of the analyzer's angle in the 0° – 180° angular space. The anisotropies of amide I and amide II components were studied in order to probe the orientation of the collagen fibrils at different tissue surfaces.</p> <p>Results</p> <p>For tendon, the anisotropy of amide I and amide II components in parallel sections is comparable to that of regular sections; and tendon's cross sections show distinct, but weak anisotropic behavior for both the amide components. For articular cartilage, parallel sections in the superficial zone have the expected infrared anisotropy that is consistent with that of regular sections. The parallel sections in the radial zone, however, have a nearly isotropic amide II absorption and a distinct amide I anisotropy.</p> <p>Conclusion</p> <p>From the inconsistency in amide anisotropy between superficial to radial zone in parallel section results, a schematic model is used to explain the origins of these amide anisotropies in cartilage and tendon.</p