Assessment Cartilage Damage Using MRI T2 Mapping And ~1H-MRS In Synovial Fluid

PURPOSE:In our study, we used the T2 mapping and 2D-'H MR Spectroscopy to quantitative assessment the T2 relaxation time of cartilage and proteoglycan concentration in synovial fluid in patients who had meniscus damage (Ⅰ-Ⅱ°) We will attempt to explore these two technology has possibility to evaluate the injured degree of articular cartilage.MATERIALS AND METHODS:Ten healthy volunteers (five female and five male, age range 24-30 years mean age is 27 years,), and fifteen patients withⅠ°-Ⅱ°degree meniscal damage(nine male and six female, age range 20-45 years, mean age is 33 years, who did not showed bone fracture or bone marrow edema-like lesion (BMEL) were recruited for this study. All these subjects were scanned with 1.5T MRI. T2 mapping was performed to calculate the cartilage T2 value by using FuncTool software.2D multi-voxels'H MR spectroscopy imaging (MRSI) was acquired to test metabolic changes in synovial fluid, and the concentration of the metabolites was expressed by peak area by using SAGE software. All the data were analyzed SPSS 13.0 software(the way of independent-samples T test, two-tailed, a=0.05).RESULTS:T2 values of articular cartilage were 39.79-47.26 ms in experimental group, with an average of 43.51±2.43 ms. In T2 mapping, the cartilage not only had smooth surface and completed continuity, but also there were uniform signal in all region. The color of cartilage showed red or orange. But for control group, T2 values were 30.47-40.7 ms, with an average of 35.73±3.11 ms. the cartilage still showed smooth surface and completed continuity, but there were heterogeneous signal intensity in some region. The color of cartilage showed green or blue. There was a significant difference between OA and control group(p<0.01). In addition, Multi-volex MR spectroscopy performed in knees was available. Concentrations of proteoglycans in synovial fluid were 3115.06±76.16 in experimental group and 2855.15±128.06 in control group. There was a significant difference between these two groups. (p<0.01) CONCLUSION:The mean cartilage T2 values were greater in patients than in controls, indicating that the T2 values in injured cartilage are not only elevated, but also more heterogeneous than those in healthy cartilage. The T2 mapping indicated that it could show the composition change before the cartilage had morphological changes. T2 mapping was beneficial for diagnosis disease, tracking disease progression and guiding clinical treatment. Concentrations of proteoglycans in the synovial fluid were significant higher patients group than in control group. Multi-volex MR spectroscopy of synovial fluid is feasible in vivo, being capable of providing quantitative assessment of cartilage damage degree, as well as T2 mapping quantification. Not only was the MRS easy to operate and it took no more than one day to obtain the result, but also it had high repeatability to refelect the dynamic changes of the metabolites. Basing on these methods, we could master the patient's any change and therapeutic effect in time.