Correlation Of MRI T2-star Mapping And The Expression Of ?-glutamyl Carboxylase In Degenerative Knee Cartilage

Objective: This work will be focus on the correlation between the T2-star-mapping magnetic resonance imaging(MRI) of knee cartilage degeneration and GGCX concentration of cartilage.Methods: Clinical cases were selected from the People's Hospital of Ningxia Hui Autonomous Region since June 2013 to June 2015. The knee cartilages were donated by the 63 voluntary patients, during to primary osteoarthritis, whose knees were replacement with artificial knees by arthroplasty or joint debridement. Both the keen of normal control volunteers and OA patients were being scanned by simens 3.0T magnetic resonance and X ray. Those samples were staining by Green-Safranin O and histological observation by group. For all interesting tissues, were cut all the full-thickness cartilage and a small amount of subchondral bone to use for histological and immunohistochemical inspection, Western blot and RT-PCR detectionResults: 1. All the samples have been successfully stained, and then five different fields of the cartilage tissue structure randomly selected by light microscope, and then graded according to the modified Mankin score. Mankin score of normal control group with 11 cases was 0.579�0.262; 13 cases of mild degeneration with2.871�0.627 Mankin score; moderate degeneration of 22 cases, Mankin score was6.152�0.923; and severe degeneration of 28 cases, Mankin score of13.182�0.652, the difference between the groups with Mankin score was statistically significant(P <0.05). 2. The average T2* values of Mild OA group, moderate group and severe OA group are significantly increased compared with the normal control group, the difference was statistically significant(P <0.01). Along with the development of OA knee cartilage degeneration levels, T2* values with articular cartilage aggravated, corresponding T2* value will be increased, the difference was statistically significant(P <0.05). 3. Using immunohistochemistry, Western blot and RT-PCR to detect the expression level of chondrocytes GGCX, and we known that it will gradually reduce with the increasing degree of cartilage degradation. 4. GGCX protein activity detected by immunohistochemistry and relative gray value of GGCX shown by Western blot, those were significantly negative correlation with T2* values. The higher T2* value, the lower GGCX activity and the lower GGCX relative gray value.Conclusions: 1. T2* values of cartilage degeneration and Mankin histological grade are correspondence, with the increasing of cartilage degeneration Mankin histological grade, the corresponding T2* value is gradually increased, there were significant statistical difference between different levels. 2. The expression of GGCX in primary osteoarthritis of the knee cartilage is lower than normal cartilage, and the more severe cartilage degeneration, the lower GGCX expression, and also related with the T2* values in the region. 3. Closely related between T2-star-mapping nuclear magnetic resonance imaging and GGCX content. Conjugating the quantitative analysis of knee cartilage degeneration by T2-star-mapping MRI imaging and the detection of GGCX will improve the accuracy of osteoarthritis diagnosis.