gms | German Medical Science

Objectives: To quantitatively determine whether T1rho and T2 mapping MRI can measure the cartilage matrix and morphology in osteonecrosis of femoral head (ONFH), and assess bone marrow edema of differ over time in patients around femoral head collapse in T2WI fs traditional MRI, and relationship of both.

Methods: We performed a case-control study, in which 53 ONFH subjects (68 hips), identified as Association of Research Circulation Osseous (ARCO) I-III, scheduled to undergo cartilage detecting. 51 matched control subjects (68 hips) were scheduled for testing. The ARCO stage III was divided into early group (crescent sign) and late group (collapse). Scanning sequence including conventional sequence and T1rho, T2 mapping as well as T2WI fs. The degree of bone marrow edema around collapse was graded 0 to 3. The correlation was explored between degeneration of articular cartilage around collapse phase and the severity of bone marrow edema.

Results and Conclusion: The values of T1 rho (57.07±10.33, P <0.01) and T2mapping (28.25±7.41, P <0.01) in ARCO stage III patients were significantly higher than those in ARCO stage I (37.81± 6.45, 21.52±8.03 (r=0.37, P<0.01) and stage II (42.21±7.67, 21.32±8.33, P<0.01). The value of T1rho and T2 mapping increased with the high ARCO stage (r=0.37, P<0.05). Bone marrow edema of the femoral head is present only in ARCO III patients. (r= 0.27, P< 0.05). At the end of stage III, the changes of T1rho and T2 mapping values were not correlated with the changes of bone marrow edema (r=0.18, P > 0.05). T1MRT and T2 mapping showed quantitative diagnosis advantage of articular cartilage degeneration of ONFH. The occurrence of bone marrow edema can be considered that ONFH has reached ARCO III stage. during the femoral head collapse, the degeneration of the hip cartilage is positive correlated with the severity of bone marrow edema expanding.