T2 mapping of articular cartilage in the healthy knee using a magnetic resonance segmentation / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate T2 mapping of the healthy knee articular cartilage in different subregions using a magnetic resonance segmentation.</p><p><b>METHODS</b>T2 mapping was performed to 77 healthy tibiofemoral cartilages, which were divided into group H1 ( <40 years old) and group H2 (≥ 40 years old). T2 values of cartilage IN 10 subregions based on the Whole-Organ Magnetic Resonance Imaging Score (WORMS) segmentation and body mass index (BMI) were calculated. T2 values of cartilage in 10 subregions were compared. The association between T2 value and BMI/age was analyzed. The intra- and inter-observer reproducibility of measurement was calculated.</p><p><b>RESULTS</b>The T2 values of all the subregions ranged 40. 3-53.5 ms. T2 values of group H2 were significantly higher than those in group H1 (P ≤ 0.032) except in posterior lateral femoral subregion. The inter-subregion differences within group were significant (P ≤ 0.001). The inter-gender differences were significant only in posterior medial tibial subregion of group H2 (P=0.048). No correlation of T2 values with BMI was found except in cetral lateral tibial subregion of group H2 (P=0.050, R=0.308). T2 values were correlated with age in anterior medial (P=0.004, R=-0.467) and anterior lateral P = 0.024, R=-0.375) tibial subregion of group H1 , and in all tibial subregion except anterior lateral tibial subregion of group H2 , and central medial femoral subregion of group H2 (P=0.004~0.015, R=0.376~0.437). The correlation coefficients for intra- and inter-observer of measurement showed good reproducibility (R>0.809, P ≤ 0.005).</p><p><b>CONCLUSION</b>T2 mapping of the healthy knee articular cartilage based on the WORMS segmentation can effectively reflect the changes and correlations of T2 values with risk factors by focusing on the functional weight-bearing subregions.</p>

T2 mapping of articular cartilage in knee osteoarthritis using a magnetic resonance staging / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate T2 mapping of articular cartilage in knee osteoarthritis (OA).</p><p><b>METHODS</b>Totally 38 healthy subjects (group H) and 53 OA patients received scoring with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)and underwent T2 mapping of tibiofemoral articular cartilages. The T2 values in 10 subregions of the cartilages were measured. Patients in the OA group were further divided into OA1 group and OA2 group using the modified Magnetic Resonance Recht Grading System. In OA group, the fat-suppressed three-dimensional fast spoiled gradient echo MRI was performed to obtain the modified Whole-Organ Magnetic Resonance Imaging Score (WORMS). The differences of T2 values among group H, group OA1, and group OA2 were compared. The correlation between T2 value and WORMS/WOMAC scores was analyzed. The intra- and inter-observer reproducibility of measurement was calculated.</p><p><b>RESULTS</b>The T2 values in all the subregions ranged 43.9-53.6ms in group H, 41.1-55.0 ms in group OA1, and 45.6-56.1ms in group OA2. T2 values in group OA2 were significantly higher in central medial femoral subregion, central medial, and lateral tibial subregions compared with group H, also significantly higher in central medial femoral subregion, anterior and central medial tibial subregions compared with group OA1 (P<0.05). T2 values were significantly correlated with WORMS scores (R=0.307-0.811, P<0.01) except in posterior lateral femoral subregion, but not with WOMAC scores. The correlation coefficients for intra- and inter-observer measurement showed good reproducibility (R>0.740, P<0.05) except in anterior lateral tibial subregion for inter-observer of measurement.</p><p><b>CONCLUSION</b>T2 mapping can differentiate the OA severity of knee cartilage using a magnetic resonance staging, and therefore can be a sensitive technique for monitoring the severity of OA.</p>