To Measure The Articular Cartilage Thickness Using 0.3T MRI In The Normal Ankle Joint

Objective:To investigate the feasibility of using low field magnetic resonance to measure the thickness of ankle joint cartilage, the relationship between the thickness of the cartilage and age, gender, weight and height were analyzed at the same time.Methods:160 healthy volunteers with normal left ankles were chosen and divided into 8 groups, and each group contains 20 volunteers according to their age,according to body mass index is divided into normal group and the overweight. All normal ankles were scanned through sagittal and coronal plane with SE-T1 WI and WF-T1 WI sequences. We chose 5 measurement from the surface of the cartilage to the subchondral to take the average.Results:The distribution of the thickness of cartilage is nonuniformity. The average thickness of cartilage measured from the lateral malleolus is 1.82 mm, and from the front, middle and rear were as follows: 1.84 mm 1.82 mm 1.81 mm, and the front in average is more than the rear. The average thickness in male is more in female,(1.81±0.30)mm and(1.79±0.25)mm respectively. The cartilage thickness of the overweight is(1.94 ± 0.29) mm, the normal is(2.25 ± 0.29) mm, P> 0.05, the difference was not statistically significant.The thickness of ankle joint was negatively related to age, weight and height before 15 years old(r=-0.889 p=0)if the height is less than 140cm(r=-0.436 p=0.03)and the weight is less than 45kg(r=-0.656 p=0). However, there was no obvious relationship between them after 15 years old(r=0.12 p=0.285)if the height is more than 140cm(r=-0.227 p=0.028)and the height is more than 45kg(r=-0.037 p=0.735).Conclusion:The distribution of the thickness of talar cartilage from normal ankle joint is nonuniformity. The thickness in male is more than in female, and it is negatively related to age, weight and height before 15 years old and there is no linear correlation after 15.