Spatial Variation of T2 Values of Knee Joint Cartilage in Healthy Adults with .5T MR System / 实用放射学杂志

ABSTRACT

Objective To study the spatial variation of T2 relaxation time of cartilage of knee in healthy adults.Methods T2 values of cartilage of knee in 21 asymptomatic young male adults ( age ranged 24 to 39 years ; mean age , 30 years) were calculated by using a multiecho,spin-echo MR imaging sequence at 1.5T MR scanner on sagittal T2 maps,including the patellar,distal femoral weight and non-weight-bearing as well as proximal tibial weight-bearing cartilages,the differences in the spatial variation between them were analysed using F test.Results All 21 asymptomatic volunteers demonstrated a consistent pattern of spatial variation of T2 values cartilage of knee with longer T2 values near the subchondral bone,decreased in deep zoon and increased in articular surface , there was difference between them (F=70.892 , P＜0.05 ) . The greates spatial variation occurred in the patella.T2 value(26.56 ms±4.4 ms) in the deeper zoon of cartilage of the patella was obviously lower than that of the weight-and non-weight-bearing articular cartilage (P = 0.001 ) . Lateral femoral weight-bearing articular cartilage showed lower T2 value ( 35.2 ms ± 6.31 ms) in the outer transitional superficial zone than thatof the patella and non-weight-bearing cartilage,P=0.002,P=0.000 respectively.Lateral tibial weight-bearing articular cartilage showed showed lower T2 value(37.11 ms±6.6 ms)in the outer transitional superficial zone than that of non-weight-bearing cartilage(P=0.000). Conclusion The spatial variation of T2 relaxation time of cartilage of knee in the vivo in the asymptomatic young adults is like slightly concave curve at 1.5T MR system,that is of reference value in study of degenerative osteoarthritis.