The Study Of Bone Marrow Around The Knee Joint On MRI

Objective: To observe the feature of different age around the knee joint bone red and yellow marrow and analyze the distribution of red and yellow marrow around the knee joint on MRI T1 W I and PDWI-FS.Methods: PDWI-FS and T1 WI of the knee joint in 67 subject, male 27, female, 40. The subjects with no known bone marrow abnormalities were divided into five age groups. To observe the femoral distal metaphysis and epiphysis,tibial proximal metaphysis and epiphysis, fibula proximal metaph- ysis and epiphysis of several regional bone marrow signal intensity, With the same level of subcutaneous fat and adjacent muscle signal as the referen- ce, according to the T1 WI image classification of bone marrow signal inten- sity.Results:The signal intensity of bone marrow in distal femoral meta- physis and tibia and fibula proximal metaphysis were grades 0-1and the signal intensity of bone marrow in epiphysis was grades 3 in group A.In group B,the signal intensity of bone marrow in distal femoral metaphysis was grades 1-3,including 3 cases of grade 3, for the rest of 1~2;The signal intensity of bone marrow in tibia and fibula proximal metaphysis were grades 2-3, including 6 cases of grade 3, for the rest of 2; the signal intensity of bone marrow in epiphysis was grades 3-4. In group C,the signal intensity of bone marrow in distal femoral metaphysis was grades 1-3,including 3 cases of grade 3 and 2 cases of grade 1, The signal intensity of bone marrow in tibia and fibula proximal metaphysis were grades 2-4.In group D,the signal intensity of bone marrow in distal femoral metaphysis and tibia and fibula proximal metaphysis were grades 3-4, 3and4 level signal ratio is about 1/1;In group E,the signal intensity of bone marrow in distal femor- al metaphysis and tibia and fibula proximal metaphysis were grades 3-4, the signal intensity of bone marrow in epiphysis was grades 3-4.Patellar ossification centers appear in 2 to 5 years old,the signal intensity of bone marrow in patellar was grades 3-4.Conclusions:1 The distal femoral metaphysis appear yellow marrow began in 6 to 10 years of age,11 to 15 years for the bone marrow into the significant period of time, 16 to 20 years of age most subjects red bone marrow into yellow bone marrow,21 to 25 years of age to complete the transformation to the yellow bo- ne marrow.2 The proximal tibial metaphysis in 5 years ago are red bone marrow, in 6to 10 years of age began to transform to the Yellow bone marrow, converse- on start time than the distal femoral metaphysis of about 1~2ears earlier, began to transformation of the completion of 16 to 20 years old, converted the emergence time of distal femoral metaphysis than early about 1~2years of age. 21 years later the bone marrow is basically uniform yellow bone marr- ow signal.3 Fibula proximal metaphyseal marrow conversion and proximal tibial metaphyseal marrow conversion are basically the same.4 Proximal fibular epiphysis appears time between 2 to 5 years old, after yellow marrow mainly; around the knee epiphyseal bone marrow are mai-nly yellow bone marrow.5 In this study, 1 cases of proximal tibial metaphysis yellow bone marrow within the residual red bone marrow island.