抄録
Retrospective magnetic resonance imaging (MRI) study was done for 11 hips of seven children with dysplasia epiphysealis capitis femoris (DECF) to evaluate the signal intensity of the each epiphysis. The mean age at the time of first presentation was 2 years and 5 months (range 1 year to 3 years and 5 months). Two hips in which the epiphysis had not appeared on the radiographs showed a rounded and low signal intensity area in the cartilaginous head on T1-weighted and T2-weighted MRI. Five hips that had granular structures in the epiphysis on the radiographs. All of these epiphysis showed low signal intensity on T1-weighted MRI. Three of them showed both intermediate and high sigial intensities on T2-weighted MRI. One of the remaining two epiphysis showed low signal intensity and the other showed intermediate signal intensity on T2-weighted MRI. The surfaces of four epiphysis were irregular on the radiographs and their T1-and T2-weighted MRI showed high intentity areas. Judging from combination of the T1-and T2-weighted MRI there were no necrotic findings in these cases of DECF. Signal intensities of these epiphysis were the same as those of growing femoral epiphysis, but they appeared to be delayed for their age. Eleven hips were followed-up, 4 were bilateral, and 3 were unilateral. One of the 11 hips had MRI at 14 month intervals (twice), and 1 hip had MRI at 5 month intervals (3 times). Signal intensity of the epiphysis had changed from low intensity to high intensity according to the growth on the T1-and T2-weighted MRI during the follow-up. Based on our MRI findings, the one of the causes of DECF appeared to be the immaturity of the femoral epiphysis.
