Experimental And Clinical MRI Study On Femoral Head Necrosis In Childhood

Purpose:1. Make the animal model with microembolism through the right immature rabbit's iliac artery or femoral artery which was close to femoral artery,observe the signs of the pathology,X-ray and MRI. 2.To evaluate the value of MRI in early diagnosis,stage, predicting the amount of eventual necrosis through 40 pediatric patients with avascu lar necrosis of the femoral capital epiphysis,who had consecutive examination of MRI and X- ray. Materal and methods:1. The 10 imma lure rabbits weighted 1.5-1.6kg, regardless of sex.the microembosms were injected in the right outer iliac artery or femoral artery which was close to femoral artery with YY 0028- 98 injection needle,the diameter of the microembolisms is 1 SOum,all the operations were done under the digital X-ray machine.each two rabbits were killed for pathological examination after operation on 1,2,3,4 and 5 month. 2.we studied 48 hips in 40 patients with femoral capital epiphyseal necrosis,there were 34 boys and 6 girls,the average age was 8.2 years,ranged from 4 to 15 years,all cases were confirmed by clinical symptoms and radiographs eventually. MRJ was performed on a 0.5T Gyroscan T5- II machine, examinations included TSE series(T1WI TRITE=560/1 5-3Oms,Turbo factor~4;T2WI TRITE=1 500/1 OOms, Turbo factor~19) on coronal and transverse planes, thick slices were Smm,the slice intergaps were 0.Smm;TSE series (T1WI TR/TE=450/lSms, Turbo factor=4)on sagittal planes, thick slices were 5 mm, the slice intergaps were 0.Smm;STIR series (TR/TE=2100/lSOms, TJ=l2Oms) on coronal planes with 6mm thickness and 0.6mm slice intergap.The acquisition matrix was III 256* 512 with a field of view 28-32cm.Radiographs were of standard antero post views,obtained from a supine,patella-forward position of legs and frog-position lateral views. Results: 1.By the microembolism can make a rabbit model of femoral epiphyseal necrosis,6 rabbits had the signs of femoral epiphyseal necrosis. there are pathological signs in early time. More longer the time,more prominent the signs in MRI and radiography. 2.MRI can correctly and clearly show the necrosis of femoral epiphy sis,cartage and effusion ofjoint, stage with the extent of necrosis,in the early stage the extent of the subchondral fracture line can accurately predict the amount of necrosis,so MRI was not only the way of early diagnosis, therapy monitor of this disease,but also the important tool of predicting.