The Value Of MR Imaging In Early Diagnosis Of Osteonecrosis Of The Femoral Head In Patients On Steroid Treatment

Purpose:To discuss the role of different MRI technology in early diagnosis of Osteonecrosis of the Femoral Head in Patients on Steroid Treatment. The author attempts to appraise the relationship between the osteonecrosis of the femoral head and the usage of steroid, and the relationship between the osteonecrosis of the knee joint and the usage of steroid, we use the conventional sequence, which consists of T2WI/TSE, SPAIR/PDW on coronal view, and SPAIR/T2WI,3D/WATS on axial view and the blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) to detect the usage of steroid in the patients who suffer from the osteonecrosis of the femoral head and the knee joint. We observe the total amount of steroid and the maximum dose of steroid on odd-numberd days, and the accumulative time of the maximum dose of steroid above5mg/kg to determine the usage of the steroid.Objects and methods:①The study population consists of10patients on steroid treatment from March2012to March2014at the MRI room of the armed police logistics college affiliated hospital who suffered Osteonecrosis of the Femoral Head on early stage. All patients undergo the conventional sequence of MRI, which consists of T2WI/TSE, SPAIR/PDW on coronal view, and SPAIR/T2W、3D/WATS on axial view.quantitative analysis of the signal-to-noise ratio(SNR=SI/SD) of the image, contrast to noise ratio(H-M CNR=[SS-SI]/SD) of the head of femur and muscles and contrast to noise ratio(CNR=[SH-SI]/SD).②In the present study, there are20hip joint scanned.We use the conventional MRI and BOLD, which using8EPI sequence(The range of TE was9.21/18.42/27.63/36.84/46.05/55.26/64.47/73.68ms), to compare the hip joint between the10patients with Osteonecrosis of the Femoral Head as above and the hip joint of10healthy control. In this section, we evaluated six parameters, analyzed morphological performance on routine MRI sequences between normal control group and head of femur avascular necrosis patient group, R2*image performance in each district of head of femur in normal group, the difference of R2*value between normal group and head of femur avascular necrosis patient group, R2*value change in the suspicious uninjured side of patients with unilateral disease, R2* image change in a patient in different time, The difference between R2*image and routine sequences in the lesion area in a patient.③The study population consists of112patients, who use plenty of glucocorticoid in short term, with knee joints and hip joints consecutively registered at our institution from March2012to March2014. According to the knee joints and head of femur in coronal T2W/TSE and SPAIR/PDW sequences scanning, the patients were classified into5groups, which include the group of osteonecrosis of the femoral head,the group of osteonecrosis of the knee joint, the group of edema of the femoral head, the group of edema of the knee joint, and the group of negative control. Comparing the differences between the different cases and controls in total amount of glucocorticoid, and the highest dosage level of daily use, and difference of medication time of daily hormone dose exceeded5mg/kg. Then we use the receiver operating characteristic(ROC curve) to differentiate the control group and the lesion groups,and determine the optimal diagnostic threshold.Result:①The images of conventional T2WI/TSE are more exquisite. However, the quality of images of SPAIR and3D/WATS is similar.(②There were no significant differences among the sequences for contrast imaging of femoral head and soft tissue.(③To depict the lesion, T2WI/SPAIR is better than3D/WATS, PWI/SPAIR is better than T2WI/SPAIR.(④Lesion could be all depicted clearly using3D/WATS PWI/SPAIR and T2WI/SPAIR. Double line sign and band sign could be seen in the sequence of T2WI in the lesion group, particularly, osteosclerosis band could not be seen in the sequence of fat saturation. Fiber granulation tissue and edema could appear hyperintense in the sequence of SPAIR.⑤The colour of R2*zone4and zone6in control group were lightest, next were zone1and zone3, and zone2and zone5were deepest.⑥In osteonecrosis group, zone4and zone6were not always involved,except of zone1and zone3between the lesion group and the control group.(⑦The R2*of suspected intact side was larger than affected side for the unilateral affected patients, but was less than that of control group which indicated that it was between normal and affected.⑧The R2*merely descended over time for zone1,zone2and zone3of affected femoral head, instead of zone4. zone5and zone6.This phenomenon indicated that R2*could screen osteonecrosis of the femoral head earlier and more sensitive than conventional sequences. In general for patients of ONFH only decrease of R2*could be seen and conventional sequence was negative because of its short time window.⑨The affected region for1or more months was larger generally in R2*than conventional sequences for the same patient.⑩The total amount of steroid and the maximum dose of steroid on odd-numberd days, and the accumulative time of the maximum dose of steroid above5mg/kg in ONFH group and knee necrosis group were higher than control group and there was statistically difference.Conclusion:MRI, which reflects the pathophysiology of the steroid related bone changes, can detect the necrosis of femoral head on early stage. First, MRI combinations of the SPAIR sequence on coronal view and T2WI are appropriate for sieving the necrosis of femoral head on early stage. Second, the blood oxygenation level-dependent magnetic resonance imaging can not only detect the necrosis of femoral head, but also detect the transitional state of the necrosis of femoral head on early stage. Third, a comprehensive analysis of the total amount of steroid and the maximum dose of steroid on odd-numberd days, and the accumulative time of the maximum dose of steroid above5mg/kg can select patients without risk.