Application Of Dynamic Contrast Enhanced MRI In ARCO Stage Of Avascular Necrosis Of The Femoral Head

The femoral head is a load-bearing organ in human body, blood supplying mainly comes from the medial femoral circumflex artery, the lateral circumflex femoral artery and the branch of obturator artery, the medial femoral circumflex artery is the main artery which supplys the femoral head. avascular necrosis of the femoral head(ANFH) is mainly caused by blood supply disorder, the etiology can be divided into two major categories, traumatic and noninvasive. Hormones, alcohol,thrombosis and other factors can lead to noninvasive ANFH. The blood circulation of ANFH is different from that of normal femoral head, and also is the hemodynamic of ANFH in different stages. The perfusion information of femoral head could be gotten by 3.0T Dynamic Contrast Enhanced MRI(DCE-MRI). Through Pharmacokinetic Model we could get the blood flow information of ANFH in different stages which includes initial area under the time-concentration curve(iAUC) and transfer rate constant( Ktrans). In this study, 50 patients with ANFH were examined by X-ray and DCE-MRI, 95 side of the femoral head can be used for analysis,in which ? stage 19, ? stage 27, ? stage 21, ? stage 28. Another 20 normal volunteers as control group, 40 side of the femoral head can be used for analysis. The iAUC values of control group, stage ?, ?, ?, ? were0.749±0.300, 7.082±2.207, 13.029±4.341, 22.789±9.815, 7.170±3.112,respectively, there were significant differences(F=85.847,P<0.001), the i AUC value of control group, stage ?, ?, ?, ? were statistics dirrerences was found in multiple comparison(P <0.05), except stage ? and ?(P >0.05). The Ktrans values of control group, stage ?, ?, ?, ? were 0.013±0.005, 0.072±0.030, 0.109±0.043, 0.158±0.126, 0.042±0.014, therewere significant differences(F=29.683,P<0.001), control group and stage ?, ?, ?, ? had significant statistical difference(P<0.001), the Ktrans values of stage ? and ?, stage ? and ?, stage ? and ?, stage ? and ? had statistical difference(P<0.05), but there were no statistical difference with stage ? and ?, ? and ?(P>0.05) The values of i AUC and Ktrans(r=0.625?0.532, P<0.001)showed positive correlation with control group, stage ?, ?,? and ?, and the values of i AUC and Ktrans(r=0.903?0.849,P<0.001)showed significant positive correlation with control group, stage ?, ? and ?. In addition, The time-concentration curve of normal femoral head showed fast rising and falling, suggested that contrast agent rapid entry,and rapid outflow, while the time-concentration curve of ANFH was continued increased, suggested that contrast agent in femoral head accumulation, and slow elimination. Thus, we can draw the following conclusions:(1) DCE-MRI can quantitatively assess the hemodynamic status of normal femoral head, and the perfusion of ANFH was significantly increased than that of the normal femoral head.(2) DCE-MRI can provide significant perfusion characters, like Ktrans and iAUC, for different ARCO stage. At the same time, Ktrans, iAUC have a high correlation with ARCO stage, which is an important index to reflect the blood perfusion of different stages of ANFH. So DCE-MRI can provide a reference for the clinical study of ANFH hemodynamic. In summary,DCE-MRI can objectively evaluate the hemodynamic status in different stages of ANFH, and provide an important evidences for option of therapeutic regimes and evaluation of therapeutic effect.