The Value Of MR Diffusion-weighted Imaging In The Diagnosis Of Ischemic Necrosis Of Femoral Head

Objective To investigate the value of MR DWI and the ADC value in the diagnosis and staging of the femoral head necrosis. Methods 80 hips of 64 patients with necrosis of the femoral head were included in the study,regarded as a experimental group,36 male,28 female,aged 19-79 years,mean age 44.3 years, with a history of the disease 2 months-17 years. 80 hips of 40 heathy volunteers were randomly selected,23 male,17 female,aged 20-76 years,mean age 51.4 years,regarded as a control group. All subjects were performed on a 1.5T MR scanner,using conventional and DWI sequences(b=800 s/mm2),ADC maps were obtained,ADC values were measured,and the results were statistically analyzed. Results DWI can clearly display the anatomic structures of necrotic and normal femoral head. The mean ADC values of the necrotic femoral heads were(7.01±1.41)×10-4mm2/s, and that of the group with bone marrow edema、hip joint effusion、bone marrow edema and hip joint effusion 、without bone marrow edema and hip joint effusion were(7.26±1.26)×10-4mm2/s、(7.43±1.05)×10-4mm2/s、(7.63±0.77)×10-4mm2/s、(4.75±0.82)×10-4mm2/s respectively. The mean ADC values of normal femoral heads were(2.94±0.76)×10-4mm2/s. Conclusions DWI can differentiate the necrotic and normal areas of femoral heads. The mean ADC values of necrotic areas were significantly higher than that of the normal. The mean ADC values of femoral head increased when accompanying with marrow edema and /or hip joint effusion.The ADC value is valuable for the early diagnosis and staging of femoral head necrosis.