Objective: To evaluate the diagnostic sensitivity of X-ray,computed tomography(CT) and magnetic resonance imaging(MRI) in diagnosis of early avascular necrosis.Methods: X-ray,CT and MRI of 150 cases(186 hips involved) with early diagnosis of avascular necrosis which were were retrospectively analyzed and compared.Results: Accuracy of X-ray,CT and MRI was 26.34%,72.04% and 100.0%,respectively in examination of early avascular necrosis(Ⅰ-Ⅱ stage).The positive rate of CT was significantly higher than that of X...