Abstract: Objective　To provide image data for prognosis evaluation after the anterior cruciate ligament reconstruction.　Methods　One hundred cases of normal knee joint and sixty-one cases of patients with Ⅲ grade, Ⅳ grade in reconstruction of the anterior cruciate ligament injury and fifty-seven cases of follow-up patients in the Affiliated Hospital of Xinxiang Medical University were selected by diffusion tensor imaging. The regions of interest of the anterior cruciate ligament injury, reconstruction and the corresponding position of normal group were divided. The fractional anisotropy (FA) values and apparent diffusion coefficient (ADC) values were measured, and the tractography images were generated.　Results　The preoperative and 1 week, 3 months postoperative FA values and ADC values of anterior cruciate ligament reconstruction were (0.395±0.047), (0.541±0.056), (0.542±0.058) and (2.791±0.336)×10-3 mm2/s, (2.263±0.224)×10-3 mm2/s, (2.028±0.341)×10-3mm2/s, respectively. There was no significant difference in the FA values between the 1 week and 3 months after the operation, there was statistical significance in the FA values and ADC values among other groups. The FA values and ADC values were (0.542±0.058), (0.595±0.056), (0.684±0.059), (0.577±0.064) and (2.028±0.341)×10-3 mm2/s, (1.699±0.175)×10-3 mm2/s, (1.375±0.151)×10-3 mm2/s, (1.324±0.160) ×10-3mm2/s at 3 months, 6 months, 1 year in postoperative follow-up and the normal group. There was no significant difference in the FA values between the 6 months in postoperative follow-up and the normal group, and the ADC values between the 1 year in postoperative follow-up and the normal group, there was statistical significance in the FA values and ADC values among other groups.   Conclusions   The diffusion tensor imaging can objectively reflect the microstructural changes after anterior cruciate ligament reconstruction, it has important diagnostic value in the prognosis evaluation. 

Key words: Anterior cruciate ligament reconstruction, 　Anterior cruciate ligament injury, 　Diffusion tensor imaging, 　Tractography imaging, 　Magnetic resonance imaging