Research progress of MRI in evaluating graft maturity after anterior cruciate ligament reconstruction

Assessing the maturity of the graft after anterior cruciate ligament (ACL) reconstruction is an important step to guide rehabilitation training for postoperative patients. However, there is still a lack of unified, quantitative, noninvasive index to evaluate the maturity of the graft. MRI is an important examination method after ACL reconstruction. It can be used to analyze the anatomical position of the graft, degree of ligamentization, degree of revascularization, mechanical characteristics and prognosis of the graft. This article reviews the mature mechanism of grafts after ACL reconstruction. This article also reviews the progresses of conventional MRI and T₂* mapping, ultra-short echo time (UTE), diffusion tensor imaging (DTI), T₁ρ mapping, and dynamic enhanced magnetic resonance imaging (DCE-MRI) and various MRI quantitative and semiquantitative analysis techniques in the evaluation of graft maturity. (authors)