Timing Of MRI in Acute Lateral Ankle Sprain: Impact On Diagnostic Findings And Clinical Interpretation – A Retrospective Observational Cohort Study

Abstract

Background: This study aimed to investigate the impact of magnetic resonance imaging (MRI) timing on radiological findings and diagnostic interpretability in patients with acute lateral ankle sprain. Methods: In this retrospective observational cohort study, 75 adult patients with acute inversion-type ankle sprain were divided into three equal groups based on MRI timing: hyperacute (0–7 days), subacute (8–21 days), and late (>21 days). All MRIs were performed using a 3.0T scanner and evaluated by a blinded musculoskeletal radiologist. Ligament integrity, bone marrow edema, joint effusion, and soft tissue edema were assessed, along with a 3-point diagnostic interpretability scale. Multivariate analyses adjusted for age, sex, and clinical severity. Results: ATFL tear classification differed significantly across groups (p<0.05), with higher rates of complete tears in the hyperacute group. Bone marrow edema and joint effusion were most pronounced in early imaging and progressively decreased over time (p<0.05). Diagnostic interpretability was lowest in the hyperacute group and highest in the subacute group (p<0.05). MRI timing remained an independent predictor of ligament injury classification and edema visibility after adjustment. Conclusion: MRI timing significantly influences both the radiological appearance and interpretability of acute lateral ankle sprain. Subacute imaging appears to provide the most balanced diagnostic clarity, suggesting that MRI should be optimally timed based on clinical objectives. Trial registration: Not applicable (retrospective study)