MRI in chronic groin pain: sequence diagnostic reliability compared to systematic surgical assessment

To determine the diagnostic reliability of magnetic resonance imaging (MRI) sequences in chronic groin pain (CGP) compared to surgery and try to propose a suitable MRI protocol.

Forty-three consecutive patients with resistant clinical CGP underwent a pre-surgical pelvis MRI. Eight MRI sequences were acquired: axial fast spin-echo T1-weighted (FSE T1), coronal FSE T1, axial-oblique (in symphysis plane) proton density weighted with fat saturation (PDFS), coronal PDFS, sagittal PDFS, axial FSE T1 with fat saturation and gadolinium enhancement (FSGE), coronal FSE T1 FSGE and axial FSE T1 with Valsalva maneuver (VM). These sequences were reviewed for pubic symphysis assessment, adductor longus (AL) tendon and abdominal wall (AW) injuries. The same surgeon operated on all of these patients (26 AL and 49 AW). Sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative prospective value (NPV) and accuracy of each sequence and combinations for AL or AW injuries were calculated in comparison to surgical findings.

One hundred ninety-two sequences were obtained. Coronal T1 FSGE and axial T1 VM proved to be the most reliable sequences (accuracy: 91.67% in AL and 83.33% in AW). The best sequence combination was coronal T1, axial PDFS, sagittal PDFS and axial T1 VM (accuracy: 77.78%; Se: 100.00%, Sp: 69.23%, PPV: 55.56%, NPV: 100.00%).

MRI has 77.78% accuracy, 100.00% sensitivity, 69.23% specificity, 55.56% PPV and 100.00% NPV in evaluating CGP, with coronal T1-axial PDFS-sagittal PDFS-axial T1 VM as the optimal protocol in terms of diagnostic performance within a reasonable scan time. Diagnostic performance of MRI was examined in the evaluation of CGP using surgery as reference standard.