Iranian Journal of Orthopedic Surgery

Abstract Introduction: Carpal tunnel syndrome (CTS) is a common compressive neuropathy of the upper limb. Given the variable performance of conventional diagnostic approaches, quantitative magnetic resonance imaging may assist clinical decision-making. This study evaluated the diagnostic value of quantitative magnetic resonance imaging metrics.
Materials & Methods: In a cross-sectional diagnostic study of 30 patients at a university center, clinical severity of CTS was assessed using the validated Persian Boston Carpal Tunnel Questionnaire, and electrodiagnostic testing and classified-involvement as mild, moderate, or severe. Wrist magnetic resonance imaging with routine sequences was performed with observer blinding to clinical and electrodiagnostic data. The median nerve cross-sectional area at the distal tunnel outlet, intraneural signal intensity, and the signal intensity ratio of nerve to hypothenar muscle were measured and compared with normal subjects. Analyses used appropriate tests with a significance threshold of p<0.05.
Results & Discussion: The median nerve cross-sectional area was larger in patients than in normal (11.36±1.89 vs 9.70±1.63 mm²; p<0.05). Intraneural signal intensity was higher in patients (597.13±52.95 vs 501.67±40.50; p<0.05). The nerve-to-hypothenar signal intensity ratio was also increased (1.31±0.26 vs 0.80±0.13; p<0.01).
Conclusion: Quantitative magnetic resonance imaging metrics demonstrate significant discriminatory power between patients and normal and may serve as adjuncts in the diagnostic pathway. This pattern accords with the pathobiology of compression (edema and structural change) and supports the utility of quantitative magnetic resonance imaging as a complement to clinical examination and electrodiagnostic testing. Standardization of measurement sites and thresholds, and multicenter prospective studies, are required to translate these findings reliably to practice.