Comparison of Median Nerve Cross-sectional Area on 3-T MRI in Patients With Carpal Tunnel Syndrome

Abstract

This study correlated morphologic abnormalities of idiopathic carpal tunnel syndrome (CTS) with the severity of CTS using 3-T magnetic resonance imaging (MRI). The relationship of the severity of CTS and the cross-sectional area of the median nerve (CSA) was assessed at several levels. Seventy wrists of 35 patients (27 women and 8 men) with unilateral idiopathic CTS underwent nerve conduction study and 3-T MRI of the wrist. The CSA at 4 levels (distal radioulnar joint, body of scaphoid, tubercule of scaphoid, and hook of hamate) and the thickness of the transverse carpal ligament at 3 levels in both affected and unaffected hands were measured using 3-T MRI and correlated with the severity of CTS assessed with distal motor latency. The CSA in the affected hand at the scaphoid body level was significantly higher than in the unaffected hand. The CSA at the scaphoid body level was positively correlated with distal motor latency in the affected hand. The CSA in the affected hand at the scaphoid tubercule level was significantly lower than in the unaffected hand. The CSA had a negative correlation with distal motor latency at the scaphoid tubercule level. The CSA at the distal radioulnar joint and the hamate hook was not significantly different between the affected hand and the unaffected hand. The CSA at the distal radioulnar joint level and hook level were not correlated significantly with distal motor latency in the affected hand. The mean CSA of the affected hand at the scaphoid body level was highest in 4 levels. [Orthopedics. 2017; 40(1):e77-e81.].

The prognostic value of median nerve thickness in diagnosing carpal tunnel syndrome using magnetic resonance imaging: a pilot study

“…Recently, CTMRI has been demonstrated to be more advantageous than electrophysiological testing [5,6,12]. CT-MRI can visualize the median nerve at high resolution and represents an effective imaging method for visualization of tendons, ligaments, carpal bones, muscles, and other wrist morphological structures [4,6,12]. Several types of research have used CTMRI for the evaluation of CTS and have described characteristic CTMRI findings in CTS patients [4,6,12,19,21].…”

“…CT-MRI can visualize the median nerve at high resolution and represents an effective imaging method for visualization of tendons, ligaments, carpal bones, muscles, and other wrist morphological structures [4,6,12]. Several types of research have used CTMRI for the evaluation of CTS and have described characteristic CTMRI findings in CTS patients [4,6,12,19,21]. The reported results include lesions with increased signal intensity on T2-weighted images, swelling of the median nerve in the distal and proximal carpal tunnel, bowing of the flexor retinaculum, and flattening of the medial nerve within the carpal tunnel.…”

“…Many previous researches have used image modalities and focused on a quantitative analysis of the MNCSA in the carpal tunnel, and reported that MNCSA measurements could be useful in assessing CTS [4,9,11,12,26,27]. Ikeda et al [4] demonstrated that CTMRI is a valuable examination for imaging the crosssectional area of the median nerve and has potential as a diagnostic modality for CTS. However, there are limited studies investigating the anatomical basis of median nerve flattening.…”

“…tunnel magnetic resonance imagings (CTMRI) have been demonstrated as a good diagnostic tool for the diagnosis of CTS [4][5][6]. CTMRI are noninvasive and can clearly depict the anatomical detail of peripheral nerves along with the pathological changes related to compression.…”

“…The morphological changes in the median nerve resulting from prolonged increased mechanical pressure within the carpal tunnel have already been demonstrated [6]. Apparently, the median nerve cross-sectional area (MNCSA) is considered a useful morphological parameter for the evaluation of CTS [4,[8][9][10][11][12]. However, there have only been limited studies involving investigation of the anatomical basis of median nerve flattening.…”