The efficacy of 0.2 T low-field open MR imaging in the diagnosis of carpal tunnel syndrome

Mehmet Sirik¹, Bozkurt Gulek*², Gokhan Soker³, Omer Kaya³, Kaan Esen⁴, Yusuf Yarar⁵, Eda Soker⁶

¹Adiyaman University  Department of Radiology, Adiyaman, Turkey

²Namik Kemal University Department of Radiology, Tekirdag, Turkey

³Numune Teaching and Research Hospital Department of Radiology, Adana, Turkey

⁴Mersin University Department of Radiology, Mersin, Turkey

⁵Numune Teaching and Research Hospital Department of Radiology, Diyarbakir, Turkey

⁶Numune Teaching and Research Hospital Department of Physical Therapy and Rehabilitation, Adana, Turkey

*Corresponding Author E-mail: bozkurtgulek@yahoo.com; Phone: +90-533-435-4686

Accepted 21 January, 2014

Abstract

The aim of this study was to image the morphologic changes that take place in the wrists of patients who had been diagnosed with carpal tunnel syndrome (CTS) and define certain magnetic resonance imaging (MRI) findings that could be characteristic for the diagnosis of CTS, without the need of going for electrodiagnostic modalities such as electromyography (EMG). We also had the intention to investigate the efficiency of 0.2 T low-field MR imaging in the diagnosis of CTS. The 52 patients who were included in this study were selected from those who had applied to the Orthopedics Department of our hospital and were diagnosed with CTS. The patients had positive EMG results, and they had no history of surgical intervention or trauma. MRI examinations were performed in a 0.2 T low-field open scanner. The most frequent morphological change encountered in CTS is diffuse or local swelling and flattening of the nerve which occurs while it traverses the carpal tunnel. Thus, the most prominent MRI finding of CTS encountered in this study was high signal intensity along the median nerve tract detected at short time inversion recovery (STIR) sequences. Another finding was flattening of the nerve tract and increase in its diameter. In addition to this finding, there was also  palmar bowing at the flexor retinaculum. Based on our observations, we conclude that the first diagnostic modality should be MRI in patients who are suspected to have CTS according to their histories and clinical examination findings. We conclude that EMG should be reserved as a secondary diagnostic tool when MRI findings are negative or suspicious. We also emphasize that detailed anatomic data supplied by MRI is of utmost importance for the reliability of both the surgical intervention itself and postoperative follow-up.

Keywords: Carpal tunnel syndrome, median nerve, MRI