High-resolution MRI predicts steroid injection response in carpal tunnel syndrome patients
- 522 Downloads
To correlate median nerve T2 signal and shape at the carpal tunnel with steroid injection (SI) response in carpal tunnel syndrome (CTS) patients.
One hundred and sixty-three CTS wrists of 92 consecutive patients who were scheduled to undergo SI were prospectively evaluated with 3-T magnetic resonance imaging (MRI) and a nerve conduction study. All patients underwent axial high-resolution T2-weighted MRI (in-plane resolution of 0.25 × 0.25 mm). The CTS wrists were classified into three groups according to the nerve T2 signal and the flattening ratio at the hook of hamate level: group 1, high and oval; group 2, high and flat; group 3, low and flat. Clinical response to SI was evaluated at 6 months after injection.
One hundred and thirteen of the 163 wrists (69.3 %) responded well to SI. The percentage of improvement was 81.7 % (49/60) in group 1, 69.9 % (51/73) in group 2, and 43.3 % (13/30) in group 3 (P < 0.01). On stepwise logistic regression analysis high-resolution MRI was the only significant independent factor for SI response in CTS patients (P < 0.01).
High-resolution MRI correlates well with SI response in CTS patients and seems useful for predicting SI response.
• MRI may help determine appropriate care in carpal tunnel syndrome.
• MRI helps in therapeutic decision-making whenever steroid injection is considered.
• T2 signal decrease of the median nerve correlates with poor outcome.
• T2 signal decrease of median nerve may reflect fibrosis and amyloid deposition.
KeywordsMRI Carpal tunnel syndrome Steroid injection Wrist 3 tesla
Carpal tunnel syndrome
Nerve conduction study