Response to: ‘Paying attention to carpal

tunnel contents lesions: ultrasound for evaluation of carpal tunnel syndrome’ by zhu and Liu Our and several previous studies demonstrated a high diagnostic value of ultrasound for carpal tunnel syndrome (CTS).1 2 Among the various abnormalities within the carpal tunnel reported, the increase of the cross-sectional area (CSA) of the median nerve is the most commonly studied ultrasound abnor-mality.3 Additionally, ultrasound allows the identification of sec-ondary causes of CTS, such as synovitis, tenosynovitis, calcified masses or tophaceous gout, as pointed out by zhu et al.4 We acknowledge that the diagnostic value of ultrasound is not perfect, as some patients may suffer from CTS despite a normal ultrasound result and, vice versa, abnormal ultrasound findings do not necessarily indicate CTS.1 In these cases, additional tests