Department of Diagnostic Radiology, Medical University Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria.
Radiology. 2011 Jun;259(3):808-15. doi: 10.1148/radiol.11101644. Epub 2011 Mar 8.
To evaluate the accuracy of ultrasonography (US) in the diagnosis of carpal tunnel syndrome (CTS) in patients with a bifid median nerve on the basis of cross-sectional area (CSA) measurements of the median nerve at the level of the carpal tunnel (CSAc), with additional measurements obtained more proximally (CSAp) at the level of the pronator quadratus muscle.
This HIPAA-compliant study was approved by the local institutional review board; informed oral and written consent were obtained. Fifty-three wrists in 49 consecutive patients with a bifid median nerve and CTS symptoms and 28 wrists in 27 healthy volunteers with a bifid median nerve were examined by using US. Two independent US examiners who were blinded to prior test results measured median nerve CSA at two levels, CSAc and CSAp. The difference between CSAc and CSAp (ΔCSA) was calculated for each wrist. Receiver operating characteristic (ROC) analysis was performed.
The study population included 17 men and 32 women (mean age, 55.1 years; age range, 24-78 years). The control population included 13 men and 14 women (mean age, 52.6 years; age range, 24-86 years). Mean CSAc was approximately 5 mm(2) greater in patients with CTS than in healthy volunteers (P < .0001), while mean ΔCSA was 5.8-5.9 mm(2) greater in patients with CTS (P < .0001). A CSAc threshold of 12 mm(2) provided sensitivity and specificity of 84.9% and 46.5%, respectively, while a ΔCSA threshold of 4 mm(2) provided sensitivity and specificity of 92.5% and 94.6%, respectively. ROC analysis demonstrated a significant advantage of ΔCSA (area under ROC curve [A(z)] = 0.95-0.96) compared with CSAc (A(z) = 0.84-0.85) for the diagnosis of CTS (P < .003).
The use of a ΔCSA parameter improves the diagnostic accuracy of US for the presence of CTS in patients with a bifid median nerve.
评估超声（US）在基于正中神经腕管（CSAc）水平的截面积（CSA）测量值诊断具有二分正中神经的腕管综合征（CTS）的准确性，并在旋前方肌水平（CSAp）获得更多的附加测量值。
本 HIPAA 合规性研究获得了当地机构审查委员会的批准；获得了知情的口头和书面同意。对 49 例具有二分正中神经和 CTS 症状的连续 53 例患者和 27 例具有二分正中神经的健康志愿者的 28 例手腕进行了 US 检查。两位独立的 US 检查者对先前的测试结果不知情，测量了两个水平的正中神经 CSA，即 CSAc 和 CSAp。计算每个手腕的 CSAc 和 CSAp 之间的差值（ΔCSA）。进行了接收器工作特征（ROC）分析。
研究人群包括 17 名男性和 32 名女性（平均年龄 55.1 岁；年龄范围 24-78 岁）。对照组包括 13 名男性和 14 名女性（平均年龄 52.6 岁；年龄范围 24-86 岁）。患有 CTS 的患者的 CSAc 平均值比健康志愿者大约大 5mm²（P<0.0001），而患有 CTS 的患者的平均 ΔCSA 大 5.8-5.9mm²（P<0.0001）。CSA c 阈值为 12mm² 时，灵敏度和特异性分别为 84.9%和 46.5%，而 ΔCSA 阈值为 4mm² 时，灵敏度和特异性分别为 92.5%和 94.6%。ROC 分析表明，与 CSAc（A（z）=0.84-0.85）相比，ΔCSA（A（z）=0.95-0.96）在诊断 CTS 方面具有显著优势（P<0.003）。
使用 ΔCSA 参数可提高超声对具有二分正中神经的患者 CTS 存在的诊断准确性。
