Department of Radiology, Oncology Hospital, Guangxi Medical University, Nanning, People's Republic of China.
Eur Radiol. 2011 Aug;21(8):1692-8. doi: 10.1007/s00330-011-2101-y. Epub 2011 Mar 11.
To explore the percentage enhancement wash-out ratio (PEW) and relative PEW (RPEW) of low-dose multi-phasic computed tomography (CT) in distinguishing benign from malignant parotid gland tumours.
This study was approved by the ethics committee, and informed patient consent was obtained. 51 patients with parotid tumours proven by histopathology received CT, including 18 with pleomorphic adenomas, 14 with Warthin's tumours and 19 with malignant tumours. Size and attenuation of parotid tumours were measured. Compared with 5-min attenuation, the 30-s and 90-s PEW (PEW(30,) PEW(90)) and RPEW (RPEW(30), RPEW(90)) were calculated.
There was a significant difference in PEW(30), RPEW(30), PEW(90) and RPEW(90) in the parotid neoplasms groups (P < 0.01), and statistical significance existed simultaneously in pleomorphic adenomas vs malignant tumours and Warthin's tumours vs malignant tumours according to SNK-q test. The optimal diagnosis results of malignancy with 100% specificity (32/32) was obtained by using a combination of the following criteria: -70% > PEW(30) < 36%, -30% > PEW(30) < 19%, PEW(90) > 12%, and the sensitivity (74%) for diagnosis of malignancy was yield.
Wash-out ratio may assist in differentiating the benign from malignant parotid gland tumours. Combining the percentage of enhanced wash-out ratios of CT protocols can yield diagnostic results for malignancy.
探讨低剂量多期 CT （CT）在鉴别腮腺良恶性肿瘤中的百分比增强洗脱率（PEW）和相对 PEW（RPEW）。
本研究经伦理委员会批准，并获得患者知情同意。51 例经组织病理学证实的腮腺肿瘤患者接受 CT 检查，其中多形性腺瘤 18 例，Warthin 瘤 14 例，恶性肿瘤 19 例。测量腮腺肿瘤的大小和衰减。与 5 分钟衰减相比，计算 30 秒和 90 秒的 PEW（PEW（30），PEW（90））和 RPEW（RPEW（30），RPEW（90））。
腮腺肿瘤组的 PEW（30）、RPEW（30）、PEW（90）和 RPEW（90）差异有统计学意义（P<0.01），SNK-q 检验显示多形性腺瘤与恶性肿瘤、Warthin 瘤与恶性肿瘤之间同时存在统计学意义。使用以下标准的组合，可获得 100%特异性（32/32）的恶性肿瘤最佳诊断结果：-70%>PEW（30）>-36%，-30%>PEW（30）>-19%，PEW（90）>12%，且诊断恶性肿瘤的敏感性（74%）。
洗脱率可辅助鉴别腮腺良恶性肿瘤。结合 CT 方案的增强洗脱率百分比可以得出恶性肿瘤的诊断结果。
