CT检查中窗技术的合理应用对提高肝内病灶检出率的意义

Significance of CT liver window setting for detecting hepatic lesions

目的评价在传统软组织窗基础上加用肝组织窗对提高肝内病灶检出率的意义。方法接受腹部CT增强扫描的859例患者的895张顺序编号的CT片是由两位有经验的放射学医师评价的。所有的肝脏成像均采用两种窗技术进行,即起初软组织窗和随后肝组织窗。逐例记录了两种技术检出的病灶数与符合率。确定了利用肝组织窗有新增病灶的患者比例。对两种窗技术在检出病灶数方面的差异进行了统计学分析。结果在859例中,205例(24%)患者在软组织窗和肝组织窗上有肝脏病灶,其中,40例(14.6%)患者随着肝组织窗的加用,检出的病灶数亦增多。这40例中的14例患者具有在软组织窗上看不见的新增病灶。两种窗技术的病灶检出率有统计学差异(P<0.05)。结论单一的软组织窗不足以全部发现肝内病灶,因此,有些病灶容易漏诊,而肝组织窗的加用,可有效提高肝脏病灶的检出率与诊断准确性。

Objective To evaluate the significance of adding CT liver windows to conventional soft - tissue windows for raising the detective rate of hepatic lesions. Methods Eight hundred and ninety - five consecutive CT films of 859 patients who underwent abdominal CT scans with contrast enhancement were evaluated by two radiologists with rich experience. All hepatic imaging was performed by using two kinds of window techniques, i. e. initial soft - tissue window and subsequent liver window. The number of lesions and correspondence of two window techniques in lesion detection were recorded for each case. The proportion of patients in whom additional lesions were found by using liver window was determined. The difference of lesion number detected on two kinds of windows was statistically analyzed. Results A- mong 859 cases, 205 （24%）patients had hepatic lesions on soft - tissue - window and liver window scans, of whom, 40（ 14.6% ）patients had new lesions seen with the addition of liver window. Fourteen of these 40 patients had additional lesions those were invisible on soft - tissue windows. There was statistic difference between the both window techniques in lesion detection（ P〈 0.05）. Conclusion Alone soft- tissue window is insufficient to find fully intrahepatic lesions so that some lesins are easily leak - diagnosed, whereas additin of liver window can effectively raise the detective rate and diagnostic accuracy of hepatic lesions.