单纯肾囊肿能谱CT假强化特征

陈文锦　　蔡彩云　　王琦　　方文鑫

[关键词] 肾囊肿;能谱CT;假强化;误诊

[中图分类号] R692;R816.7          [文献标识码] B          [文章编号] 1673-9701（2021）20-0112-04

False enhancement characteristics of simple renal cyst with energy spectrum CT

CHEN Wenjin   CAI Caiyun   WANG Qi   FANG Wenxin

Department of Imaging，Xiamen no.5 Hospital of Fujian Province，Xiamen   361101， China

[Abstract] Objective To evaluate the false enhancement characteristics of simple renal cyst on energy spectrum CT scan. Methods The patients with simple renal cyst who were treated with energy spectrum CT and MRI scans in our hospital from January 2019 to January 2020 were reviewed.GSI Viewer analysis software was used for image processing，and the effects of renal cyst diameter，CT value，location and renal parenchyma density on false enhancement were measured. Results Ninety patients with renal cysts were enrolled in this study.A total of 122 cysts with diameters greater than 1 cm were detected.The incidence of false enhancement was significantly higher in cysts 1-2 cm in diameter than in cysts 2-3 cm in diameter （53%，36/68 vs. 15%，4/26，χ2=10.852，P=0.001）.The incidence of false enhancement of cysts was significantly higher in patients with renal parenchymal density >200 HU than in patients with renal parenchymal density ≤200 HU （50%，30/60 vs.17%，10/62，χ2=15.874，P=0.000<0.05）.The incidence of false enhancement in renal cysts was significantly higher than that in peripheral cysts （43%，28/65 vs. 21%，12/57，χ2=6.685，P=0.010）. The cyst size and renal parenchyma density after enhancement were risk factors for false enhancement. Conclusion Patients with the smaller cyst diameter and higher renal parenchyma density around the cyst should be on the alert for false enhancement to avoid misdiagnosis.

[Key words] Renal cyst; Energy spectrum CT; False enhancement; Misdiagnose

在我國，肾囊肿是常见的肾脏良性病变，50岁以上成人其发病率高达50%[1-2]。单纯性肾囊肿无需干预及长期随访。CT增强扫描是临床上诊断良性肾囊肿的主要方法。理论上单纯肾囊肿边缘清晰、外形规则、水样密度，无强化[3]。而部分单纯肾囊肿CT增强扫描后其CT值出现不同程度的增加，超过10 HU以上，这就是肾囊肿的假强化现象。假强化现象与容积效应、X线硬化、CT影像重建算法、解剖变异以及囊肿周围肾组织干扰等因素有关[3-5]。直径不超过2 cm的肾内小囊肿由于假强化现象的存在，使其与缺乏血供的肾内肿瘤鉴别困难，导致不必要的影像检查或长期随访[6]。能谱CT可以提供病变有无强化的确切信息，有助于克服假强化现象，然而针对这一问题尚缺乏充分的临床研究证实。因此，本研究探讨能谱CT扫描模式下肾脏囊肿大小、位置等参数与假强化的关系，进一步评估能谱CT在克服假强化方面的效果。

1 资料与方法

1.1一般资料

收集2019年1月至2020年1月在我院放射科接受能谱CT增强扫描的单纯性肾囊肿（Bosniak I型）患者。纳入标准：年龄>18岁的成年患者接受腹部CT增强扫描;核磁共振检查支持单纯性囊肿诊断;核磁和CT扫描时间间隔3个月以内[5-7]。排除标准：肾脏周围伪影严重影响囊肿测量;患者失访;随访过程中肾囊肿直径增大或密度增强不支持单纯囊肿诊断[8]。