常规CT扫描中尿酸结石与非尿酸结石的区别

基础医学与临床 ›› 2021, Vol. 41 ›› Issue (6): 885-889.

常规CT扫描中尿酸结石与非尿酸结石的区别

刘欢^1,2, 杨学东¹, 石凤祥¹, 吴哲^2,3, 孙昊^2*, 金征宇²

1.中国中医科学院广安门医院放射科,北京 100053;
2.中国医学科学院北京协和医院放射科,北京 100730;
3.抚顺市中心医院放射科, 辽宁抚顺 113006

收稿日期:2020-07-08 修回日期:2020-09-02 出版日期:2021-06-05 发布日期:2021-05-31
通讯作者: ^*sunhao_robert@126.com

Difference between uric acid stones and non-uric acid stones in conventional CT scanning

LIU Huan^1,2, YANG Xue-dong¹, SHI Feng-xiang¹, WU Zhe^2,3, SUN Hao^2*, JIN Zheng-yu²

1. Department of Radiology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053;
2. Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing 100730;
3. Department of Radiology, Fushun Central Hospital, Fushun 113006, China

Received:2020-07-08 Revised:2020-09-02 Online:2021-06-05 Published:2021-05-31
Contact: ^*sunhao_robert@126.com

摘要/Abstract

摘要： 目的通过测量结石的CT值、大小、密度是否均匀以及结石与肾脏CT值比、身体宽度,找出用常规CT预测尿酸结石的方法。方法共入组尿酸结石50例,非尿酸结石60例,患者在常规CT扫描检出结石后,通过双能量CT区分出尿酸结石与非尿酸结石,选取的结石长径均＞7 mm,由一名影像医师在不知道结石成分的情况下,对入组的患者进行数据采集,采用SPSS22.0软件进行统计分析,通过独立样本t检验、卡方检验、受试者工作特征曲线(ROC)评价各指标的预测价值。结果尿酸结石与非尿酸结石的CT值有统计学意义(P＜0.01),结石大小、密度是否均匀也具有统计学意义(P＜0.05)。用结石CT值诊断尿酸结石具有较高的预测价值,AUC=0.948,灵敏度94%,特异度85%;根据ROC曲线,以CT值730 HU为阈值诊断尿酸结石,其阳性预测值83.9%,阴性预测值94.4%,准确度80.1%。结石的大小也具有一定预测价值,AUC=0.63,灵敏度36%,特异度88.3%;根据ROC曲线以结石平均径＞18.05 mm诊断尿酸结石,其阳性预测值72%,阴性预测值62.4%,准确度64.5%。以结石CT值730 HU为阈值且结石密度均匀预测尿酸结石,其特异度100%,阳性预测值100%。结论常规CT通过测量结石CT值、平均径大小、密度是否均匀以鉴别尿酸结石与非尿酸结石具有较高价值,当结石CT值与结石密度是否均匀结合考虑时,则诊断尿酸结石的特异度、阳性预测值明显增高。

关键词: 尿酸结石, 常规CT, 双能量CT, 结石CT值, 结石密度是否均匀

Abstract: Objective To investigate methods for predicting uric acid stones with conventional CT by measuring the CT value of stones, mean diameter size, density of stones, stone to kidney CT value ratio, and body width. Methods Patients underwent conventional CT scanning and were diagnosed postoperatively before uric acid stones and non-uric acid stones were detected by dual-energy CT.A total of 50 patients with uric acid stones and 60 patients with non-uric acid stones were enrolled, and after stones were detected by conventional CT scan, uric acid stones and non-uric acid stones were distinguished by dual-energy CT. The selected stones were ＞ 7 mm in long diameter. Data acquisition was performed on enrolled patients by a radiologist blinded to stone composition. The predictive value of each index was evaluated by independent sample t test, chi-square test, and receiver operating characteristic curve (ROC). Results There was great value in distinguishing uric acid stones from non-uric acid stones in stone CT value (P＜0.01), significant statistical difference in uniform stones or not and in size (P＜ 0.05). The CT scan showed a high predictive value for the diagnosis of uric acid stones, with AUC=0.948, sensitivity as 94%,and specificity as 85%.According to the ROC curve, the CT scaning value of 730 HU was adopted as the threshold for the diagnosis of uric acid stones, with a positive predictive value of 83.9%, a negative predictive value of 94.4%, and an accuracy of 80.1%. The size of the stone also had a predictive value, AUC=0.63, sensitivity 36%, and specificity 88.3%, and the mean diameter of the stone greater than 18.05 mm was defined as a diagnosis standard of uric acid stones according to the ROC curve, which had a positive predictive value of 72%, a negative predictive value of 62.4%, and an accuracy of 64.5%. Using a stone CT value of 730 HU as the threshold combined with a uniform stone density to predict uric acid stones, its specificity was 100% and the positive predictive value was 100%. Conclusions Conventional CT is of high value in differentiating uric acid calculi from non-uric acid calculi by measuring the mean diameter size and density of calculi. When evaluate CT result with or without homogenous stone density as the diagnostic criteria, the specificity and positive predictive value of diagnosing uric acid calculi are significantly higher.

Key words: uric acid stones, conventional CT, dual-energy CT, stone CT value, stone density

中图分类号:

R816.7

刘欢, 杨学东, 石凤祥, 吴哲, 孙昊, 金征宇. 常规CT扫描中尿酸结石与非尿酸结石的区别[J]. 基础医学与临床, 2021, 41(6): 885-889.

LIU Huan, YANG Xue-dong, SHI Feng-xiang, WU Zhe, SUN Hao, JIN Zheng-yu. Difference between uric acid stones and non-uric acid stones in conventional CT scanning[J]. Basic & Clinical Medicine, 2021, 41(6): 885-889.

参考文献

[1] Neisius A,Preminger GM. Stones in 2012:epidemiology,prevention and redefining therapeutic standards[J]. Nat Rev Urol,2013,10:75-77.
[2] 董浩,王琦,彭泳涵,等.泌尿系上尿路结石成分的单中心研究[J]. 第二军医大学学报,2018,39:450-454.
[3] 郑媛慧,崔晓东,徐卫国.双源CT分析结石成分的临床应用进展[J]. 外科研究与新技术,2018,7:130-134.
[4] Zeng GH,Mai ZL,Xia SJ,et al. Prevalence of kidney stones in China: an ultrasonography based cross-sectional study[J]. BJU Int,2017,120:109-116.
[5] Bultitude M,Smith D,Thomas K.Contemporary manage-ment of stone disease:the New EAU Urolithiasis Guide-lines for 2015[J]. Eur Urol,2016,69:483-484.
[6] Kambadakone AR,Eisner BH,Catalano OA,et al.New and evolving concepts in the imaging and management of urolithiasis: urologists'perspective[J]. Radiographics,2010,30: 603-623.
[7] 张古沐阳,石冰,薛华丹,等.双源双能量CT前瞻性分析体内泌尿系结石的主要成分[J]. 放射学实践,2018,33:55-59.
[8] Primak AN,Fletcher JG,Vrtiska TJ,et al.Noninvasive differentiation of uric acid versus non-uric acid kidney stones using dual-energy CT[J]. Acad Radiol,2007,14: 1441-1447.
[9] Stewart G,Johnson L,Ganesh H,et al.Stone size limits the use of Hounsfield units for prediction of calcium oxalate stone composition[J]. Urology,2015,85:292-295.
[10] Bellin MF,Renard-penna R,Conort P,et al.Helical CT evaluation of the chemical composition of urinary tract calculi with a discriminant analysis of CT-attenuation values and density[J]. Eur Radiol,2004,14:2134-2140.
[11] Torricelli FCM,Marchini GS,De S,et al.Predicting urinary stone composition based on single-energy noncontrast computed tomography:the challenge of cystine[J]. Urology,2014,83:1259-1263.
[12] 李丽超,宫凤玲,于鹏,等.常规CT鉴别诊断尿酸与非尿酸结石的价值[J]. 广西医学,2018,40:284-286.
[13] Liden M.A new method for predicting uric acid composi-tion in urinary stones using routine single-energy CT[J]. Urolithiasis,2018,46:325-332.
[14] Spettel S,Shah P,Sekhar K,et al.Using Hounsfield unit measurement and urine parameters to predict uric acid stones[J]. Urologt,2013,82:22-26.
[15] Kordbacheh H,Baliyan V,Uppot RN,et al.Dual-source dual-dnergy CT in detection and characterization of urinary stones in patients with large body habitus:observations in a large cohort[J]. AJR Am J Roentgenol,2019,212: 796-801.
[16] Al-Ali BM,Patzak J,Lutfi A,et al.Impact of urinary stone volume on computed tomography stone attenuations measured in Hounsfield units in a large group of Austrian patients with urolithiasis[J]. Cent European J Urol,2014,67:289-295.
[17] Kim JH,Doo SW,Cho KS,et al.Which anthropometric measurements including visceral fat,subcutaneous fat,body mass index,and waist circumference could predict the urinary stone composition most?[J]. BMC Urol,2015,15:17.