能谱CT定量参数鉴别肾盂旁囊肿和非结石性肾积水的可行性研究

Feasibility of quantitative parameters of spectral CT in differentiating parapelvic cysts and acalculous hydronephrosis

目的探讨能谱CT定量参数鉴别肾盂旁囊肿和非结石性肾积水的可行性。方法抽取2020年1月至2022年5月于商丘市第一人民医院行CT尿路成像确诊的肾盂旁囊肿患者14例(肾盂旁囊肿组)及非结石性肾积水患者22例(非结石性肾积水组)。采用能谱CT对两组患者进行平扫,之后进行碘对比剂泌尿系常规皮质期和实质期增强扫描及较长时间延迟扫描(20~30 min),收集病灶的70 keV单能量CT值、有效原子序数(Zeff)、碘浓度(IC)、水浓度(WC)、能谱曲线斜率(λ)等数据,进行线性对照。结果肾盂旁囊肿组70 keV单能量CT值高于非结石性肾积水组,差异有统计学意义(t=4.31,P<0.05)。肾盂旁囊肿组WC值稍高于非结石性肾积水组,差异有统计学意义(t=2.24,P<0.05)。两组λ_(40-140)、Z_(eff)、IC值比较差异均未见统计学意义(P均>0.05)。结论能谱CT平扫成像所获得的70 keV单能量CT值和WC值,可对肾盂旁囊肿和非结石性肾积水进行鉴别诊断,具有一定的诊断价值,利用该检查可一定程度上免除多期动态增强扫描或CT尿路成像,从而减少辐射剂量和碘剂载荷,但是20~30 min延迟扫描更具有鉴别诊断意义。

Objective To investigate the feasibility of quantitative parameters of spectral computed tomography(CT)in differentiating parapelvic cysts and acalculous hydronephrosis.Methods Fourteen patients with parapelvic cysts(parapelvic cyst group)and 22 patients with acalculous hydronephrosis(acalculous hydronephrosis group)diagnosed by CT urography in Shangqiu First People’s Hospital from January 2020 to May 2022 were selected.Spectral CT scans were performed on the two groups of patients,followed by routine cortical and parenchymal phase enhanced scans and longer delay scans(20-30 min)of the urinary system with iodine contrast agent.Data such as 70 keV single-energy CT value,effective atomic number(Zeff),iodine concentration(IC),water concentration(WC),and energy spectrum curve slope(λ)of lesions were collected for linear comparison.Results The 70 keV single-energy CT value in the parapelvic cyst group was higher than that in the acalculous hydronephrosis group,and the difference was significant(t=4.31,P<0.05).The WC value of the parapelvic cyst group was slightly higher than that of the acalculous hydronephrosis group,and the difference was significant(t=2.24,P<0.05).There was no significant difference inλ_(40-140),Z_(eff) and IC values between the two groups(all P>0.05).Conclusions The 70 keV single-energy CT value and WC value obtained by energy spectral CT plain scan imaging can be used for the differential diagnosis of parapelvic cyst and acalculous hydronephrosis,which has a certain diagnostic value.This examination can avoid multi-phase dynamic contrast-enhanced scanning or CT urography to a certain extent,thereby reducing radiation dose and iodine load.However,20-30 min delayed scan has more value in differential diagnosis.