双源CT泌尿系成像双能量虚拟平扫的临床评估

Clinical Application of Dual-source Computed Tomographic Urography Using Dual-energy Virtual Non-enhanced Computed Tomography

目的评价FLASH双源CT泌尿系成像双能量虚拟平扫临床应用的可行性。方法对240例患者进行FLASH双源CT泌尿系成像,包括常规平扫、肾实质期双能量扫描(100kVp/230mAs和Sn140kVp/178mAs)和排泄期扫描。顺序注射造影剂100ml(370mgI/ml)和100ml生理盐水,注射速度均为4.5ml/s。利用LiverVNC软件处理得到虚拟平扫CT图像,与常规平扫比较在器官CT值、噪声、信号噪声比、图像质量和放射剂量等方面的差异。结果常规平扫和虚拟平扫所测器官CT值差异均无统计学意义(P>0.05),虚拟平扫图像噪声明显低于常规平扫而信号噪声比明显高于常规平扫(P<0.05),虚拟平扫图像质量低于常规平扫但差异无统计学意义(P>0.05),肾实质期双能量扫描放射剂量高于常规平扫和排泄期扫描(P<0.05)。结论在FLASH双源CT泌尿系成像中,双能量虚拟平扫具有取代常规平扫的可能,减少1次平扫的放射剂量,具有临床应用价值。

Objective To evaluate the clinical feasibility of dual-source computed tomographic urography using dual-energy virtual non-enhanced CT.Methods Totally 240 patients received dual-source CT,which included true non-enhanced CT （TNCT）,nephrographic phase scanning with dual-energy mode （100kVp/230mAs and Sn140kVp/178mAs）,and excretory phase scanning.A contrast bolus injection of 100 ml （370 mgI/ml） contrast agent was applied （4.5ml/s）,followed by 100ml normal saline （4.5ml/s）.Virtual non-enhanced CT （VNCT） image sets were reformatted from ‘Liver VNC’ software.The mean CT number,noise,signal to noise ratio （SNR）,image quality,and radiation dose were compared between TNCT and VNCT image sets.Results There was no significant difference in mean CT numbers of all organs （P0.05）.However,VNCT images had significantly lower noise and higher SNR than TNCT images （both P0.05）.Image quality of VNCT was lower than that of TNCT without significant difference （P0.05）.Radiation dose of nephrographic phase with dual-energy mode was significantly higher than that of TNCT and excretory phase scanning （P0.05）.Conclusion Dual-energy VNCT requires less radiation dose and therefore has a potential to replace TNCT in the dual-source CT urography.