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 (P>0.05) . However, VNCT images had significantly lower noise and higher SNR than TNCT images (both P<0.05) . Image quality of VNCT was lower than that of TNCT without significant difference (P>0.05) . Radiation dose of nephrographic phase with dual-energy mode was significantly higher than that of TNCT and excretory phase scanning (P<0.05) .
Conclusion: Dual-energy VNCT requires less radiation dose and therefore has a potential to replace TNCT in the dual-source CT urography.