OBJECTIVETo assess the upper urinary tract opacification and the diagnostic performance of one-bolus dual-source dual-energy CT urography (CTU) for painless hematuria.

METHODSTotally 205 patients who underwent dual-source dual-energy CTU for painless hematuria were enrolled in this study. CTU included true non-enhanced phase, dual-energy mode nephrographic phase, and FLASH mode excretory phase imaging of the urinary tract. Two radiologists independently evaluated the degree of upper urinary tract opacification. Prospective interpretations using true non-enhanced, nephrographic and excretory phase imaging for hematuria were recorded, as well as retrospective diagnosis using virtual non-enhanced, nephrographic and excretory phase imaging. The standard of reference included all available clinical, imaging, laboratory and follow-up data for up to 36 months after CTU exam. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, and accuracy were calculated. Receiver-operating characteristic (ROC) analysis was undertaken and the area under the curve (AUC) calculated. The prospective and retrospective diagnostic performance for hematuria and the radiation dose of two CTU protocols were compared.

RESULTSIt was found that 87.8% and 86.8% of segments were at least 50% opacified, respectively. The sensitivity, specificity, PPV, NPV and accuracy for hematuria for prospective interpretation were 95.2%, 91.9%, 98.2%, 81.0% and 94.6%, respectively. Comparable figures for retrospective diagnosis were 98.8%, 91.9%,98.2%, 94.4% and 97.6%. The AUC for prospective and retrospective diagnosis were 0.931±0.027 and 0.940±0.026, respectively (z=1.425, Bonferroni-corrected P>0.05). The radiation dose of the CTU protocol using in retrospective diagnosis[(12.732±3.485)mSv] was significantly lower than that of prospective diagnosis [(17.002±4.013)mSv] (P<0.05), with dose reduction of (32.74±8.92)%.

CONCLUSIONOne-bolus two-phase dual-source dual-energy CT urography provides at least 50% opacification of upper urinary tract segments and has high diagnostic performance for painless hematuria with relatively low radiation dose.