Multiple Row Spiral Computer Tomography Urinary Tract Imaging In Clinical Application Of A Series Of Research

Purpose To retrospectively evaluate the effects of saline administration following contrast material injection, abdominal compression and two delay phase acquisition on image quality improvement of CT urography (CTU).Materials and Methods Medical records and informed consents of patients were obtained. In totally122patients (50men,72women), two delay phase images with MDCT(Siemens Somatom Sensation64) were performed. Scans began simultaneously with a contrast bolus injection of100ml (300mgI/ml) and or not a saline bolus injection of100ml at a rate of5ml/s. Two delay phase images were undergone at400and550seconds for each patient. Examinations were taken by using abdominal compression or not. The distention and opacification of the urinary tract were evaluated by two interpreters together on transverse images and post-processing3D images (VRT and MIP). Effects of four techniques (saline administration and abdominal compression, saline administration only, compression only, and neither saline administration nor compression) and two delay phase acquisition on image quality improvement were analysed by using ANOVA and Chi-square test.Results Saline administration improved opacification (P<0.05) and increased overall image quality (P<0.01) of the intrarenal collecting system and proximal ureter. Abdominal compression (P<0.05) and delayed phase image acquisition of550seconds (P<0.01) all improved distention of the intrarenal collecting system and proximal ureter but did not improve opacification. No statistically significant effects on the distal ureter were found. However, there were more visualized distal ureteral segments with the longer imaging delay.Conclusion Saline administration, abdominal compression and longer imaging delays are all effective in improving image quality of64-detector row CTU. Purpose To evaluate the clinical feasibility of dual-source CT urography using dual-energy virtual non-enhanced CT.Materials and Methods Totally240patients 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 of100ml (370mgI/ml) contrast material following100ml saline which were all at a rate of5ml/s. Virtual non-enhanced CT (VNCT) image sets were reformatted from ’LiverVNC’ 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 (both P<0.05).Conclusions In dual-source CT urography, dual-energy VNCT has potential clinical values in replacing TNCT with consequent saving in radiation dose. Purpose To assess upper urinary tract opacification and the performance of one-bolus dual-dource dual-energy CT urography for painless hematuria.Materials and Methods Between August2010and December2010, we identified205patients (137men,68women; age range,18-89years; mean±SD,61.1±14.9years) who underwent dual-source dual-energy CT urography (CTU) for painless hematuria. CTU included true non-enhanced phase, dual-energy mode nephrographic phase (100kVp/230mAs and Sn140kVp/178mAs) and FLASH mode (pitch3.0) 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, and laboratory data for up to15months after CT urography. 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 protocol were compared.Results87.8%and86.8%of segments were at least50%opacified, respectively. Sensitivity, specificity, PPV, NPV and accuracy for hematuria for prospective interpretation were95.2%,91.9%,98.2%,81.0%and94.6%, respectively. Comparable figures for retrospective diagnosis were98.8%,91.9%,98.2%,94.4%and97.6%. The AUC for prospective and retrospective diagnosis were (0.991±0.007) and (0.993±0.006), respectively (z=1.425, Bonferroni-corrected P>0.05). The radiation dose of CTU protocol using in retrospective diagnosis[(12,732±3.485)mSv] was significantly lower than that of prospective diagnosis [(17.002±4.013)mSv], with dose reduction of (32.74±8.92)%.Conclusion One-bolus two-phase dual-source dual-energy CT urography provided at least50%opacification of upper urinary tract segments and had high diagnostic performance for painless hematuria, as well as with relatively low radiation dose. Purpose To assess the clinical value of multi-detector row CT urography(MDCTU) in follow-up of patients with a history of previous urothelial tumor.Materials and Methods At our department, totally2800MDCTU examinations were performed from January2006through July2010. Of these,466CT urograms in413patients evaluated for a history of urothelial tumor, were included in the study. MDCTU was used for non-enhanced, nephrographic phase and excretory phase scanning that began with a contrast bolus injection of100ml (370mgI/ml) contrast material following100ml saline which were all at a rate of5ml/s. Axial and three-dimensional reformation images were prospectively evaluated for urothelial tumor recurrence. Sensitivity, specificity, accuracy, positive and negative predictive values were analyzed with the standard of reference, including all available pathological and clinical materials.Results In the post-operative follow-up of patients with previous urothelial cancer, sensitivity, specificity, accuracy, positive and negative predictive values of MDCTU for tumor recurrence were92.0%、99.0%、97.1%、97.2%and97.1%, respectively.Conclusions MDCTU plays an important role in the post-operative follow-up of patients with a history of urothelial cancer for recurrence.