A Study Of Clinical Application Of Dual-source CT Dual-energy Technique In Patients With Kindney Tumor Lesions

ObjectivesTo investigate the clinical value of Flash CT dual energy (DE) technique in the kindney tumor lesions.Materials and Methods46case confirmed as kindney tumor lesions by pathology were retrospectively analyzed from in January2012to on March2013in our hospital with Flash CT. It is a total of60lesions, of which32patients had complete surgical and pathological data,some of14patients with multiple imaging diagnosis and follow-up diagnosis. The selected patients underwent conventional plain and the cortex and medulla of dual energy mode enhanced scanning and substance of ordinary enhanced scan.The data were reconstructed with filtered back-projection FBP and Safire (Strength1-5)technique.The mean CT value, CT values, noise, signal-to-noise ratio (SNR), contrast to noise ratio (CNR), image quality score and lesions detectability were compared between six reconstructed data.140kV,80kV, weighted fusion120kV, virtual non-contrast (VNC)and iodine-enhanced images which were obtained through dual energy post-processing software were got by dual energy scan. VNC and TNC image were compared in the mean CT number, noise, signal-to-noise ratio (SNR),conventional non-contrast(TNC), image quality, lesions detectability and radiation dose (with CTDIvol and DLP). The contrast images in one phases of60cervical kindney tumor lesions were retrospectively analyzed. The mean CT number signal-to-noise ratio(SNR) and contrast to noise ratio (CNR) of kindney tumor lesions in140kV,100kV, weighted fusion the120kV images were measured. The degree of enhancement of renal cyst, angiomyolipoma and renal cell carcinoma in cortex and medulla of phases on iodine-enhanced and weighted fusion120kV images were evaluated. The mean CT numbers of kindney tumor lesions in the one phases on iodine-enhanced and weighted fusion120kV images for were measured to evaluate the effect of mean CT number for differentiating the benign and malignant cervical tumor of kidney. The mean CT numbers of dual-phase enhancemen on iodine-enhanced image for the enlarged kindney tumor lesions derived from different pathological change were compared to conclude the enhanced characteristics for the different pathological enlarge kindney tumor lesions.Totally46patientswith clinically or pathologically diagnosed kindney tumor lesions in this retrospective study. Definition Flash CT was used and dual-energy scan mode was used in their corticomedullary phase scan (100kVp、Sn140kVp).Kindney tumor lesions CT value difference, ratio of tumor to kindney tumor lesions and the line and draw energy spectrum curve maps, calculate three different renal parenchyma and the nature of the resulting spectrum of renal mass slope, research and analysis of three different properties placeholder CT values under different kev characteristic curve of the obtained spectra are compared, analyzed three kinds placeholder characteristics by Mono-energetic40kev-140kev.The data were analyzed in the use of Statistic Package for Social Science (SPSS)17.0. The enumeration data were shown as percentage (%).The numerical variable data were Gaussian distribution and the results were measured by mean number±standard deviation (x±s).The data were reconstructed with filtered back-projection FBP and Safire (Strength1-5)technique.The mean CT value, CT values, noise, signal-to-noise ratio (SNR), contrast to noise ratio (CNR), image quality score and lesions detectability were compared between six reconstructed data.The mean CT number, SNR and radiation dose on TNC, VNC images were compared with single factor variance analysis. The comparison between two groups was performed with SNK-q test when the comparision of multiple groups appeared P<0.05.The mean CT numbers of benign and malignant lymph nodes on iodine-enhanced image were compared with test. The detectilities of necrosis and calcification wihtin the enlarged kindney tumor lesions were compared with Fisher’s test. The mean CT numbers of enlarged kindney tumor lesions among different pathological types in corticomedullary phase on iodine-enhanced image were compared with single factor variance analysis. The comparison between two groups was performed with SNK-q test when the comparision of multiple groups appeared P<0.05. The mean CT numbers of diffent nature on iodine-enhanced image in corticomedullary phase were compared with tes0.05was the level of test and a value less than0.05was considered as significance.Results1.Pathology resultsIn the study, there were46patients with complete surgical and pathology data, including18cases of renal cell carcinoma and6cases derived from other renal cyst,14cases renal angiomyolipoma.,anotherl4cases make definite diagnosis by imageology.2.The comparative analysis of CT number, SNR, image quality, calcification of kindney tumor lesions between FBP and Safire techniqueThere was no statistically significant between FBP and Safire(Strengthl-5) technique of the CT numbers (P>0.05) in renal CT scan.but the noise respectively increased.There were differences among the six groups(P<0.05).The SAFIRE-5is lower than any others,it was respectively increased by48.26%.There was statistically significant between FBP and Safire(Strengthl-5)technique of the SNR (P<0.05) in renal CT scan.The SAF1RE-5is higher than any others,it was respectively increased by88.08%.There was statistically significant between FBP and Safire(Strengthl-5)technique of the CNR(P<0.05) in renal CT scan.The SAFIRE-5is higher than any others,it was respectively increased by69.23%.Image quality scores of Safire-1and5were lower than FBP. Safire2-4was higher than Safire3. The lesions detectability were similar in the reconstructed image.3.The comparative analysis of CT number, SNR, image quality, necrosis and calcification of renal cell carcinonu renal cyst and renal angiomyolipoma betweenThe mean CT numbers of renal cell carcinom、renal cyst and renal angiomyolipoma on TNC were respectively40.63±2.47、38.34±2.89and12.07±1.92.On VNC were respectively40.74±2.28、38.94±3.07and12.78±1.35. There were differences among the two groups(P <0.05). The SNR of renal cell carcinom、renal cyst and renal angiomyolipoma on TNC and VNC were respectively5.31±0.40、5.52±0.63、1.98±0.39and7.02±0.51、6.96±0.70、2.55±0.34.There were differences among the two groups(P<0.05).The CNR of renal cell carcinom、renal cyst and renal angiomyolipoma on TNC and VNC were respectively17.00±1.82,16.30±1.42、10.60±1.45and17.33±1.85、16.85±1.43、10.91±1.44.There were differences among the two groups(P<0.05).The score of image quality for TNC and VNC about renal cell carcinom、renal cyst and renal angiomyolipoma were respectively4.03±0.54,4.13±0.64and4.24±0.56. The score of VNC is lower than that of TNC, but there was no statistically significant (P>0.05).Althogh calcification in enlarged kindney tumor lesions be detected on VNC and TNC, VNC may miss the small calcification.4.The comparative analysis of effective radiation dose between TNC and DE scan.The effective radiation dose (ED) of TNC and DE scan were6.56±1.03mSv,7.73±1.34mSv and6.50±0.87mSv. The ED of DE scan for two phases was6.56mSv (about31.55%) lower than of TNC scan for three phases.5.The comparative analysis of CT number, SNR, CNR of kindney tumor lesions in corticomedullary phase between different kV.The mean CT numbers of enlarged renal cell carcinom、renal cyst and renal angiomyolipoma in corticomedullary phase on140kV、100kV and120kV images were89.23±2.38、59.86±2.70、8.11±0.54,133.26±2.69、88.61±3.31、12.24±1.29and109.47±2.99、74.31±3.37、10.42±0.96, There were differences among the three groups (P<0.05). In further comparison, there was difference between100kV and140kV、120kV weighted-average images. The mean CT number of100kV image was the higest among the three groups.There was no difference between140kV and weighted-average images.The mean SNR of enlarged renal cell carcinom、renal cyst and renal angiomyolipoma in corticomedullary phase on140kV、100kV and120kV images were20.23±5.03、12.05±1.32、1.92±0.24,29.21±6.20、18.93±4.31、2.01±0.30and30.86±8.09、17.53±1.53、2.19±0.31, There were differences among the three groups (P<0.05). In further comparison, there was difference between100kV and140kV、120kV weighted-average images. The mean SNR of100kV image was the higest among the three groups.There was no difference between140kV and weighted-average images.The mean CNR of enlarged renal cell carcinom、renal cyst and renal angiomyolipoma in corticomedullary phase on140kV、100kV and120kV images were29.86±3.76,20.42±1.70、9.95±1.31,36.24±3.86,25.03±2.92,10.81±1.42and31.54±2.73、22.31±1.96、9.71±1.11.There were differences among the three groups (P<0.05). In further comparison, there was difference between100kV and140kV、120kV weighted-average images. The mean CNR of100kV image was the higest among the three groups.There was no difference between140kV and weighted-average images.6.The iodine-enhanced images in corticomedullary phase between the kindney tumor lesions.The mean CT numbers of enlarged kindney tumor lesions on iodine-enhanced images in corticomedullary phase were39.81±2.38,26.40±1.88and10.26±1.91.There were differences among the three groups (P<0.05). In further comparison, there was difference between renal cell carcinom and renal cyst, renal cell carcinomrenal and renal angiomyolipomaN renal cyst and renal angiomyolipoma of the mean CT numbers.The mean CT numbers of renal cell carcinom image was the higest among the three groups.The iodine-enhanced in corticomedullary phase between the three lesions of the mean CT numbers/aorta abdominalis CT numbers degree of enhancement.There were0.18±0.02、0.12±0.02,0.05±0.01. There were differences among the three groups. In further comparison, there was difference between the other. It was the higest among the three groups.There was0.18±0.02.7、The different between the mono-energetic images in corticomedullary phase kindney tumor lesions.Contrast normal renal parenchymal tissue and mono-energetic40-140keV images in corticomedullary phase, CT values changed greatly,in the range of100-140keV slow decline spectroscopy curve was not significantly different, out of shape trends parallel, the CT values change about10HU less; renal angiomyolipoma was shown in40-90keV down more quickly after getting out of shape trends in parallel; renal cysts in the range of40-140keV CT values within little change tends to parallel. Contrast different kinds of kindney tumor lesions mono-energetic40-140keV images in corticomedullary phase, where kidney cancer, renal cyst hamartoma spectrum slope of the curve were3.21±0.35,2.94±0.06and0.26±0.07, three statistically significant difference between the further pairwise comparison, renal cysts, renal cancer and renal cysts and hamartomas are.according to a statistical difference (P<0.05), kidney cancer and hamartoma was no statistical difference between the two (P>0.05).Conclusionsl.Only one single DE enhanced scan can obtain contrast and VNC images in the examination of the kindney tumor lesions. There was no difference in the image quality between VNC and CNC. However, the mean CT number of VNC is higer than that of CNC.VNC may replace the CNC in the cervical lymph nodes imaging in the thorax.2. Under the same scan parameters,CT renal scan combined with Safire technique can effectively reduce image noise and improve image quality with the lower radiation dose.3. The effective radiation dose of dual enerey scan in the kindney tumor lesions is decreased about32.5%than that of conventional enhancement scan.4. The100kV images CT valume were higher than Sn140kV and120kV images, suitable check up the lesions.5.Both the iodine concentration of the iodine density images and the spectral curve of monochromatic images of spectral CT imaging demonstrated the potential in kindney tumor lesions.