Chiao-Yun Chen1,2,3, Jui-Sheng Hsu1,3, Twei-Shiun Jaw2,3, Ming-Chen Paul Shih2,4, Lo-Jeh Lee3, Tzu-Hsueh Tsai3, Gin-Chung Liu1,2,3. 1. 1 Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. 2. 2 Department of Radiology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. 3. 3 Department of Medical Imaging, Kaohsiung Medical University Hospital, 100 Tz You First Rd, Kaohsiung 807, Taiwan. 4. 4 Department of Medical Imaging, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung, Taiwan.
Abstract
OBJECTIVE: The purpose of this study is to evaluate the image quality of split-bolus portal venous phase urography and the potential reduction of radiation dose by using a second-generation dual-source dual-energy CT (DECT) scanner. MATERIALS AND METHODS: DECT urography was performed in 84 patients. Unenhanced CT was performed 20 minutes after drinking 800 mL of water. The split-bolus protocol consisted of a sequence of injections, as follows: 200 mL of normal saline (2.0 mL/s), 50 mL of contrast medium (2.5 mL/s) at 0 second, 70 mL of contrast medium (2.5 mL/s) at 360 seconds, and a saline flush of 25 mL. The scan was started at 420 seconds. Virtual unenhanced images were reconstructed from contrast-enhanced images. The mean CT density and signal-to-noise ratio (SNR) of the renal parenchyma, vessels, upper urinary tract, normal reference tissues, and tumors were measured for image quantitative analysis. Image quality and opacification of the collecting systems were rated by two radiologists using 3- or 4-point scales. RESULTS: The SNR of all measured sites, except the renal pelvis, showed a statistically significant correlation (p < 0.001) between the true unenhanced and virtual unenhanced images. The overall sensitivity of stone detection was 87.5% (28/32) in virtual unenhanced images. Image quality of the renal parenchyma, arteries, and veins was excellent in 59.5%, 75.0%, and 97.6% of cases, respectively. Opacification of the intrarenal collecting systems, proximal, middle, and distal ureters, and bladder was complete in 92.9%, 83.9%, 78.6%, 77.4%, and 26.2% of patients, respectively. Omitting the unenhanced scan can reduce the mean radiation dose from 15.6 to 6.7 mSv. CONCLUSION: Portal venous phase split-bolus DECT urography provides sufficient image quality with potential to reduce radiation exposure.
OBJECTIVE: The purpose of this study is to evaluate the image quality of split-bolus portal venous phase urography and the potential reduction of radiation dose by using a second-generation dual-source dual-energy CT (DECT) scanner. MATERIALS AND METHODS: DECT urography was performed in 84 patients. Unenhanced CT was performed 20 minutes after drinking 800 mL of water. The split-bolus protocol consisted of a sequence of injections, as follows: 200 mL of normal saline (2.0 mL/s), 50 mL of contrast medium (2.5 mL/s) at 0 second, 70 mL of contrast medium (2.5 mL/s) at 360 seconds, and a saline flush of 25 mL. The scan was started at 420 seconds. Virtual unenhanced images were reconstructed from contrast-enhanced images. The mean CT density and signal-to-noise ratio (SNR) of the renal parenchyma, vessels, upper urinary tract, normal reference tissues, and tumors were measured for image quantitative analysis. Image quality and opacification of the collecting systems were rated by two radiologists using 3- or 4-point scales. RESULTS: The SNR of all measured sites, except the renal pelvis, showed a statistically significant correlation (p < 0.001) between the true unenhanced and virtual unenhanced images. The overall sensitivity of stone detection was 87.5% (28/32) in virtual unenhanced images. Image quality of the renal parenchyma, arteries, and veins was excellent in 59.5%, 75.0%, and 97.6% of cases, respectively. Opacification of the intrarenal collecting systems, proximal, middle, and distal ureters, and bladder was complete in 92.9%, 83.9%, 78.6%, 77.4%, and 26.2% of patients, respectively. Omitting the unenhanced scan can reduce the mean radiation dose from 15.6 to 6.7 mSv. CONCLUSION: Portal venous phase split-bolus DECT urography provides sufficient image quality with potential to reduce radiation exposure.
Authors: Mohammad H Bagheri; Mark A Ahlman; Liza Lindenberg; Baris Turkbey; Jeffrey Lin; Ali Cahid Civelek; Ashkan A Malayeri; Piyush K Agarwal; Peter L Choyke; Les R Folio; Andrea B Apolo Journal: Urol Oncol Date: 2017-05-12 Impact factor: 3.498
Authors: Hanns Leonhard Kaatsch; Benjamin Valentin Becker; Simone Schüle; Patrick Ostheim; Kai Nestler; Julia Jakobi; Barbara Schäfer; Thomas Hantke; Marc A Brockmann; Michael Abend; Stephan Waldeck; Matthias Port; Harry Scherthan; Reinhard Ullmann Journal: Sci Rep Date: 2021-06-08 Impact factor: 4.379