Acta Scientific Medical Sciences (ASMS)(ISSN: 2582-0931)

Research Article Volume 6 Issue 1

Dose Exposure and Diagnostic Capability of Split Bolus Computed Tomography Urography (CTU): Comparison with Single Bolus Technique

Clarissa Valle1,2*, Pietro Andrea Bonaffini1, Maurizio Balbi1,2, Francesca Invernizzi2, Noemi Liggeri1,3, Carlo Maria Ludovico Mondellini1,3, Annalisa Pappini2 and Sandro Sironi1,3

1Post-Graduate School of Diagnostic Radiology, University of Milano-Bicocca, Italy

2 Desio Hospital, Department of Diagnostic Radiology, University of Milano-Bicocca, Italy

3ASST Papa Giovanni XXIII, Department of Diagnostic Radiology, University of Milano-Bicocca, Italy

*Corresponding Author: Clarissa Valle, Post-Graduate School of Diagnostic Radiology, University of Milano-Bicocca, Italy.

Received: September 27, 2021; Published: December 08, 2021


Objectives: To compare CT urography (CTU) split bolus with standard protocol in terms of urinary tract opacification, parenchymal and vascular enhancement, and radiation dose exposure. To assess split bolus CTU diagnostic capability.

Methods: Forty-eight patients (18-83 years) were retrospectively analysed: 24 (study group) performed a split-bolus CTU (combined nephrographic-excretory phase), 24 (control group) a single bolus protocol. On combined and portal venous phases, quantitative analysis of intraluminal opacification and parenchymal-vascular enhancement (HU) was achieved by placing regions of interest (ROI) in urinary tract, liver, spleen, kidneys, abdominal aorta and inferior vena cava. The corresponding mean HU values were compared between 2 groups. Qualitative analysis of urinary intraluminal opacification was performed by two radiologists using a four-point scale; inter-observer agreement was calculated. Radiation dose was calculated as Dose Length Product (DLP) and Computed Tomography Dose Index Volume (CTDIvol). The diagnostic capability was evaluated using a 2-point scale, using histology, imaging follow-up and endoscopy as reference standard.

Results: The split-bolus protocol demonstrated lower mean urinary attenuation compared to the control group but no differences in quality of urinary tract opacification or in parenchymal-vascular enhancement. Mean DLP was lower (p = 0.045) in the study group (reduction of 37%). Split-bolus protocol answered the clinical question in 22/24 cases.

Conclusions: With a comparable urinary tract opacification, parenchymal organs and vessels enhancement, split-bolus CTU results in a proper accuracy with a dose reduction of 37%, as compared to single-bolus protocols.

Keywords: Computed Tomography; Split Bolus; Radiation Dose; Kidneys; Urinary Tract


  1. Potenta SE., et al. “CT Urography for evaluation of the Ureter”. RadioGraphics 35 (2015): 709-726.
  2. Van der Molen AJ., et al. “CT urography: definition, indications and techniques. A guideline for clinical practice”. European Radiology 18 (2008): 4-17.
  3. Silverman SG., et al. “What is the current role of CT urography and MR urography in the evaluation of the urinary tract?”. Radiology 250 (2009): 309-323.
  4. Sung MK., et al. “Current status of low dose multi-detector CT in the urinary tract”. World Journal of Radiology 3 (2011): 256-265.
  5. Poletti PA., et al. “Low-dose versus standard-dose CT protocol in patients with clinically suspected renal colic.” AJR American Journal of Roentgenology 188 (2007): 927-933.
  6. Geyer LL., et al. “State of the art: iterative CT reconstruction techniques”. Radiology 276 (2015): 339-357.
  7. World Health Organization. “Basics of radiation protection for everyday use. How to achieve ALARA: working tips and guidelines”. World Health Organization, Geneva.
  8. Scialpi M. et al, “Split-Bolus Single-Pass Multidetector-Row CT Protocol for Diagnosis of Acute Pulmonary Embolism”. Iranian Journal of Radiology 13 (2016): e19844.
  9. Chai RY., et al. “Comprehensive evaluation of patients with haematuria on multi-slice computed tomography scanner: protocol design and preliminary observations”. Australas Radiology 45 (2001): 536-538.
  10. Scialpi M., et al. “Split bolus multi detector-row computed tomography technique for characterization of focal liver lesions in oncologic patients”. Iranian Journal of Radiology 13 (2016): e20143.
  11. Brook OR., et al.” Split-bolus spectral multi detector CT of the pancreas: assessment of radiation dose and tumor conspicuity”. Radiology 269 (2013): 139-148.
  12. American College of Radiology ACR Appropriateness Criteria® (Revised 2018) Acute pyelonephritis.
  13. McColloug CH., et al. “CT dose reduction and dose management tools: overview of available options”. RadioGraphics 26 (2006): 503-512.
  14. Lescay HA., et al. “Anatomy, Abdomen and Pelvis, Ureter”. Stat Pearls Publishing.
  15. Landis JR., et al. “The measurement of observer agreement for categorical data”. Biometrics 33 (1977): 159-174.
  16. Sheth S., et al. “Current concepts in the diagnosis and management of renal cell carcinoma: role of multidetector ct and three-dimensional CT”. Radiographics 21 (2001): S237-S254.
  17. Wang L.J., et al. “Diagnosis of acute flank pain caused by ureteral stones: value of combined direct and indirect signs on IVU and unenhanced helical CT”. European Radiology 14 (2004): 1634-1640.
  18. Karlo CA., et al. “Split-bolus dual-energy CT urography: protocol optimization and diagnostic performance for the detection of urinary stones”. Abdom Imaging 38 (2013): 1136-1143.
  19. Kekelidze M., et al. “Kidney and urinary tract imaging: triple-bolus multidetector CT urography as a one-stop shop - protocol design, opacification, and image quality analysis”. Radiology 255 (2010): 508-516. 
  20. Chow L., et al. “Split-Bolus MDCT Urography with Synchronous Nephrographic and Excretory Phase Enhancement”. AJR American Journal of Roentgenology 189 (2007): 314-322.
  21. Martignano P., et al. “64-Slice CT urography: 30 months of clinical experience”. Radiologia Medica 115 (2010): 920-935.
  22. Cohan RH., et al. “MDCT urography: exploring a new paradigm for imaging of bladder cancer”. AJR American Journal of Roentgenology 192 (2009): 1501-1508.
  23. Babjuk M., et al. “EAU guidelines on non-muscle-invasive urothelial carcinoma of the bladder: update 2016”. European Urology 71 (2017): 447-461.
  24. Lee D., et al. “Optimization of split-bolus CT urography: effect of differences in allocation of contrast medium and prolongation of imaging delay”. AJR American Journal of Roentgenology 209 (2017): W10-W17.
  25. Chen CY., et al. “Diagnostic performance of split-bolus portal venous phase dual-energy CT urography in patients with hematuria”. AJR American Journal of Roentgenology 206 (2016): 1013-1022.
  26. Van der Molen A.J., et al. “A survey of radiation doses in CT urography before and after implementation of iterative reconstruction”. AJR American Journal of Roentgenology 205 (2015): 572-577.
  27. Jinzaki M., et al. “Role of computed tomography urography in the clinical evaluation of upper tract urothelial carcinoma”. International Journal of Urology 23 (2016): 284-298.
  28. Seyal AR., et al. “CT of the Abdomen with Reduced Tube Voltage in Adults: A Practical Approach”. RadioGraphics 35 (2015): 1922-1939.
  29. Nakayama Y., et al. “Lower tube voltage reduces contrast material and radiation doses on 16-MDCT aortography". AJR American Journal of Roentgenology 187 (2006): W490-W497.
  30. Ippolito D., et al. “Low kV settings CT angiography (CTA) with low dose contrast medium volume protocol in the assessment of thoracic and abdominal aorta disease: a feasibility study”. British Journal of Radiology 88 (2015): 20140140.


Citation: Clarissa Valle., et al. “Dose Exposure and Diagnostic Capability of Split Bolus Computed Tomography Urography (CTU): Comparison with Single Bolus Technique". Acta Scientific Medical Sciences 6.1 (2022): 62-71.


Copyright: © 2022 Clarissa Valle., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Acceptance rate30%
Acceptance to publication20-30 days
Impact Factor1.403

Indexed In

News and Events

  • Certification for Review
    Acta Scientific certifies the Editors/reviewers for their review done towards the assigned articles of the respective journals.
  • Submission Timeline for Upcoming Issue
    The last date for submission of articles for regular Issues is July 30, 2024.
  • Publication Certificate
    Authors will be issued a "Publication Certificate" as a mark of appreciation for publishing their work.
  • Best Article of the Issue
    The Editors will elect one Best Article after each issue release. The authors of this article will be provided with a certificate of "Best Article of the Issue"
  • Welcoming Article Submission
    Acta Scientific delightfully welcomes active researchers for submission of articles towards the upcoming issue of respective journals.

Contact US