Abstract
Objective
To investigate the impact of automated attenuation-based tube potential selection on image quality and exposure parameters in polytrauma patients undergoing contrast-enhanced thoraco-abdominal CT.
Methods
One hundred patients were examined on a 16-slice device at 120 kV with 190 ref.mAs and automated mA modulation only. Another 100 patients underwent 128-slice CT with automated mA modulation and topogram-based automated tube potential selection (autokV) at 100, 120 or 140 kV. Volume CT dose index (CTDIvol), dose–length product (DLP), body diameters, noise, signal-to-noise ratio (SNR) and subjective image quality were compared.
Results
In the autokV group, 100 kV was automatically selected in 82 patients, 120 kV in 12 patients and 140 kV in 6 patients. Patient diameters increased with higher kV settings. The median CTDIvol (8.3 vs. 12.4 mGy; −33 %) and DLP (594 vs. 909 mGy cm; −35 %) in the entire autokV group were significantly lower than in the group with fixed 120 kV (p < 0.05 for both). Image quality remained at a constantly high level at any selected kV level.
Conclusion
Topogram-based automated selection of the tube potential allows for significant dose savings in thoraco-abdominal trauma CT while image quality remains at a constantly high level.
Key Points
• Automated kV selection in thoraco-abdominal trauma CT results in significant dose savings
• Most patients benefit from a 100-kV protocol with relevant DLP reduction
• Constantly good image quality is ensured
• Image quality benefits from higher kV when arms are positioned downward
Similar content being viewed by others
References
Boehm T, Alkadhi H, Schertler T et al (2004) Application of multislice spiral CT (MSCT) in multiple injured patients and its effect on diagnostic and therapeutic algorithms. Röfo 176(12):1734–1742
Hessmann MH, Hofmann A, Kreitner KF, Lott C, Rommens PM (2006) The benefit of multislice CT in the emergency room management of polytraumatized patients. Acta Chir Belg 106(5):500–507
Huber-Wagner S, Lefering R, Qvick LM et al (2009) Effect of whole-body CT during trauma resuscitation on survival: a retrospective, multicentre study. Lancet 373(9673):1455–1461
Wurmb TE, Fruhwald P, Hopfner W et al (2009) Whole-body multislice computed tomography as the first line diagnostic tool in patients with multiple injuries: the focus on time. J Trauma 66(3):658–665
Wurmb TE, Quaisser C, Balling H et al (2011) Whole-body multislice computed tomography (MSCT) improves trauma care in patients requiring surgery after multiple trauma. Emerg Med J 28(4):300–304
Pfeifer R, Tarkin IS, Rocos B, Pape HC (2009) Patterns of mortality and causes of death in polytrauma patients-has anything changed? Injury 40(9):907–911
Wada D, Nakamori Y, Yamakawa K et al (2013) Impact on survival of whole-body computed tomography before emergency bleeding control in patients with severe blunt trauma. Crit Care 17(4):R178
Yeguiayan JM, Yap A, Freysz M et al (2012) Impact of whole-body computed tomography on mortality and surgical management of severe blunt trauma. Crit Care 16(3):R101
Brenner DJ, Hall EJ (2007) Computed tomography-an increasing source of radiation exposure. N Engl J Med 357(22):2277–2284
Shuryak I, Sachs RK, Brenner DJ (2010) Cancer risks after radiation exposure in middle age. J Natl Cancer Inst 102(21):1628–1636
DGU (2012) http://www.traumaregister.de/images/stories/downloads/jahresberichte/tr-dgu-jahresbericht_2012.pdf. Accessed 4 Nov 2013
Brenner D, Elliston C, Hall E, Berdon W (2001) Estimated risks of radiation-induced fatal cancer from pediatric CT. AJR Am J Roentgenol 176(2):289–296
Kepros JP, Opreanu RC, Samaraweera R et al (2013) Whole body imaging in the diagnosis of blunt trauma, ionizing radiation hazards and residual risk. Eur J Trauma Emerg Surg 39:15–24
Kalra MK, Maher MM, Toth TL et al (2004) Techniques and applications of automatic tube current modulation for CT. Radiology 233(3):649–657
McCollough CH, Bruesewitz MR, Kofler JM Jr (2006) CT dose reduction and dose management tools: overview of available options. Radiographics 26(2):503–512
Raman SP, Johnson PT, Deshmukh S, Mahesh M, Grant KL, Fishman EK (2013) CT dose reduction applications: available tools on the latest generation of CT scanners. J Am Coll Radiol 10(1):37–41
Soderberg M, Gunnarsson M (2010) The effect of different adaptation strengths on image quality and radiation dose using Siemens Care Dose 4D. Radiat Prot Dosim 139(1–3):173–179
Hough DM, Fletcher JG, Grant KL et al (2012) Lowering kilovoltage to reduce radiation dose in contrast-enhanced abdominal CT: initial assessment of a prototype automated kilovoltage selection tool. AJR Am J Roentgenol 199(5):1070–1077
Marin D, Nelson RC, Barnhart H et al (2010) Detection of pancreatic tumors, image quality, and radiation dose during the pancreatic parenchymal phase: effect of a low-tube-voltage, high-tube-current CT technique - preliminary results. Radiology 256(2):450–459
Hendee WR, O'Connor MK (2012) Radiation risks of medical imaging: separating fact from fantasy. Radiology 264(2):312–321
Bayer J, Pache G, Strohm PC et al (2011) Influence of arm positioning on radiation dose for whole body computed tomography in trauma patients. J Trauma 70(4):900–905
Brink M, de Lange F, Oostveen LJ et al (2008) Arm raising at exposure-controlled multidetector trauma CT of thoracoabdominal region: higher image quality, lower radiation dose. Radiology 249(2):661–670
Loewenhardt B, Buhl M, Gries A et al (2012) Radiation exposure in whole-body computed tomography of multiple trauma patients: bearing devices and patient positioning. Injury 43(1):67–72
Gnannt R, Winklehner A, Eberli D, Knuth A, Frauenfelder T, Alkadhi H (2012) Automated tube potential selection for standard chest and abdominal CT in follow-up patients with testicular cancer: comparison with fixed tube potential. Eur Radiol 22(9):1937–1945
Goetti R, Winklehner A, Gordic S et al (2012) Automated attenuation-based kilovoltage selection: preliminary observations in patients after endovascular aneurysm repair of the abdominal aorta. AJR Am J Roentgenol 199(3):W380–W385
Ghoshhajra BB, Engel LC, Karolyi M et al (2013) Cardiac computed tomography angiography with automatic tube potential selection: effects on radiation dose and image quality. J Thorac Imaging 28(1):40–48
Karlo C, Gnannt R, Frauenfelder T et al (2011) Whole-body CT in polytrauma patients: effect of arm positioning on thoracic and abdominal image quality. Emerg Radiol 18(4):285–293
Acknowledgements
The scientific guarantor of this publication is Dr. Ralf Bauer. Drs. Ralf Bauer and Matthias Kerl declare relationships with Siemens AG.
The authors state that this work has not received any funding. Dr. Hanns Ackermann kindly provided statistical advice for this manuscript. Institutional review board approval was obtained. Written informed consent was waived by the institutional review board. None of the study subjects or cohorts have been previously reported. Methodology: retrospective, performed at one institution.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Frellesen, C., Stock, W., Kerl, J.M. et al. Topogram-based automated selection of the tube potential and current in thoraco-abdominal trauma CT – a comparison to fixed kV with mAs modulation alone. Eur Radiol 24, 1725–1734 (2014). https://doi.org/10.1007/s00330-014-3197-7
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00330-014-3197-7