Less radiation, same quality: contrast-enhanced multi-detector computed tomography investigation of thoracic lymph nodes with one milli-sievert
- 80 Downloads
Mediastinal, hilar, and peripheral pulmonary lymphadenopathy is a hallmark sign of different benign and malignant diseases of the chest. Contrast-enhanced (CE) chest CT is a test frequently applied to examine thoracic lymph node zones. We attempted to find out whether mediastinal, hilar, and peripheral lymph nodes delineate equally in CE chest CT with reduced dose (CE-LDCT, about 1 mSv) when compared with accepted standard CE chest CT (CE-SDCT).
Materials and methods
In this ethics committee-approved, mono-institutional, retrospective (20 months) matched case–control study, two independent, blinded observers compared measurable lymph node delineation (yes–no) in six different International Association for the Study of Lung Cancer (IASLC) zones (upper mediastinal, aortopulmonary, subcarinal, lower mediastinal, hilar, peripheral) between 62 CE-LDCT cases and 124 CE-SDCT controls (respective tube charge, 100, 120 KVp, computed tomography dose index, 1.66 ± 0.51, 5.36 ± 2.24 mGy, automatic exposure control-modulated 64-row multi-detector chest CT with iterative image reconstruction). Individual matching for gender (53% female), age (53 ± 19 years), body height, weight, anterior–posterior and transverse diameters of chest and lung ruled out pre-test confounders. Lymph node size (cut-off value, 1 cm) was a potential post-test confounder. Two-tailed T test and Chi-square test were significant for p < 0.05.
Measurable lymph nodes delineated equally in cases (261/372 IASLC zones, 70%; 280/372, 75%) and controls (528/744, 71%; 519/744, 70%; no significant differences, power 90%). One observer delineated significantly more peripheral zone lymph nodes in cases (35/62) than in controls (43/124); there were no significant differences otherwise. Lymph node size did not differ significantly; effective dose was 1.0 ± 0.3 mSv in cases and 3.4 ± 1.5 mSv in controls.
CE-LDCT with about 1 mSv demonstrated equal delineation of thoracic lymph nodes when compared with accepted standard CE-SDCT.
KeywordsChest CT Low dose Contrast media Lymph node delineation IASLC classification
Automatic exposure control
Body mass index
Intravenous contrast enhancement or intravenously contrast-enhanced
Contrast-enhanced highly dose-saving computed tomography of the chest
Contrast-enhanced computed tomography of the chest with standard dose
Computed tomography dose index
Dose length product
Conversion factor of EUR 16262 EN
International Association for the Study of Lung Cancer
Iterative image reconstruction
Highly dose-saving computed tomography of the chest
Multi-detector row-computed tomography
Picture archiving and communication system
Computed tomography of the chest with standard dose
This manuscript includes results of doctoral thesis work in preparation by Larissa Marwitz at the Faculty of Medicine of the University of Munich (“Ludwig-Maximilians-Universität”, LMU), Germany. Authors acknowledge the kind support of their research activities by Professors Maximilian F. Reiser and Jens Ricke, Directors of the Department of Radiology of the Faculty of Medicine of the University of Munich (“Ludwig-Maximilians-Universität”, LMU), Germany.
Compliance with ethical standards
Conflict of interest
All authors declare that there is no conflict of interest.
This was a retrospective study. It was performed in accordance with the Declaration of Helsinki and approved by the local ethics committee. This article does not contain any studies with animals.
- 2.Shrimpton PC, Hillier MC, Meeson S et al (2014) Doses from computed tomography (ct) examinations in the UK—2011 review. Public Health England, Centre for Radiation, Chemical and Environmental Hazards, September, 2014. PHE publications gateway number: 2014179. www.gov.uk/phe. Accessed 16 May 2016
- 4.Federal Office for Radiation Protection (2015) Radiation topics: X-ray diagnosis—harmful or useful? Salzgitter, Germany: Federal Office for Radiation Protection; September, 2015. https://www.bfs.de/SharedDocs/Downloads/BfS/DE/broschueren/ion/stth-roentgen.pdf. Accessed 16 May 2016 (in German)
- 6.Bundesministerium fuer Umwelt, Naturschutz, Bau und Reaktorsicherheit (2015) Umweltradioaktivitaet und Strahlenbelastung Jahresbericht 2013. BMUB, Bonn, Germany (in German, Summary in English, French, and German) Google Scholar
- 8.Mueck FG, Michael L, Deak Z et al (2013) Upgrade to iterative image reconstruction (IR) in MDCT imaging: a clinical study for detailed parameter optimization beyond vendor recommendations using the adaptive statistical iterative reconstruction environment (ASIR) part 2: the chest. Rofo 185:644–654CrossRefPubMedGoogle Scholar
- 10.Deutsche Gesetzliche Unfallversicherung (DGUV) (2011) Falkensteiner Empfehlung - Empfehlung für die Begutachtung asbestbedingter Berufskrankheiten. Berlin, Germany. http://publikationen.dguv.de/dguv/udt_dguv_main.aspx?FDOCUID=25466. Accessed 16 May 2016 (in German)
- 11.Bongartz G, Golding SJ, Jurik AG et al (2004) Appendix B—European field survey on MSCT. In: European guidelines for multislice computed tomography. Funded by the European Commission, Contract number FIGM-CT2000-20078-CT-TIP. http://www.msct.eu/CT_Quality_Criteria.htm. Accessed 16 May 2016
- 12.Friberg EG, Widmark A, Ryste Hauge ICH (2009) National collection of local diagnostic reference levels in Norway and their role in optimization of X-ray examinations. Norwegian Radiation Protection Authority, ØsteråsGoogle Scholar
- 13.Federal Office for Radiation Protection (2015) Notice of diagnostic reference levels for radiology and nuclear medicine examinations. Federal Office for Radiation Protection, Salzgitter, Germany. https://www.bfs.de/SharedDocs/Downloads/BfS/DE/fachinfo/ion/drw-roentgen.pdf. Accessed 16 May 2016 (in German)
- 15.Ebner L, Knobloch F, Huber A et al (2014) Feasible dose reduction in routine chest computed tomography maintaining constant image quality using the last three scanner generations: from filtered back projection to sinogram-affirmed iterative reconstruction and impact of the novel fully integrated detector design minimizing electronic noise. J Clin Imaging Sci 4:38. https://doi.org/10.4103/2156-7514.137826 CrossRefPubMedPubMedCentralGoogle Scholar
- 20.Menzel HG, Schibilla H, Teunen D (eds.). European guidelines on quality criteria for computed tomography. EUR 16262 EN. http://www.drs.dk/guidelines/ct/quality/mainindex.htm. Accessed 16 May 2016
- 24.Hulley SB, Cummings SR, Browner WS et al (2007) Estimating sample size and power: applications and examples. In: Hulley SB, Cummings SR, Browner WS, Grady DG, Newman TB (eds) Designing clinical research, chapter 6, 3rd edn. Lippincott Williams and Wilkins, Philadelphia, pp 65–96Google Scholar
- 25.Glantz SA (1997) How to analyze rates and proportions. In: Glantz SA (ed) Primer of biostatistics, chapter 5, 4th edn. McGraw-Hill Health Professions Division, New York, St. Louis, San Francisco, Auckland, Bogota, Caracas, Lisbon, London, Madrid, Mexico City, Milan, Montreal, New Delhi, San Juan, Sydney, Tokyo, Toronto, pp 108–150Google Scholar
- 27.Glantz SA (2012) The special case of two groups: the t-test. In: Glantz SA (eds) Primer of biostatistics, chapter 4, . 7th edn. McGraw-Hill Medical, New York Chicago San Francisco Lisbon London Madrid Mexico City Milan New Delhi San Juan Seoul Singapore Sydney Toronto, pp 49–72Google Scholar
- 30.Bundesamt für Strahlenschutz (2016) Diagnostic reference values for diagnostic and interventional X-ray applications. Salzgitter, Germany, BAnz AT 15.07.2016 B8. https://www.bfs.de/SharedDocs/Downloads/BfS/DE/rsh/rsh/A25-Roentgen-DRW.pdf;jsessionid=17BC3192738EDB6864E5A4D1BFB14504.1_cid391?__blob=publicationFile&v=1. Accessed 11 October 2016 (in German)
- 31.Khawaja RD, Singh S, Gilman M et al (2014) Computed tomography (CT) of the chest at less than 1 mSv: an ongoing prospective clinical trial of chest CT at submillisievert radiation doses with iterative model image reconstruction and iDose4 technique. J Comput Assist Tomogr 38:613–619CrossRefPubMedGoogle Scholar