La radiologia medica

, Volume 123, Issue 11, pp 818–826 | Cite as

Less radiation, same quality: contrast-enhanced multi-detector computed tomography investigation of thoracic lymph nodes with one milli-sievert

  • Ullrich G. Mueller-LisseEmail author
  • Larissa Marwitz
  • Amanda Tufman
  • Rudolf M. Huber
  • Hanna A. Zimmermann
  • Annemarie Walterham
  • Stefan Wirth
  • Marco Paolini



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.


Chest 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


Computed tomography dose index


Dose length product


Effective dose


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


Standard deviation


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.

Ethical standards

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.


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Copyright information

© Italian Society of Medical Radiology 2018

Authors and Affiliations

  • Ullrich G. Mueller-Lisse
    • 1
    • 3
    Email author
  • Larissa Marwitz
    • 1
  • Amanda Tufman
    • 2
    • 3
  • Rudolf M. Huber
    • 2
    • 3
  • Hanna A. Zimmermann
    • 1
  • Annemarie Walterham
    • 1
  • Stefan Wirth
    • 1
  • Marco Paolini
    • 1
    • 3
  1. 1.Department of Radiology, Klinikum der Universität MünchenLMU - University of MunichMunichGermany
  2. 2.Department of Pneumology, Klinikum der Universität MünchenLMU - University of MunichMunichGermany
  3. 3.Member of the German Centre for Lung Research (DZL) – CPC-MMunichGermany

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