Systematic Evaluation of Low-dose MDCT for Planning Purposes of Lumbosacral Periradicular Infiltrations

  • Nico SollmannEmail author
  • Kai Mei
  • Simon Schön
  • Isabelle Riederer
  • Felix K. Kopp
  • Maximilian T. Löffler
  • Monika Probst
  • Ernst J. Rummeny
  • Claus Zimmer
  • Jan S. Kirschke
  • Peter B. Noël
  • Thomas Baum
Original Article



To evaluate image quality and confidence for planning of periradicular infiltrations using virtually lowered tube currents and in-house developed iterative reconstruction (IR) for multidetector computed tomography (MDCT).


A total of 20 patients (mean age 54.9 ± 13.1 years) underwent MDCT for planning purposes of periradicular infiltrations at the lumbosacral spine (120 kVp and 100 mAs). Planning scans were simulated as if they were performed at 50% (D50), 10% (D10), 5% (D5), and 1% (D1) of the tube current of original scanning. Image reconstruction was achieved with two levels of IR (A: similar in appearance to clinical reconstructions, B: 10 times stronger noise reduction). Qualitative image evaluation was performed by two readers (R1 and R2) considering overall image quality and artifacts, image contrast, determination of nerve root, and confidence for intervention planning (scoring: 1 high, 2 medium, and 3 low confidence).


Level A of IR was favorable regarding overall image quality, artifacts, image contrast, and nerve root depiction according to both readers, with preserved good to excellent scores down to D10 scans. The confidence for intervention planning was not significantly different (p > 0.05) between scans with tube currents virtually lowered down to 10% as compared to the original scans when using level A of IR (R1: 1.2 ± 0.4, R2: 1.1 ± 0.3). Inter-reader agreement for planning confidence was good to excellent (range of weighted Cohen’s kappa: 0.62–1.00).


The use of MDCT for planning purposes of lumbosacral periradicular infiltrations may be possible with tube currents lowered down to 10% of standard dose (equal to 10 mAs) without limitations in planning confidence.


Image processing Interventional radiology Multidetector computed tomography Radiation dosage Spine 



As low as reasonably achievable


Volumetric CT dose index


Field of view


Hounsfield Units


Iterative reconstruction


Multidetector computed tomography


Picture archiving and communication system


Reader 1


Reader 2


Standard deviation



We acknowledge support through the University of Pennsylvania Research Foundation (URF) and Philips Healthcare.

Compliance with ethical guidelines

Conflict of interest

N. Sollmann, K. Mei, S. Schön, I. Riederer, F.K. Kopp, M.T. Löffler, M. Probst, E.J. Rummeny, C. Zimmer, J.S. Kirschke, P.B. Noël and T. Baum declare that they have no conflict of interest regarding the methods used or results presented in this study.

Ethical standards

All investigations described in this manuscript were carried out with the approval of the responsible ethics committee and in accordance with national law and the Helsinki Declaration of 1975 (in its current revised form). Informed consent was obtained from the patient in this case if identifiable from images or other information within the manuscript. Ethics Committee Registration Number: 62/18 S


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Nico Sollmann
    • 1
    • 2
    Email author
  • Kai Mei
    • 3
  • Simon Schön
    • 1
  • Isabelle Riederer
    • 1
  • Felix K. Kopp
    • 3
  • Maximilian T. Löffler
    • 1
  • Monika Probst
    • 1
  • Ernst J. Rummeny
    • 3
  • Claus Zimmer
    • 1
  • Jan S. Kirschke
    • 1
    • 2
  • Peter B. Noël
    • 3
    • 4
  • Thomas Baum
    • 1
  1. 1.Department of Diagnostic and Interventional Neuroradiology, Klinikum rechts der IsarTechnische Universität MünchenMunichGermany
  2. 2.TUM-Neuroimaging Center, Klinikum rechts der IsarTechnische Universität MünchenMunichGermany
  3. 3.Department of Diagnostic and Interventional Radiology, Klinikum rechts der IsarTechnische Universität MünchenMunichGermany
  4. 4.Department of Radiology, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaUSA

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