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Optimization of radiation dose for CT detection of lytic and sclerotic bone lesions: a phantom study

  • Computed Tomography
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European Radiology Aims and scope Submit manuscript



To determine the best compromise between low radiation dose and suitable image quality for the detection of lytic and sclerotic bone lesions of the lumbar spine and pelvis.


A phantom was scanned using the routine protocol (STD, 13 mGy) and six decreasing dose levels. Raw data were reconstructed using level 3 of iterative reconstruction (IR3) with 1-mm slice thickness for the STD protocol and highest IR levels with 3-mm slice thickness for the others. CTDIvol was used for radiation dose assessment. Quantitative criteria (noise power spectrum [NPS], task-based transfer function [TTF], and the detectability index [d′]), as well as qualitative analysis, were used to compare protocols. NPS and TTF were computed using specific software (imQuest). d′ was computed for two imaging tasks: lytic and sclerotic bone lesions. A subjective analysis was performed to validate the image quality obtained on the anthropomorphic phantom with the different dose values.


Similar d′ values were found for CTDIvol from 3 to 4 mGy with IR4 and from 1 to 2 mGy for IR5 compared with d′ values using the STD protocol. Image quality was validated subjectively for IR4 but rejected for IR5 (image smoothing). Finally, for the same d′, the dose was reduced by 74% compared with the STD protocol, with the CTDIvol being 3.4 mGy for the lumbar spine and for the pelvis.


A dose level as low as 3.4 mGy, in association with high levels of IR, provides suitable image quality for the detection of lytic and sclerotic bone lesions of the lumbar spine and pelvis.

Key Points

• A CTDI vol of 3.4 mGy, in association with high iterative reconstruction level, provides suitable image quality for the detection of lytic and sclerotic bone lesions, both at objective and subjective analysis.

• Compared with the standard protocol, radiation dose can be reduced up to 74% for the lumbar spine and pelvis.

• A task-based image quality assessment using  the detectability index represents an objective method for the assessment of image quality and bridges the gap between complex physical metrics and subjective image analysis.

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Fig. 1

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Computed tomography

CTDIvol :

Volume-computed tomography dose index


Detectability index


Dose length product


Effective dose


Edge-spread function


Filtered back projection


Iterative reconstruction


Line-spread function


Noise power spectrum


Nonprewhitening observer model with eye filter


Region of interest


Sinogram-affirmed iterative reconstruction


Standard protocol


Task-based transfer function


  1. Brenner DJ, Hall EJ (2007) Computed tomography--an increasing source of radiation exposure. N Engl J Med 357:2277–2284

    Article  CAS  Google Scholar 

  2. Laurent G, Villani N, Hossu G et al (2019) Full model-based iterative reconstruction (MBIR) in abdominal CT increases objective image quality, but decreases subjective acceptance. Eur Radiol 29:4016–4025

    Article  Google Scholar 

  3. Racine D, Ryckx N, Ba A et al (2018) Task-based quantification of image quality using a model observer in abdominal CT: a multicentre study. Eur Radiol 28:5203–5210

    Article  Google Scholar 

  4. Greffier J, Macri F, Larbi A et al (2016) Dose reduction with iterative reconstruction in multi-detector CT: what is the impact on deformation of circular structures in phantom study? Diagn Interv Imaging 97:187–196

    Article  CAS  Google Scholar 

  5. Larbi A, Orliac C, Frandon J et al (2018) Detection and characterization of focal liver lesions with ultra-low dose computed tomography in neoplastic patients. Diagn Interv Imaging 99:311–320

    Article  CAS  Google Scholar 

  6. Suntharalingam S, Mikat C, Wetter A et al (2018) Whole-body ultra-low dose CT using spectral shaping for detection of osteolytic lesion in multiple myeloma. Eur Radiol 28:2273–2280

    Article  Google Scholar 

  7. Park JH, Jeon JJ, Lee SS et al (2018) Can we perform CT of the appendix with less than 1 mSv? A De-escalating dose-simulation study. Eur Radiol 28:1826–1834

    Article  Google Scholar 

  8. Fingerle AA, Noël PB (2018) Dose reduction in abdominal CT: the road to submillisievert imaging. Eur Radiol 28:2743–2744

    Article  Google Scholar 

  9. Omoumi P, Verdun FR, Becce F (2015) Optimization of radiation dose and image quality in musculoskeletal CT: emphasis on iterative reconstruction techniques (part 2). Semin Musculoskelet Radiol 19:422–430

    Article  Google Scholar 

  10. Samei E, Richard S (2015) Assessment of the dose reduction potential of a model-based iterative reconstruction algorithm using a task-based performance metrology. Med Phys 42:314–323

    Article  Google Scholar 

  11. Solomon J, Zhang Y, Wilson J, Samei E (2018) An automated software tool for task-based image quality assessment and matching in clinical CTusing the TG-233 framework. AAPM 2018, Nashville TN

  12. Gervaise A, Gervaise-Henry C, Pernin M, Naulet P, Junca-Laplace C, Lapierre-Combes M (2016) How to perform low-dose computed tomography for renal colic in clinical practice. Diagn Interv Imaging 97:393–400

    Article  CAS  Google Scholar 

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We are deeply grateful to Dr. J. Solomon for support regarding the use of the imQuest software.


The authors state that this work has not received any funding.

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Correspondence to J. Greffier.

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The scientific guarantor of this publication is Jean Paul Beregi.

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The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.

Statistics and biometry

No complex statistical methods were necessary for this paper.

Informed consent

Written informed consent was not required for this study because this is a phantom study.

Ethical approval

Institutional Review Board approval was not required because this is a phantom study.


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Greffier, J., Frandon, J., Pereira, F. et al. Optimization of radiation dose for CT detection of lytic and sclerotic bone lesions: a phantom study. Eur Radiol 30, 1075–1078 (2020).

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