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Deep learning reconstruction CT for liver metastases: low-dose dual-energy vs standard-dose single-energy

  • Computed Tomography
  • Published:
European Radiology Aims and scope Submit manuscript

A Commentary to this article was published on 04 August 2023

Abstract

Objectives

To assess image quality and liver metastasis detection of reduced-dose dual-energy CT (DECT) with deep learning image reconstruction (DLIR) compared to standard-dose single-energy CT (SECT) with DLIR or iterative reconstruction (IR).

Methods

In this prospective study, two groups of 40 participants each underwent abdominal contrast-enhanced scans with full-dose SECT (120-kVp images, DLIR and IR algorithms) or reduced-dose DECT (40- to 60-keV virtual monochromatic images [VMIs], DLIR algorithm), with 122 and 106 metastases, respectively. Groups were matched by age, sex ratio, body mass index, and cross-sectional area. Noise power spectrum of liver images and task-based transfer function of metastases were calculated to assess the noise texture and low-contrast resolution. The image noise, signal-to-noise ratios (SNR) of liver and portal vein, liver-to-lesion contrast-to-noise ratio (LLR), lesion conspicuity, lesion detection rate, and the subjective image quality metrics were compared between groups on 1.25-mm reconstructed images.

Results

Compared to 120-kVp images with IR, 40- and 50-keV VMIs with DLIR showed similar noise texture and LLR, similar or higher image noise and low-contrast resolution, improved SNR and lesion conspicuity, and similar or better perceptual image quality. When compared to 120-kVp images with DLIR, 50-keV VMIs with DLIR had similar low-contrast resolution, SNR, LLR, lesion conspicuity, and perceptual image quality but lower frequency noise texture and higher image noise. For the detection of hepatic metastases, reduced-dose DECT by 34% maintained observer lesion detection rates.

Conclusion

DECT assisted with DLIR enables a 34% dose reduction for detecting hepatic metastases while maintaining comparable perceptual image quality to full-dose SECT.

Clinical relevance statement

Reduced-dose dual-energy CT with deep learning image reconstruction is as accurate as standard-dose single-energy CT for the detection of liver metastases and saves more than 30% of the radiation dose.

Key Points

• The 40- and 50-keV virtual monochromatic images (VMIs) with deep learning image reconstruction (DLIR) improved lesion conspicuity compared with 120-kVp images with iterative reconstruction while providing similar or better perceptual image quality.

• The 50-keV VMIs with DLIR provided comparable perceptual image quality and lesion conspicuity to 120-kVp images with DLIR.

• The reduction of radiation by 34% by DLIR in low-keV VMIs is clinically sufficient for detecting low-contrast hepatic metastases.

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Abbreviations

CTDIvol:

Volumetric CT dose index

CT:

Computed tomography

DECT:

Dual-energy CT

DLIR:

Deep learning image reconstruction

DM:

Medium-strength deep learning image reconstruction

DH:

High-strength deep learning image reconstruction

FBP:

Filtered back projection

GEE:

Generalized estimating equations

IR:

Iterative reconstruction

NPS:

Noise power spectrum

TTF:

Task-based transfer function

SNR:

Signal-to-noise ratio

SECT:

Single-energy CT

VMIs:

Virtual monochromatic images

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Funding

Dr. Peijie Lyu received financial support from Key Scientific Research Project of Higher Education in Henan Province (22A320057).

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Corresponding author

Correspondence to Jianbo Gao.

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Guarantor

The scientific guarantor of this publication is Dr. Jianbo Gao.

Conflict of interest

The authors of this manuscript declare relationships with the following companies: GE Healthcare China for Luotong Wang. The other authors declare that they have no conflict of interest.

Statistics and biometry

No complex statistical methods were necessary for this paper.

Informed consent

The institutional review board approved this single-institution prospective study (Registry number: ChiCTR-DPD-16010302), and all participants provided written informed consent before enrollment.

Ethical approval

Institutional Review Board approval was obtained (The First Affiliated Hospital of Zhengzhou University).

Study subjects or cohorts overlap

No study subjects or cohorts have been previously reported.

Methodology

  • Prospective

  • Diagnostic study

  • Performed at one institution

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Lyu, P., Li, Z., Chen, Y. et al. Deep learning reconstruction CT for liver metastases: low-dose dual-energy vs standard-dose single-energy. Eur Radiol 34, 28–38 (2024). https://doi.org/10.1007/s00330-023-10033-3

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