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Virtual monoenergetic images by spectral detector computed tomography may improve image quality and diagnostic ability for ischemic lesions in acute ischemic stroke

Mellander, Helena LU orcid ; Bengtsson, Pär LU orcid ; Fransson, Veronica LU orcid ; Ramgren, Birgitta LU ; Undrén, Per LU ; Drake, Mattias LU ; Ydström, Kristina LU ; Lätt, Jimmy LU ; Hilal, Amir and Wassélius, Johan LU , et al. (2023) In Acta Radiologica 64(4). p.1631-1640
Abstract

Background: Acute ischemic lesions are challenging to detect by conventional computed tomography (CT). Virtual monoenergetic images may improve detection rates by increased tissue contrast. Purpose: To compare the ability to detect ischemic lesions of virtual monoenergetic with conventional images in patients with acute stroke. Material and Methods: We included consecutive patients at our center that underwent brain CT in a spectral scanner for suspicion of acute stroke, onset <12 h, with or without (negative controls) a confirmed cortical ischemic lesion in the initial scan or a follow-up CT or magnetic resonance imaging. Attenuation was measured in predefined areas in ischemic gray (guided by follow-up exams), normal gray, and... (More)

Background: Acute ischemic lesions are challenging to detect by conventional computed tomography (CT). Virtual monoenergetic images may improve detection rates by increased tissue contrast. Purpose: To compare the ability to detect ischemic lesions of virtual monoenergetic with conventional images in patients with acute stroke. Material and Methods: We included consecutive patients at our center that underwent brain CT in a spectral scanner for suspicion of acute stroke, onset <12 h, with or without (negative controls) a confirmed cortical ischemic lesion in the initial scan or a follow-up CT or magnetic resonance imaging. Attenuation was measured in predefined areas in ischemic gray (guided by follow-up exams), normal gray, and white matter in conventional images and retrieved in spectral diagrams for the same locations in monoenergetic series at 40–200 keV. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Visual assessment of diagnostic measures was performed by independent review by two neuroradiologists blinded to reconstruction details. Results: In total, 29 patients were included (January 2018 to July 2019). SNR was higher in virtual monoenergetic compared to conventional images, significantly at 60–150 keV. CNR between ischemic gray and normal white matter was higher in monoenergetic images at 40–70 keV compared to conventional images. Virtual monoenergetic images received higher scores in overall image quality. The sensitivity for diagnosing acute ischemia was 93% and 97%, respectively, for the reviewers, compared to 55% of the original report based on conventional images. Conclusion: Virtual monoenergetic reconstructions of spectral CIs may improve image quality and diagnostic ability in stroke assessment.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Dual-energy computed tomography, dual-layer computed tomography detector, image quality, ischemic stroke, monochromatic computed tomography images
in
Acta Radiologica
volume
64
issue
4
pages
1631 - 1640
publisher
SAGE Publications
external identifiers
  • scopus:85140098556
  • pmid:36255120
ISSN
0284-1851
DOI
10.1177/02841851221130612
language
English
LU publication?
yes
id
272338e7-7a76-4cf0-8744-0df2ed18d9f4
date added to LUP
2023-02-09 11:19:30
date last changed
2024-04-30 09:17:11
@article{272338e7-7a76-4cf0-8744-0df2ed18d9f4,
  abstract     = {{<p>Background: Acute ischemic lesions are challenging to detect by conventional computed tomography (CT). Virtual monoenergetic images may improve detection rates by increased tissue contrast. Purpose: To compare the ability to detect ischemic lesions of virtual monoenergetic with conventional images in patients with acute stroke. Material and Methods: We included consecutive patients at our center that underwent brain CT in a spectral scanner for suspicion of acute stroke, onset &lt;12 h, with or without (negative controls) a confirmed cortical ischemic lesion in the initial scan or a follow-up CT or magnetic resonance imaging. Attenuation was measured in predefined areas in ischemic gray (guided by follow-up exams), normal gray, and white matter in conventional images and retrieved in spectral diagrams for the same locations in monoenergetic series at 40–200 keV. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Visual assessment of diagnostic measures was performed by independent review by two neuroradiologists blinded to reconstruction details. Results: In total, 29 patients were included (January 2018 to July 2019). SNR was higher in virtual monoenergetic compared to conventional images, significantly at 60–150 keV. CNR between ischemic gray and normal white matter was higher in monoenergetic images at 40–70 keV compared to conventional images. Virtual monoenergetic images received higher scores in overall image quality. The sensitivity for diagnosing acute ischemia was 93% and 97%, respectively, for the reviewers, compared to 55% of the original report based on conventional images. Conclusion: Virtual monoenergetic reconstructions of spectral CIs may improve image quality and diagnostic ability in stroke assessment.</p>}},
  author       = {{Mellander, Helena and Bengtsson, Pär and Fransson, Veronica and Ramgren, Birgitta and Undrén, Per and Drake, Mattias and Ydström, Kristina and Lätt, Jimmy and Hilal, Amir and Wassélius, Johan and Ullberg, Teresa}},
  issn         = {{0284-1851}},
  keywords     = {{Dual-energy computed tomography; dual-layer computed tomography detector; image quality; ischemic stroke; monochromatic computed tomography images}},
  language     = {{eng}},
  number       = {{4}},
  pages        = {{1631--1640}},
  publisher    = {{SAGE Publications}},
  series       = {{Acta Radiologica}},
  title        = {{Virtual monoenergetic images by spectral detector computed tomography may improve image quality and diagnostic ability for ischemic lesions in acute ischemic stroke}},
  url          = {{http://dx.doi.org/10.1177/02841851221130612}},
  doi          = {{10.1177/02841851221130612}},
  volume       = {{64}},
  year         = {{2023}},
}