Can iterative reconstruction algorithms replace tube loading compensation in low kVp hepatic CT? : Subjective versus objective image quality
(2020) In Acta Radiologica Open 9(3).- Abstract
Background: Hepatic computed tomography (CT) with decreased peak kilovoltage (kVp) may be used to reduce contrast medium doses in patients at risk of contrast-induced acute kidney injury (CI-AKI); however, it increases image noise. To preserve image quality, noise has been controlled by X-ray tube loading (mAs) compensation (TLC), i.e. increased mAs. Another option to control image noise would be to use iterative reconstructions (IR) algorithms without TLC (No-TLC). It is unclear whether this may preserve image quality or only reduce image noise.
Purpose: To evaluate image quality of 80 kVp hepatic CT with TLC and filtered back projection (FBP) compared with 80 kVp with No-TLC and IR algorithms (SAFIRE 3 and 5) in patients with... (More)
Background: Hepatic computed tomography (CT) with decreased peak kilovoltage (kVp) may be used to reduce contrast medium doses in patients at risk of contrast-induced acute kidney injury (CI-AKI); however, it increases image noise. To preserve image quality, noise has been controlled by X-ray tube loading (mAs) compensation (TLC), i.e. increased mAs. Another option to control image noise would be to use iterative reconstructions (IR) algorithms without TLC (No-TLC). It is unclear whether this may preserve image quality or only reduce image noise.
Purpose: To evaluate image quality of 80 kVp hepatic CT with TLC and filtered back projection (FBP) compared with 80 kVp with No-TLC and IR algorithms (SAFIRE 3 and 5) in patients with eGFR <45 mL/min.
Material and Methods: Forty patients (BMI 18-32 kg/m2) were examined with both protocols following injection of 300 mg I/kg. Hepatic attenuation, image noise, enhancement, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and subjective image quality were evaluated for each patient.
Results: Comparing TLC/FBP with No-TLC/IR-S5, there were no significant differences regarding hepatic attenuation, image noise, enhancement, SNR and CNR: 114 vs. 115 HU, 14 vs. 14 HU, 55 vs. 57 HU, 8.0 vs. 8.4, and 3.8 vs. 4.0 in median, respectively. No-TLC/IR-S3 resulted in higher image noise and lower SNR and CNR than TLC/FBP. Subjective image quality scoring with visual grading showed statistically significantly inferior scores for IR-S5 images.
Conclusion: CT of 80 kVp to reduce contrast medium dose in patients at risk of CI-AKI combined with IR algorithms with unchanged tube loading to control image noise does not provide sufficient diagnostic quality.
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- author
- Holmquist, Fredrik LU ; Söderberg, Marcus LU ; Nyman, Ulf LU ; Fält, Tobias LU ; Siemund, Roger LU and Geijer, Mats LU
- organization
- publishing date
- 2020-03
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Acta Radiologica Open
- volume
- 9
- issue
- 3
- pages
- 9 pages
- publisher
- SAGE Publications
- external identifiers
-
- pmid:32206344
- ISSN
- 2058-4601
- DOI
- 10.1177/2058460120910575
- language
- English
- LU publication?
- yes
- additional info
- © The Foundation Acta Radiologica 2020.
- id
- e7b2b467-836c-4216-bb1e-660064c112f5
- date added to LUP
- 2021-01-07 23:17:52
- date last changed
- 2021-01-08 16:42:02
@article{e7b2b467-836c-4216-bb1e-660064c112f5, abstract = {{<p>Background: Hepatic computed tomography (CT) with decreased peak kilovoltage (kVp) may be used to reduce contrast medium doses in patients at risk of contrast-induced acute kidney injury (CI-AKI); however, it increases image noise. To preserve image quality, noise has been controlled by X-ray tube loading (mAs) compensation (TLC), i.e. increased mAs. Another option to control image noise would be to use iterative reconstructions (IR) algorithms without TLC (No-TLC). It is unclear whether this may preserve image quality or only reduce image noise.</p><p>Purpose: To evaluate image quality of 80 kVp hepatic CT with TLC and filtered back projection (FBP) compared with 80 kVp with No-TLC and IR algorithms (SAFIRE 3 and 5) in patients with eGFR <45 mL/min.</p><p>Material and Methods: Forty patients (BMI 18-32 kg/m2) were examined with both protocols following injection of 300 mg I/kg. Hepatic attenuation, image noise, enhancement, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and subjective image quality were evaluated for each patient.</p><p>Results: Comparing TLC/FBP with No-TLC/IR-S5, there were no significant differences regarding hepatic attenuation, image noise, enhancement, SNR and CNR: 114 vs. 115 HU, 14 vs. 14 HU, 55 vs. 57 HU, 8.0 vs. 8.4, and 3.8 vs. 4.0 in median, respectively. No-TLC/IR-S3 resulted in higher image noise and lower SNR and CNR than TLC/FBP. Subjective image quality scoring with visual grading showed statistically significantly inferior scores for IR-S5 images.</p><p>Conclusion: CT of 80 kVp to reduce contrast medium dose in patients at risk of CI-AKI combined with IR algorithms with unchanged tube loading to control image noise does not provide sufficient diagnostic quality.</p>}}, author = {{Holmquist, Fredrik and Söderberg, Marcus and Nyman, Ulf and Fält, Tobias and Siemund, Roger and Geijer, Mats}}, issn = {{2058-4601}}, language = {{eng}}, number = {{3}}, publisher = {{SAGE Publications}}, series = {{Acta Radiologica Open}}, title = {{Can iterative reconstruction algorithms replace tube loading compensation in low kVp hepatic CT? : Subjective versus objective image quality}}, url = {{http://dx.doi.org/10.1177/2058460120910575}}, doi = {{10.1177/2058460120910575}}, volume = {{9}}, year = {{2020}}, }