Optimizing dual‐energy CT technique for iodine‐based contrast‐to‐noise ratio, a theoretical study.
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| Title: | Optimizing dual‐energy CT technique for iodine‐based contrast‐to‐noise ratio, a theoretical study. |
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| Authors: | Terzioglu, Fatma1 (AUTHOR) fterzioglu@ncsu.edu, Sidky, Emil Y.2 (AUTHOR), Phillips, John Paul2 (AUTHOR), Reiser, Ingrid S.2 (AUTHOR), Bal, Guillaume3 (AUTHOR), Pan, Xiaochuan2 (AUTHOR) |
| Source: | Medical Physics. Apr2024, Vol. 51 Issue 4, p2871-2881. 11p. |
| Subjects: | Dual energy CT (Tomography), Line integrals, Jacobian matrices, Contrast media, X-ray tubes |
| Abstract: | Background: Dual‐energy CT (DECT) systems provide valuable material‐specific information by simultaneously acquiring two spectral measurements, resulting in superior image quality and contrast‐to‐noise ratio (CNR) while reducing radiation exposure and contrast agent usage. The selection of DECT scan parameters, including x‐ray tube settings and fluence, is critical for the stability of the reconstruction process and hence the overall image quality. Purpose: The goal of this study is to propose a systematic theoretical method for determining the optimal DECT parameters for minimal noise and maximum CNR in virtual monochromatic images (VMIs) for fixed subject size and total radiation dose. Methods: The noise propagation in the process of projection based material estimation from DECT measurements is analyzed. The main components of the study are the mean pixel variances for the sinogram and monochromatic image and the CNR, which were shown to depend on the Jacobian matrix of the sinograms‐to‐DECT measurements map. Analytic estimates for the mean sinogram and monochromatic image pixel variances and the CNR as functions of tube potentials, fluence, and VMI energy are derived, and then used in a virtual phantom experiment as an objective function for optimizing the tube settings and VMI energy to minimize the image noise and maximize the CNR. Results: It was shown that DECT measurements corresponding to kV settings that maximize the square of Jacobian determinant values over a domain of interest lead to improved stability of basis material reconstructions. Instances of non‐uniqueness in DECT were addressed, focusing on scenarios where the Jacobian determinant becomes zero within the domain of interest despite significant spectral separation. The presence of non‐uniqueness can lead to singular solutions during the inversion of sinograms‐to‐DECT measurements, underscoring the importance of considering uniqueness properties in parameter selection. Additionally, the optimal VMI energy and tube potentials for maximal CNR was determined. When the x‐ray beam filter material was fixed at 2 mm of aluminum and the photon fluence for low and high kV scans were considered equal, the tube potential pair of 60/120 kV led to the maximal iodine CNR in the VMI at 53 keV. Conclusions: Optimizing DECT scan parameters to maximize the CNR can be done in a systematic way. Also, choosing the parameters that maximize the Jacobian determinant over the set of expected line integrals leads to more stable reconstructions due to the reduced amplification of the measurement noise. Since the values of the Jacobian determinant depend strongly on the imaging task, careful consideration of all of the relevant factors is needed when implementing the proposed framework. [ABSTRACT FROM AUTHOR] |
| Copyright of Medical Physics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
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| Header | DbId: egs DbLabel: Engineering Source An: 176451142 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Optimizing dual‐energy CT technique for iodine‐based contrast‐to‐noise ratio, a theoretical study. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Terzioglu%2C+Fatma%22">Terzioglu, Fatma</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> fterzioglu@ncsu.edu</i><br /><searchLink fieldCode="AR" term="%22Sidky%2C+Emil+Y%2E%22">Sidky, Emil Y.</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Phillips%2C+John+Paul%22">Phillips, John Paul</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Reiser%2C+Ingrid+S%2E%22">Reiser, Ingrid S.</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Bal%2C+Guillaume%22">Bal, Guillaume</searchLink><relatesTo>3</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Pan%2C+Xiaochuan%22">Pan, Xiaochuan</searchLink><relatesTo>2</relatesTo> (AUTHOR) – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Medical+Physics%22">Medical Physics</searchLink>. Apr2024, Vol. 51 Issue 4, p2871-2881. 11p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Dual+energy+CT+%28Tomography%29%22">Dual energy CT (Tomography)</searchLink><br /><searchLink fieldCode="DE" term="%22Line+integrals%22">Line integrals</searchLink><br /><searchLink fieldCode="DE" term="%22Jacobian+matrices%22">Jacobian matrices</searchLink><br /><searchLink fieldCode="DE" term="%22Contrast+media%22">Contrast media</searchLink><br /><searchLink fieldCode="DE" term="%22X-ray+tubes%22">X-ray tubes</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Background: Dual‐energy CT (DECT) systems provide valuable material‐specific information by simultaneously acquiring two spectral measurements, resulting in superior image quality and contrast‐to‐noise ratio (CNR) while reducing radiation exposure and contrast agent usage. The selection of DECT scan parameters, including x‐ray tube settings and fluence, is critical for the stability of the reconstruction process and hence the overall image quality. Purpose: The goal of this study is to propose a systematic theoretical method for determining the optimal DECT parameters for minimal noise and maximum CNR in virtual monochromatic images (VMIs) for fixed subject size and total radiation dose. Methods: The noise propagation in the process of projection based material estimation from DECT measurements is analyzed. The main components of the study are the mean pixel variances for the sinogram and monochromatic image and the CNR, which were shown to depend on the Jacobian matrix of the sinograms‐to‐DECT measurements map. Analytic estimates for the mean sinogram and monochromatic image pixel variances and the CNR as functions of tube potentials, fluence, and VMI energy are derived, and then used in a virtual phantom experiment as an objective function for optimizing the tube settings and VMI energy to minimize the image noise and maximize the CNR. Results: It was shown that DECT measurements corresponding to kV settings that maximize the square of Jacobian determinant values over a domain of interest lead to improved stability of basis material reconstructions. Instances of non‐uniqueness in DECT were addressed, focusing on scenarios where the Jacobian determinant becomes zero within the domain of interest despite significant spectral separation. The presence of non‐uniqueness can lead to singular solutions during the inversion of sinograms‐to‐DECT measurements, underscoring the importance of considering uniqueness properties in parameter selection. Additionally, the optimal VMI energy and tube potentials for maximal CNR was determined. When the x‐ray beam filter material was fixed at 2 mm of aluminum and the photon fluence for low and high kV scans were considered equal, the tube potential pair of 60/120 kV led to the maximal iodine CNR in the VMI at 53 keV. Conclusions: Optimizing DECT scan parameters to maximize the CNR can be done in a systematic way. Also, choosing the parameters that maximize the Jacobian determinant over the set of expected line integrals leads to more stable reconstructions due to the reduced amplification of the measurement noise. Since the values of the Jacobian determinant depend strongly on the imaging task, careful consideration of all of the relevant factors is needed when implementing the proposed framework. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Medical Physics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1002/mp.17010 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 11 StartPage: 2871 Subjects: – SubjectFull: Dual energy CT (Tomography) Type: general – SubjectFull: Line integrals Type: general – SubjectFull: Jacobian matrices Type: general – SubjectFull: Contrast media Type: general – SubjectFull: X-ray tubes Type: general Titles: – TitleFull: Optimizing dual‐energy CT technique for iodine‐based contrast‐to‐noise ratio, a theoretical study. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Terzioglu, Fatma – PersonEntity: Name: NameFull: Sidky, Emil Y. – PersonEntity: Name: NameFull: Phillips, John Paul – PersonEntity: Name: NameFull: Reiser, Ingrid S. – PersonEntity: Name: NameFull: Bal, Guillaume – PersonEntity: Name: NameFull: Pan, Xiaochuan IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 04 Text: Apr2024 Type: published Y: 2024 Identifiers: – Type: issn-print Value: 00942405 Numbering: – Type: volume Value: 51 – Type: issue Value: 4 Titles: – TitleFull: Medical Physics Type: main |
| ResultId | 1 |
