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Influence of adaptive statistical iterative reconstruction algorithm on image quality in coronary computed tomography angiography

View Article: PubMed Central - PubMed

ABSTRACT

Background: Coronary computed tomography angiography (CCTA) requires high spatial and temporal resolution, increased low contrast resolution for the assessment of coronary artery stenosis, plaque detection, and/or non-coronary pathology. Therefore, new reconstruction algorithms, particularly iterative reconstruction (IR) techniques, have been developed in an attempt to improve image quality with no cost in radiation exposure.

Purpose: To evaluate whether adaptive statistical iterative reconstruction (ASIR) enhances perceived image quality in CCTA compared to filtered back projection (FBP).

Material and methods: Thirty patients underwent CCTA due to suspected coronary artery disease. Images were reconstructed using FBP, 30% ASIR, and 60% ASIR. Ninety image sets were evaluated by five observers using the subjective visual grading analysis (VGA) and assessed by proportional odds modeling. Objective quality assessment (contrast, noise, and the contrast-to-noise ratio [CNR]) was analyzed with linear mixed effects modeling on log-transformed data. The need for ethical approval was waived by the local ethics committee as the study only involved anonymously collected clinical data.

Results: VGA showed significant improvements in sharpness by comparing FBP with ASIR, resulting in odds ratios of 1.54 for 30% ASIR and 1.89 for 60% ASIR (P = 0.004). The objective measures showed significant differences between FBP and 60% ASIR (P < 0.0001) for noise, with an estimated ratio of 0.82, and for CNR, with an estimated ratio of 1.26.

Conclusion: ASIR improved the subjective image quality of parameter sharpness and, objectively, reduced noise and increased CNR.

No MeSH data available.


Example of ROI locations for objective measures of contrast with a ROI diameter of 3 mm in measure A (a) and 5 mm in measure B (b).
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fig1-2058460116684884: Example of ROI locations for objective measures of contrast with a ROI diameter of 3 mm in measure A (a) and 5 mm in measure B (b).

Mentions: Contrast was determined as the difference in HU between two adjacent anatomical structures (13) as indicated in Fig. 1;


Influence of adaptive statistical iterative reconstruction algorithm on image quality in coronary computed tomography angiography
Example of ROI locations for objective measures of contrast with a ROI diameter of 3 mm in measure A (a) and 5 mm in measure B (b).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2 - License 3
Show All Figures
getmorefigures.php?uid=PMC5384491&req=5

fig1-2058460116684884: Example of ROI locations for objective measures of contrast with a ROI diameter of 3 mm in measure A (a) and 5 mm in measure B (b).
Mentions: Contrast was determined as the difference in HU between two adjacent anatomical structures (13) as indicated in Fig. 1;

View Article: PubMed Central - PubMed

ABSTRACT

Background: Coronary computed tomography angiography (CCTA) requires high spatial and temporal resolution, increased low contrast resolution for the assessment of coronary artery stenosis, plaque detection, and/or non-coronary pathology. Therefore, new reconstruction algorithms, particularly iterative reconstruction (IR) techniques, have been developed in an attempt to improve image quality with no cost in radiation exposure.

Purpose: To evaluate whether adaptive statistical iterative reconstruction (ASIR) enhances perceived image quality in CCTA compared to filtered back projection (FBP).

Material and methods: Thirty patients underwent CCTA due to suspected coronary artery disease. Images were reconstructed using FBP, 30% ASIR, and 60% ASIR. Ninety image sets were evaluated by five observers using the subjective visual grading analysis (VGA) and assessed by proportional odds modeling. Objective quality assessment (contrast, noise, and the contrast-to-noise ratio [CNR]) was analyzed with linear mixed effects modeling on log-transformed data. The need for ethical approval was waived by the local ethics committee as the study only involved anonymously collected clinical data.

Results: VGA showed significant improvements in sharpness by comparing FBP with ASIR, resulting in odds ratios of 1.54 for 30% ASIR and 1.89 for 60% ASIR (P = 0.004). The objective measures showed significant differences between FBP and 60% ASIR (P < 0.0001) for noise, with an estimated ratio of 0.82, and for CNR, with an estimated ratio of 1.26.

Conclusion: ASIR improved the subjective image quality of parameter sharpness and, objectively, reduced noise and increased CNR.

No MeSH data available.