Iterative Reconstruction Algorithm for CT: Can Radiation Dose Be Decreased While Low-Contrast Detectability Is Preserved?

Schindera, Sebastian T.; Odedra, Devang; Raza, Syed Musa; Kim, Tae Kyoung; Jang, Hyun‐Jung; Szücs-Farkas, Zsolt; Rogalla, Patrik

doi:10.1148/radiol.13122349

Cited by 136 publications

(56 citation statements)

References 17 publications

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“…When the radiation dose level is reduced excessively, the use of IR algorithms is unable to preserve image quality, as seen in studies by Hwang et al 21 and Hur et al, 41 where subjective image scores of IRIS images acquired at 50% and 70% dose respectively were considerably poorer than standard-dose FBP images. Similar findings were reported in two other studies by Love et al 50 and Schindera et al, 56 which assessed the performance of the iDose 4 and AIDR 3D algorithms respectively. It is difficult to quantify the optimal amount of dose reduction that IR algorithms are able to provide without compromising on image quality, since it is dependent on various factors such as the type of IR algorithm used and the anatomy of interest that is examined, although one study by Korn et al 23 suggested that the use of an IRIS algorithm preserves image quality up to a 20.4% reduction in dose level.…”

supporting

confidence: 89%

“…The study by Schindera et al 56 noted no significant improvement in low-contrast detectability, when AIDR 3D was used for scans on obese patients. Yet, a separate liver phantom study conducted by the same authors evaluating the use of AIDR 3D in general abdominal scans, reported that the use of AIDR 3D failed to preserve low-contrast detectability when the radiation dose level was reduced by 80%.…”

Section: Performance Of Aidr and Aidr 3d Algorithmsmentioning

confidence: 95%

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Does Iterative Reconstruction Improve Image Quality and Reduce Dose in Computed Tomography?

Qiu¹,

Seeram²

2016

Radiol Open J

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CitationA total of 57 articles were categorized as either synopsis articles or performance evaluation clinical studies, where the latter was further divided into 6 sub-categories according to the type of IR algorithm examined. The results show that the use of IR algorithms reduces objective image noise, and at least preserves spatial resolution and low contrast detectability, even when dose is reduced. The findings are also applicable to specific patient groups, such as pediatrics and obese patients. In conclusion, there is a general consensus that IR algorithms can faithfully reduce radiation dose and improve image quality in CT in comparison with the FBP algorithm.

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supporting

confidence: 89%

Section: Performance Of Aidr and Aidr 3d Algorithmsmentioning

confidence: 95%

Does Iterative Reconstruction Improve Image Quality and Reduce Dose in Computed Tomography?

Qiu¹,

Seeram²

2016

Radiol Open J

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“…Second, only two IR algorithms were assessed. A recent article on low-contrast performance in clinical studies for a third manufacturer (Toshiba Medical Systems) similarly concluded that LCR performance is degraded at reduced dose levels with IR techniques (9). Thus, while we have not assessed all manufacturers or algorithms, it appears that the current findings may not be unique to the two manufacturers evaluated in our article.…”

Section: Discussionmentioning

confidence: 99%

Degradation of CT Low-Contrast Spatial Resolution Due to the Use of Iterative Reconstruction and Reduced Dose Levels

et al. 2015

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Purpose To determine the dose reduction that could be achieved without degrading low-contrast spatial resolution (LCR) performance for two commercial iterative reconstruction (IR) techniques, each evaluated at two strengths with many repeated scans. Materials and Methods Two scanner models were used to image the American College of Radiology (ACR) CT Accreditation Phantom LCR section at volume CT dose indexes of 8, 12, and 16 mGy. Images were reconstructed by using filtered-back projection (FBP) and two manufacturers’ IR techniques, each at two strengths (moderate and strong). Data acquisition and reconstruction were repeated 100 times for each, yielding 1800 images. Three diagnostic medical physicists reviewed the LCR images in a blinded fashion and graded the visibility of four 6-mm rods with a six-point scale. Noninferiority and inferiority-superiority analyses were used to interpret the differences in LCR relative to FBP images acquired at 16 mGy. Results LCR decreased with decreasing dose for all reconstructions. Relative to FBP and full dose, 25%–50% dose reductions resulted in inferior LCR for vendors 1 and 2 for FBP and 25% dose reductions resulted in inferior and equivalent performance for vendor 1 and equivalent and superior performance for vendor 2 at moderate and strong IR settings, respectively. When dose was reduced by 50%, both IR techniques resulted in inferior LCR at both strength settings. Conclusion For radiation dose reductions of 25% or more, the ability to resolve the four 6-mm rods in the ACR CT Accreditation Phantom can be lost.

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“…For example, recent studies reported degraded low-contrast detectability using IR and decreased radiation doses, although conventional image quality is still maintained. [11][12][13] Task-based image quality metrics based on model observers have gained popularity in CT image quality evaluation, especially for application in image-quality assessment of IR algorithms. [14][15][16][17][18][19][20] Several previous studies have demonstrated a good correlation between the performance of human observer and model observer.…”

Section: Introductionmentioning

confidence: 99%

Construction of realistic phantoms from patient images and a commercial three-dimensional printer

et al. 2016

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Abstract. The purpose of this study was to use three-dimensional (3-D) printing techniques to construct liver and brain phantoms having realistic pathologies, anatomic structures, and heterogeneous backgrounds. Patient liver and head computed tomography (CT) images were segmented into tissue, vessels, liver lesion, white and gray matter, and cerebrospinal fluid (CSF). Stereolithography files of each object were created and imported into a commercial 3-D printer. Printing materials were assigned to each object after test scans, which showed that the printing materials had CT numbers ranging from 70 to 121 HU at 120 kV. Printed phantoms were scanned on a CT scanner and images were evaluated. CT images of the liver phantom had measured CT numbers of 77.8 and 96.6 HU for the lesion and background, and 137.5 to 428.4 HU for the vessels channels, which were filled with iodine solutions. The difference in CT numbers between lesions and background (18.8 HU) was representative of the low-contrast values needed for optimization tasks. The liver phantom background was evaluated with Haralick features and showed similar texture between patient and phantom images. CT images of the brain phantom had CT numbers of 125, 134, and 108 HU for white matter, gray matter, and CSF, respectively. The CT number differences were similar to those in patient images.

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Iterative Reconstruction Algorithm for CT: Can Radiation Dose Be Decreased While Low-Contrast Detectability Is Preserved?

Abstract: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13122349/-/DC1.

Cited by 136 publications

References 17 publications

Does Iterative Reconstruction Improve Image Quality and Reduce Dose in Computed Tomography?

Does Iterative Reconstruction Improve Image Quality and Reduce Dose in Computed Tomography?

Degradation of CT Low-Contrast Spatial Resolution Due to the Use of Iterative Reconstruction and Reduced Dose Levels

Construction of realistic phantoms from patient images and a commercial three-dimensional printer

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