Radiation Dose Reduction

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Mannudeep K Kalra - One of the best experts on this subject based on the ideXlab platform.

  • Radiation Dose Reduction in kidney stone ct a randomized facility based intervention
    Journal of The American College of Radiology, 2021
    Co-Authors: Christopher L Moore, Mythreyi Bhargavanchatfield, Melissa Shaw, Karrin Weisenthal, Mannudeep K Kalra
    Abstract:

    Abstract Objective Kidney stones are common, tend to recur, and afflict a young population. Despite evidence and recommendations, adoption of reduced-Radiation Dose CT (RDCT) for kidney stone CT (KSCT) is slow. We sought to design and test an intervention to improve adoption of RDCT protocols for KSCT using a randomized facility-based intervention. Methods Facilities contributing at least 40 KSCTs to the American College of Radiology Dose index registry (DIR) during calendar year 2015 were randomized to intervention or control groups. The Dose Optimization for Stone Evaluation intervention included customized CME modules, personalized consultation, and protocol recommendations for RDCT. Dose length product (DLP) of all KSCTs was recorded at baseline (2015) and compared with 2017, 2018, and 2019. Change in mean DLP was compared between facilities that participated (intervened-on), facilities randomized to intervention that did not participate (intervened-off), and control facilities. Difference-in-difference between intervened-on and control facilities is reported before and after intervention. Results Of 314 eligible facilities, 155 were randomized to intervention and 159 to control. There were 25 intervened-on facilities, 71 intervened-off facilities, and 96 control facilities. From 2015 to 2017, there was a drop of 110 mGy ∙ cm (a 16% Reduction) in the mean DLP in the intervened-on group, which was significantly lower compared with the control group (P Discussion The Dose Optimization for Stone Evaluation intervention resulted in a significant (P

  • Radiation Dose Reduction in pediatric cardiac computed tomography experience from a tertiary medical center
    Pediatric Cardiology, 2014
    Co-Authors: Brian B Ghoshhajra, Mannudeep K Kalra, Sjirk J Westra, Leif Christopher Engel, Ashley M Lee, Csilla Celeng, Thomas J Brady, Udo Hoffmann, Suhny Abbara
    Abstract:

    Cardiac CT angiography (cCTA) has become an established method for the assessment of congenital heart disease. However, the potential harmful effects of ionizing Radiation must be considered, particularly in younger, more radiosensitive patients. In this study, we sought to assess the temporal change in Radiation Doses from pediatric cCTA during an 8-year period at a tertiary medical center. This retrospective study included all patients ≤18 years old who were referred to electrocardiography (ECG)-gated cCTA for the assessment of congenital heart disease or inflammatory disease (Kawasaki disease) from November 2004 to September 2012. During the study period, 95 patients were scanned using 3 different scanner models—64-slice multidetector CT (64-MDCT) and first- (64-DSCT) and second-generation (128-DSCT) dual-source CT—and 3 scan protocols—retrospective ECG-gated helical scanning (RG), prospective ECG-triggered axial scanning (PT), or prospective ECG-triggered high-pitch helical scanning (HPH). Effective Dose (ED) was calculated with the Dose length product method with a conversion factor (k) adjusted for age. ED was then compared among scan protocols. Image quality was extracted from clinical cCTA reports when available. Overall, 94 % of scans were diagnostic (80 % for 64-slice MDCT, 93 % for 64-slice DSCT, and 97 % for 128-slice DSCT).With 128-DSCT, median ED (1.0 [range 0.6–2.0] mSv) decreased by 85.8 % and 66.8 % compared with 64-MDCT (6.8 [range 2.9–13.6] mSv) and 64-DSCT (2.9 [range 0.9–4.1] mSv), respectively. With HPH, median ED (0.9 [range 0.6–1.8] mSv) decreased by 59.4 % and 85.4 % compared with PT (2.2 [range 0.9–3.4] mSv) and RG (6.1 [range 2.5–10.6] mSv). cCTA can now be obtained at very low Radiation Doses in pediatric patients using the latest dual-source CT technology in combination with prospective ECG-triggered HPH acquisition.

  • Radiation Dose Reduction for chest ct with non linear adaptive filters
    Acta Radiologica, 2013
    Co-Authors: Sarabjeet Singh, Subba R Digumarthy, Anni Back, Joanne O Shepard, Mannudeep K Kalra
    Abstract:

    BackgroundCT Radiation Dose Reduction results in increased noise or graininess of images which affects the diagnostic information. One of the approaches to lower Radiation exposure to patients is t...

  • Radiation Dose Reduction with hybrid iterative reconstruction for pediatric ct
    Radiology, 2012
    Co-Authors: Sarabjeet Singh, Mannudeep K Kalra, Anuradha S Shenoybhangle, Aashna Saini, Debra A Gervais, Sjirk J Westra, James H Thrall
    Abstract:

    Hybrid iterative reconstruction enables substantial Dose Reduction for pediatric body CT and maintains acceptable image quality when compared with conventional filtered back projection.

  • Radiation Dose Reduction with application of non linear adaptive filters for abdominal ct
    World Journal of Radiology, 2012
    Co-Authors: Sarabjeet Singh, Mannudeep K Kalra, Anni Back, Mi Kim Sung, Michael A. Blake
    Abstract:

    AIM: To evaluate the effect of non-linear adaptive filters (NLAF) on abdominal computed tomography (CT) images acquired at different Radiation Dose levels. METHODS: Nineteen patients (mean age 61.6 ± 7.9 years, M:F = 8:11) gave informed consent for an Institutional Review Board approved prospective study involving acquisition of 4 additional image series (200, 150, 100, 50 mAs and 120 kVp) on a 64 slice multidetector row CT scanner over an identical 10 cm length in the abdomen. The CT images acquired at 150, 100 and 50 mAs were processed with the NLAF. Two radiologists reviewed unprocessed and processed images for image quality in a blinded randomized manner. CT Dose index volume, Dose length product, patient weight, transverse diameters, objective noise and CT numbers were recorded. Data were analyzed using Analysis of Variance and Wilcoxon signed rank test. RESULTS: Of the 31 lesions detected in abdominal CT images, 28 lesions were less than 1 cm in size. Subjective image noise was graded as unacceptable in unprocessed images at 50 and 100 mAs, and in NLAF processed images at 50 mAs only. In NLAF processed images, objective image noise was decreased by 21% (14.4 ± 4/18.2 ± 4.9) at 150 mAs, 28.3% (15.7 ± 5.6/21.9 ± 4) at 100 mAs and by 39.4% (18.8 ± 9/30.4 ± 9.2) at 50 mAs compared to unprocessed images acquired at respective Radiation Dose levels. At 100 mAs the visibility of smaller structures improved from suboptimal in unprocessed images to excellent in NLAF processed images, whereas diagnostic confidence was respectively improved from probably confident to fully confident. CONCLUSION: NLAF lowers image noise, improves the visibility of small structures and maintains lesion conspicuity at down to 100 mAs for abdominal CT.

Sarabjeet Singh - One of the best experts on this subject based on the ideXlab platform.

  • Radiation Dose Reduction for chest ct with non linear adaptive filters
    Acta Radiologica, 2013
    Co-Authors: Sarabjeet Singh, Subba R Digumarthy, Anni Back, Joanne O Shepard, Mannudeep K Kalra
    Abstract:

    BackgroundCT Radiation Dose Reduction results in increased noise or graininess of images which affects the diagnostic information. One of the approaches to lower Radiation exposure to patients is t...

  • Radiation Dose Reduction with hybrid iterative reconstruction for pediatric ct
    Radiology, 2012
    Co-Authors: Sarabjeet Singh, Mannudeep K Kalra, Anuradha S Shenoybhangle, Aashna Saini, Debra A Gervais, Sjirk J Westra, James H Thrall
    Abstract:

    Hybrid iterative reconstruction enables substantial Dose Reduction for pediatric body CT and maintains acceptable image quality when compared with conventional filtered back projection.

  • Radiation Dose Reduction with application of non linear adaptive filters for abdominal ct
    World Journal of Radiology, 2012
    Co-Authors: Sarabjeet Singh, Mannudeep K Kalra, Anni Back, Mi Kim Sung, Michael A. Blake
    Abstract:

    AIM: To evaluate the effect of non-linear adaptive filters (NLAF) on abdominal computed tomography (CT) images acquired at different Radiation Dose levels. METHODS: Nineteen patients (mean age 61.6 ± 7.9 years, M:F = 8:11) gave informed consent for an Institutional Review Board approved prospective study involving acquisition of 4 additional image series (200, 150, 100, 50 mAs and 120 kVp) on a 64 slice multidetector row CT scanner over an identical 10 cm length in the abdomen. The CT images acquired at 150, 100 and 50 mAs were processed with the NLAF. Two radiologists reviewed unprocessed and processed images for image quality in a blinded randomized manner. CT Dose index volume, Dose length product, patient weight, transverse diameters, objective noise and CT numbers were recorded. Data were analyzed using Analysis of Variance and Wilcoxon signed rank test. RESULTS: Of the 31 lesions detected in abdominal CT images, 28 lesions were less than 1 cm in size. Subjective image noise was graded as unacceptable in unprocessed images at 50 and 100 mAs, and in NLAF processed images at 50 mAs only. In NLAF processed images, objective image noise was decreased by 21% (14.4 ± 4/18.2 ± 4.9) at 150 mAs, 28.3% (15.7 ± 5.6/21.9 ± 4) at 100 mAs and by 39.4% (18.8 ± 9/30.4 ± 9.2) at 50 mAs compared to unprocessed images acquired at respective Radiation Dose levels. At 100 mAs the visibility of smaller structures improved from suboptimal in unprocessed images to excellent in NLAF processed images, whereas diagnostic confidence was respectively improved from probably confident to fully confident. CONCLUSION: NLAF lowers image noise, improves the visibility of small structures and maintains lesion conspicuity at down to 100 mAs for abdominal CT.

  • Radiation Dose Reduction with Sinogram Affirmed Iterative Reconstruction technique for abdominal computed tomography.
    Journal of Computer Assisted Tomography, 2012
    Co-Authors: Mannudeep K Kalra, Sarabjeet Singh, Martin Sedlmair, Mischa Woisetschläger, Nils Dahlström, Maria Lindblom, Garry Choy, Petter Quick, Bernhard Schmidt, Michael A. Blake
    Abstract:

    Purpose: The objective of this study was to assess the effect of Sinogram Affirmed Iterative Reconstruction (SAFIRE) and filtered back-projection (FBP) techniques on abdominal computed tomography (CT) performed with 50% and 75% Radiation Dose Reductions.Methods: Twenty-four patients (mean age, 64 ± 14 years; male-female ratio, 10:14) gave informed consent for an institutional review board–approved prospective study involving acquisition of additional research images through the abdomen on 128-slice multi–detector-row CT (SOMATOM Definition Flash) at quality reference mAs of 100 (50% lower Dose) and 50 (75% lower Dose) over a scan length of 10 cm using combined modulation (CARE Dose 4D). Standard-of-care abdominal CT was performed at 200 quality reference mAs, with remaining parameters held constant. The 50- and 100-mAs data sets were reconstructed with FBP and at 4 SAFIRE settings (S1, S2, S3, S4). Higher number of SAFIRE settings denotes increased strength of the algorithm resulting in lower image noise. Two abdominal radiologists independently compared the FBP and SAFIRE images for lesion number, location, size and conspicuity, and visibility of small structures, image noise, and diagnostic confidence. Objective noise and Hounsfield units (HU) were measured in the liver and the descending aorta.Results: All 43 lesions were detected on both FBP and SAFIRE images. Minor blocky, pixelated appearance of 50% and 75% reduced Dose images was noted at S3 and S4 SAFIRE but not at S1 and S2 settings. Subjective noise was suboptimal in both 50% and 75% lower-Dose FBP images but was deemed acceptable on all SAFIRE settings. Sinogram Affirmed Iterative Reconstruction images were deemed acceptable in all patients at 50% lower Dose and in 22 of 24 patients at 75% lower Dose. As compared with 75% reduced Dose FBP, objective noise was lower by 22.8% (22.9/29.7), 35% (19.3/29.7), 44.3% (16.7/29.3), and 54.8% (13.4/29.7) on S1 to S4 settings, respectively (P < 0.001).Conclusions: Sinogram Affirmed Iterative Reconstruction–enabled reconstruction provides abdominal CT images without loss in diagnostic value at 50% reduced Dose and in some patients also at 75% reduced Dose.

  • adaptive statistical iterative reconstruction technique for Radiation Dose Reduction in chest ct a pilot study
    Radiology, 2011
    Co-Authors: Sarabjeet Singh, Mannudeep K Kalra, Subba R Digumarthy, Matthew D Gilman, Jiang Hsieh, Homer H Pien, Joanne O Shepard
    Abstract:

    CT Radiation Dose Reduction down to 3.5 mGy is achievable for adaptive statistical iterative reconstructed chest CT while maintaining acceptable image noise and diagnostic confidence.

J. De ,mey - One of the best experts on this subject based on the ideXlab platform.

  • the impact of ct Radiation Dose Reduction and iterative reconstruction algorithms from four different vendors on coronary calcium scoring
    European Radiology, 2014
    Co-Authors: Martin J Willemink, Marco Das, Joachim E. Wildberger, P.a. De ,jong, Richard A P Takx, Ricardo P J Budde, Ronald L A W Bleys, Mathias Prokop, Nico Buls, J. De ,mey
    Abstract:

    Objectives To analyse the effects of Radiation Dose Reduction and iterative reconstruction (IR) algorithms on coronary calcium scoring (CCS).

  • the impact of ct Radiation Dose Reduction and iterative reconstruction algorithms from four different vendors on coronary calcium scoring
    European Radiology, 2014
    Co-Authors: Martin J Willemink, Marco Das, Joachim E. Wildberger, P.a. De ,jong, Richard A P Takx, Ricardo P J Budde, Ronald L A W Bleys, Mathias Prokop, Nico Buls, J. De ,mey
    Abstract:

    To analyse the effects of Radiation Dose Reduction and iterative reconstruction (IR) algorithms on coronary calcium scoring (CCS). Fifteen ex vivo human hearts were examined in an anthropomorphic chest phantom using computed tomography (CT) systems from four vendors and examined at four Dose levels using unenhanced prospectively ECG-triggered protocols. Tube voltage was 120 kV and tube current differed between protocols. CT data were reconstructed with filtered back projection (FBP) and reduced Dose CT data with IR. CCS was quantified with Agatston scores, calcification mass and calcification volume. Differences were analysed with the Friedman test. Fourteen hearts showed coronary calcifications. Dose Reduction with FBP did not significantly change Agatston scores, calcification volumes and calcification masses (P > 0.05). Maximum differences in Agatston scores were 76, 26, 51 and 161 units, in calcification volume 97, 27, 42 and 162 mm3, and in calcification mass 23, 23, 20 and 48 mg, respectively. IR resulted in a trend towards lower Agatston scores and calcification volumes with significant differences for one vendor (P < 0.05). Median relative differences between reference FBP and reduced Dose IR for Agatston scores remained within 2.0–4.6 %, 1.0–5.3 %, 1.2–7.7 % and 2.6–4.5 %, for calcification volumes within 2.4–3.9 %, 1.0–5.6 %, 1.1–6.4 % and 3.7–4.7 %, for calcification masses within 1.9–4.1 %, 0.9–7.8 %, 2.9–4.7 % and 2.5–3.9 %, respectively. IR resulted in increased, decreased or similar calcification masses. CCS derived from standard FBP acquisitions was not affected by Radiation Dose Reductions up to 80 %. IR resulted in a trend towards lower Agatston scores and calcification volumes. • In this ex vivo study, Radiation Dose could be reduced by 80 % for coronary calcium scoring • Iterative reconstruction resulted in a trend towards lower Agatston scores and calcification volumes • Caution should be taken for coronary calcium scoring with iterative reconstruction

  • Computed Tomography Radiation Dose Reduction: Effect of Different Iterative Reconstruction Algorithms on Image Quality
    'Ovid Technologies (Wolters Kluwer Health)', 2014
    Co-Authors: Willemink M.j., Takx R.a.p., P.a. De ,jong, Budde R.p., Bleys R.l., Das M., Wildberger J.e., Prokop M., Buls N., J. De ,mey
    Abstract:

    Item does not contain fulltextWe evaluated the effects of hybrid and model-based iterative reconstruction (IR) algorithms from different vendors at multiple Radiation Dose levels on image quality of chest phantom scans.A chest phantom was scanned on state-of-the-art computed tomography scanners from 4 vendors at 4 Dose levels (4.1 mGy, 3.0 mGy, 1.9 mGy, and 0.8 mGy). All data were reconstructed with filtered back projection (FBP) and reduced-Dose data also with IR (iDose4, Adaptive Iterative Dose Reduction 3D, Adaptive Statistical Iterative Reconstruction, Sinogram-Affirmed Iterative Reconstruction, prototype Iterative Model Reconstruction, and Veo). Computed tomography numbers and noise were measured in the spine and lungs. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated and differences were analyzed with the Friedman test.For all vendors, Radiation Dose Reduction with FBP resulted in significantly increased noise levels (≤148\%) as well as decreased SNR (≤57\%) and CNR (≤58\%) (P < 0.001). Conversely, IR resulted in decreased noise levels (≤48\%) as well as increased SNR (≤94\%) and CNR (≤94\%). The SNRs and CNRs of the model-based algorithms at 80\% reduced Dose were similar to reference-Dose FBP.Hybrid IR algorithms have the potential to reduce Radiation Dose with 27\% to 54\% and model-based IR algorithms with up to 80\%

  • Computed Tomography Radiation Dose Reduction: Effect of Different Iterative Reconstruction Algorithms on Image Quality
    2014
    Co-Authors: Willemink M.j., Takx R.a.p., P.a. De ,jong, Budde R.p., Bleys R.l., Das M., Wildberger J.e., Prokop M., Buls N., J. De ,mey
    Abstract:

    We evaluated the effects of hybrid and model-based iterative reconstruction (IR) algorithms from different vendors at multiple Radiation Dose levels on image quality of chest phantom scans.A chest phantom was scanned on state-of-the-art computed tomography scanners from 4 vendors at 4 Dose levels (4.1 mGy, 3.0 mGy, 1.9 mGy, and 0.8 mGy). All data were reconstructed with filtered back projection (FBP) and reduced-Dose data also with IR (iDose4, Adaptive Iterative Dose Reduction 3D, Adaptive Statistical Iterative Reconstruction, Sinogram-Affirmed Iterative Reconstruction, prototype Iterative Model Reconstruction, and Veo). Computed tomography numbers and noise were measured in the spine and lungs. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated and differences were analyzed with the Friedman test.For all vendors, Radiation Dose Reduction with FBP resulted in significantly increased noise levels (≤148\%) as well as decreased SNR (≤57\%) and CNR (≤58\%) (P < 0.001). Conversely, IR resulted in decreased noise levels (≤48\%) as well as increased SNR (≤94\%) and CNR (≤94\%). The SNRs and CNRs of the model-based algorithms at 80\% reduced Dose were similar to reference-Dose FBP.Hybrid IR algorithms have the potential to reduce Radiation Dose with 27\% to 54\% and model-based IR algorithms with up to 80\%

Cynthia H Mccollough - One of the best experts on this subject based on the ideXlab platform.

  • Dose Reduction for sinus and temporal bone imaging using photon counting detector ct with an additional tin filter
    Investigative Radiology, 2020
    Co-Authors: Kishore Rajendran, Joel G Fletcher, Benjamin Voss, Wei Zhou, Shengzhen Tao, David R Delone, John I Lane, Jayse M Weaver, Matthew L Carlson, Cynthia H Mccollough
    Abstract:

    ObjectiveThe aim of this study was to quantitatively demonstrate Radiation Dose Reduction for sinus and temporal bone examinations using high-resolution photon-counting detector (PCD) computed tomography (CT) with an additional tin (Sn) filter.Materials and MethodsA multienergy CT phantom, an anthro

  • pilot study of Radiation Dose Reduction for pediatric head ct in evaluation of ventricular size
    American Journal of Neuroradiology, 2014
    Co-Authors: S Gabriel, Cynthia H Mccollough, David R Delone, Laurence J Eckel, Karl N Krecke, Patrick H Luetmer, Joel G Fletcher
    Abstract:

    BACKGROUND AND PURPOSE: CT is a ubiquitous, efficient, and cost-effective method to evaluate pediatric ventricular size, particularly in patients with CSF shunt diversion who often need emergent imaging. We therefore sought to determine the minimum Dose output or CT Dose index required to produce clinically acceptable examinations. MATERIALS AND METHODS: Using a validated noise insertion method and CT projection data from 22 patients, standard pediatric head CT images were reconstructed with weighted filtered back-projection and sinogram-affirmed iterative reconstruction corresponding to routine, 25%, and 10% Dose. Reconstructed images were then evaluated by 3 neuroradiologists (blinded to Dose and reconstruction method) for ventricular size, diagnostic confidence, image quality, evidence of hemorrhage, and shunt tip location, and compared with the reference standard. RESULTS: There was no significant difference in the ventricular size ranking, and the sensitivity for moderate to severe hydrocephalus was 100%. There was no significant difference between the full-Dose level and the ventricular size rankings at the 25% or the 10% Dose level for either reconstruction kernel (P > .979). Diagnostic confidence was maintained across Doses and kernel. Hemorrhage was more difficult to identify as image quality degraded as Dose decreased but was still seen in a majority of cases. Shunts were identified by all readers across all Doses and reconstruction methods. CONCLUSIONS: CT images having Dose Reductions of 90% relative to routine head CT examinations provide acceptable image quality to address the specific clinical task of evaluating ventricular size.

  • optimal tube potential for Radiation Dose Reduction in pediatric ct principles clinical implementations and pitfalls
    Radiographics, 2011
    Co-Authors: Michael R Bruesewitz, Joel G Fletcher, James M Kofler, Kristen B Thomas, Cynthia H Mccollough
    Abstract:

    The basic principles of tube potential optimization to reduce Radiation Dose in pediatric CT examinations are described, and a tutorial on how to clinically implement the optimal tube potential is provided.

  • automatic selection of tube potential for Radiation Dose Reduction in ct a general strategy
    Medical Physics, 2009
    Co-Authors: Lifeng Yu, Hua Li, Joel G Fletcher, Cynthia H Mccollough
    Abstract:

    Purpose: To optimize Radiation Dose efficiency in CT while maintaining image quality, it is important to select the optimal tube potential. The selection of optimal tube potential, however, is highly dependent on patient size and diagnostic task. The purpose of this work was to develop a general strategy that allows for automatic tube potential selection for each individual patient and each diagnostic task. Methods: The authors propose a general strategy that allows automatic adaptation of the tube potential as a function of patient size and diagnostic task, using a novel index of image quality, “iodine contrast to noise ratio with a noise constraint (iCNR_NC),” to characterize the different image quality requirements by various clinical applications. The relative Dose factor (RDF) at each tube potential to achieve a target image quality was then determined as a function of patient size and the noise constraint parameter. A workflow was developed to automatically identify the optimal tube potential that is both Dose efficient and practically feasible, incorporating patient size and diagnostic task. An experimental study using a series of semianthropomorphic thoracic phantoms was used to demonstrate how the proposed general strategy can be implemented and how the Radiation Dose Reduction achievable by the tube potential selection depends on phantom sizes and noise constraint parameters. Results: The proposed strategy provides a flexible and quantitative way to select the optimal tube potential based on the patient size and diagnostic task. The noise constraint parameter α can be adapted for different clinical applications. For example, α = 1 for noncontrast routine exams; α = 1.1 – 1.25 for contrast-enhanced routine exams; and α = 1.5 – 2.0 for CT angiography. For the five thoracic phantoms in the experiment, when α = 1 , the optimal tube potentials were 80, 100, 100, 120, 120, respectively. The corresponding RDFs (relative to 120 kV) were 78.0%, 90.9%, 95.2%, 100%, and 100%. When α = 1.5 , the optimal tube potentials were 80, 80, 80, 100, 100, respectively, with corresponding RDFs of 34.7%, 44.7%, 54.7%, 60.8%, and 89.5%. Conclusions: A general strategy to automatically select the most Dose efficient tube potential for CT exams was developed that takes into account patient size and diagnostic task. Dependent on the patient size and the selection of noise constraint parameter for different diagnostic tasks, the Dose Reduction at each tube potential, quantified explicitly with the RDF, varies significantly.

  • Radiation Dose Reduction in computed tomography techniques and future perspective
    Imaging in Medicine, 2009
    Co-Authors: Xin Liu, Juan Carlos Ramirezgiraldo, Joel G Fletcher, Shuai Leng, James M Kofler, Jodie A Christner, Cynthia H Mccollough
    Abstract:

    Despite universal consensus that computed tomography (CT) overwhelmingly benefits patients when used for appropriate indications, concerns have been raised regarding the potential risk of cancer induction from CT due to the exponentially increased use of CT in medicine. Keeping Radiation Dose as low as reasonably achievable, consistent with the diagnostic task, remains the most important strategy for decreasing this potential risk. This article summarizes the general technical strategies that are commonly used for Radiation Dose management in CT. Dose-management strategies for pediatric CT, cardiac CT, dual-energy CT, CT perfusion and interventional CT are specifically discussed, and future perspectives on CT Dose Reduction are presented.

Richard A P Takx - One of the best experts on this subject based on the ideXlab platform.

  • the impact of ct Radiation Dose Reduction and iterative reconstruction algorithms from four different vendors on coronary calcium scoring
    European Radiology, 2014
    Co-Authors: Martin J Willemink, Marco Das, Joachim E. Wildberger, P.a. De ,jong, Richard A P Takx, Ricardo P J Budde, Ronald L A W Bleys, Mathias Prokop, Nico Buls, J. De ,mey
    Abstract:

    Objectives To analyse the effects of Radiation Dose Reduction and iterative reconstruction (IR) algorithms on coronary calcium scoring (CCS).

  • the impact of ct Radiation Dose Reduction and iterative reconstruction algorithms from four different vendors on coronary calcium scoring
    European Radiology, 2014
    Co-Authors: Martin J Willemink, Marco Das, Joachim E. Wildberger, P.a. De ,jong, Richard A P Takx, Ricardo P J Budde, Ronald L A W Bleys, Mathias Prokop, Nico Buls, J. De ,mey
    Abstract:

    To analyse the effects of Radiation Dose Reduction and iterative reconstruction (IR) algorithms on coronary calcium scoring (CCS). Fifteen ex vivo human hearts were examined in an anthropomorphic chest phantom using computed tomography (CT) systems from four vendors and examined at four Dose levels using unenhanced prospectively ECG-triggered protocols. Tube voltage was 120 kV and tube current differed between protocols. CT data were reconstructed with filtered back projection (FBP) and reduced Dose CT data with IR. CCS was quantified with Agatston scores, calcification mass and calcification volume. Differences were analysed with the Friedman test. Fourteen hearts showed coronary calcifications. Dose Reduction with FBP did not significantly change Agatston scores, calcification volumes and calcification masses (P > 0.05). Maximum differences in Agatston scores were 76, 26, 51 and 161 units, in calcification volume 97, 27, 42 and 162 mm3, and in calcification mass 23, 23, 20 and 48 mg, respectively. IR resulted in a trend towards lower Agatston scores and calcification volumes with significant differences for one vendor (P < 0.05). Median relative differences between reference FBP and reduced Dose IR for Agatston scores remained within 2.0–4.6 %, 1.0–5.3 %, 1.2–7.7 % and 2.6–4.5 %, for calcification volumes within 2.4–3.9 %, 1.0–5.6 %, 1.1–6.4 % and 3.7–4.7 %, for calcification masses within 1.9–4.1 %, 0.9–7.8 %, 2.9–4.7 % and 2.5–3.9 %, respectively. IR resulted in increased, decreased or similar calcification masses. CCS derived from standard FBP acquisitions was not affected by Radiation Dose Reductions up to 80 %. IR resulted in a trend towards lower Agatston scores and calcification volumes. • In this ex vivo study, Radiation Dose could be reduced by 80 % for coronary calcium scoring • Iterative reconstruction resulted in a trend towards lower Agatston scores and calcification volumes • Caution should be taken for coronary calcium scoring with iterative reconstruction

  • coronary ct angiography image quality diagnostic accuracy and potential for Radiation Dose Reduction using a novel iterative image reconstruction technique comparison with traditional filtered back projection
    European Radiology, 2011
    Co-Authors: Richard A P Takx, Joseph U Schoepf, Antonio Moscariello, Matthias Renker, Peter L Zwerner, Terrence X Obrien, Thomas Allmendinger
    Abstract:

    To compare image noise, image quality and diagnostic accuracy of coronary CT angiography (cCTA) using a novel iterative reconstruction algorithm versus traditional filtered back projection (FBP) and to estimate the potential for Radiation Dose savings. Sixty five consecutive patients (48 men; 59.3 ± 7.7 years) prospectively underwent cCTA and coronary catheter angiography (CCA). Full Radiation Dose data, using all projections, were reconstructed with FBP. To simulate image acquisition at half the Radiation Dose, 50% of the projections were discarded from the raw data. The resulting half-Dose data were reconstructed with sinogram-affirmed iterative reconstruction (SAFIRE). Full-Dose FBP and half-Dose iterative reconstructions were compared with regard to image noise and image quality, and their respective accuracy for stenosis detection was compared against CCA. Compared with full-Dose FBP, half-Dose iterative reconstructions showed significantly (p = 0.001 – p = 0.025) lower image noise and slightly higher image quality. Iterative reconstruction improved the accuracy of stenosis detection compared with FBP (per-patient: accuracy 96.9% vs. 93.8%, sensitivity 100% vs. 100%, specificity 94.6% vs. 89.2%, NPV 100% vs. 100%, PPV 93.3% vs. 87.5%). Iterative reconstruction significantly reduces image noise without loss of diagnostic information and holds the potential for substantial Radiation Dose Reduction from cCTA.