Assessing image quality and dose reduction of a new x-ray computed tomography iterative reconstruction algorithm using model observers

2014 ◽  
Vol 41 (7) ◽  
pp. 071910 ◽  
Author(s):  
Hsin-Wu Tseng ◽  
Jiahua Fan ◽  
Matthew A. Kupinski ◽  
Paavana Sainath ◽  
Jiang Hsieh
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Dose Reduction ◽  
Iterative Reconstruction ◽  
Reconstruction Algorithm ◽  
X Ray ◽  
Iterative Reconstruction Algorithm ◽  
X Ray Computed ◽  
Model Observers

High-Resolution Computed Tomography Examinations for Chronic Suppurative Lung Disease in Early Childhood: Radiation Exposure and Image Quality Evaluations with Iterative Reconstruction Algorithm Use

2016 ◽  
Vol 67 (3) ◽  
pp. 218-224 ◽  
Author(s):  
Magdalini Smarda ◽  
Efstathios Efstathopoulos ◽  
Argyro Mazioti ◽  
Sofia Kordolaimi ◽  
Agapi Ploussi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Image Quality ◽  
Radiation Exposure ◽  
Iterative Reconstruction ◽  
Reconstruction Algorithm ◽  
Filtered Backprojection ◽  
Reconstruction Algorithms ◽  
High Resolution Computed Tomography ◽  
Iterative Reconstruction Algorithm

Purpose High radiosensitivity of children undergoing repetitive computed tomography examinations necessitates the use of iterative reconstruction algorithms in order to achieve a significant radiation dose reduction. The goal of this study is to compare the iDose iterative reconstruction algorithm with filtered backprojection in terms of radiation exposure and image quality in 33 chest high-resolution computed tomography examinations performed in young children with chronic bronchitis. Methods Fourteen patients were scanned using the filtered backprojection protocol while 19 patients using the iDose protocol and reduced milliampere-seconds, both on a 64-detector row computed tomography scanner. The iDose group images were reconstructed with different iDose levels (2, 4, and 6). Radiation exposure quantities were estimated, while subjective and objective image qualities were evaluated. Unpaired t tests were used for data statistical analysis. Results The iDose application allowed significant effective dose reduction (about 80%). Subjective image quality evaluation showed satisfactory results even with iDose level 2, whereas it approached excellent image with iDose level 6. Subjective image noise was comparable between the 2 groups with the use of iDose level 4, while objective noise was comparable between filtered backprojection and iterative reconstruction level 6 images. Conclusions The iDose algorithm use in pediatric chest high-resolution computed tomography reduces radiation exposure without compromising image quality. Further evaluation with iterative reconstruction algorithms is needed in order to establish high-resolution computed tomography as the gold standard low-dose method for children suffering from chronic lung diseases.

CT pulmonary angiography: dose reduction via a next generation iterative reconstruction algorithm

2018 ◽  
Vol 60 (4) ◽  
pp. 478-487 ◽  
Author(s):  
Andreas Sauter ◽  
Thomas Koehler ◽  
Bernhard Brendel ◽  
Juliane Aichele ◽  
Jan Neumann ◽  
...  
Keyword(s):  
Image Quality ◽  
Dose Reduction ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Reconstruction Algorithm ◽  
Pulmonary Angiography ◽  
Reconstruction Algorithms ◽  
Iterative Reconstruction Algorithm ◽  
Dose Levels ◽  
Rule Out

Background Computed tomography pulmonary angiography (CTPA) is the standard imaging modality for detection or rule out of pulmonary embolism (PE); however, radiation exposure is a serious concern. With iterative reconstruction algorithms a distinct dose reduction could be achievable. Purpose To evaluate a next generation iterative reconstruction algorithm for detection or rule-out of PE in simulated low-dose CTPA. Material and Methods Low-dose CT datasets with 50%, 25%, and 12.5% of the original tube current were simulated based on CTPA examinations of 92 patients with suspected PE. All datasets were reconstructed with two reconstruction algorithms: standard filtered back-projection (FBP) and iterative model reconstruction (IMR). In total, 736 CTPA datasets were evaluated by three blinded radiologists regarding image quality, diagnostic confidence, and detectability of PE. Furthermore, contrast-to-noise ratio (CNR) was calculated. Results Images reconstructed with IMR showed better detectability of PE than images reconstructed with FBP, especially at lower dose levels. With IMR, sensitivity was over 95% for central and segmental PE down to a dose level of 25%. Significantly higher subjective image quality was shown at lower dose levels (25% and 12.5%) for IMR images whereas it was higher for FBP images at higher dose levels. FBP was rated as showing less artificial image appearance. CNR was significantly higher with IMR at all dose levels. Conclusion By using IMR, a dose reduction of up to 50% while maintaining satisfactory image quality seems feasible in standard clinical situations, resulting in a mean effective dose of 1.38 mSv for CTPA.

Sign in / Sign up

Export Citation Format

Share Document