Noise indices adjusted to body mass index and an iterative reconstruction algorithm maintain image quality on low-dose contrast-enhanced liver CT

2017 ◽  
Vol 25 (4) ◽  
pp. 597-611 ◽  
Author(s):  
Yongxia Zhao ◽  
Hongna Suo ◽  
Yanmin Wu ◽  
Ziwei Zuo ◽  
Sisi Zhao ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Image Quality ◽  
Body Mass ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Reconstruction Algorithm ◽  
Liver Ct ◽  
Iterative Reconstruction Algorithm ◽  
Contrast Enhanced

scholarly journals Inter-Observer Agreement and Image Quality of Model-Based Algorithm Applied to the Coronary Artery Disease Reporting and Data System Score

2021 ◽  
Author(s):  
Davide Ippolito ◽  
Cammillo Talei Franzesi ◽  
Cecilia Cangiotti ◽  
Luca Riva ◽  
Andrea De Vito ◽  
...  
Keyword(s):  
Image Quality ◽  
Effective Dose ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Reconstruction Algorithm ◽  
Observer Agreement ◽  
Iterative Reconstruction Algorithm ◽  
Model Based ◽  
The Mean ◽  
Lower Noise

Abstract Purpose: To evaluate the inter-observer agreement of the CAD-RADS reporting system and compare image quality between model-based iterative reconstruction algorithm (MBIR) and standard iterative reconstruction algorithm (IR) of low dose cardiac computed tomography angiography (CCTA). Methods: One-hundred-sixty patients undergone a 256-slice MDCT scanner using low-dose CCTA combined with prospective ECG-gated techniques were prospectively enrolled. CCTA protocols were reconstructed with both MBIR and IR. Each study was evaluated by two readers using the CAD-RADS lexicon. Vessels enhancement, image noise, SNR, and CNR were computed in the axial native images and inter-observer agreement was assessed. Radiation dose exposure as dose–length product (DLP) and effective dose (ED) were finally reported. Results: The overall agreement was very good (k = 0.90). Moreover, a significantly higher value of subjective qualitative analysis, SNR, and CNR in MBIR images compared to IR were found, due to a lower noise level (p<0.05). The mean DLP measured was 63.9 mGy*cm and the mean effective dose was 0.9 mSv.Conclusion: Inter-observer agreement of CAD-RADS was excellent confirming the importance, the feasibility, and the reproducibility of the CAD-RADS scoring system for CCTA. Moreover, lower noise and higher image quality with MBIR compared to IR were found.

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.

SAT0550 SPINAL AND PELVIC MDCT USING “iDose5” ITERATIVE RECONSTRUCTION ALGORITHM IN PATIENTS WITH PSORIATIC SPONDYLOARTHRITIS: DIAGNOSTIC CAPABILITIES AND IMAGE QUALITY IN RELATION TO RADIATION EXPOSURE

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1232-1233
Author(s):  
V. Bizimi ◽  
P. Katsimbri ◽  
A. Plousi ◽  
D. Tseronis ◽  
N. Sideri ◽  
...  
Keyword(s):  
Ankylosing Spondylitis ◽  
Image Quality ◽  
Radiation Dose ◽  
Effective Dose ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Reconstruction Algorithm ◽  
Low Dose Ct ◽  
Iterative Reconstruction Algorithm ◽  
Diagnostic Capabilities

Background:Psoriatic spondyloarthritis (PsSpA) is an inflammatory arthritis related to psoriasis, whereas a large number of patients may have persistent inflammation developing gradual and in some cases extensive joint involvement of the axial skeleton.Conventional radiographs (CRs) have been used for the detection of structural damage (syndesmophyte formation, paravertebral ossification, sacroiliitis, ankyloses and erosions), facilitating as an important measure of efficacy of various therapies. However overlapping of anatomic structures of pelvis and spine as well as limited capabilities to visualize soft tissue have led to the development of newer imaging technologies (1). Multidetector CT technology (MDCT), it is now possible to perform low dose CT (ldCT) of the entire vertebral column, viewed in multiple planes and without overprojection with a low radiation dose. (2) Still, the capabilities of ldCT algorithms in the diagnosis and progression of PsSpA has not been fully explored.Objectives:The aim of this study is to examine the effect of “iDose5” iterative reconstruction algorithm on radiation dose, diagnostic capabilities and image quality in spine-pelvis (S-P) CT scanning compared with CRs, in detection of findings suggestive of PsSpA.Methods:Thirty-nine patients with PsSpA (26 females and 13 males, age range: 23 to 70 years old) were prospectively studied with “iDose5” CT of spine and pelvis on a 64-row MDCT scanner. Multiplannar reformats followed. All patients satisfied the Psoriatic Arthritis (CASPAR) classification criteria and had undergone standard AP and lateral CRs of the cervical, thoracic and lumbar spine and AP radiographs of the pelvis within one months of the iDose CT. Twenty-five patients underwent, additional MR imaging (MRI) of the same anatomic areas. Written consent was obtained from all patients. Two musculoskeletal radiologists read and scored CT scans and CRs in consensus, according to the PASRI criteria and the CTSS score. CT image quality and effective dose for CT and radiographs were assessed.All data were analyzed using SPSS 24.0 statistical software.Results:CT revealed erosions and ankyloses of the sacroiliac joints, fusion of the posterior elements of vertebra especially in the thoracic spine, enthesophytes, not seen with CRs, in 26 patients (p<0,05).Level of diagnostic confidence was higher when interpreting CT compared to CRs, in cases of erosions and ankyloses, in 35 patients (p<0,05).CT was slightly superior in the detection and characterization of syndesmophytes, enthesopathy and calcifications.Effective dose for “i-Dose 5” CT was 1.20 ± 0.26 mSv and for CR =1.07 ± 0.21 mSv. The difference was not statistically significant (p=0.588).Conclusion:iDose CT of spine and pelvis at an effective dose, lower than previously published, seems to perform better than radiographs in the detection of structural changes of PsSpA. Further studies are needed to document the capabilities of iDose CT for the imaging assessment of PsSpA in daily clinical practice.References:[1]Baraliakos Χ, et al (2009)The Natural Course of Radiographic Progression in Ankylosing Spondylitis — Evidence for Major Individual Variations in a Large Proportion of Patients The Journal of Rheumatology May, 36 (5) 997-1002[2]de Koning A et, al (2018) Low-dose CT detects more progression of bone formation in comparison to conventional radiography in patients with ankylosing spondylitis: results from the SIAS cohort. Ann Rheum Dis.;77(2):293-299.Disclosure of Interests:None declared

scholarly journals Influence of model based iterative reconstruction algorithm on image quality of multiplanar reformations in reduced dose chest CT

2016 ◽  
Vol 5 (8) ◽  
pp. 205846011666229 ◽  
Author(s):  
Heloise Barras ◽  
Vincent Dunet ◽  
Anne-Lise Hachulla ◽  
Jochen Grimm ◽  
Catherine Beigelman-Aubry
Keyword(s):  
Image Quality ◽  
Iterative Reconstruction ◽  
Reconstruction Algorithm ◽  
Chest Ct ◽  
Iterative Reconstruction Algorithm ◽  
Reduced Dose ◽  
Model Based ◽  
Multiplanar Reformations
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