scholarly journals The influence of model iterative reconstruction on image quality in standard and low-dose computer tomography of the chest. experimental study.

2020 ◽  
Author(s):  
Антон Yu. Silin ◽  
Ivan S. Gruzdev ◽  
Sergey P. Morozov
Keyword(s):  
Radiation Dose ◽  
Dose Reduction ◽  
Spatial Resolution ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Reconstruction Algorithms ◽  
Anthropomorphic Phantom ◽  
Pulmonary Lesions ◽  
Calibration Phantom

Background: One of the ways to reduce the radiation dose in CT is to improve image reconstruction algorithms. The latest offer from scanner manufacturers is Model Iterative Reconstruction (MIR). Aims: To compare the quality of visualization of the structures of the organs of the chest and to prove the effectiveness of the low-dose protocol with iterative model reconstruction. Materials and methods: A calibration phantom with a spatial resolution module and an anthropomorphic phantom of the upper body of an adult with nodules in the lungs was scanned on two CT scanners of different manufacturers using the standard dose protocol (SDCT) with algorithms of hybrid iterative reconstruction (HIR) of images and MIR and low-dose protocol (LDCT) and MIR algorithm. The quality of the obtained images was evaluated by the parameters: noise (SD), the contrast-to-noise ratio (CNR), spatial resolution and visualization of pulmonary nodules. The radiation dose was calculated according to the scanner data, the data of individual dosimeters placed on the anthropomorphic phantom, and using a dosimetric phantom. Results: The average SD was 11.5; 24.4 and 21.6; CNR 85.47; 40.6 and 45.6; spatial resolution 2 mm; 2 mm and 3 mm for SDCT with MIR, SDCT with HIR and LDCT with MIR, respectively. Visualization of pulmonary lesions remained excellent in all cases. The radiation dose in case of SDCT was 2.7, and in case of LDCT - 0.67 mSv. The dose reduction was confirmed by dosimeter data. Similar results were obtained by repeating the experiment on a second scanner. Conclusions: The average SD was 11.5; 24.4 and 21.6; CNR 85.47; 40.6 and 45.6; spatial resolution 2 mm; 2 mm and 3 mm for SDCT with MIR, SDCT with HIR and LDCT with MIR, respectively. Visualization of pulmonary lesions remained excellent in all cases. The radiation dose in case of SDCT was 2.7, and in case of LDCT - 0.67 mSv. The dose reduction was confirmed by dosimeter data. Similar results were obtained by repeating the experiment on a second scanner.

Ultra-Low-Dose CT of the Thorax Using Iterative Reconstruction: Evaluation of Image Quality and Radiation Dose Reduction

2015 ◽  
Vol 204 (6) ◽  
pp. 1197-1202 ◽  
Author(s):  
Yookyung Kim ◽  
Yoon Kyung Kim ◽  
Bo Eun Lee ◽  
Seok Jeong Lee ◽  
Yon Ju Ryu ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Dose Reduction ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Radiation Dose Reduction ◽  
Low Dose Ct

Application of low-dose CT combined with model-based iterative reconstruction algorithm in oncologic patients during follow-up: dose reduction and image quality

2021 ◽  
pp. 20201223
Author(s):  
Davide Ippolito ◽  
Cesare Maino ◽  
Anna Pecorelli ◽  
Ilaria Salemi ◽  
Davide Gandola ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Dose Reduction ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Ct Images ◽  
Ct Attenuation ◽  
Oncologic Patients ◽  
Attenuation Values

Objectives: To compare image quality and radiation dose of CT images reconstructed with model-based iterative reconstruction (MBIR) and hybrid-iterative (HIR) algorithm in oncologic patients. Methods: 125 oncologic patients underwent both contrast-enhanced low- (100 kV), and standard (120 kV) dose CT, were enrolled. Image quality was assessed by using a 4-point Likert scale. CT attenuation values, expressed in Hounsfield unit (HU), were recorded within a regions of interest (ROI) of liver, spleen, paraspinal muscle, aortic lumen, and subcutaneous fat tissue. Image noise, expressed as standard deviation (SD), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated. Radiation dose were analyzed. Paired Student’s t-test was used to compare all continuous variables. Results: The overall median score assessed as image quality for CT images with the MBIR algorithm was significantly higher in comparison with HIR [4 (range 3–4) vs 3 (3-4), p = 0.017]. CT attenuation values and SD were significantly higher and lower, respectively, in all anatomic districts in images reconstructed with MBIR in comparison with HIR ones (all p < 0.001). SNR and CNR values were higher in CT images reconstructed with MBIR, reaching a significant difference in all districts (all p < 0.001). Radiation dose were significantly lower in the MBIR group compared with the HIR group (p < 0.001). Conclusions: MBIR combined with low-kV setting allows an important dose reduction in whole-body CT imaging, reaching a better image quality both qualitatively and quantitatively. Advances in knowledge: MBIR with low-dose approach allows a reduction of dose exposure, maintaining high image quality, especially in patients which deserve a longlasting follow-up.

The impact of CT radiation dose reduction and iterative reconstruction algorithms from four different vendors on coronary calcium scoring

2014 ◽  
Vol 24 (9) ◽  
pp. 2201-2212 ◽  
Author(s):  
Martin J. Willemink ◽  
Richard A. P. Takx ◽  
Pim A. de Jong ◽  
Ricardo P. J. Budde ◽  
Ronald L. A. W. Bleys ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Dose Reduction ◽  
Iterative Reconstruction ◽  
Radiation Dose Reduction ◽  
Coronary Calcium ◽  
Calcium Scoring ◽  
Reconstruction Algorithms ◽  
Coronary Calcium Scoring ◽  
Ct Radiation ◽  
The Impact

Evaluation of an iterative model-based CT reconstruction algorithm by intra-patient comparison of standard and ultra-low-dose examinations

2018 ◽  
Vol 59 (10) ◽  
pp. 1225-1231 ◽  
Author(s):  
Peter B Noël ◽  
Stephan Engels ◽  
Thomas Köhler ◽  
Daniela Muenzel ◽  
Daniela Franz ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Dose Reduction ◽  
Low Dose ◽  
Standard Dose ◽  
Health Concern ◽  
Generation Model ◽  
Reconstruction Algorithms ◽  
Low Dose Ct ◽  
Model Based

Background The explosive growth of computer tomography (CT) has led to a growing public health concern about patient and population radiation dose. A recently introduced technique for dose reduction, which can be combined with tube-current modulation, over-beam reduction, and organ-specific dose reduction, is iterative reconstruction (IR). Purpose To evaluate the quality, at different radiation dose levels, of three reconstruction algorithms for diagnostics of patients with proven liver metastases under tumor follow-up. Material and Methods A total of 40 thorax–abdomen–pelvis CT examinations acquired from 20 patients in a tumor follow-up were included. All patients were imaged using the standard-dose and a specific low-dose CT protocol. Reconstructed slices were generated by using three different reconstruction algorithms: a classical filtered back projection (FBP); a first-generation iterative noise-reduction algorithm (iDose4); and a next generation model-based IR algorithm (IMR). Results The overall detection of liver lesions tended to be higher with the IMR algorithm than with FBP or iDose4. The IMR dataset at standard dose yielded the highest overall detectability, while the low-dose FBP dataset showed the lowest detectability. For the low-dose protocols, a significantly improved detectability of the liver lesion can be reported compared to FBP or iDose4 ( P = 0.01). The radiation dose decreased by an approximate factor of 5 between the standard-dose and the low-dose protocol. Conclusion The latest generation of IR algorithms significantly improved the diagnostic image quality and provided virtually noise-free images for ultra-low-dose CT imaging.

scholarly journals The results of approbation of a comprehensive expert assessment of the quality of CT images of the chest obtained on low-dose scanning protocols using iterative reconstruction methods

2021 ◽  
Vol 12 (3) ◽  
pp. 54-71
Author(s):  
G. V. Berkovich ◽  
A. V. Vodovatov ◽  
L. A. Chipiga ◽  
G. E. Trufanov
Keyword(s):  
Iterative Reconstruction ◽  
Low Dose ◽  
Ct Images ◽  
Expert Assessment ◽  
Reconstruction Algorithms ◽  
Suspected Infection ◽  
Reconstruction Methods ◽  
Method Of Assessment ◽  
Ct Image Quality

Introduction. Сomputed tomography (CT) is associated with high individual patient doses. Hence, the process of optimization in CT examinations by developing low-dose scan protocols is important.Purpose of the study. Clinical approbation of low-dose protocols developed by the authors earlier, selection of the most promising protocol, assessment of the applicability of the developed algorithm for expert assessment of the quality of CT images.Materials and methods. The study was based on the data from 96 patients who underwent cardiac surgery with suspected infection in the lungs or sternal wound infection. CT examinations were performed using standard, low-dose and ultra-low-dose protocols (effective dose 3,5±0,9, 1,7±0,1 and 0,8±0,1 mSv, respectively) using two iterative reconstruction algorithms (IMR and iDose). The quality of the obtained data was assessed by 5 radiologists with more than 5-year experience in chest radiology.Results. In terms of the number of misinterpretations, no significant differences were estimated between the standard and lowdose protocols for all reconstruction methods. The ultra-low-dose protocol was characterized by a significantly higher number of missing lesions compared to other protocols.Conclusion. The developed method of assessment of the CT image quality has proven to be informative and reproducible and can be used to assess new scanning protocols.

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