Ultra-low-dose lung screening CT with model-based iterative reconstruction: an assessment of image quality and lesion conspicuity

2017 ◽  
Vol 59 (5) ◽  
pp. 553-559 ◽  
Author(s):  
Yun Hye Ju ◽  
Geewon Lee ◽  
Ji Won Lee ◽  
Seung Baek Hong ◽  
Young Ju Suh ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Image Noise ◽  
Low Dose Ct ◽  
Group 5 ◽  
Lung Screening ◽  
Lesion Conspicuity ◽  
Group 1

Background Reducing radiation dose inevitably increases image noise, and thus, it is important in low-dose computed tomography (CT) to maintain image quality and lesion detection performance. Purpose To assess image quality and lesion conspicuity of ultra-low-dose CT with model-based iterative reconstruction (MBIR) and to determine a suitable protocol for lung screening CT. Material and Methods A total of 120 heavy smokers underwent lung screening CT and were randomly and equally assigned to one of five groups: group 1 = 120 kVp, 25 mAs, with FBP reconstruction; group 2 = 120 kVp, 10 mAs, with MBIR; group 3 = 100 kVp, 15 mAs, with MBIR; group 4 = 100 kVp, 10 mAs, with MBIR; and group 5 = 100 kVp, 5 mAs, with MBIR. Two radiologists evaluated intergroup differences with respect to radiation dose, image noise, image quality, and lesion conspicuity using the Kruskal–Wallis test and the Chi-square test. Results Effective doses were 61–87% lower in groups 2–5 than in group 1. Image noises in groups 1 and 5 were significantly higher than in the other groups ( P < 0.001). Overall image quality was best in group 1, but diagnostic acceptability of overall image qualities in groups 1–3 was not significantly different (all P values > 0.05). Lesion conspicuities were similar in groups 1–4, but were significantly poorer in group 5. Conclusion Lung screening CT with MBIR obtained at 100 kVp and 15 mAs enables a ∼60% reduction in radiation dose versus low-dose CT, while maintaining image quality and lesion conspicuity.

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

scholarly journals Abdominal CT radiation dose optimization at Siriraj Hospital

2020 ◽  
Vol 21 (2) ◽  
pp. 28-43
Author(s):  
Piyaporn Apisarnthanarak ◽  
Chosita Buranont ◽  
Chulaluck Boonma ◽  
Sureerat Janpanich ◽  
Tarntip Suwatananonthakij ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Low Dose ◽  
Standard Dose ◽  
Image Noise ◽  
Abdominal Ct ◽  
Low Dose Ct ◽  
Excellent Image Quality ◽  
Ct Dose ◽  
The Mean

OBJECTIVE: To compare radiation dose and image quality between standard dose abdominal CT currently performed at our hospital and new low dose abdominal CT using various percentages (0%, 10%, 20%, and 30%) of Adaptive Statistical Iterative Reconstruction (ASiR). MATERIALS AND METHODS: We prospectively performed low dose abdominal CT (30% reduction of standard tube current) in 119 participants. The low dose CT images were post processed with four parameters (0%, 10%, 20% and 30%) of ASiR. The volume CT dose index (CTDIvol) of standard and low dose CT were compared. Four experienced abdominal radiologists independently assessed the quality of low dose CT with aforementioned ASiR parameters using a 5-point-scale satisfaction score (1 = unacceptable, 2 = poor, 3 = average, 4 = good, and 5 = excellent image quality) by using prior standard dose CT as a reference of excellent image quality (5). Each reader selected the preference ASiR parameter for each participant. The image noise of the liver and the aorta in all 5 (1 prior standard dose and 4 current low dose) image sets was measured.     RESULTS: The mean CTDIvol of low dose CT was significantly lower than of standard dose CT (7.17 ± 0.08 vs 12.02 ±1.61 mGy, p<0.001). The mean satisfaction scores for low dose CT with 0%, 10%, 20% and 30% ASiR were 3.95, 3.99, 3.91 and 3.87, respectively with the ranges of 3 to 5 in all techniques. The preferred ASiR parameters of each participant randomly selected by each reader were varied, depending on the readers’ opinions. The mean image noise of the aorta on standard dose CT and low dose CT with 0%, 10%, 20%, and 30% ASiR was 29.07, 36.97, 33.92, 31.49, and 29.11, respectively, while the mean image noise of the liver was 24.60, 30.21, 28.33, 26.25, and 24.32, respectively. CONCLUSION: Low dose CT with 30% reduction of standard mA had acceptable image quality with significantly reduced radiation dose. The increment of ASiR was helpful in reducing image noise.  

Reducing the radiation dose for low-dose CT of the paranasal sinuses using iterative reconstruction: Feasibility and image quality

2012 ◽  
Vol 81 (9) ◽  
pp. 2246-2250 ◽  
Author(s):  
Stefan Bulla ◽  
Philipp Blanke ◽  
Frederike Hassepass ◽  
Tobias Krauss ◽  
Jan Thorsten Winterer ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Paranasal Sinuses ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Low Dose Ct

scholarly journals Abdominal CT radiation dose reduction at Siriraj Hospital (Phase III)

2021 ◽  
Vol 22 (1) ◽  
pp. 5-19
Author(s):  
Piyaporn Apisarnthanarak ◽  
Anawat Sriwaleephun ◽  
Sastrawut Thammakittiphan ◽  
Wimonrat Lornimitdee ◽  
Atchariya Klinhom ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Low Dose ◽  
Image Noise ◽  
Phase Iii ◽  
Abdominal Ct ◽  
Low Dose Ct ◽  
Tube Current ◽  
Image Set ◽  
The Mean

OBJECTIVE: To compare the image quality and the radiation dose between fixed tube current (FTC) low dose abdominal CT currently performed at our hospital and new automatic tube current modulation (ATCM) low dose abdominal CT. MATERIALS AND METHODS: We prospectively performed ATCM low dose abdominal CT in 88 participants who had prior FTC low dose CT for comparison. Four experienced abdominal radiologists independently and blindly assessed the quality of FTC and ATCM low dose CT images by using a 5-point-scale satisfaction score (1 = unacceptable, 2 = poor, 3 = average, 4 = good, and 5 = excellent image quality). Each reader selected the preferred image set between FTC and ATCM low dose techniques for each participant. The image noise of the liver and the aorta in both techniques was measured. The volume CT dose index (CTDIvol) of both techniques was compared. RESULTS: The mean satisfaction scores (SD) for FTC and ATCM low dose CT were 4.38 (0.66) and 4.38 (0.64), respectively with the ranges of 3 to 5 in both techniques, which were all acceptable for CT interpretation. The preferred image set between FTC and ATCM low dose techniques of each participant randomly selected by each reader were varied, depending on the readers’ opinions. The mean image noise of the aorta on FTC and ATCM low dose CT accounted for 34.75 and 36.46, respectively, while the mean image noise of the liver was 28.86 and 29.81, respectively. The mean CTDIvol (SD) of FTC and ATCM low dose CT were 8.42 (0.32) and 8.12 (0.43) mGy, respectively.   CONCLUSION: FTC and ATCM low dose abdominal CT provided comparable acceptable image quality and showed no clinical significance in radiation dose optimization.

scholarly journals Abdominal CT radiation dose optimization at Siriraj Hospital

2020 ◽  
pp. 28-43
Author(s):  
Piyaporn Apisarnthanarak ◽  
Chosita Buranont ◽  
Chulaluck Boonma ◽  
Sureerat Janpanich ◽  
Tarntip Suwatananonthakij ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Low Dose ◽  
Standard Dose ◽  
Image Noise ◽  
Abdominal Ct ◽  
Low Dose Ct ◽  
Excellent Image Quality ◽  
Ct Dose ◽  
The Mean

OBJECTIVE: To compare radiation dose and image quality between standard dose abdominal CT currently performed at our hospital and new low dose abdominal CT using various percentages (0%, 10%, 20%, and 30%) of Adaptive Statistical Iterative Reconstruction (ASiR). MATERIALS AND METHODS: We prospectively performed low dose abdominal CT (30% reduction of standard tube current) in 119 participants. The low dose CT images were post processed with four parameters (0%, 10%, 20% and 30%) of ASiR. The volume CT dose index (CTDIvol) of standard and low dose CT were compared. Four experienced abdominal radiologists independently assessed the quality of low dose CT with aforementioned ASiR parameters using a 5-point-scale satisfaction score (1 = unacceptable, 2 = poor, 3 = average, 4 = good, and 5 = excellent image quality) by using prior standard dose CT as a reference of excellent image quality (5). Each reader selected the preference ASiR parameter for each participant. The image noise of the liver and the aorta in all 5 (1 prior standard dose and 4 current low dose) image sets was measured.     RESULTS: The mean CTDIvol of low dose CT was significantly lower than of standard dose CT (7.17 ± 0.08 vs 12.02 ±1.61 mGy, p<0.001). The mean satisfaction scores for low dose CT with 0%, 10%, 20% and 30% ASiR were 3.95, 3.99, 3.91 and 3.87, respectively with the ranges of 3 to 5 in all techniques. The preferred ASiR parameters of each participant randomly selected by each reader were varied, depending on the readers’ opinions. The mean image noise of the aorta on standard dose CT and low dose CT with 0%, 10%, 20%, and 30% ASiR was 29.07, 36.97, 33.92, 31.49, and 29.11, respectively, while the mean image noise of the liver was 24.60, 30.21, 28.33, 26.25, and 24.32, respectively. CONCLUSION: Low dose CT with 30% reduction of standard mA had acceptable image quality with significantly reduced radiation dose. The increment of ASiR was helpful in reducing image noise.

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 Abdominal CT radiation dose reduction at Siriraj Hospital (Phase II)

2020 ◽  
Vol 21 (3) ◽  
pp. 5-24
Author(s):  
Piyaporn Apisarnthanarak ◽  
Suchanya Hongpinyo ◽  
Krittya Saysivanon ◽  
Chulaluck Boonma ◽  
Sureerat Janpanich ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Dose Reduction ◽  
Low Dose ◽  
Standard Dose ◽  
Image Noise ◽  
Satisfaction Score ◽  
Abdominal Ct ◽  
Low Dose Ct ◽  
The Mean

Objective: To compare radiation dose, radiologists’ satisfaction, and image noise between the standard dose abdominal CT currently performed at our hospital and the new automatic tube current modulation (ATCM) low dose abdominal CT, using various parameters (0%, 10%, 20%, and 30%) of the Adaptive Statistical Iterative Reconstruction (ASiR). Materials and Methods: We prospectively performed the ATCM low dose abdominal CT in 111 participants who had prior standard dose CT for comparison. The ATCM low dose CT images were post processed with 4 parameters (0%, 10%, 20% and 30%) of ASiR on a CT workstation. The volume CT dose index (CTDIvol) of the ATCM low dose and the standard dose CT were compared. Four experienced abdominal radiologists independently assessed the quality of the ATCM low dose CT with the aforementioned ASiR parameters using a 5-point-scale satisfaction score (1 = unacceptable, 2 = poor, 3 = average, 4 = good, and 5 = excellent image quality) by using the prior standard dose CT as a reference of an excellent image quality (5). Each reader selected the preferred ASiR parameter for each participant. The image noise of the liver and the aorta in all 5 techniques (1 prior standard dose and 4 current ATCM low dose techniques) was measured. The correlation between the image quality vs the participants’ body mass index (BMI) and waist circumferences were analyzed. Results: The mean CTDIvol of the ATCM low dose CT was significantly lower than of the standard dose CT (7.29 ± 0.20 vs 11.28 ± 0.23 mGy, p<0.001). The mean satisfaction score for the ATCM low dose CT with 0%, 10%, 20% and 30% ASiR were 4.14, 4.16, 4.17, and 4.26, respectively with the ranges of 3 to 5 in all techniques. The preferred ASiR parameters of each participant randomly selected by each reader were varied, depending on the readers’ opinions. The mean image noise of the aorta on the standard dose CT and the ATCM low dose CT with 0%, 10%, 20%, and 30% ASiR was 30.69, 36.60, 34.05, 31.43, and 29.09, respectively, while the mean image noise of the liver was 24.96, 29.90, 27.86, 25.66, and 23.68, respectively. There was a correlation between the image quality (satisfaction score and image noise) vs the participants’ BMI and waist circumferences. Conclusion: The ATCM low dose CT received acceptable radiologists’ satisfaction with significant radiation dose reduction. The increment of ASiR was helpful in reducing the image noise and had a tendency to increase the radiologists’ satisfaction score.

Combination of Deep Learning–Based Denoising and Iterative Reconstruction for Ultra-Low-Dose CT of the Chest: Image Quality and Lung-RADS Evaluation

2020 ◽  
Vol 215 (6) ◽  
pp. 1321-1328
Author(s):  
Akinori Hata ◽  
Masahiro Yanagawa ◽  
Yuriko Yoshida ◽  
Tomo Miyata ◽  
Mitsuko Tsubamoto ◽  
...  
Keyword(s):  
Deep Learning ◽  
Image Quality ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Low Dose Ct
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