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Ichikawa S, Motosugi U, Shimizu T, Kromrey ML, Aikawa Y, Tamada D, Onishi H. Diagnostic performance and image quality of low-tube voltage and low-contrast medium dose protocol with hybrid iterative reconstruction for hepatic dynamic CT. Br J Radiol 2021; 94:20210601. [PMID: 34586900 DOI: 10.1259/bjr.20210601] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE To evaluate the diagnostic performance and image quality of the low-tube voltage and low-contrast medium dose protocol for hepatic dynamic CT. METHODS This retrospective study was conducted between January and May 2018. All patients underwent hepatic dynamic CT using one of the two protocols: tube voltage, 80 kVp and contrast dose, 370 mgI/kg with hybrid iterative reconstruction or tube voltage, 120 kVp and contrast dose, 600 mgI/kg with filtered back projection. Two radiologists independently scored lesion conspicuity and image quality. Another radiologist measured the CT numbers of abdominal organs, muscles, and hepatocellular carcinoma (HCC) in each phase. Lesion detectability, HCC diagnostic ability, and image quality of the arterial phase were compared between the two protocols using the non-inferiority test. CT numbers and HCC-to-liver contrast were compared between the protocols using the Mann-Whitney U test. RESULTS 424 patients (70.5 ± 10.1 years) were evaluated. The 80-kVp protocol showed non-inferiority in lesion detectability and diagnostic ability for HCC (sensitivity, 85.7-89.3%; specificity, 96.3-98.6%) compared with the 120-kVp protocol (sensitivity, 91.0-93.3%; specificity, 93.6-97.3%) (p < 0.001-0.038). The ratio of fair image quality in the 80-kVp protocol also showed non-inferiority compared with that in the 120-kVp protocol in assessments by both readers (p < 0.001). HCC-to-liver contrast showed no significant differences for all phases (p = 0.309-0.705) between the two protocols. CONCLUSION The 80-kVp protocol with hybrid iterative reconstruction for hepatic dynamic CT can decrease iodine doses while maintaining diagnostic performance and image quality compared with the 120-kVp protocol. ADVANCES IN KNOWLEDGE The 80- and 120-kVp protocols showed equivalent hepatic lesion detectability, diagnostic ability for HCC, image quality, and HCC-to-liver contrast.The 80-kVp protocol showed a 38.3% reduction in iodine dose compared with the 120-kVp protocol.
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Affiliation(s)
- Shintaro Ichikawa
- Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, Japan
| | - Utaroh Motosugi
- Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, Japan.,Department of Diagnostic Radiology, Kofu Kyoritsu Hospital, 1-9-1 Takara, Kofu, Yamanashi, Japan
| | - Tatsuya Shimizu
- Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, Japan
| | - Marie Luise Kromrey
- Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, Japan.,Department of Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, Domstraße 11, Greifswald, Germany
| | - Yoshihito Aikawa
- Division of Radiology, University of Yamanashi Hospital, 1110 Shimokato, Chuo, Yamanashi, Japan
| | - Daiki Tamada
- Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, Japan
| | - Hiroshi Onishi
- Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, Japan
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Leon S, Olguin E, Schaeffer C, Olguin C, Verma N, Mohammed TL, Grajo J, Arreola M. Comparison of CT image quality between the AIDR 3D and FIRST iterative reconstruction algorithms: an assessment based on phantom measurements and clinical images. Phys Med Biol 2021; 66. [PMID: 34015770 DOI: 10.1088/1361-6560/ac0391] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 05/20/2021] [Indexed: 11/11/2022]
Abstract
Modern CT iterative reconstruction algorithms are transitioning from a statistical-based to model-based approach. However, increasing complexity does not ensure improved image quality for all indications, and thorough characterization of new algorithms is important to understand their potential clinical impacts. This study performs both quantitative and qualitative analyses of image quality to compare Canon's statistical-based Adaptive Iterative Dose Reduction 3D (AIDR 3D) algorithm to its model-based algorithm, Forward-projected model-based Iterative Reconstruction SoluTion(FIRST). A phantom was used to measure the task-specific modulation transfer function (MTFTask), the noise power spectrum (NPS), and the low-contrast object-specific CNR (CNRLO) for each algorithm using three dose levels and the convolution algorithm (kernel) appropriate for abdomen, lung, and brain imaging. Additionally, MTFTaskwas measured at four contrast levels, and CNRLOwas measured for two object sizes. Lastly, three radiologists participated in a preference study to compare clinical image quality for three study types: non-contrast abdomen, pulmonary embolism (PE), and lung screening. Nine questions related to the appearance of anatomical features or image quality characteristics were scored for twenty exams of each type. The behavior of both algorithms depended strongly on the kernel selected. Phantom measurements suggest that FIRST should be beneficial over AIDR 3D for abdomen imaging, but do not suggest a clear overall benefit to FIRST for lung or brain imaging; metrics suggest performance may be equivalent to or slightly favor AIDR 3D, depending on the size of the object being imaged and whether spatial resolution or low-contrast resolution is more important for the task at hand. Overall, radiologists strongly preferred AIDR 3D for lung screening, slightly preferred AIDR 3D for non-contrast abdomen, and had no preference for PE. FIRST was superior for the reduction of metal artifacts. Radiologist preference may be influenced by changes to noise texture.
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Affiliation(s)
- Stephanie Leon
- University of Florida, Gainesville, FL, United States of America
| | - Edmond Olguin
- University of Florida, Gainesville, FL, United States of America
| | - Colin Schaeffer
- University of Florida, Gainesville, FL, United States of America
| | - Catherine Olguin
- University of Florida, Gainesville, FL, United States of America
| | - Nupur Verma
- University of Florida, Gainesville, FL, United States of America
| | | | - Joseph Grajo
- University of Florida, Gainesville, FL, United States of America
| | - Manuel Arreola
- University of Florida, Gainesville, FL, United States of America
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Ahmad MS, Suardi N, Shukri A, Mohammad H, Oglat AA, Alarab A, Makhamrah O. Chemical Characteristics, Motivation and Strategies in choice of Materials used as Liver Phantom: A Literature Review. J Med Ultrasound 2020; 28:7-16. [PMID: 32368444 PMCID: PMC7194418 DOI: 10.4103/jmu.jmu_4_19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 02/26/2019] [Accepted: 05/24/2019] [Indexed: 12/27/2022] Open
Abstract
Liver phantoms have been developed as an alternative to human tissue and have been used for different purposes. In this article, the items used for liver phantoms fabrication are mentioned same as in the previous literature reviews. Summary and characteristics of these materials are presented. The main factors that need to be available in the materials used for fabrication in computed tomography, ultrasound, magnetic resonance imaging, and nuclear medicine were analyzed. Finally, the discussion focuses on some purposes and aims of the liver phantom fabrication for use in several areas such as training, diagnoses of different diseases, and treatment planning for therapeutic strategies – for example, in selective internal radiation therapy, stereotactic body radiation therapy, laser-induced thermotherapy, radiofrequency ablation, and microwave coagulation therapy. It was found that different liver substitutes can be developed to fulfill the different requirements.
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Affiliation(s)
- Muntaser S Ahmad
- Department of Medical Physics and Radiation Science, School of Physics, Universiti Sains Malaysia, Malaysia
| | - Nursakinah Suardi
- Department of Medical Physics and Radiation Science, School of Physics, Universiti Sains Malaysia, Malaysia
| | - Ahmad Shukri
- Department of Medical Physics and Radiation Science, School of Physics, Universiti Sains Malaysia, Malaysia
| | - Hjouj Mohammad
- Department of Medical Imaging, Faculty of Health Professions, Al-Quds University, Abu Deis - Main Campus, Jerusalem, Palestine
| | - Ammar A Oglat
- Department of Medical Imaging, Faculty of Allied Health Sciences, The Hashemite University, Zarqa, Jordan, Palestine
| | - Azzam Alarab
- Department of Medical Imaging, Faculty of Allied Medical Health, Palestine Ahlyia University, Bethlehem, Palestine
| | - Osama Makhamrah
- Department of Medical Imaging, Faculty of Health Professions, Al-Quds University, Abu Deis - Main Campus, Jerusalem, Palestine
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Gerbl A, Lewin M, Zeiske T, Ziegert M, Schwarz FB, Hamm B, Scheel M, Jahnke P. Characterization of office laser printers for 3-D printing of soft tissue CT phantoms. J Med Imaging (Bellingham) 2019; 6:021602. [PMID: 30820442 DOI: 10.1117/1.jmi.6.2.021602] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 12/27/2018] [Indexed: 11/14/2022] Open
Abstract
The purpose of our study is to develop and evaluate a method for radiopaque 3-D printing (R3P) of soft tissue computed tomography (CT) phantoms with office laser printers. Five laser printers from different vendors are tested for toner CT attenuation. A liver phantom is created by printing CT images of a patient liver on office paper. One thousand eight hundred sixty paper sheets are printed with three repeated prints per page, resulting in a stack of 18.6 cm. The phantom is examined with 12 tube current settings. Images are reconstructed using filtered back projection (FBP) and iterative reconstruction [adaptive iterative dose reduction 3D (AIDR 3D)]. Seven radiologists rated image quality of all acquisitions. Toner attenuation of all investigated printers increased linearly with the print template grayscale. The liver phantom reproduced anatomic detail and attenuation values of the patient ( mean ± SD HU difference 12.68 ± 7.74 ). Image quality scores increased with dose but did not vary significantly above a threshold dose for AIDR 3D. Overall, AIDR 3D reconstructed images are rated superior to FBP reconstructions ( p < 0.001 ). In conclusion, R3P with standard office laser printers can generate soft tissue CT phantoms without hardware manipulations but with limited flexibility regarding attenuation properties of the printed toner material.
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Affiliation(s)
- Andreas Gerbl
- Charité-Universitätsmedizin Berlin, Department of Radiology, Berlin, Germany
| | - Marcel Lewin
- Charité-Universitätsmedizin Berlin, Department of Radiology, Berlin, Germany
| | - Tim Zeiske
- Charité-Universitätsmedizin Berlin, Department of Radiology, Berlin, Germany
| | - Marco Ziegert
- Charité-Universitätsmedizin Berlin, Department of Radiology, Berlin, Germany
| | | | - Bernd Hamm
- Charité-Universitätsmedizin Berlin, Department of Radiology, Berlin, Germany
| | - Michael Scheel
- Charité-Universitätsmedizin Berlin, Department of Radiology, Berlin, Germany
| | - Paul Jahnke
- Charité-Universitätsmedizin Berlin, Department of Radiology, Berlin, Germany
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Yu S, Zheng J, Zhang L. Craniocervical computed tomography angiography with adaptive iterative dose reduction 3D algorithm and automatic tube current modulation in patients with different body mass indexes. Medicine (Baltimore) 2018; 97:e11841. [PMID: 30200068 PMCID: PMC6133620 DOI: 10.1097/md.0000000000011841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The aim of this study was to investigate the feasibility of head and neck computed tomography angiography (CTA) using the 80-kV tube voltage and the adaptive iterative dose reduction (AIDR) 3D algorithm in patients with different body mass indexes (BMIs).From November 2016 to January 2017, 128 consecutive patients scheduled for head and neck CTA examinations were randomized into the 100-kV group (n = 60) and the 80-kV group (n = 68). Both groups used the automatic tube current modulation technique and the AIDR 3D algorithm. The patients were further grouped as slender (BMI < 22 kg/m), normal weight (22 kg/m≤BMI < 25 kg/m), and overweight (BMI ≥25 kg/m). The image quality and the radiation dose of each subgroup were analyzed.The images of the head and neck vessels and the brain tissue obtained with 100 kV were all of diagnostic quality. Slender and normal weight patients imaged with 80 kV also produced images of diagnostic quality. However, 80 kV in the overweight patients failed to produce images of diagnostic quality. The radiation dose in the patients imaged with 80 kV was significantly decreased in comparison with those imaged with 100 kV. The effective dose was 0.36 ± 0.06 and 0.41 ± 0.05 mSv in the slender and normal weight patients imaged with 80 kV.Head and neck CTA scanning with 80 kV, automatic tube current modulation, and AIDR 3D algorithm can produce high quality images with reduced radiation dose in slender or normal weight patients.
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Minamishima K, Sugisawa K, Yamada Y, Jinzaki M. Quantitative and qualitative evaluation of hybrid iterative reconstruction, with and without noise power spectrum models: A phantom study. J Appl Clin Med Phys 2018; 19:318-325. [PMID: 29493077 PMCID: PMC5978737 DOI: 10.1002/acm2.12304] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/10/2017] [Accepted: 01/27/2018] [Indexed: 01/06/2023] Open
Abstract
The purpose of this phantom study was to investigate the feasibility of dose reduction with hybrid iterative reconstruction, with and without a noise power spectrum (NPS) model, using both quantitative and qualitative evaluations. Standard dose (SD), three‐quarter dose (TQD), and half‐dose (HD) of radiation were used. Images were reconstructed with filtered back projection (FBP), adaptive iterative dose reduction 3D (AIDR 3D) (MILD, STR), and AIDR 3D enhanced (eAIDR 3D) (eMILD, eSTR). An NPS analysis, task‐based modulation transfer function (MTFtask) analysis, and comparisons of low‐contrast detectability and image texture were performed. Although the eAIDR 3D had a higher NPS value in the high‐frequency range and improved image texture and resolution as compared with AIDR 3D at the same radiation dose and iteration levels, it yielded higher noise than AIDR 3D. Additionally, although there was no statistically significant difference between SD‐FBP and the TQD series in the comparison of the mean area under the curve (AUC), the mean AUC was statistically significantly different between SD‐FBP and the HD series. NPS values in the high‐frequency range, 10% MTFtask values, low‐contrast detectability, and image textures of TQD‐eMILD were comparable to those of SD‐FBP. Our findings suggested that using eMILD can reduce the radiation dose by 25%, while potentially maintaining diagnostic performance, spatial resolution, and image texture; this could support selecting the appropriate protocol in a clinical setting.
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Affiliation(s)
- Kazuya Minamishima
- Office of Radiation Technology, Keio University Hospital, Shinjuku, Japan
| | - Koichi Sugisawa
- Office of Radiation Technology, Keio University Hospital, Shinjuku, Japan
| | - Yoshitake Yamada
- Department of Radiology, Keio University School of Medicine, Tokyo, Japan
| | - Masahiro Jinzaki
- Department of Radiology, Keio University School of Medicine, Tokyo, Japan
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Diagnostic performance of reduced-dose CT with a hybrid iterative reconstruction algorithm for the detection of hypervascular liver lesions: a phantom study. Eur Radiol 2016; 27:2995-3003. [DOI: 10.1007/s00330-016-4687-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 10/15/2016] [Accepted: 11/29/2016] [Indexed: 12/26/2022]
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Yu S, Zhang L, Zheng J, Xu Y, Chen Y, Song Z. A comparison of adaptive iterative dose reduction 3D and filtered back projection in craniocervical CT angiography. Clin Radiol 2016; 72:96.e1-96.e6. [PMID: 27647546 DOI: 10.1016/j.crad.2016.08.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/01/2016] [Accepted: 08/03/2016] [Indexed: 02/03/2023]
Abstract
AIM To compare the effects of exposure parameters on image quality and radiation dose for craniocervical computed tomography angiography (CTA) using adaptive iterative dose reduction in three dimensions (AIDR 3D) and filtered back projection (FBP) algorithms. MATERIALS AND METHODS One hundred and eighty patients were divided into three groups; group A (120 kV, 300 mA, FBP), group B (100 kV, automatic mA, AIDR 3D) and group C (80kV, automatic mA, AIDR 3D). Image quality and radiation dose were evaluated for each group. RESULTS For both cervical and intracranial vessels, CT attenuation, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were higher in the AIDR 3D groups. The difference in mean vascular noise was also statistically significant (p<0.001), with group B having the lowest value at 16.5±3.2 HU and group C having the highest at 19.1±2.9 HU. FBP reconstruction resulted in lower image-quality scores for the common carotid artery. Parenchymal image-quality scores also varied significantly different between groups with group C partially failing to meet the minimum standards for diagnostic use. For the middle cerebral artery, image-quality scores were significantly better in group A, although images from groups B and C also satisfied clinical diagnostic requirements. The image quality of the internal carotid artery was the best in group B. Image-quality scores between groups were not significantly different for the carotid sinus. Radiation doses in the groups using AIDR 3D were >70% lower than in the FBP group. CONCLUSION AIDR 3D (100 kV, automatic modulation) provides optimal image quality of vascular and parenchymal tissues at significantly lower radiation doses (mSV) than FBP in craniocervical CTA. For cases in which highly accurate parenchymal assessment is not required, the tube voltage can be lowered to 80 kV to further decrease radiation dose.
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Affiliation(s)
- S Yu
- Department of CT Diagnosis, Cangzhou Central Hospital, Cangzhou, Hebei, 061001, China.
| | - L Zhang
- Department of CT Diagnosis, Cangzhou Central Hospital, Cangzhou, Hebei, 061001, China
| | - J Zheng
- Department of CT Diagnosis, Cangzhou Central Hospital, Cangzhou, Hebei, 061001, China
| | - Y Xu
- Department of CT Diagnosis, Cangzhou Central Hospital, Cangzhou, Hebei, 061001, China
| | - Y Chen
- Department of CT Diagnosis, Cangzhou Central Hospital, Cangzhou, Hebei, 061001, China
| | - Z Song
- Department of CT Diagnosis, Cangzhou Central Hospital, Cangzhou, Hebei, 061001, China
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