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Yuan D, Wang Y, Lin S, Gutjahr R, Lyu P, Zhang Y, Gao J, Liu J. Patient-specific post-trigger delay in coronary CT angiography: A prospective study comparing with fixed delay. Eur J Radiol 2023; 163:110813. [PMID: 37043884 DOI: 10.1016/j.ejrad.2023.110813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 03/31/2023] [Accepted: 04/03/2023] [Indexed: 04/14/2023]
Abstract
OBJECTIVES To validate the peak enhancement timing of a patient-specific post-trigger delay (PTD) in Coronary CT angiography (CCTA) and compare its image quality against a fixed PTD. METHODS In this prospective study, 204 consecutive participants were randomly divided into two groups to perform CCTA in bolus tracking with either a fixed 5-second PTD (Group A) or a patient-specific PTD (Group B). Test bolus was also performed in Group B to determine the reference peak enhancement timing. One reader evaluated objective image quality, while two readers rated subjective image quality. The predicted PTD was validated through correlation and agreement analysis with the reference measurement. Objective image quality was compared between groups via two-sample t-test and linear regression, while the subjective ratings were compared with chi-square analysis. RESULTS The two groups each had 102 participants with comparable characteristics (52.9 ± 11.3 versus 52.1 ± 11.3 years of age, and 53 versus 52 males). The scan timing from patient-specific PTD demonstrated strong correlation (R = 0.77) and consistency (ICC = 0.618) with the reference peak timing. Both readers rated better subjective image quality for the Group B (p < 0.001). The mean vessel enhancement was significantly higher in Group B in all coronary vessels (all p < 0.05). After adjusting for the participant variation, the patient-specific PTD strategy was associated with an average of 33.5 HU higher enhancement compared to the fixed PTD. CONCLUSIONS Patient-specific delay could achieve reliable scan timing, optimize vessel opacification and obtain better image quality in CCTA.
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Affiliation(s)
- Dian Yuan
- The Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, Eastern Jianshe Road, Zhengzhou 450052, Henan Province, China
| | - Yiran Wang
- The Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, Eastern Jianshe Road, Zhengzhou 450052, Henan Province, China
| | - Shushen Lin
- Siemens Healthineers GmbH, Forchheim, Germany
| | | | - Peijie Lyu
- The Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, Eastern Jianshe Road, Zhengzhou 450052, Henan Province, China
| | - Yonggao Zhang
- The Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, Eastern Jianshe Road, Zhengzhou 450052, Henan Province, China
| | - Jianbo Gao
- The Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, Eastern Jianshe Road, Zhengzhou 450052, Henan Province, China
| | - Jie Liu
- The Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, Eastern Jianshe Road, Zhengzhou 450052, Henan Province, China.
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Kozuma K, Chikamori T, Hashimoto J, Honye J, Ikeda T, Ishiwata S, Kato M, Kondo H, Matsubara K, Matsumoto K, Matsumoto N, Motoyama S, Obunai K, Sakamoto H, Soejima K, Suzuki S, Abe K, Amano H, Hioki H, Iimori T, Kawai H, Kosuge H, Nakama T, Suzuki Y, Takeda K, Ueda A, Yamashita T, Hirao K, Kimura T, Nagai R, Nakamura M, Shimizu W, Tamaki N. JCS 2021 Guideline on Radiation Safety in Cardiology. Circ J 2022; 86:1148-1203. [DOI: 10.1253/circj.cj-21-0379] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ken Kozuma
- Division of Cardiology, Teikyo University Hospital
| | | | - Jun Hashimoto
- Department of Radiology, Tokai University School of Medicine
| | - Junko Honye
- Department of Cardiology, Kikuna Memorial Hospital
| | - Takanori Ikeda
- Department of Cardiovascular Medicine, Toho University Faculty of Medicine
| | | | - Mamoru Kato
- Department of Radiology, Akita Cerebrospinal and Cardiovascular Center
| | | | - Kosuke Matsubara
- Department of Quantum Medical Technology, Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University
| | - Kazuma Matsumoto
- Department of Radiological Technology, Hyogo College of Medicine College Hospital
| | | | | | | | - Hajime Sakamoto
- Department of Radiological Technology, Faculty of Health Science, Juntendo University
| | - Kyoko Soejima
- Department of Cardiology, Kyorin University Hospital
| | - Shigeru Suzuki
- Department of Radiology, Totsuka Kyouritsu Daini Hospital
| | - Koichiro Abe
- Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women's Medical University
| | - Hideo Amano
- Department of Cardiovascular Medicine, Toho University Faculty of Medicine
| | | | | | - Hideki Kawai
- Department of Cardiology, Fujita Health University
| | | | | | | | | | - Akiko Ueda
- Division of Advanced Arrhythmia Management, Kyorin University Hospital
| | | | - Kenzo Hirao
- Division of Cardiovascular Medicine, AOI Universal Hospital
| | - Takeshi Kimura
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine
| | - Ryozo Nagai
- Department of Cardiovascular Medicine, Jichi Medical University
| | - Masato Nakamura
- Division of Cardiovascular Medicine, Toho University Ohashi Medical Center
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School
| | - Nagara Tamaki
- Department of Radiology, Kyoto Prefectural University of Medicine
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Liu P, Wang M, Wang Y, Yu M, Wang Y, Liu Z, Li Y, Jin Z. Impact of Deep Learning-based Optimization Algorithm on Image Quality of Low-dose Coronary CT Angiography with Noise Reduction: A Prospective Study. Acad Radiol 2020; 27:1241-1248. [PMID: 31864809 DOI: 10.1016/j.acra.2019.11.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 11/12/2019] [Accepted: 11/14/2019] [Indexed: 01/19/2023]
Abstract
RATIONALE AND OBJECTIVES To evaluate deep learning (DL)-based optimization algorithm for low-dose coronary CT angiography (CCTA) image noise reduction and image quality (IQ) improvement. MATERIALS AND METHODS A postprocessing platform for the CCTA image was built using a DL-based algorithm. Seventy subjects referred for CCTA were randomly divided into two groups (study group A with 80 kVp and control group B with 100 kVp). Group C was obtained by DL optimization of group A. Subjective IQ was blindly graded by two experienced radiologists on a four-point scale (4-excellent,1-poor). The image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated to evaluate IQ objectively. The difference between the time consumed of iterative reconstruction and DL algorithm was also recorded. RESULTS The subjective IQ score of group C using the DL algorithm was significantly better than that of group A (p = 0.005). The noise of group C was significantly decreased, while SNR and CNR were significantly increased compared to group A (p < 0.001). The subjective IQ scores were lower in group A compared to group B (p = 0.037), whereas subjective IQ scores in group C were not significantly different (p = 0.874). For objective IQ, the noise of group A was significantly higher, while SNR and CNR were significantly lower than that of group B (p < 0.05). There was no significant difference in noise and SNR between group C and group B (p > 0.05), but CNR in group C was significantly higher than that in group B (p < 0.05). The DL algorithm processes the image twice as fast as the iterative reconstruction speed. CONCLUSION The DL-based optimization algorithm could effectively improve the IQ of low-dose CCTA by noise reduction.
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Affiliation(s)
- Peijun Liu
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Man Wang
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Yining Wang
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.
| | - Min Yu
- CT Business Unit, Neusoft Medical System Company, Shenyang, China
| | - Yun Wang
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Zhuoheng Liu
- CT Business Unit, Neusoft Medical System Company, Shenyang, China
| | - Yumei Li
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Zhengyu Jin
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
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Takao S, Nishie A, Asayama Y, Ishigami K, Ushijima Y, Kakihara D, Nakayama T, Fujita N, Morita K, Ishimatsu K, Yoshizumi T, Ikegami T, Kondo M, Honda H. Improved visualization of a fine intrahepatic biliary duct on drip infusion cholangiography-computed tomography: Impact of knowledge-based iterative model reconstruction. Hepatol Res 2020; 50:629-634. [PMID: 31863713 DOI: 10.1111/hepr.13477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 12/07/2019] [Accepted: 12/17/2019] [Indexed: 02/08/2023]
Abstract
AIM The purpose of this study was to investigate the visualization of fine biliary ducts with knowledge-based iterative model reconstruction (IMR) in low-dose drip infusion computed tomography (CT) cholangiography (DIC-CT) as compared with filtered back projection (FBP) and hybrid iterative reconstruction (iDose4 ). METHODS A total of 38 patients underwent DIC-CT for living donor liver transplantation. CT was performed approximately 20 min after the end of the infusion of meglumine iotroxate (100 mL). Images were reconstructed using FBP, iDose4 , and IMR, and 1-mm slice images at fixed window level and width were prepared for assessment. Two reviewers independently evaluated the quality of visualization of the fine biliary ducts of the caudate lobe (B1) using a 5-point scale. The visualization scores of three reconstructed images were compared using the Kruskal-Wallis test and Mann-Whitney U-test. RESULTS For reviewer 1, the visualization score of IMR was significantly higher than that of FBP (P = 0.012), and tended to be higher than that of iDose4 (P = 0.078). For reviewer 2, the visualization score of IMR was significantly higher than those of both FBP and iDose4 (P < 0.01). CONCLUSIONS IMR showed better visualization of B1 on DIC-CT than FBP or iDose4 . DIC-CT reconstructed with IMR may be useful to the anatomical grasp of biliary tracts in cases of hepatectomy.
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Affiliation(s)
- Seiichiro Takao
- Departments of Clinical Radiology, Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Akihiro Nishie
- Departments of Clinical Radiology, Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yoshiki Asayama
- Departments of Clinical Radiology, Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kousei Ishigami
- Departments of Clinical Radiology, Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yasuhiro Ushijima
- Departments of Clinical Radiology, Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Daisuke Kakihara
- Departments of Clinical Radiology, Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Tomohiro Nakayama
- Departments of Clinical Radiology, Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Nobuhiro Fujita
- Departments of Clinical Radiology, Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Koichiro Morita
- Departments of Clinical Radiology, Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Keisuke Ishimatsu
- Departments of Clinical Radiology, Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Tomoharu Yoshizumi
- Departments of Clinical Radiology, Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Toru Ikegami
- Departments of Clinical Radiology, Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Masatoshi Kondo
- Department of Medical Technology, Kyushu University Hospital, Fukuoka, Japan
| | - Hiroshi Honda
- Departments of Clinical Radiology, Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Li T, Tang T, Yang L, Zhang X, Li X, Luo C. Coronary CT Angiography with Knowledge-Based Iterative Model Reconstruction for Assessing Coronary Arteries and Non-Calcified Predominant Plaques. Korean J Radiol 2020; 20:729-738. [PMID: 30993924 PMCID: PMC6470089 DOI: 10.3348/kjr.2018.0435] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 01/21/2019] [Indexed: 11/15/2022] Open
Abstract
Objective To assess the effects of iterative model reconstruction (IMR) on image quality for demonstrating non-calcific high-risk plaque characteristics of coronary arteries. Materials and Methods This study included 66 patients (53 men and 13 women; aged 39–76 years; mean age, 55 ± 13 years) having single-vessel disease with predominantly non-calcified plaques evaluated using prospective electrocardiogram-gated 256-slice CT angiography. Paired image sets were created using two types of reconstruction: hybrid iterative reconstruction (HIR) and IMR. Plaque characteristics were compared using the two algorithms. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the images and the CNR between the plaque and adjacent adipose tissue were also compared between the two reformatted methods. Results Seventy-seven predominantly non-calcified plaques were detected. Forty plaques showed napkin-ring sign with the IMR reformatted method, while nineteen plaques demonstrated napkin-ring sign with HIR. There was no statistically significant difference in the presentation of positive remodeling, low attenuation plaque, and spotty calcification between the HIR and IMR reconstructed methods (all p > 0.5); however, there was a statistically significant difference in the ability to discern the napkin-ring sign between the two algorithms (χ2 = 12.12, p < 0.001). The image noise of IMR was lower than that of HIR (10 ± 2 HU versus 12 ± 2 HU; p < 0.01), and the SNR and CNR of the images and the CNR between plaques and surrounding adipose tissues on IMR were better than those on HIR (p < 0.01). Conclusion IMR can significantly improve image quality compared with HIR for the demonstration of coronary artery and atherosclerotic plaques using a 256-slice CT.
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Affiliation(s)
- Tao Li
- Department of Radiology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - Tian Tang
- Department of Radiology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - Li Yang
- Department of Radiology, Chinese People's Liberation Army General Hospital, Beijing, China.
| | - Xinghua Zhang
- Department of Radiology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - Xueping Li
- Department of Radiology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - Chuncai Luo
- Department of Radiology, Chinese People's Liberation Army General Hospital, Beijing, China
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Hsu JC, Cruz ED, Lau KC, Bouché M, Kim J, Maidment ADA, Cormode DP. Renally Excretable and Size-Tunable Silver Sulfide Nanoparticles for Dual-Energy Mammography or Computed Tomography. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2019; 31:7845-7854. [PMID: 33005070 PMCID: PMC7523639 DOI: 10.1021/acs.chemmater.9b01750] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Significant effort has been focused on developing renally-clearable nanoparticle agents since efficient renal clearance is important for eventual clinical translation. Silver sulfide nanoparticles (Ag2S-NP) have recently been identified as contrast agents for dual energy mammography, computed tomography (CT) and fluorescence imaging and probes for drug delivery and photothermal therapy with good biocompatibility. However, most Ag2S-NP reported to date are not renally excretable and are observed in vivo to accumulate and remain in the reticuloendothelial system (RES) organs, i.e. liver and spleen, for a long time, which could negatively impact their likelihood for translation. Herein, we present renally-clearable, 3.1 nm Ag2S-NP with 85% of the injected dose (ID) being excreted within 24 hours of intravenous injection, which is amongst the best clearance of similarly sized nanoparticles reported thus far (mostly between 20-75% of ID). The urinary excretion and low RES accumulation of these nanoparticles in mice were indicated by in vivo CT imaging and biodistribution analysis. In summary, these ultrasmall Ag2S-NP can be effectively eliminated via urine and have high translational potential for various biomedical applications.
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Affiliation(s)
- Jessica C. Hsu
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Emma D. Cruz
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | - Kristen C. Lau
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Mathilde Bouché
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | - Johoon Kim
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Andrew D. A. Maidment
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | - David P. Cormode
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
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Yi Y, Zhao XM, Wu RZ, Wang Y, Vembar M, Jin ZY, Wang YN. Low Dose and Low Contrast Medium Coronary CT Angiography Using Dual-Layer Spectral Detector CT. Int Heart J 2019; 60:608-617. [PMID: 31105142 DOI: 10.1536/ihj.18-340] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The aim of the present study was to investigate the performance of low keV mono-energetic reconstructions in spectral coronary computed tomography angiography (CCTA) using spectral detector CT (SDCT) with reduced contrast media and radiation dose.Sixty patients were randomly assigned to Groups A and B (both n = 30) to undergo CCTA on a dual-layer SDCT with tube voltage 120 kVp and 100 kVp (average tube current: 108.5 and 73.8 mAs, respectively), with contrast media volume of 36 mL used in both groups. The mono-energetic 40-80 keV and conventional 120 kVp images in Group A and conventional 100 kVp images in Group B were reconstructed. Quantitative and qualitative image quality (IQ) were evaluated in the aortic root and distal segments of the coronary arteries.The patient characteristics were not significantly different between the two groups (all P≥ 0.47), nor was the effective radiation dose (1.5 ± 0.3 and 1.4 ± 0.3 mSv, P = 0.20). The quantitative IQ in aorta and coronary arteries of mono-energetic 40-60 keV was superior to conventional 120 kVp and 100 kVp images (all P < 0.05). The noise in spectral images was lower compared to conventional images (all P < 0.01). The subjective IQ score of 40-50 keV images was not significantly different from that of 100 kVp images (P > 0.8).The mono-energetic 40-50 keV reconstructions from spectral CCTA using SDCT provide improved IQ compared to conventional techniques while facilitating reduced radiation dose and contrast media.
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Affiliation(s)
- Yan Yi
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College
| | - Xue-Mei Zhao
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College
| | - Run-Ze Wu
- CT Clinical Science, Philips Healthcare, Cleveland
| | - Yun Wang
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College
| | - Mani Vembar
- CT Clinical Science, Philips Healthcare, Cleveland
| | - Zheng-Yu Jin
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College
| | - Yi-Ning Wang
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College
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Lee J, Kim TH, Lee BK, Yoon YW, Kwon HM, Hong BK, Min PK, Choi EY, Oh CS, Park CH. Diagnostic accuracy of low-radiation coronary computed tomography angiography with low tube voltage and knowledge-based model reconstruction. Sci Rep 2019; 9:1308. [PMID: 30718631 PMCID: PMC6362232 DOI: 10.1038/s41598-018-37870-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/10/2018] [Indexed: 12/23/2022] Open
Abstract
We aimed to evaluate the accuracy of coronary computed tomography angiography (CCTA) with a low-radiation protocol and iterative model reconstruction (IMR), in comparison with invasive coronary angiography (ICA). Sixty-one patients (45 males; mean age, 61.9 ± 9.2 years) with suspected coronary artery disease who underwent CCTA and ICA were retrospectively enrolled. CCTA was performed with low tube voltage (80 or 100 kVp), low tube current (100–200 mAs), prospective ECG triggering, and IMR using a 64-slice computed tomography scanner. Coronary artery disease was defined as luminal narrowing of >50%, as assessed using CCTA and ICA. The sensitivity, specificity, positive (PPV) and negative (NPV) predictive value, and accuracy of CCTA were examined. The mean radiation dose of CCTA was 1.05 ± 0.36 mSv. No non-diagnostic segment was noted. The sensitivity, specificity, PPV, NPV, and accuracy of CCTA were 86.4%, 96.1%, 80.3%, 97.5%, and 94.6% on a per segment basis, 93.1%, 94.7%, 88.3%, 97.0%, and 94.2% on a per vessel basis, and 100%, 83.3%, 93.5%, 100%, and 95.1% on a per patient basis, respectively. In conclusion, a low-radiation CCTA protocol with IMR may be useful for diagnosing coronary artery disease, as it reduces the radiation dose while maintaining diagnostic accuracy.
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Affiliation(s)
- Joohee Lee
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Tae Hoon Kim
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Byoung Kwon Lee
- Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Young Won Yoon
- Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hyuck Moon Kwon
- Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Bum Kee Hong
- Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Pil-Ki Min
- Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Eui-Young Choi
- Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Chi Suk Oh
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Chul Hwan Park
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
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9
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Benz DC, Fuchs TA, Gräni C, Studer Bruengger AA, Clerc OF, Mikulicic F, Messerli M, Stehli J, Possner M, Pazhenkottil AP, Gaemperli O, Kaufmann PA, Buechel RR. Head-to-head comparison of adaptive statistical and model-based iterative reconstruction algorithms for submillisievert coronary CT angiography. Eur Heart J Cardiovasc Imaging 2019; 19:193-198. [PMID: 28200212 DOI: 10.1093/ehjci/jex008] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 01/16/2017] [Indexed: 01/04/2023] Open
Abstract
Aims Iterative reconstruction (IR) algorithms allow for a significant reduction in radiation dose of coronary computed tomography angiography (CCTA). We performed a head-to-head comparison of adaptive statistical IR (ASiR) and model-based IR (MBIR) algorithms to assess their impact on quantitative image parameters and diagnostic accuracy for submillisievert CCTA. Methods and results CCTA datasets of 91 patients were reconstructed using filtered back projection (FBP), increasing contributions of ASiR (20, 40, 60, 80, and 100%), and MBIR. Signal and noise were measured in the aortic root to calculate signal-to-noise ratio (SNR). In a subgroup of 36 patients, diagnostic accuracy of ASiR 40%, ASiR 100%, and MBIR for diagnosis of coronary artery disease (CAD) was compared with invasive coronary angiography. Median radiation dose was 0.21 mSv for CCTA. While increasing levels of ASiR gradually reduced image noise compared with FBP (up to - 48%, P < 0.001), MBIR provided largest noise reduction (-79% compared with FBP) outperforming ASiR (-59% compared with ASiR 100%; P < 0.001). Increased noise and lower SNR with ASiR 40% and ASiR 100% resulted in substantially lower diagnostic accuracy to detect CAD as diagnosed by invasive coronary angiography compared with MBIR: sensitivity and specificity were 100 and 37%, 100 and 57%, and 100 and 74% for ASiR 40%, ASiR 100%, and MBIR, respectively. Conclusion MBIR offers substantial noise reduction with increased SNR, paving the way for implementation of submillisievert CCTA protocols in clinical routine. In contrast, inferior noise reduction by ASiR negatively affects diagnostic accuracy of submillisievert CCTA for CAD detection.
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Affiliation(s)
- Dominik C Benz
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Tobias A Fuchs
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Christoph Gräni
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Annina A Studer Bruengger
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Olivier F Clerc
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Fran Mikulicic
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Michael Messerli
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Julia Stehli
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Mathias Possner
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Aju P Pazhenkottil
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Oliver Gaemperli
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Philipp A Kaufmann
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
| | - Ronny R Buechel
- Department of Nuclear Medicine, Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland
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Park IK, Park J, Kim TH, Lee J, Han K, Oh C, Park CH. Non-inferior low-dose coronary computed tomography angiography image quality with knowledge-based iterative model reconstruction for overweight patients. PLoS One 2018; 13:e0209243. [PMID: 30586449 PMCID: PMC6306215 DOI: 10.1371/journal.pone.0209243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 12/03/2018] [Indexed: 11/29/2022] Open
Abstract
We investigated the feasibility of low-dose coronary computed tomography angiography (CCTA), using a prospective electrocardiogram (ECG)-triggered axial scan protocol, knowledge-based iterative model reconstruction (IMR), and fixed tube current, in overweight subjects. Forty non-overweight (group A; body-mass index [BMI] < 25 kg/m2) and 40 overweight individuals (group B; BMI = 25–30 kg/m2), who underwent CCTA for coronary artery disease screening, were retrospectively and consecutively enrolled. A 64-slice CT scanner was used at 100-kVp tube voltage and 150-mA tube current, and images were reconstructed using IMR techniques. Image noise, attenuation at the aorta, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) at the proximal right and left main coronary arteries (pRCA and LMCA) were calculated. CCTA images were qualitatively evaluated using a four-point scale (1, poor; 4, excellent) and analyzed using a non-inferiority test with a pre-defined non-inferiority margin of -0.2. The mean CCTA radiation dose (Group A: 1.33 ± 0.02 mSv; Group B: 1.35 ± 0.10 mSv; p = 0.151) and mean aortic root CT attenuation values (Group A: 447.9 ± 81.6 HU; Group B: 439.5 ± 63.6 HU; p = 0.571) did not differ significantly between the two groups. The mean noise in groups A and B was 26.0 ± 4.8 HU and 29.2 ± 4.4 HU, respectively (p = 0.005). The noise reduction ratio in the groups, compared to filtered back projection, was 65.0% and 68.1%, respectively. The mean grade of image quality did not differ significantly (3.75 ± 0.04 vs. 3.71 ± 0.04, p = 0.478). Group B CCTA image quality was non-inferior (mean difference = -0.043, 95% CI = -0.162–0.077) to that of Group A. We concluded that low-dose CCTA with prospective ECG-triggering and IMR might be applied to overweight subjects, as well as to normal-weight subjects, by using a fixed tube current without an increase in tube current based on the patient’s body size.
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Affiliation(s)
- In Kyung Park
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jeffrey Park
- College of Letters and Science, University of California Berkeley, Berkeley, CA, United States of America
| | - Tae Hoon Kim
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Joohee Lee
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Kyunghwa Han
- Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Chisuk Oh
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Chul Hwan Park
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
- * E-mail:
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11
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Zhang H, Wang J, Zeng D, Tao X, Ma J. Regularization strategies in statistical image reconstruction of low-dose x-ray CT: A review. Med Phys 2018; 45:e886-e907. [PMID: 30098050 PMCID: PMC6181784 DOI: 10.1002/mp.13123] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/22/2018] [Accepted: 08/04/2018] [Indexed: 12/17/2022] Open
Abstract
Statistical image reconstruction (SIR) methods have shown potential to substantially improve the image quality of low-dose x-ray computed tomography (CT) as compared to the conventional filtered back-projection (FBP) method. According to the maximum a posteriori (MAP) estimation, the SIR methods are typically formulated by an objective function consisting of two terms: (a) a data-fidelity term that models imaging geometry and physical detection processes in projection data acquisition, and (b) a regularization term that reflects prior knowledge or expectations of the characteristics of the to-be-reconstructed image. SIR desires accurate system modeling of data acquisition, while the regularization term also has a strong influence on the quality of reconstructed images. A variety of regularization strategies have been proposed for SIR in the past decades, based on different assumptions, models, and prior knowledge. In this paper, we review the conceptual and mathematical bases of these regularization strategies and briefly illustrate their efficacies in SIR of low-dose CT.
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Affiliation(s)
- Hao Zhang
- Department of Radiation OncologyStanford UniversityStanfordCA94304USA
| | - Jing Wang
- Department of Radiation OncologyUT Southwestern Medical CenterDallasTX75390USA
| | - Dong Zeng
- School of Biomedical EngineeringSouthern Medical UniversityGuangzhou510515China
| | - Xi Tao
- School of Biomedical EngineeringSouthern Medical UniversityGuangzhou510515China
| | - Jianhua Ma
- School of Biomedical EngineeringSouthern Medical UniversityGuangzhou510515China
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12
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Park CJ, Kim KW, Lee HJ, Kim MJ, Kim J. Contrast-Enhanced CT with Knowledge-Based Iterative Model Reconstruction for the Evaluation of Parotid Gland Tumors: A Feasibility Study. Korean J Radiol 2018; 19:957-964. [PMID: 30174486 PMCID: PMC6082760 DOI: 10.3348/kjr.2018.19.5.957] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 02/10/2018] [Indexed: 11/20/2022] Open
Abstract
Objective The purpose of this study was to determine the diagnostic utility of low-dose CT with knowledge-based iterative model reconstruction (IMR) for the evaluation of parotid gland tumors. Materials and Methods This prospective study included 42 consecutive patients who had undergone low-dose contrast-enhanced CT for the evaluation of suspected parotid gland tumors. Prior or subsequent non-low-dose CT scans within 12 months were available in 10 of the participants. Background noise (BN), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were compared between non-low-dose CT images and images generated using filtered back projection (FBP), hybrid iterative reconstruction (iDose4; Philips Healthcare), and knowledge-based IMR. Subjective image quality was rated by two radiologists using five-point grading scales to assess the overall image quality, delineation of lesion contour, image sharpness, and noise. Results With the IMR algorithm, background noise (IMR, 4.24 ± 3.77; iDose4, 8.77 ± 3.85; FBP, 11.73 ± 4.06; p = 0.037 [IMR vs. iDose4] and p < 0.001 [IMR vs. FBP]) was significantly lower and SNR (IMR, 23.93 ± 7.49; iDose4, 10.20 ± 3.29; FBP, 7.33 ± 2.03; p = 0.011 [IMR vs. iDose4] and p < 0.001 [IMR vs. FBP]) was significantly higher compared with the other two algorithms. The CNR was also significantly higher with the IMR compared with the FBP (25.76 ± 11.88 vs. 9.02 ± 3.18, p < 0.001). There was no significant difference in BN, SNR, and CNR between low-dose CT with the IMR algorithm and non-low-dose CT. Subjective image analysis revealed that IMR-generated low-dose CT images showed significantly better overall image quality and delineation of lesion contour with lesser noise, compared with those generated using FBP by both reviewers 1 and 2 (4 vs. 3; 4 vs. 3; and 3–4 vs. 2; p < 0.05 for all pairs), although there was no significant difference in subjective image quality scores between IMR-generated low-dose CT and non-low-dose CT images. Conclusion Iterative model reconstruction-generated low-dose CT is an alternative to standard non-low-dose CT without significantly affecting image quality for the evaluation of parotid gland tumors.
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Affiliation(s)
- Chae Jung Park
- Department of Radiology, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Ki Wook Kim
- Department of Radiology, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Ho-Joon Lee
- Department of Radiology, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Myeong-Jin Kim
- Department of Radiology, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Jinna Kim
- Department of Radiology, Yonsei University College of Medicine, Seoul 03722, Korea
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Halliburton SS, Tanabe Y, Partovi S, Rajiah P. The role of advanced reconstruction algorithms in cardiac CT. Cardiovasc Diagn Ther 2017; 7:527-538. [PMID: 29255694 DOI: 10.21037/cdt.2017.08.12] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Non-linear iterative reconstruction (IR) algorithms have been increasingly incorporated into clinical cardiac CT protocols at institutions around the world. Multiple IR algorithms are available commercially from various vendors. IR algorithms decrease image noise and are primarily used to enable lower radiation dose protocols. IR can also be used to improve image quality for imaging of obese patients, coronary atherosclerotic plaques, coronary stents, and myocardial perfusion. In this article, we will review the various applications of IR algorithms in cardiac imaging and evaluate how they have changed practice.
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Affiliation(s)
| | - Yuki Tanabe
- Cardiothoracic Imaging, Radiology Department, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sasan Partovi
- University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Prabhakar Rajiah
- Cardiothoracic Imaging, Radiology Department, UT Southwestern Medical Center, Dallas, TX, USA
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Kim J, Chhour P, Hsu J, Litt HI, Ferrari VA, Popovtzer R, Cormode DP. Use of Nanoparticle Contrast Agents for Cell Tracking with Computed Tomography. Bioconjug Chem 2017; 28:1581-1597. [PMID: 28485976 PMCID: PMC5481820 DOI: 10.1021/acs.bioconjchem.7b00194] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
![]()
Efforts
to develop novel cell-based therapies originated with the
first bone marrow transplant on a leukemia patient in 1956. Preclinical
and clinical examples of cell-based treatment strategies have shown
promising results across many disciplines in medicine, with recent
advances in immune cell therapies for cancer producing remarkable
response rates, even in patients with multiple treatment failures.
However, cell-based therapies suffer from inconsistent outcomes, motivating
the search for tools that allow monitoring of cell delivery and behavior
in vivo. Noninvasive cell imaging techniques, also known as cell tracking,
have been developed to address this issue. These tools can allow real-time,
quantitative, and long-term monitoring of transplanted cells in the
recipient, providing insight on cell migration, distribution, viability,
differentiation, and fate, all of which play crucial roles in treatment
efficacy. Understanding these parameters allows the optimization of
cell choice, delivery route, and dosage for therapy and advances cell-based
therapy for specific clinical uses. To date, most cell tracking work
has centered on imaging modalities such as MRI, radionuclide imaging,
and optical imaging. However, X-ray computed tomography (CT) is an
emerging method for cell tracking that has several strengths such
as high spatial and temporal resolution, and excellent quantitative
capabilities. The advantages of CT for cell tracking are enhanced
by its wide availability and cost effectiveness, allowing CT to become
one of the most popular clinical imaging modalities and a key asset
in disease diagnosis. In this review, we will discuss recent advances
in cell tracking methods using X-ray CT in various applications, in
addition to predictions on how the field will progress.
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Affiliation(s)
| | | | | | | | | | - Rachela Popovtzer
- Department of Engineering, Bar-Ilan University , Ramat Gan, 5290002, Israel
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15
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Wellenberg RHH, Boomsma MF, van Osch JAC, Vlassenbroek A, Milles J, Edens MA, Streekstra GJ, Slump CH, Maas M. Low-dose CT imaging of a total hip arthroplasty phantom using model-based iterative reconstruction and orthopedic metal artifact reduction. Skeletal Radiol 2017; 46:623-632. [PMID: 28204857 PMCID: PMC5355502 DOI: 10.1007/s00256-017-2580-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 01/11/2017] [Accepted: 01/13/2017] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To compare quantitative measures of image quality, in terms of CT number accuracy, noise, signal-to-noise-ratios (SNRs), and contrast-to-noise ratios (CNRs), at different dose levels with filtered-back-projection (FBP), iterative reconstruction (IR), and model-based iterative reconstruction (MBIR) alone and in combination with orthopedic metal artifact reduction (O-MAR) in a total hip arthroplasty (THA) phantom. MATERIALS AND METHODS Scans were acquired from high- to low-dose (CTDIvol: 40.0, 32.0, 24.0, 16.0, 8.0, and 4.0 mGy) at 120- and 140- kVp. Images were reconstructed using FBP, IR (iDose4 level 2, 4, and 6) and MBIR (IMR, level 1, 2, and 3) with and without O-MAR. CT number accuracy in Hounsfield Units (HU), noise or standard deviation, SNRs, and CNRs were analyzed. RESULTS The IMR technique showed lower noise levels (p < 0.01), higher SNRs (p < 0.001) and CNRs (p < 0.001) compared with FBP and iDose4 in all acquisitions from high- to low-dose with constant CT numbers. O-MAR reduced noise (p < 0.01) and improved SNRs (p < 0.01) and CNRs (p < 0.001) while improving CT number accuracy only at a low dose. At the low dose of 4.0 mGy, IMR level 1, 2, and 3 showed 83%, 89%, and 95% lower noise values, a factor 6.0, 9.2, and 17.9 higher SNRs, and 5.7, 8.8, and 18.2 higher CNRs compared with FBP respectively. CONCLUSIONS Based on quantitative analysis of CT number accuracy, noise values, SNRs, and CNRs, we conclude that the combined use of IMR and O-MAR enables a reduction in radiation dose of 83% compared with FBP and iDose4 in the CT imaging of a THA phantom.
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Affiliation(s)
- R H H Wellenberg
- Department of Radiology, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
| | - M F Boomsma
- Department of Radiology, Isala, Zwolle, The Netherlands
| | | | | | - J Milles
- Philips Medical Systems, Eindhoven, The Netherlands
| | - M A Edens
- Department of Innovation and Science, Isala, Zwolle, The Netherlands
| | - G J Streekstra
- Department of Radiology, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - C H Slump
- MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - M Maas
- Department of Radiology, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
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Usefulness of a Low Tube Voltage: Knowledge-Based Iterative Model Reconstruction Algorithm for Computed Tomography Venography. J Comput Assist Tomogr 2017; 41:811-816. [PMID: 28448403 DOI: 10.1097/rct.0000000000000600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The objective of this study was to evaluate the use of 80-kVp scans with knowledge-based iterative model reconstruction (IMR) for computed tomography venography (CTV). METHODS This prospective study received institutional review board approval; a previous informed consent was obtained from all participants. We enrolled 30 patients with suspected deep venous thrombosis or pulmonary embolism who were to undergo 80-kVp CTV studies. The images were reconstructed with filtered back projection (FBP), hybrid iterative reconstruction (HIR), and IMR. The venous attenuation, image noise, and contrast-to-noise ratio at the iliac, femoral, and popliteal veins were compared on FBP, HIR, and IMR images. We performed qualitative image analysis (image noise, image contrast, image sharpness, streak artifacts, and overall image quality) of the 3 reconstruction methods and measured their reconstruction times. RESULTS There was no significant difference in venous attenuation among the 3 reconstruction methods (P > 0.05). On IMR images, the image noise was lowest at all 3 venous locations, and the contrast-to-noise ratio was highest. Qualitative evaluation scores were also highest for IMR images. The reconstruction time for FBP, HIR, and IMR imaging was 25.4 ± 1.9 seconds, 43.3 ± 3.3 seconds, and 78.7 ± 6.0 seconds, respectively. CONCLUSIONS At clinically acceptable reconstruction times, 80-kVp CTV using the IMR technique yielded better qualitative and quantitative image quality than HIR and FBP.
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Computed Tomography Imaging of a Hip Prosthesis Using Iterative Model-Based Reconstruction and Orthopaedic Metal Artefact Reduction: A Quantitative Analysis. J Comput Assist Tomogr 2017; 40:971-978. [PMID: 27331924 DOI: 10.1097/rct.0000000000000449] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To quantify the combined use of iterative model-based reconstruction (IMR) and orthopaedic metal artefact reduction (O-MAR) in reducing metal artefacts and improving image quality in a total hip arthroplasty phantom. METHODS Scans acquired at several dose levels and kVps were reconstructed with filtered back-projection (FBP), iterative reconstruction (iDose) and IMR, with and without O-MAR. Computed tomography (CT) numbers, noise levels, signal-to-noise-ratios and contrast-to-noise-ratios were analysed. RESULTS Iterative model-based reconstruction results in overall improved image quality compared to iDose and FBP (P < 0.001). Orthopaedic metal artefact reduction is most effective in reducing severe metal artefacts improving CT number accuracy by 50%, 60%, and 63% (P < 0.05) and reducing noise by 1%, 62%, and 85% (P < 0.001) whereas improving signal-to-noise-ratios by 27%, 47%, and 46% (P < 0.001) and contrast-to-noise-ratios by 16%, 25%, and 19% (P < 0.001) with FBP, iDose, and IMR, respectively. CONCLUSIONS The combined use of IMR and O-MAR strongly improves overall image quality and strongly reduces metal artefacts in the CT imaging of a total hip arthroplasty phantom.
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The feasibility of Forward-projected model-based Iterative Reconstruction SoluTion (FIRST) for coronary 320-row computed tomography angiography: A pilot study. J Cardiovasc Comput Tomogr 2017; 11:40-45. [DOI: 10.1016/j.jcct.2016.11.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 10/31/2016] [Accepted: 11/06/2016] [Indexed: 11/20/2022]
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Iterative model reconstruction reduces calcified plaque volume in coronary CT angiography. Eur J Radiol 2016; 87:83-89. [PMID: 28065380 DOI: 10.1016/j.ejrad.2016.12.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 11/25/2016] [Accepted: 12/13/2016] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To assess the impact of iterative model reconstruction (IMR) on calcified plaque quantification as compared to filtered back projection reconstruction (FBP) and hybrid iterative reconstruction (HIR) in coronary computed tomography angiography (CTA). METHODS Raw image data of 52 patients who underwent 256-slice CTA were reconstructed with IMR, HIR and FBP. We evaluated qualitative, quantitative image quality parameters and quantified calcified and partially calcified plaque volumes using automated software. RESULTS Overall qualitative image quality significantly improved with HIR as compared to FBP, and further improved with IMR (p<0.01 all). Contrast-to-noise ratios were improved with IMR, compared to HIR and FBP (51.0 [43.5-59.9], 20.3 [16.2-25.9] and 14.0 [11.2-17.7], respectively, all p<0.01) Overall plaque volumes were lowest with IMR and highest with FBP (121.7 [79.3-168.4], 138.7 [90.6-191.7], 147.0 [100.7-183.6]). Similarly, calcified volumes (>130 HU) were decreased with IMR as compared to HIR and FBP (105.9 [62.1-144.6], 110.2 [63.8-166.6], 115.9 [81.7-164.2], respectively, p<0.05 all). High-attenuation non-calcified volumes (90-129 HU) yielded similar values with FBP and HIR (p=0.81), however it was lower with IMR (p < 0.05 both). Intermediate- (30-89 HU) and low-attenuation (<30 HU) non-calcified volumes showed no significant difference (p=0.22 and p=0.67, respectively). CONCLUSIONS IMR improves image quality of coronary CTA and decreases calcified plaque volumes.
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Iyama Y, Nakaura T, Kidoh M, Oda S, Utsunomiya D, Sakaino N, Tokuyasu S, Osakabe H, Harada K, Yamashita Y. Submillisievert Radiation Dose Coronary CT Angiography: Clinical Impact of the Knowledge-Based Iterative Model Reconstruction. Acad Radiol 2016; 23:1393-1401. [PMID: 27665234 DOI: 10.1016/j.acra.2016.07.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/30/2016] [Accepted: 07/06/2016] [Indexed: 11/26/2022]
Abstract
RATIONALE AND OBJECTIVES The purpose of this study was to evaluate the noise and image quality of images reconstructed with a knowledge-based iterative model reconstruction (knowledge-based IMR) in ultra-low dose cardiac computed tomography (CT). MATERIALS AND METHODS We performed submillisievert radiation dose coronary CT angiography on 43 patients. We also performed a phantom study to evaluate the influence of object size with the automatic exposure control phantom. We reconstructed clinical and phantom studies with filtered back projection (FBP), hybrid iterative reconstruction (hybrid IR), and knowledge-based IMR. We measured effective dose of patients and compared CT number, image noise, and contrast noise ratio in ascending aorta of each reconstruction technique. We compared the relationship between image noise and body mass index for the clinical study, and object size for phantom study. RESULTS The mean effective dose was 0.98 ± 0.25 mSv. The image noise of knowledge-based IMR images was significantly lower than those of FBP and hybrid IR images (knowledge-based IMR: 19.4 ± 2.8; FBP: 126.7 ± 35.0; hybrid IR: 48.8 ± 12.8, respectively) (P < .01). The contrast noise ratio of knowledge-based IMR images was significantly higher than those of FBP and hybrid IR images (knowledge-based IMR: 29.1 ± 5.4; FBP: 4.6 ± 1.3; hybrid IR: 13.1 ± 3.5, respectively) (P < .01). There were moderate correlations between image noise and body mass index in FBP (r = 0.57, P < .01) and hybrid IR techniques (r = 0.42, P < .01); however, these correlations were weak in knowledge-based IMR (r = 0.27, P < .01). CONCLUSION Compared to FBP and hybrid IR, the knowledge-based IMR offers significant noise reduction and improvement in image quality in submillisievert radiation dose cardiac CT.
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Coronary Computed Tomographic Angiography at 80 kVp and Knowledge-Based Iterative Model Reconstruction Is Non-Inferior to that at 100 kVp with Iterative Reconstruction. PLoS One 2016; 11:e0163410. [PMID: 27658197 PMCID: PMC5033462 DOI: 10.1371/journal.pone.0163410] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 09/08/2016] [Indexed: 11/19/2022] Open
Abstract
The aims of this study were to compare the image noise and quality of coronary computed tomographic angiography (CCTA) at 80 kVp with knowledge-based iterative model reconstruction (IMR) to those of CCTA at 100 kVp with hybrid iterative reconstruction (IR), and to evaluate the feasibility of a low-dose radiation protocol with IMR. Thirty subjects who underwent prospective electrocardiogram-gating CCTA at 80 kVp, 150 mAs, and IMR (Group A), and 30 subjects with 100 kVp, 150 mAs, and hybrid IR (Group B) were retrospectively enrolled after sample-size calculation. A BMI of less than 25 kg/m2 was required for inclusion. The attenuation value and image noise of CCTA were measured and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated at the proximal right coronary artery and left main coronary artery. The image noise was analyzed using a non-inferiority test. The CCTA images were qualitatively evaluated using a four-point scale. The radiation dose was significantly lower in Group A than Group B (0.69 ± 0.08 mSv vs. 1.39 ± 0.15 mSv, p < 0.001). The attenuation values were higher in Group A than Group B (p < 0.001). The SNR and CNR in Group A were higher than those of Group B. The image noise of Group A was non-inferior to that of Group B. Qualitative image quality of Group A was better than that of Group B (3.6 vs. 3.4, p = 0.017). CCTA at 80 kVp with IMR could reduce the radiation dose by about 50%, with non-inferior image noise and image quality than those of CCTA at 100 kVp with hybrid IR.
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Naha PC, Lau KC, Hsu JC, Hajfathalian M, Mian S, Chhour P, Uppuluri L, McDonald ES, Maidment ADA, Cormode DP. Gold silver alloy nanoparticles (GSAN): an imaging probe for breast cancer screening with dual-energy mammography or computed tomography. NANOSCALE 2016; 8:13740-54. [PMID: 27412458 PMCID: PMC4955565 DOI: 10.1039/c6nr02618d] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Earlier detection of breast cancer reduces mortality from this disease. As a result, the development of better screening techniques is a topic of intense interest. Contrast-enhanced dual-energy mammography (DEM) is a novel technique that has improved sensitivity for cancer detection. However, the development of contrast agents for this technique is in its infancy. We herein report gold-silver alloy nanoparticles (GSAN) that have potent DEM contrast properties and improved biocompatibility. GSAN formulations containing a range of gold : silver ratios and capped with m-PEG were synthesized and characterized using various analytical methods. DEM and computed tomography (CT) phantom imaging showed that GSAN produced robust contrast that was comparable to silver alone. Cell viability, reactive oxygen species generation and DNA damage results revealed that the formulations with 30% or higher gold content are cytocompatible to Hep G2 and J774A.1 cells. In vivo imaging was performed in mice with and without breast tumors. The results showed that GSAN produce strong DEM and CT contrast and accumulated in tumors. Furthermore, both in vivo imaging and ex vivo analysis indicated the excretion of GSAN via both urine and feces. In summary, GSAN produce strong DEM and CT contrast, and has potential for both blood pool imaging and for breast cancer screening.
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Affiliation(s)
- Pratap C Naha
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA.
| | - Kristen C Lau
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA.
| | - Jessica C Hsu
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA. and Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Maryam Hajfathalian
- Department of Mechanical Engineering, Temple University, Philadelphia, PA, USA
| | - Shaameen Mian
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Peter Chhour
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA. and Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Lahari Uppuluri
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA.
| | - Elizabeth S McDonald
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA.
| | - Andrew D A Maidment
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA.
| | - David P Cormode
- Department of Radiology, University of Pennsylvania 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA. and Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA and Department of Cardiology, University of Pennsylvania, Philadelphia, PA, USA
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Bernstein AL, Dhanantwari A, Jurcova M, Cheheltani R, Naha PC, Ivanc T, Shefer E, Cormode DP. Improved sensitivity of computed tomography towards iodine and gold nanoparticle contrast agents via iterative reconstruction methods. Sci Rep 2016; 6:26177. [PMID: 27185492 PMCID: PMC4868985 DOI: 10.1038/srep26177] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 04/27/2016] [Indexed: 01/13/2023] Open
Abstract
Computed tomography is a widely used medical imaging technique that has high spatial and temporal resolution. Its weakness is its low sensitivity towards contrast media. Iterative reconstruction techniques (ITER) have recently become available, which provide reduced image noise compared with traditional filtered back-projection methods (FBP), which may allow the sensitivity of CT to be improved, however this effect has not been studied in detail. We scanned phantoms containing either an iodine contrast agent or gold nanoparticles. We used a range of tube voltages and currents. We performed reconstruction with FBP, ITER and a novel, iterative, modal-based reconstruction (IMR) algorithm. We found that noise decreased in an algorithm dependent manner (FBP > ITER > IMR) for every scan and that no differences were observed in attenuation rates of the agents. The contrast to noise ratio (CNR) of iodine was highest at 80 kV, whilst the CNR for gold was highest at 140 kV. The CNR of IMR images was almost tenfold higher than that of FBP images. Similar trends were found in dual energy images formed using these algorithms. In conclusion, IMR-based reconstruction techniques will allow contrast agents to be detected with greater sensitivity, and may allow lower contrast agent doses to be used.
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Affiliation(s)
| | | | - Martina Jurcova
- Department of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | - Rabee Cheheltani
- Department of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | - Pratap Chandra Naha
- Department of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | | | | | - David Peter Cormode
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
- Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Abstract
OBJECTIVE The objective of the present study is to quantify the diagnostic yield of triple-rule-out (TRO) CT for the evaluation of acute chest pain in emergency department patients. MATERIALS AND METHODS All TRO CT studies performed at our institution from 2006 to 2015 were reviewed. Scans were performed on a 256-MDCT scanner, with the use of ECG gating and a biphasic contrast injection. Radiology reports were reviewed to identify diagnoses that could explain chest pain, including coronary and noncoronary diagnoses, and significant incidental findings that did not account for the patient's presentation. The total numbers of coronary and noncoronary diagnoses and incidental findings were calculated. RESULTS Four of 1196 total cases that were identified were excluded from the study because of inadequate image quality. A total of 970 patients (81.4%) had a negative study result without a significant coronary or noncoronary diagnosis. A total of 139 patients (11.7%) had significant coronary artery disease (50% stenosis or greater). One hundred six patients (8.9%) had a noncoronary diagnosis that could explain chest pain (p < 0.02), most commonly pulmonary embolism (28 patients [2.3%]), aortic aneurysm (24 patients [2.0%]), or pneumonia (20 patients [1.7%]). Thirty cases (27.3%) of pulmonary embolism and aortic pathologic findings would not have been detected with coronary CT angiography because of unopacified right-side circulation or limited z-axis coverage. A total of 528 incidental findings not considered to explain chest pain were noted in 418 patients (35.1%). CONCLUSION In 8.9% of patients, TRO CT detected a significant noncoronary diagnosis that could explain acute chest pain, including pathologic findings that would not be identified on dedicated coronary CT angiography.
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Impact of Knowledge-Based Iterative Model Reconstruction in Abdominal Dynamic CT With Low Tube Voltage and Low Contrast Dose. AJR Am J Roentgenol 2016; 206:687-93. [PMID: 26974470 DOI: 10.2214/ajr.15.14518] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to compare iterative model reconstruction (IMR) and hybrid iterative reconstruction (HIR) of 80-kVp abdominal dynamic CT scans obtained with a low-dose contrast agent. SUBJECTS AND METHODS A group of 27 consecutively registered patients underwent abdominal dynamic CT with an 80-kVp protocol and a low dose of contrast agent (300 mg I/kg). Another 27 patients who had previously undergone a 120-kVp protocol with filtered back projection (FBP) and a standard contrast dose (600 mg I/kg) acted as control subjects. Effective dose, image noise, CT number, and contrast-to-noise ratio were compared between the 120-kVp and 80-kVp images with FBP, HIR, and IMR. Image contrast, image noise, image sharpness, noise texture, and overall image quality were evaluated for the four protocols. RESULTS The effective dose of the 80-kVp protocol was lower than that with the 120-kVp protocol. The 80-kVp protocol with HIR and IMR decreased image noise by 45% and 70% compared with the 80-kVp protocol with FBP. The contrast-to-noise ratio of the 80-kVp protocol with IMR was higher than that of the 120-kVp protocol. Qualitatively, the 80-kVp protocol with IMR improved image noise more than the 120-kVp protocol did, but noise texture was worse. HIR and the 120-kVp protocol yielded similar subjective image quality. CONCLUSION Use of the 80-kVp protocol with HIR allowed an approximately 50% reduction in contrast dose and an approximately 40% reduction in radiation dose compared with use of the 120-kVp protocol while preserving image quality. IMR reduced image noise more than HIR with this protocol but worsened noise texture.
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Chhour P, Naha PC, O'Neill SM, Litt HI, Reilly MP, Ferrari VA, Cormode DP. Labeling monocytes with gold nanoparticles to track their recruitment in atherosclerosis with computed tomography. Biomaterials 2016; 87:93-103. [PMID: 26914700 DOI: 10.1016/j.biomaterials.2016.02.009] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 01/26/2016] [Accepted: 02/07/2016] [Indexed: 01/21/2023]
Abstract
Monocytes are actively recruited from the circulation into developing atherosclerotic plaques. In the plaque, monocytes differentiate into macrophages and eventually form foam cells. Continued accumulation of foam cells can lead to plaque rupture and subsequent myocardial infarction. X-ray computed tomography (CT) is the best modality to image the coronary arteries non-invasively, therefore we have sought to track the accumulation of monocytes into atherosclerotic plaques using CT. Gold nanoparticles were synthesized and stabilized with a variety of ligands. Select formulations were incubated with an immortalized monocyte cell line in vitro and evaluated for cytotoxicity, effects on cytokine release, and cell uptake. These data identified a lead formulation, 11-MUDA capped gold nanoparticles, to test for labeling primary monocytes. The formulation did not the affect the viability or cytokine release of primary monocytes and was highly taken up by these cells. Gold labeled primary monocytes were injected into apolipoprotein E deficient mice kept on Western diet for 10 weeks. Imaging was done with a microCT scanner. A significant increase in attenuation was measured in the aorta of mice receiving the gold labeled cells as compared to control animals. Following the experiment, the biodistribution of gold was evaluated in major organs. Additionally, plaques were sectioned and examined with electron microscopy. The results showed that gold nanoparticles were present inside monocytes located within plaques. This study demonstrates the feasibility of using gold nanoparticles as effective cell labeling contrast agents for non-invasive imaging of monocyte accumulation within plaques with CT.
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Affiliation(s)
- Peter Chhour
- Department of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA; Department of Bioengineering, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | - Pratap C Naha
- Department of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | - Sean M O'Neill
- Department of Medicine, Division of Cardiovascular Medicine, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | - Harold I Litt
- Department of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA; Department of Medicine, Division of Cardiovascular Medicine, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | - Muredach P Reilly
- Department of Medicine, Division of Cardiovascular Medicine, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | - Victor A Ferrari
- Department of Medicine, Division of Cardiovascular Medicine, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA
| | - David P Cormode
- Department of Radiology, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA; Department of Bioengineering, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA; Department of Medicine, Division of Cardiovascular Medicine, University of Pennsylvania, 3400 Spruce St, 1 Silverstein, Philadelphia, PA 19104, USA.
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Halliburton SS, Rajiah P. Cardiac CT Scanner Technology: What Is New and What Is Next? CURRENT CARDIOVASCULAR IMAGING REPORTS 2016. [DOI: 10.1007/s12410-016-9370-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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28
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Low-Contrast and Low-Radiation Dose Protocol in Cardiac Computed Tomography. J Comput Assist Tomogr 2016; 40:941-947. [PMID: 27224224 DOI: 10.1097/rct.0000000000000440] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Zhang F, Yang L, Song X, Li YN, Jiang Y, Zhang XH, Ju HY, Wu J, Chang RP. Feasibility study of low tube voltage (80 kVp) coronary CT angiography combined with contrast medium reduction using iterative model reconstruction (IMR) on standard BMI patients. Br J Radiol 2015; 89:20150766. [PMID: 26607646 DOI: 10.1259/bjr.20150766] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To investigate the feasibility of low-tube-voltage (80 kVp) coronary CT angiography (CCTA) combined with contrast medium (CM) reduction and iterative model reconstruction (IMR) on patients with standard body mass index compared with clinical routine protocol. METHODS Retrospectively gated helical CCTA scans were acquired using a 256-slice multi-slice CT (Brilliance iCT; Philips Healthcare, Cleveland, OH) on 94 patients with standard body mass index (20-25 kg m(-2)) who were randomly assigned into 2 groups. The scan protocol for Group 1 was 100 kVp and 600 mAs with 70 ml CM at an injection rate of 4.5-5.5 ml s(-1); images were reconstructed by a hybrid iterative reconstruction technique (iDose(4); Philips Healthcare). Group 2 was scanned at 80 kVp and 600 mAs with 35 ml CM at an injection rate of 3.5-4.5 ml s(-1); images were reconstructed with IMR. Objective measurements such as the mean image noise and contrast-to-noise ratio of the two groups were measured on CT images and compared using the paired t-test. In addition, a subjective image quality evaluation was performed by two radiologists who were blinded to the scan protocol, using a 5-point scale [1 (poor) to 5 (excellent)]. The results of the two groups were compared using Mann-Whitney U test. RESULTS The iodine delivery rate of Group 2 was 1.0 ± 0.5 gI s(-1) compared with 2.1 ± 0.5 gI s(-1) in Group 1 resulting in a reduction of 52.4%. In addition, an effective radiation dose reduction of 56.4% was achieved in Group 2 (2.4 ± 1.2 mSv) compared with Group 1 (5.5 ± 1.4 mSv). The mean CT attenuation, contrast-to-noise ratio and image quality of all segments in Group 2 were significantly improved compared with those in Group 1 (all, p < 0.01). CONCLUSION The use of IMR along with a low tube voltage (80 kVp) combined with a low CM protocol for CCTA can reduce both radiation and CM dose with improved image quality. ADVANCES IN KNOWLEDGE In this study, we used a novel knowledge-based IMR which remarkably reduced the image noise. We compared the quality of the images obtained when the tube voltage was reduced to 80 kVp and that of those obtained according to the clinical routine protocols to determine whether ultra-low-dose imaging plus IMR is feasible in CCTA scans. We found that a low dose protocol combined with 80 kVp and reduced CM for CCTA can reduce both radiation dose and CM dose with improved image quality by the use of IMR in non-obese patients.
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Affiliation(s)
- Fan Zhang
- 1 Department of Radiology, Hainan Branch of Chinese People's Liberation Army General Hospital, Sanya, China
| | - Li Yang
- 2 Department of Radiology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - Xiang Song
- 2 Department of Radiology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - Ying-Na Li
- 2 Department of Radiology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - Yan Jiang
- 3 Clinical Science Imaging System, Philips Healthcare, Shanghai, China
| | - Xing-Hua Zhang
- 2 Department of Radiology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - Hai-Yue Ju
- 2 Department of Radiology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - Jian Wu
- 2 Department of Radiology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - Rui-Ping Chang
- 2 Department of Radiology, Chinese People's Liberation Army General Hospital, Beijing, China
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Habib Geryes B, Calmon R, Khraiche D, Boddaert N, Bonnet D, Raimondi F. Radiation dose reduction in paediatric coronary computed tomography: assessment of effective dose and image quality. Eur Radiol 2015; 26:2030-8. [PMID: 26433957 DOI: 10.1007/s00330-015-4032-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Revised: 09/07/2015] [Accepted: 09/15/2015] [Indexed: 01/13/2023]
Abstract
OBJECTIVES To assess the impact of different protocols on radiation dose and image quality for paediatric coronary computed tomography (cCT). MATERIALS AND METHODS From January-2012 to June-2014, 140 children who underwent cCT on a 64-slice scanner were included. Two consecutive changes in imaging protocols were performed: 1) the use of adaptive statistical iterative reconstruction (ASIR); 2) the optimization of acquisition parameters. Effective dose (ED) was calculated by conversion of the dose-length product. Image quality was assessed as excellent, good or with significant artefacts. RESULTS Patients were divided in three age groups: 0-4, 5-7 and 8-18 years. The use of ASIR combined to the adjustment of scan settings allowed a reduction in the median ED of 58 %, 82 % and 85 % in 0-4, 5-7 and 8-18 years group, respectively (7.3 ± 1.4 vs 3.1 ± 0.7 mSv, 5.5 ± 1.6 vs 1 ± 1.9 mSv and 5.3 ± 5.0 vs 0.8 ± 2.0 mSv, all p < 0,05). Prospective protocol was used in 51 % of children. The reduction in radiation dose was not associated with reduction in diagnostic image quality as assessed by the frequency of coronary segments with excellent or good image quality (88 %). CONCLUSIONS cCT can be obtained at very low radiation doses in children using ASIR, and prospective acquisition with optimized imaging parameters. KEY POINTS • Using ASIR allows 25 % to 41 % reduction in the ED. • Prospective protocol is used up to 51 % of children after premedication. • Low dose is possible using ASIR and optimized prospective paediatric cCT.
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Affiliation(s)
- Bouchra Habib Geryes
- Direction de la qualité et de la gestion des risques, Hôpital Universitaire Necker Enfants Malades, 149, rue de Sèvres, 75743, Paris Cedex 15, France
| | - Raphael Calmon
- Service de Radiologie pédiatrique, Hôpital Universitaire Necker Enfants Malades, 149, rue de Sèvres, 75743, Paris Cedex 15, France.,Sorbonne Paris Cité, Université Paris Descartes, Paris, France
| | - Diala Khraiche
- Unité Médico-Chirurgicale de Cardiologie Congénitale et Pédiatrique, Centre de référence Malformations Cardiaques Congénitales Complexes - M3C, 149, rue de Sèvres, 75743, Paris Cedex 15, France.,Sorbonne Paris Cité, Université Paris Descartes, Paris, France
| | - Nathalie Boddaert
- Service de Radiologie pédiatrique, Hôpital Universitaire Necker Enfants Malades, 149, rue de Sèvres, 75743, Paris Cedex 15, France.,Sorbonne Paris Cité, Université Paris Descartes, Paris, France
| | - Damien Bonnet
- Unité Médico-Chirurgicale de Cardiologie Congénitale et Pédiatrique, Centre de référence Malformations Cardiaques Congénitales Complexes - M3C, 149, rue de Sèvres, 75743, Paris Cedex 15, France.,Sorbonne Paris Cité, Université Paris Descartes, Paris, France
| | - Francesca Raimondi
- Service de Radiologie pédiatrique, Hôpital Universitaire Necker Enfants Malades, 149, rue de Sèvres, 75743, Paris Cedex 15, France. .,Unité Médico-Chirurgicale de Cardiologie Congénitale et Pédiatrique, Centre de référence Malformations Cardiaques Congénitales Complexes - M3C, 149, rue de Sèvres, 75743, Paris Cedex 15, France. .,Sorbonne Paris Cité, Université Paris Descartes, Paris, France.
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Szilveszter B, Elzomor H, Károlyi M, Kolossváry M, Raaijmakers R, Benke K, Celeng C, Bartykowszki A, Bagyura Z, Lux Á, Merkely B, Maurovich-Horvat P. The effect of iterative model reconstruction on coronary artery calcium quantification. Int J Cardiovasc Imaging 2015; 32:153-60. [DOI: 10.1007/s10554-015-0740-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 08/11/2015] [Indexed: 01/07/2023]
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33
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Updates on Coronary CTA in the Emergency Department. CURRENT RADIOLOGY REPORTS 2015. [DOI: 10.1007/s40134-015-0096-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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34
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Iterative reconstruction in cardiac CT. J Cardiovasc Comput Tomogr 2015; 9:255-63. [PMID: 26088375 DOI: 10.1016/j.jcct.2015.04.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 04/15/2015] [Accepted: 04/15/2015] [Indexed: 12/29/2022]
Abstract
Iterative reconstruction (IR) has the ability to reduce image noise in CT without compromising diagnostic quality, which permits a significant reduction in effective radiation dose. This been increasingly integrated into clinical CT practice over the past 7 years and has been particularly important in the field of cardiac CT with multiple vendors introducing cardiac CT-compatible IR algorithms. The following review will summarize the principles of IR algorithms, studies validating their noise- and dose-reducing abilities, and the specific applications of IR in cardiac CT.
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Leng S, Hruska CB, McCollough CH. Use of ionizing radiation in screening examinations for coronary artery calcium and cancers of the lung, colon, and breast. Semin Roentgenol 2015; 50:148-60. [PMID: 25770345 DOI: 10.1053/j.ro.2014.10.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Shuai Leng
- Department of Radiology, Mayo Clinic, Rochester, MN.
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Khawaja RDA, Singh S, Blake M, Harisinghani M, Choy G, Karosmangulu A, Padole A, Do S, Brown K, Thompson R, Morton T, Raihani N, Koehler T, Kalra MK. Ultra-low dose abdominal MDCT: using a knowledge-based Iterative Model Reconstruction technique for substantial dose reduction in a prospective clinical study. Eur J Radiol 2014; 84:2-10. [PMID: 25458225 DOI: 10.1016/j.ejrad.2014.09.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 09/08/2014] [Accepted: 09/29/2014] [Indexed: 01/21/2023]
Abstract
PURPOSE To assess lesion detection and image quality parameters of a knowledge-based Iterative Model Reconstruction (IMR) in reduced dose (RD) abdominal CT examinations. MATERIALS AND METHODS This IRB-approved prospective study included 82 abdominal CT examinations performed for 41 consecutive patients (mean age, 62 ± 12 years; F:M 28:13) who underwent a RD CT (SSDE, 1.5 mGy ± 0.4 [∼ 0.9 mSv] at 120 kV with 17-20 mAs/slice) immediately after their standard dose (SD) CT exam (10 mGy ± 3 [∼ 6 mSv] at 120 kV with automatic exposure control) on 256 MDCT (iCT, Philips Healthcare). SD data were reconstructed using filtered back projection (FBP). RD data were reconstructed with FBP and IMR. Four radiologists used a five-point scale (1=image quality better than SD CT to 5=image quality unacceptable) to assess both subjective image quality and artifacts. Lesions were first detected on RD FBP images. RD IMR and RD FBP images were then compared side-by-side to SD-FBP images in an independent, randomized and blinded fashion. Friedman's test and intraclass correlation coefficient were used for data analysis. Objective measurements included image noise and attenuation as well as noise spectral density (NSD) curves to assess the noise in frequency domain were obtained. In addition, a low-contrast phantom study was performed. RESULTS All true lesions (ranging from 32 to 55) on SD FBP images were detected on RD IMR images across all patients. RD FBP images were unacceptable for subjective image quality. Subjective ratings showed acceptable image quality for IMR for organ margins, soft-tissue structures, and retroperitoneal lymphadenopathy, compared to RD FBP in patients with a BMI ≤ 25 kg/m(2) (median-range, 2-3). Irrespective of patient BMI, subjective ratings for hepatic/renal cysts, stones and colonic diverticula were significantly better with RD IMR images (P<0.01). Objective image noise for RD FBP was 57-66% higher, and for RD IMR was 8-56% lower than that for SD-FBP (P<0.01). NSD showed significantly lower noise in the frequency domain with IMR in all patients compared to FBP. CONCLUSION IMR considerably improved both objective and subjective image quality parameters of RD abdominal CT images compared to FBP in patients with BMI less than or equal to 25 kg/m(2).
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Affiliation(s)
| | - Sarabjeet Singh
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Michael Blake
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Mukesh Harisinghani
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Garry Choy
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Ali Karosmangulu
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Atul Padole
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Synho Do
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Kevin Brown
- CT Research and Advanced Development, Philips Healthcare, Cleveland, OH, USA
| | - Richard Thompson
- CT Research and Advanced Development, Philips Healthcare, Cleveland, OH, USA
| | - Thomas Morton
- CT Research and Advanced Development, Philips Healthcare, Cleveland, OH, USA
| | - Nilgoun Raihani
- CT Research and Advanced Development, Philips Healthcare, Cleveland, OH, USA
| | - Thomas Koehler
- Philips Technologie GmbH, Innovative Technologies, Hamburg, Germany
| | - Mannudeep K Kalra
- MGH Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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