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Zarei M, Abadi E, Segars WP, Samei E. Coronary stenosis quantification in cardiac computed tomography angiography: multi-factorial optimization of image quality and radiation dose. J Med Imaging (Bellingham) 2023; 10:063502. [PMID: 38156332 PMCID: PMC10752565 DOI: 10.1117/1.jmi.10.6.063502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 09/18/2023] [Accepted: 11/14/2023] [Indexed: 12/30/2023] Open
Abstract
Background The accuracy and variability of quantification in computed tomography angiography (CTA) are affected by the interplay of imaging parameters and patient attributes. The assessment of these combined effects has been an open engineering challenge. Purpose In this study, we developed a framework that optimizes imaging parameters for accurate and consistent coronary stenosis quantification in cardiac CTA while accounting for patient-specific variables. Methods The framework utilizes a task-specific image quality index, the estimability index (e ' ), approximated by a surrogate estimability polynomial function (EPF) capable of finding the optimal protocol that (1) maximizes image quality with an upper bound for desired radiation dose or (2) minimizes the dose level with a lower bound of acceptable image quality. The optimization process was formulated with the decision variables being subject to a set of constraints. The methodology was verified using CTA data from a prior clinical trial (prospective multi-center imaging study for evaluation of chest pain) by assessing the concordance of its prediction with the trial results. Further, the framework was used to derive an optimum protocol for each case based on the patient attributes, gauging how much improvement would have been possible if the derived optimized protocol would have been deployed. Results The framework produced results consistent with imaging physics principles with approximated EPFs of 97% accuracy. The feature importance evaluation demonstrated a close match with earlier studies. The verification study found e ' scores closely predicting the cardiologist scores to within 95% in terms of the area under the receiver operating characteristic curve and predicting potential for either an average of fourfold increase in e ' within a targeted dose or a reduction in radiation dose by an average of 57% without reducing the image quality. Conclusions The protocol optimization framework provides means to assess and optimize CTA in terms of either image quality or radiation dose objectives with its results predicting prior clinical trial findings.
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Affiliation(s)
- Mojtaba Zarei
- Duke University, Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Durham, North Carolina, United States
- Duke University, Department of Electrical and Computer Engineering, Durham, North Carolina, United States
| | - Ehsan Abadi
- Duke University, Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Durham, North Carolina, United States
- Duke University, Department of Electrical and Computer Engineering, Durham, North Carolina, United States
- Duke University School of Medicine, Department of Radiology, Durham, North Carolina, United States
| | - William Paul Segars
- Duke University, Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Durham, North Carolina, United States
- Duke University School of Medicine, Department of Radiology, Durham, North Carolina, United States
| | - Ehsan Samei
- Duke University, Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Durham, North Carolina, United States
- Duke University, Department of Electrical and Computer Engineering, Durham, North Carolina, United States
- Duke University School of Medicine, Department of Radiology, Durham, North Carolina, United States
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Koo SA, Jung Y, Um KA, Kim TH, Kim JY, Park CH. Clinical Feasibility of Deep Learning-Based Image Reconstruction on Coronary Computed Tomography Angiography. J Clin Med 2023; 12:jcm12103501. [PMID: 37240607 DOI: 10.3390/jcm12103501] [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: 03/19/2023] [Revised: 04/24/2023] [Accepted: 05/14/2023] [Indexed: 05/28/2023] Open
Abstract
This study evaluated the feasibility of deep-learning-based image reconstruction (DLIR) on coronary computed tomography angiography (CCTA). By using a 20 cm water phantom, the noise reduction ratio and noise power spectrum were evaluated according to the different reconstruction methods. Then 46 patients who underwent CCTA were retrospectively enrolled. CCTA was performed using the 16 cm coverage axial volume scan technique. All CT images were reconstructed using filtered back projection (FBP); three model-based iterative reconstructions (MBIR) of 40%, 60%, and 80%; and three DLIR algorithms: low (L), medium (M), and high (H). Quantitative and qualitative image qualities of CCTA were compared according to the reconstruction methods. In the phantom study, the noise reduction ratios of MBIR-40%, MBIR-60%, MBIR-80%, DLIR-L, DLIR-M, and DLIR-H were 26.7 ± 0.2%, 39.5 ± 0.5%, 51.7 ± 0.4%, 33.1 ± 0.8%, 43.2 ± 0.8%, and 53.5 ± 0.1%, respectively. The pattern of the noise power spectrum of the DLIR images was more similar to FBP images than MBIR images. In a CCTA study, CCTA yielded a significantly lower noise index with DLIR-H reconstruction than with the other reconstruction methods. DLIR-H showed a higher SNR and CNR than MBIR (p < 0.05). The qualitative image quality of CCTA with DLIR-H was significantly higher than that of MBIR-80% or FBP. The DLIR algorithm was feasible and yielded a better image quality than the FBP or MBIR algorithms on CCTA.
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Affiliation(s)
- Seul Ah Koo
- Department of Radiology and The Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea
| | - Yunsub Jung
- Research Team, GE Healthcare Korea, Seoul 04637, Republic of Korea
| | - Kyoung A Um
- Research Team, GE Healthcare Korea, Seoul 04637, Republic of Korea
| | - Tae Hoon Kim
- Department of Radiology and The Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea
| | - Ji Young Kim
- Department of Radiology and The Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea
| | - Chul Hwan Park
- Department of Radiology and The Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea
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Guido G, Polici M, Nacci I, Bozzi F, De Santis D, Ubaldi N, Polidori T, Zerunian M, Bracci B, Laghi A, Caruso D. Iterative Reconstruction: State-of-the-Art and Future Perspectives. J Comput Assist Tomogr 2023; 47:244-254. [PMID: 36728734 DOI: 10.1097/rct.0000000000001401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
ABSTRACT Image reconstruction processing in computed tomography (CT) has evolved tremendously since its creation, succeeding at optimizing radiation dose while maintaining adequate image quality. Computed tomography vendors have developed and implemented various technical advances, such as automatic noise reduction filters, automatic exposure control, and refined imaging reconstruction algorithms.Focusing on imaging reconstruction, filtered back-projection has represented the standard reconstruction algorithm for over 3 decades, obtaining adequate image quality at standard radiation dose exposures. To overcome filtered back-projection reconstruction flaws in low-dose CT data sets, advanced iterative reconstruction algorithms consisting of either backward projection or both backward and forward projections have been developed, with the goal to enable low-dose CT acquisitions with high image quality. Iterative reconstruction techniques play a key role in routine workflow implementation (eg, screening protocols, vascular and pediatric applications), in quantitative CT imaging applications, and in dose exposure limitation in oncologic patients.Therefore, this review aims to provide an overview of the technical principles and the main clinical application of iterative reconstruction algorithms, focusing on the strengths and weaknesses, in addition to integrating future perspectives in the new era of artificial intelligence.
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Affiliation(s)
- Gisella Guido
- From the Department of Surgical Medical Sciences and Translational Medicine, Sapienza University of Rome - Radiology Unit, Sant'Andrea University Hospital, Rome, Italy
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Impact of Morphotype on Image Quality and Diagnostic Performance of Ultra-Low-Dose Chest CT. J Clin Med 2021; 10:jcm10153284. [PMID: 34362068 PMCID: PMC8348164 DOI: 10.3390/jcm10153284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/22/2021] [Accepted: 07/22/2021] [Indexed: 11/23/2022] Open
Abstract
Objectives: The image quality of an Ultra-Low-Dose (ULD) chest CT depends on the patient’s morphotype. We hypothesize that there is a threshold beyond which the diagnostic performance of a ULD chest CT is too degraded. This work assesses the influence of morphotype (Body Mass Index BMI, Maximum Transverse Chest Diameter MTCD and gender) on image quality and the diagnostic performance of a ULD chest CT. Methods: A total of 170 patients from three prior prospective monocentric studies were retrospectively included. Renewal of consent was waived by our IRB. All the patients underwent two consecutive unenhanced chest CT acquisitions with a full dose (120 kV, automated tube current modulation) and a ULD (135 kV, fixed tube current at 10 mA). Image noise, subjective image quality and diagnostic performance for nine predefined lung parenchyma lesions were assessed by two independent readers, and correlations with the patient’s morphotype were sought. Results: The mean BMI was 26.6 ± 5.3; 20.6% of patients had a BMI > 30. There was a statistically significant negative correlation of the BMI with the image quality (ρ = −0.32; IC95% = (−0.468; −0.18)). The per-patient diagnostic performance of ULD was sensitivity, 77%; specificity, 99%; PPV, 94% and NPV, 65%. There was no statistically significant influence of the BMI, the MTCD nor the gender on the per-patient and per-lesion diagnostic performance of a ULD chest CT, apart from a significant negative correlation for the detection of emphysema. Conclusions: Despite a negative correlation between the BMI and the image quality of a ULD chest CT, we did not find a correlation between the BMI and the diagnostic performance of the examination, suggesting a possible use of the ULD protocol in obese patients.
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Abdullah KA, McEntee MF, Reed W, Kench PL. Evaluation of an integrated 3D-printed phantom for coronary CT angiography using iterative reconstruction algorithm. J Med Radiat Sci 2020; 67:170-176. [PMID: 32219989 PMCID: PMC7476188 DOI: 10.1002/jmrs.387] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/26/2020] [Accepted: 03/02/2020] [Indexed: 02/05/2023] Open
Abstract
INTRODUCTION 3D-printed imaging phantoms are now increasingly available and used for computed tomography (CT) dose optimisation study and image quality analysis. The aim of this study was to evaluate the integrated 3D-printed cardiac insert phantom when evaluating iterative reconstruction (IR) algorithm in coronary CT angiography (CCTA) protocols. METHODS The 3D-printed cardiac insert phantom was positioned into a chest phantom and scanned with a 16-slice CT scanner. Acquisitions were performed with CCTA protocols using 120 kVp at four different tube currents, 300, 200, 100 and 50 mA (protocols A, B, C and D, respectively). The image data sets were reconstructed with a filtered back projection (FBP) and three different IR algorithm strengths. The image quality metrics of image noise, signal-noise ratio (SNR) and contrast-noise ratio (CNR) were calculated for each protocol. RESULTS Decrease in dose levels has significantly increased the image noise, compared to FBP of protocol A (P < 0.001). As a result, the SNR and CNR were significantly decreased (P < 0.001). For FBP, the highest noise with poor SNR and CNR was protocol D with 19.0 ± 1.6 HU, 18.9 ± 2.5 and 25.1 ± 3.6, respectively. For IR algorithm, the highest strength (AIDR3Dstrong ) yielded the lowest noise with excellent SNR and CNR. CONCLUSIONS The use of IR algorithm and increasing its strengths have reduced noise significantly and thus increased the SNR and CNR when compared to FBP. Therefore, this integrated 3D-printed phantom approach could be used for dose optimisation study and image quality analysis in CCTA protocols.
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Affiliation(s)
| | - Mark F. McEntee
- Discipline of Medical Radiation SciencesFaculty of Health SciencesThe University of SydneyLidcombeNew South WalesAustralia
| | - Warren Reed
- Discipline of Medical Radiation SciencesFaculty of Health SciencesThe University of SydneyLidcombeNew South WalesAustralia
| | - Peter L. Kench
- Discipline of Medical Radiation SciencesFaculty of Health SciencesThe University of SydneyLidcombeNew South WalesAustralia
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De Rubeis G, Napp AE, Schlattmann P, Geleijns J, Laule M, Dreger H, Kofoed K, Sørgaard M, Engstrøm T, Tilsted HH, Boi A, Porcu M, Cossa S, Rodríguez-Palomares JF, Xavier Valente F, Roque A, Feuchtner G, Plank F, Štěchovský C, Adla T, Schroeder S, Zelesny T, Gutberlet M, Woinke M, Károlyi M, Karády J, Donnelly P, Ball P, Dodd J, Hensey M, Mancone M, Ceccacci A, Berzina M, Zvaigzne L, Sakalyte G, Basevičius A, Ilnicka-Suckiel M, Kuśmierz D, Faria R, Gama-Ribeiro V, Benedek I, Benedek T, Adjić F, Čanković M, Berry C, Delles C, Thwaite E, Davis G, Knuuti J, Pietilä M, Kepka C, Kruk M, Vidakovic R, Neskovic AN, Lecumberri I, Diez Gonzales I, Ruzsics B, Fisher M, Dewey M, Francone M. Pilot study of the multicentre DISCHARGE Trial: image quality and protocol adherence results of computed tomography and invasive coronary angiography. Eur Radiol 2019; 30:1997-2009. [PMID: 31844958 DOI: 10.1007/s00330-019-06522-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/20/2019] [Accepted: 10/17/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To implement detailed EU cardiac computed tomography angiography (CCTA) quality criteria in the multicentre DISCHARGE trial (FP72007-2013, EC-GA 603266), we reviewed image quality and adherence to CCTA protocol and to the recommendations of invasive coronary angiography (ICA) in a pilot study. MATERIALS AND METHODS From every clinical centre, imaging datasets of three patients per arm were assessed for adherence to the inclusion/exclusion criteria of the pilot study, predefined standards for the CCTA protocol and ICA recommendations, image quality and non-diagnostic (NDX) rate. These parameters were compared via multinomial regression and ANOVA. If a site did not reach the minimum quality level, additional datasets had to be sent before entering into the final accepted database (FADB). RESULTS We analysed 226 cases (150 CCTA/76 ICA). The inclusion/exclusion criteria were not met by 6 of the 226 (2.7%) datasets. The predefined standard was not met by 13 of 76 ICA datasets (17.1%). This percentage decreased between the initial CCTA database and the FADB (multinomial regression, 53 of 70 vs 17 of 75 [76%] vs [23%]). The signal-to-noise ratio and contrast-to-noise ratio of the FADB did not improve significantly (ANOVA, p = 0.20; p = 0.09). The CTA NDX rate was reduced, but not significantly (initial CCTA database 15 of 70 [21.4%]) and FADB 9 of 75 [12%]; p = 0.13). CONCLUSION We were able to increase conformity to the inclusion/exclusion criteria and CCTA protocol, improve image quality and decrease the CCTA NDX rate by implementing EU CCTA quality criteria and ICA recommendations. KEY POINTS • Failure to meet protocol adherence in cardiac CTA was high in the pilot study (77.6%). • Image quality varies between sites and can be improved by feedback given by the core lab. • Conformance with new EU cardiac CT quality criteria might render cardiac CTA findings more consistent and comparable.
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Affiliation(s)
- Gianluca De Rubeis
- Department of Radiology, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy
| | - Adriane E Napp
- Department of Radiology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Peter Schlattmann
- Department of Statistics, Informatics and Data Science, Jena University Hospital, Jena, Germany
| | - Jacob Geleijns
- Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Michael Laule
- Department of Cardiology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Henryk Dreger
- Department of Cardiology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Klaus Kofoed
- Department of Radiology, Rigshospitalet Region Hovedstaden, Rigshospitalet 9, 2100, Copenhagen, Denmark.,Department of Cardiology, Rigshospitalet Region Hovedstaden, Rigshospitalet 9, 2100, Copenhagen, Denmark
| | - Mathias Sørgaard
- Department of Cardiology, Rigshospitalet Region Hovedstaden, Rigshospitalet 9, 2100, Copenhagen, Denmark
| | - Thomas Engstrøm
- Department of Cardiology, Rigshospitalet Region Hovedstaden, Rigshospitalet 9, 2100, Copenhagen, Denmark
| | - Hans Henrik Tilsted
- Department of Cardiology, Rigshospitalet Region Hovedstaden, Rigshospitalet 9, 2100, Copenhagen, Denmark
| | - Alberto Boi
- Department of Cardiology, Azienda Ospedaliera Brotzu, Cagliari, CA, Italy
| | - Michele Porcu
- Department of Radiology, Azienda Ospedaliera Universitaria di Cagliari, AOU di Cagliari - Polo di Monserrato, 09042, Monserrato, CA, Italy
| | - Stefano Cossa
- Department of Radiology, Azienda Ospedaliera Brotzu, Cagliari, CA, Italy
| | - José F Rodríguez-Palomares
- Department of Cardiology, Hospital Universitari Vall d´Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Passeig de Vall d'Hebron 119, 08035, Barcelona, Spain
| | - Filipa Xavier Valente
- Department of Cardiology, Hospital Universitari Vall d´Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Passeig de Vall d'Hebron 119, 08035, Barcelona, Spain
| | - Albert Roque
- Department of Radiology, Hospital Universitari Vall d´Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Passeig de Vall d'Hebron 119, 08035, Barcelona, Spain
| | - Gudrun Feuchtner
- Department of Radiology, Medical University Innsbruck, Anichstr. 35, 6020, Innsbruck, Austria
| | - Fabian Plank
- Department of Cardiology, Medical University Innsbruck, Anichstr. 35, 6020, Innsbruck, Austria
| | - Cyril Štěchovský
- Department of Cardiology, University Hospital Motol, Vuvalu 84, 150 06, Prague 5, Czech Republic
| | - Theodor Adla
- Department of Radiology, University Hospital Motol, Vuvalu 84, 150 06, Prague 5, Czech Republic
| | - Stephen Schroeder
- Department of Cardiology, ALB FILS KLINIKEN GmbH, Eichertstrasse 3, 73035, Goeppingen, Germany
| | - Thomas Zelesny
- Department of Radiology, ALB FILS KLINIKEN GmbH, Eichertstrasse 3, 73035, Goeppingen, Germany
| | - Matthias Gutberlet
- Department of Radiology, University of Leipzig Heart Centre, Strümpellstrasse 39, 04289, Leipzig, Germany
| | - Michael Woinke
- Department of Cardiology, University of Leipzig Heart Centre, Strümpellstrasse 39, 04289, Leipzig, Germany
| | - Mihály Károlyi
- MTA-SE Cardiovascular Imaging Center, Heart and Vascular Center, Semmelweis University, Varosmajor u 68, Budapest, 1122, Hungary
| | - Júlia Karády
- Department of Cardiology, Southeastern Health and Social Care Trust, Upper Newtownards Road Ulster, Belfast, BT16 1RH, UK
| | - Patrick Donnelly
- Department of Cardiology, Southeastern Health and Social Care Trust, Upper Newtownards Road Ulster, Belfast, BT16 1RH, UK
| | - Peter Ball
- Department of Radiology, Southeastern Health and Social Care Trust, Upper Newtownards Road Ulster, Belfast, BT16 1RH, UK
| | - Jonathan Dodd
- Department of Radiology, St. Vincent's University Hospital and National University of Ireland, Belfield Campus, 4, Dublin, Ireland
| | - Mark Hensey
- Department of Cardiology, St. Vincent's University Hospital, Belfield Campus, 4, Dublin, Ireland
| | - Massimo Mancone
- Department of Cardiovascular, Respiratory, Nephrology, Anesthesiology and Geriatric Sciences, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy
| | - Andrea Ceccacci
- Department of Cardiovascular, Respiratory, Nephrology, Anesthesiology and Geriatric Sciences, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy
| | - Marina Berzina
- Department of Cardiology, Paul Stradins Clinical University Hospital, Pilsoņu Street 13, Riga, 1002, Latvia
| | - Ligita Zvaigzne
- Department of Radiology, Paul Stradins Clinical University Hospital, Pilsoņu Street 13, Riga, 1002, Latvia
| | - Gintare Sakalyte
- Department of Cardiology, Lithuanian University of Health Sciences, Eivelniu 2, 50009, Kaunas, Lithuania
| | - Algidas Basevičius
- Department of Radiology, Lithuanian University of Health Sciences, Eivelniu 2, 50009, Kaunas, Lithuania
| | - Małgorzata Ilnicka-Suckiel
- Department of Cardiology, Wojewodzki Szpital Specjalistyczny We Wroclawiu, Ul. Henryka Michala Kamienskiego, 51124, Wroclaw, Poland
| | - Donata Kuśmierz
- Department of Radiology, Wojewodzki Szpital Specjalistyczny We Wroclawiu, Ul. Henryka Michala Kamienskiego, 51124, Wroclaw, Poland
| | - Rita Faria
- Department of Cardiology, Centro Hospitalar de Vila Nova de Gaia, Rua Conceicao Fernandes, 4434 502, Vila Nova de Gaia, Portugal
| | - Vasco Gama-Ribeiro
- Department of Cardiology, Centro Hospitalar de Vila Nova de Gaia, Rua Conceicao Fernandes, 4434 502, Vila Nova de Gaia, Portugal
| | - Imre Benedek
- Department of Cardiology, Cardio Med Medical Center, 22 decembrie 1989, 540156, Targu-Mures, Romania
| | - Teodora Benedek
- Department of Cardiology, Cardio Med Medical Center, 22 decembrie 1989, 540156, Targu-Mures, Romania
| | - Filip Adjić
- Radiology Department Imaging Center, Institute of Cardiovascular Diseases of Vojvodina, Put dr Goldmana 4, Sremska Kamenica, Novi Sad, 212014, Serbia
| | - Milenko Čanković
- Department of Cardiology, Institute of Cardiovascular Diseases of Vojvodina, Put dr Goldmana 4, Sremska Kamenica, Novi Sad, 212014, Serbia
| | - Colin Berry
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, University Place 126, Glasgow, G12 8TA, UK
| | - Christian Delles
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, University Place 126, Glasgow, G12 8TA, UK
| | - Erica Thwaite
- Department of Radiology, Aintree University Hospital, Longmoor Lane, Liverpool, L9 7AL, UK
| | - Gershan Davis
- Department of Cardiology, Aintree University Hospital, Longmoor Lane, Liverpool, L9 7AL, UK
| | - Juhani Knuuti
- Turku PET Centre, Turku University Hospital and University of Turku, Kiinamyllynkatu 4-8, 20120, Turku, Finland
| | - Mikko Pietilä
- Heart Centre, Turku University Hospital, Kiinamyllynkatu 4-8, FI 20120, Turku, Finland
| | - Cezary Kepka
- Department of Radiology, The Institute of Cardiology in Warsaw, Ul. Alpejska 42, 04-628, Warsaw, Poland
| | - Mariusz Kruk
- Department of Cardiology, The Institute of Cardiology in Warsaw, Ul. Alpejska 42, 04-628, Warsaw, Poland
| | - Radosav Vidakovic
- Department of Cardiology, Clinical Hospital Center Zemun, Vukova 9, Belgrade-Zemun, 11080, Serbia
| | - Aleksandar N Neskovic
- Department of Cardiology, Clinical Hospital Center Zemun, Vukova 9, Belgrade-Zemun, 11080, Serbia
| | - Iñigo Lecumberri
- Department of Radiology, Basurto University Hospital, Avenida Montevideo 18, 48013, Bilbao, Spain
| | - Ignacio Diez Gonzales
- Department of Cardiology, Basurto University Hospital, Avenida Montevideo 18, 48013, Bilbao, Spain
| | - Balazs Ruzsics
- Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Prescot Street, Liverpool, L7 8XP, UK
| | - Mike Fisher
- Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Prescot Street, Liverpool, L7 8XP, UK
| | - Marc Dewey
- Department of Radiology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Marco Francone
- Department of Radiology, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy. .,Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, V.le Regina Elena, 324 00161, Rome, Italy.
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Richards CE, Obaid DR. Low-Dose Radiation Advances in Coronary Computed Tomography Angiography in the Diagnosis of Coronary Artery Disease. Curr Cardiol Rev 2019; 15:304-315. [PMID: 30806322 PMCID: PMC8142354 DOI: 10.2174/1573403x15666190222163737] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 12/24/2018] [Accepted: 12/26/2018] [Indexed: 01/16/2023] Open
Abstract
Background
Coronary computed tomography angiography (CCTA) is now widely used in the diagnosis of coronary artery disease since it is a rapid, minimally invasive test with a diagnostic accuracy comparable to coronary angiography. However, to meet demands for increasing spatial and temporal resolution, higher x-ray radiation doses are required to circumvent the resulting increase in image noise. Exposure to high doses of ionizing radiation with CT imaging is a major health concern due to the potential risk of radiation-associated malignancy. Given its increasing use, a number of dose saving algorithms have been implemented to CCTA to minimize radiation exposure to “as low as reasonably achievable (ALARA)” without compromising diagnostic image quality. Objective
The purpose of this review is to outline the most recent advances and current status of dose saving techniques in CCTA. Method
PubMed, Medline, EMBASE and Scholar databases were searched to identify feasibility studies, clinical trials, and technology guidelines on the technical advances in CT scanner hardware and reconstruction software. Results
Sub-millisievert (mSv) radiation doses have been reported for CCTA due to a combination of strategies such as prospective electrocardiogram-gating, high-pitch helical acquisition, tube current modulation, tube voltage reduction, heart rate reduction, and the most recent novel adaptive iterative reconstruction algorithms. Conclusion
Advances in radiation dose reduction without loss of image quality justify the use of CCTA as a non-invasive alternative to coronary catheterization in the diagnosis of coronary artery disease.
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Affiliation(s)
- Caryl E Richards
- Department of Cardiology, Morriston Hospital, Heol Maes Eglwys, Morriston, Swansea, SA6 6NL, United Kingdom
| | - Daniel R Obaid
- Department of Cardiology, Morriston Hospital, Heol Maes Eglwys, Morriston, Swansea, SA6 6NL, United Kingdom.,Swansea University Medical School, Swansea University, Grove Building, Singleton Park, Sketty, Swansea SA2 8PP, United Kingdom
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8
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The usefulness of low radiation dose subtraction coronary computed tomography angiography for patients with calcification using 320-row area detector CT. J Cardiol 2019; 73:58-64. [DOI: 10.1016/j.jjcc.2018.05.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 05/10/2018] [Accepted: 05/22/2018] [Indexed: 01/05/2023]
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9
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Abdullah KA, McEntee MF, Reed W, Kench PL. Development of an organ-specific insert phantom generated using a 3D printer for investigations of cardiac computed tomography protocols. J Med Radiat Sci 2018; 65:175-183. [PMID: 29707915 PMCID: PMC6119733 DOI: 10.1002/jmrs.279] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 03/28/2018] [Indexed: 12/13/2022] Open
Abstract
INTRODUCTION An ideal organ-specific insert phantom should be able to simulate the anatomical features with appropriate appearances in the resultant computed tomography (CT) images. This study investigated a 3D printing technology to develop a novel and cost-effective cardiac insert phantom derived from volumetric CT image datasets of anthropomorphic chest phantom. METHODS Cardiac insert volumes were segmented from CT image datasets, derived from an anthropomorphic chest phantom of Lungman N-01 (Kyoto Kagaku, Japan). These segmented datasets were converted to a virtual 3D-isosurface of heart-shaped shell, while two other removable inserts were included using computer-aided design (CAD) software program. This newly designed cardiac insert phantom was later printed by using a fused deposition modelling (FDM) process via a Creatbot DM Plus 3D printer. Then, several selected filling materials, such as contrast media, oil, water and jelly, were loaded into designated spaces in the 3D-printed phantom. The 3D-printed cardiac insert phantom was positioned within the anthropomorphic chest phantom and 30 repeated CT acquisitions performed using a multi-detector scanner at 120-kVp tube potential. Attenuation (Hounsfield Unit, HU) values were measured and compared to the image datasets of real-patient and Catphan® 500 phantom. RESULTS The output of the 3D-printed cardiac insert phantom was a solid acrylic plastic material, which was strong, light in weight and cost-effective. HU values of the filling materials were comparable to the image datasets of real-patient and Catphan® 500 phantom. CONCLUSIONS A novel and cost-effective cardiac insert phantom for anthropomorphic chest phantom was developed using volumetric CT image datasets with a 3D printer. Hence, this suggested the printing methodology could be applied to generate other phantoms for CT imaging studies.
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Affiliation(s)
- Kamarul A. Abdullah
- Discipline of Medical Radiation SciencesFaculty of Health SciencesThe University of SydneyLidcombeNew South WalesAustralia
- Faculty of Health SciencesUniversiti Sultan Zainal AbidinTerengganuMalaysia
| | - Mark F. McEntee
- Discipline of Medical Radiation SciencesFaculty of Health SciencesThe University of SydneyLidcombeNew South WalesAustralia
| | - Warren Reed
- Discipline of Medical Radiation SciencesFaculty of Health SciencesThe University of SydneyLidcombeNew South WalesAustralia
| | - Peter L. Kench
- Discipline of Medical Radiation SciencesFaculty of Health SciencesThe University of SydneyLidcombeNew South WalesAustralia
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Garmer M, Bonsels M, Metz F, Klein-Wiele O, Brandts B, Grönemeyer D. Coronary computed tomography angiography and endocardial leads - Image quality in 320-row CT using iterative reconstruction. Clin Imaging 2018; 50:157-163. [PMID: 29567628 DOI: 10.1016/j.clinimag.2018.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 02/08/2018] [Accepted: 03/01/2018] [Indexed: 11/25/2022]
Abstract
PURPOSE To investigate whether the presence of endocardial leads has an impact on image quality in coronary computed tomography angiography (CCTA), when current technique is employed using a 320-row computed tomography and iterative reconstruction. MATERIALS AND METHODS CCTA was performed in 1641 patients, from these we identified 51 patients (study group) with endocardial leads and 51 matched partners (control group) without endocardial leads. Noise was determined in the ascending aorta and the left ventricle; signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were determined in the left and right coronary artery. Subjective image quality was rated separately for the 15 segments of the coronary arteries by 2 radiologists. RESULTS Current CCTA technique still shows slight impairment of objective image quality in patients with endocardial leads with inferior SNR in the aorta (median 15.04 versus 16.6; p = 0.004) and inferior SNR in the left/right coronary artery (median 15.3/13.81 versus 16.1/15.41; p = 0.013/0.002). CNR of the left/right coronary artery was also inferior (median 17.4/16.46 versus 19.26/19.24; p = 0.002/<0.001). The subjective image quality was rated significantly inferior only in segment 8 (p = 0.001) compared to the control group. Artifacts by ventricular leads were found in 65% of the patients in segment 8 with non-diagnostic rating in 9 cases (18%). Atrial leads resulted in artifacts predominantly in segment 1 (45%) with non-diagnostic rating in only 2 cases (4%). CONCLUSION CCTA is feasible with slight restrictions for patients in the presence of implanted cardiac devices when current technique is used.
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Affiliation(s)
- Marietta Garmer
- Witten/Herdecke University, Grönemeyer Institute for Microtherapy, Germany; Witten/Herdecke University, Clinical Radiology Wuppertal, Germany.
| | - Marc Bonsels
- Witten/Herdecke University, Grönemeyer Institute for Microtherapy, Germany
| | - Frauke Metz
- Witten/Herdecke University, Grönemeyer Institute for Microtherapy, Germany
| | - Oliver Klein-Wiele
- Witten/Herdecke University, Grönemeyer Institute for Microtherapy, Germany
| | - Bodo Brandts
- Witten/Herdecke University, Dept. of Cardiology, Augusta-Kranken-Anstalt Bochum, Germany
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Elsholtz FHJ, Schaafs LA, Erxleben C, Hamm B, Niehues SM. Periradicular infiltration of the lumbar spine: is iterative reconstruction software necessary to establish ultra-low-dose protocols? A quantitative and qualitative approach. Radiol Med 2018; 123:827-832. [PMID: 29923084 DOI: 10.1007/s11547-018-0913-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/12/2018] [Indexed: 12/18/2022]
Abstract
PURPOSE Computed tomography (CT)-guided periradicular infiltration therapy has emerged as an effective treatment option for patients with low back pain. Concern about radiation exposure requires approaches allowing significant dose reduction. The purpose of this study is to evaluate the need for iterative reconstruction software in CT-guided periradicular infiltration therapy with an ultra-low-dose protocol. MATERIALS AND METHODS One hundred patients underwent CT-guided periradicular infiltration therapy of the lumbar spine using an ultra-low-dose protocol with adaptive iterative dose reduction 3D (AIDR 3D) for image reconstruction. In addition, images were reconstructed with filtered back-projection (FBP). Four experienced raters evaluated both reconstruction types for conspicuity of anatomical and instrumental features important for ensuring safe patient treatment. Image noise was measured as a quantitative marker of image quality. RESULTS Interrater agreement was good for both AIDR 3D (Kendall's W = 0.83) and FBP (0.78) reconstructions. Readers assigned the same scores for all features and both reconstruction algorithms in 81.3% of cases. Image noise was significantly lower (average SD of 60.07 vs. 99.54, p < 0.05) for AIDR 3D-reconstructed images. CONCLUSION Although it significantly lowers image noise, iterative reconstruction software is not mandatory to achieve adequate image quality with an ultra-low-dose CT protocol for guiding periradicular infiltration therapy of the lumbar spine.
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Affiliation(s)
- Fabian Henry Jürgen Elsholtz
- Klinik und Hochschulambulanz für Radiologie, Charité- Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany.
| | - Lars-Arne Schaafs
- Klinik und Hochschulambulanz für Radiologie, Charité- Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Christoph Erxleben
- Klinik und Hochschulambulanz für Radiologie, Charité- Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Bernd Hamm
- Klinik und Hochschulambulanz für Radiologie, Charité- Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Stefan Markus Niehues
- Klinik und Hochschulambulanz für Radiologie, Charité- Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany
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Fareed A, Vavere AL, Zimmermann E, Tanami Y, Steveson C, Matheson M, Paul N, Clouse M, Cox C, Lima JA, Arbab-Zadeh A. Impact of iterative reconstruction vs. filtered back projection on image quality in 320-slice CT coronary angiography: Insights from the CORE320 multicenter study. Medicine (Baltimore) 2017; 96:e8452. [PMID: 29310329 PMCID: PMC5728730 DOI: 10.1097/md.0000000000008452] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Iterative reconstruction has been shown to reduce image noise compared with traditional filtered back projection with quantum denoising software (FBP/QDS+) in CT imaging but few comparisons have been made in the same patients without the influence of interindividual factors. The objective of this study was to investigate the impact of adaptive iterative dose reduction in 3-dimensional (AIDR 3D) and FBP/QDS+-based image reconstruction on image quality in the same patients.We randomly selected 100 patients enrolled in the coronary evaluation using 320-slice CT study who underwent CT coronary angiography using prospectively electrocardiogram triggered image acquisition with a 320-detector scanner. Both FBP/QDS+ and AIDR 3D reconstructions were performed using original data. Studies were blindly analyzed for image quality by measuring the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Image quality was assessed qualitatively using a 4-point scale.Median age was 63 years (interquartile range [IQR]: 56-71) and 72% were men, median body mass index 27 (IQR: 24-30) and median calcium score 222 (IQR: 11-644). For all regions of interest, mean image noise was lower for AIDR 3D vs. FBP/QDS+ (31.69 vs. 34.37, P ≤ .001). SNR and CNR were significantly higher for AIDR 3D vs. FBP/QDS+ (16.28 vs. 14.64, P < .001 and 19.21 vs. 17.06, P < .001, respectively). Subjective (qualitative) image quality scores were better using AIDR 3D vs. FBP/QDS+ with means of 1.6 and 1.74, respectively (P ≤ .001).Assessed in the same individuals, iterative reconstruction decreased image noise and raised SNR/CNR as well as subjective image quality scores compared with traditional FBP/QDS+ in 320-slice CT coronary angiography at standard radiation doses.
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Affiliation(s)
- Ahmed Fareed
- Department of Medicine/Cardiology Division, Johns Hopkins University, Baltimore, MD
- Department of Medicine/Cardiology Division, Suez Canal University, Ismailia, Egypt
| | - Andrea L. Vavere
- Department of Medicine/Cardiology Division, Johns Hopkins University, Baltimore, MD
| | - Elke Zimmermann
- Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Yutaka Tanami
- Department of Medicine/Cardiology Division, Johns Hopkins University, Baltimore, MD
| | - Chloe Steveson
- Toshiba Medical Systems, Otawara, Minato-Ku, Tokyo, Japan
| | - Matthew Matheson
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Narinder Paul
- Joint Department of Medical Imaging, Toronto General Hospital, Toronto, Canada
| | - Melvin Clouse
- Beth Israel Deaconess Medical Center, Harvard University, Boston, MA
| | - Christopher Cox
- Joint Department of Medical Imaging, Toronto General Hospital, Toronto, Canada
| | - João A.C. Lima
- Department of Medicine/Cardiology Division, Johns Hopkins University, Baltimore, MD
| | - Armin Arbab-Zadeh
- Department of Medicine/Cardiology Division, Johns Hopkins University, Baltimore, MD
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Submillisievert imaging protocol using full reconstruction and advanced patient motion correction in 320-row area detector coronary CT angiography. Int J Cardiovasc Imaging 2017; 34:465-474. [PMID: 28900781 DOI: 10.1007/s10554-017-1237-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 08/20/2017] [Indexed: 12/29/2022]
Abstract
Radiation exposure remains a concern in the use of coronary CT angiography (CCTA). Full reconstruction (Full) and reconstruction using advanced patient motion correction (APMC) could obtain a lower radiation dose using low tube current scanning in a 320-row Area Detector CT (320-ADCT). The radiation dose for an imaging protocol using Full and APMC in daily practice was estimated. A total of 209 patients who underwent CCTA in 1 rotation scanning with 100 kv and adaptive iterative dose reduction 3D in 320-ADCT were enrolled. Imaging protocols were classified into 3 groups based on estimated slow filling time: (1) slow filling time ≥ 275 msec, Full with 30% of usual tube current (N = 43)(Full30%mA) (2) 206.3 msec ≤ slow filling time < 275 msec, APMC with 50% of usual tube current (N = 48)(APMC50%mA); and (3) 137.5 msec ≤ slow filling time < 206.3 msec, Half reconstruction with usual tube current (N = 118)(Half100%mA). Radiation dose was estimated by the effective dose. The diagnostic accuracy of CCTA was compared with that of invasive coronary angiography in 28 patients. The effective doses of Full30%mA, APMC50%mA, and Half100%mA were 0.77 ± 0.31, 1.30 ± 0.85, and 1.98 ± 0.68, respectively. Of 28 patients, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value in vessel-based analyses were: Full30%mA, 66.7, 82.4, 80.0, 40.0, and 93.3%; APMC50%mA, 100.0, 80.0, 83.3, 50.05, and 100.0%; and Half100%mA, 90.9, 83.0, 86.3, 78.95, and 92.9%, respectively. An imaging protocol using Full30%mA and APMC50%mA was one of the methods how radiation dose could be reduced radiation dose maintained diagnostic accuracy compared to imaging using conventional Half100%mA.
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Ghekiere O, Salgado R, Buls N, Leiner T, Mancini I, Vanhoenacker P, Dendale P, Nchimi A. Image quality in coronary CT angiography: challenges and technical solutions. Br J Radiol 2017; 90:20160567. [PMID: 28055253 PMCID: PMC5605061 DOI: 10.1259/bjr.20160567] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 10/13/2016] [Accepted: 01/03/2017] [Indexed: 11/05/2022] Open
Abstract
Multidetector CT angiography (CTA) has become a widely accepted examination for non-invasive evaluation of the heart and coronary arteries. Despite its ongoing success and worldwide clinical implementation, it remains an often-challenging procedure in which image quality, and hence diagnostic value, is determined by both technical and patient-related factors. Thorough knowledge of these factors is important to obtain high-quality examinations. In this review, we discuss several key elements that may adversely affect coronary CTA image quality as well as potential measures that can be taken to mitigate their impact. In addition, several recent vendor-specific advances and future directions to improve image quality are discussed.
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Affiliation(s)
- Olivier Ghekiere
- Department of Radiology, Centre Hospitalier Chrétien (CHC), Liège, Belgium
- Department of Radiology, Jessa Ziekenhuis, Hasselt, Belgium
- Faculty of Medicine and Life Sciences, Hasselt University, Hasselt, Belgium
| | - Rodrigo Salgado
- Department of Radiology, Antwerp University Hospital (UZA), Edegem, Belgium
| | - Nico Buls
- Department of Radiology, UZ Brussel, Brussels, Belgium
| | - Tim Leiner
- Department of Radiology, Utrecht University Medical Center, Utrecht, Netherlands
| | - Isabelle Mancini
- Department of Radiology, Centre Hospitalier Chrétien (CHC), Liège, Belgium
| | | | - Paul Dendale
- Heart Center Hasselt, Jessa Ziekenhuis, Hasselt, Belgium
| | - Alain Nchimi
- GIGA Cardiovascular Sciences, Liège University (ULg), Domaine Universitaire du Sart Tilman, Rue de l'hôpital, Liège, Belgium
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Urabe Y, Yamamoto H, Kitagawa T, Utsunomiya H, Tsushima H, Tatsugami F, Awai K, Kihara Y. Identifying Small Coronary Calcification in Non-Contrast 0.5-mm Slice Reconstruction to Diagnose Coronary Artery Disease in Patients with a Conventional Zero Coronary Artery Calcium Score. J Atheroscler Thromb 2016; 23:1324-1333. [PMID: 27397477 PMCID: PMC5221495 DOI: 10.5551/jat.35808] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Aims: In a new-generation computed tomography (CT) scanner, coronary artery calcium (CAC) scores were measured using 3.0-mm slice reconstruction images originally acquired with 0.5 mm thickness scans in a single beat. This study investigated the usefulness of thin-slice (0.5 mm) reconstruction for identifying small calcifications in coronary arteries and evaluated the association with coronary plaques and stenosis compared to conventional 3.0-mm reconstruction images. Methods: We evaluated 132 patients with zero CAC scores in conventional 3.0-mm Agatston method using a 320-slice CT. Then, 0.5-mm slice reconstruction was performed to identify small calcifications. The presence of stenosis and coronary plaques was assessed using coronary CT angiography. Results: In total, 22 small calcifications were identified in 18 patients. There were 28 (21%) patients with any (≥ 25%) stenosis (34 lesions). Forty-seven coronary plaques were found in 33 patients (25%), including 7 calcified plaques in 7 patients (5%), 34 noncalcified plaques in 27 patients (20%), and 6 partially calcified plaques in 5 patients (4%). Patients with small calcifications had a significantly higher prevalence of noncalcified or partially calcified plaques (83% vs 14%; p < 0.001) and obstructive stenosis (33% vs 5.2%; p < 0.001) compared to those without small calcifications. The addition of small calcifications to the coronary risk factors when diagnosing stenosis significantly improved the diagnostic value. Conclusion: Small calcifications detected by thin-slice 0.5-mm reconstruction are useful for distinguishing coronary atherosclerotic lesions in patients with zero CAC scores from conventional CT reconstruction.
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Affiliation(s)
- Yoji Urabe
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences
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Qi L, Wu SY, Meinel FG, Zhou CS, Wang QQ, McQuiston AD, Ji XM, Schoepf UJ, Lu GM, Zhang LJ. Prospectively ECG-triggered high-pitch 80 kVp coronary computed tomography angiography with 30 mL of 270 mg I/mL contrast material and iterative reconstruction. Acta Radiol 2016; 57:287-94. [PMID: 26091686 DOI: 10.1177/0284185115590433] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 05/10/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND The smallest diagnostically appropriate amount of contrast medium should be used in coronary computed tomography angiography (CCTA). PURPOSE To investigate the feasibility of prospectively ECG-triggered high-pitch CCTA using 30 mL of 270 mg I/mL contrast material, 80 kVp, and iterative reconstruction (IR). MATERIAL AND METHODS Eighty-two consecutive patients underwent CCTA with a prospectively ECG-triggered high-pitch protocol. Forty-three patients were examined at 100 kVp with filtered back projection after 60 mL of 370 mg I/mL contrast material was administered. Another 39 patients were examined at 80 kVp with IR after 30 mL of 270 mg I/mL contrast material was administered. Subjective and objective image quality was evaluated for each patient. Radiation doses were estimated and compared. RESULTS Mean attenuation, noise and signal-to-noise ratio in 80 kVp group were significantly lower than in 100 kVp group (all P < 0.05), while there was no significant difference in contrast-to-noise ratio (CNR), although a trend towards a lower CNR in 80 kVp group was observed (P = 0.099). The subjective image quality between the two groups was not significantly different (P = 0.905). The effective dose and iodine load in 80 kVp group were reduced by 54% and 64%, respectively, when compared with 100 kVp group. CONCLUSION Prospectively ECG-triggered high-pitch CCTA at 80 kVp with 30 mL of 270 mg I/mL contrast material and IR is feasible for patients with BMI less than 25 kg/m(2) and reduces radiation dose and iodine load when compared with the standard CCTA protocol.
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Affiliation(s)
- Li Qi
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, PR China
| | | | - Felix G Meinel
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Chang Sheng Zhou
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, PR China
| | - Qing Qing Wang
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, PR China
| | - Andrew D McQuiston
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Xue Man Ji
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, PR China
| | - U Joseph Schoepf
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Guang Ming Lu
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, PR China
| | - Long Jiang Zhang
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, PR China
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Image Quality and Radiation Dose of CT Coronary Angiography with Automatic Tube Current Modulation and Strong Adaptive Iterative Dose Reduction Three-Dimensional (AIDR3D). PLoS One 2015; 10:e0142185. [PMID: 26599111 PMCID: PMC4657884 DOI: 10.1371/journal.pone.0142185] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 10/19/2015] [Indexed: 02/07/2023] Open
Abstract
Purpose To investigate image quality and radiation dose of CT coronary angiography (CTCA) scanned using automatic tube current modulation (ATCM) and reconstructed by strong adaptive iterative dose reduction three-dimensional (AIDR3D). Methods Eighty-four consecutive CTCA patients were collected for the study. All patients were scanned using ATCM and reconstructed with strong AIDR3D, standard AIDR3D and filtered back-projection (FBP) respectively. Two radiologists who were blinded to the patients' clinical data and reconstruction methods evaluated image quality. Quantitative image quality evaluation included image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). To evaluate image quality qualitatively, coronary artery is classified into 15 segments based on the modified guidelines of the American Heart Association. Qualitative image quality was evaluated using a 4-point scale. Radiation dose was calculated based on dose-length product. Results Compared with standard AIDR3D, strong AIDR3D had lower image noise, higher SNR and CNR, their differences were all statistically significant (P<0.05); compared with FBP, strong AIDR3D decreased image noise by 46.1%, increased SNR by 84.7%, and improved CNR by 82.2%, their differences were all statistically significant (P<0.05 or 0.001). Segments with diagnostic image quality for strong AIDR3D were 336 (100.0%), 486 (96.4%), and 394 (93.8%) in proximal, middle, and distal part respectively; whereas those for standard AIDR3D were 332 (98.8%), 472 (93.7%), 378 (90.0%), respectively; those for FBP were 217 (64.6%), 173 (34.3%), 114 (27.1%), respectively; total segments with diagnostic image quality in strong AIDR3D (1216, 96.5%) were higher than those of standard AIDR3D (1182, 93.8%) and FBP (504, 40.0%); the differences between strong AIDR3D and standard AIDR3D, strong AIDR3D and FBP were all statistically significant (P<0.05 or 0.001). The mean effective radiation dose was (2.55±1.21) mSv. Conclusion Compared with standard AIDR3D and FBP, CTCA with ATCM and strong AIDR3D could significantly improve both quantitative and qualitative image quality.
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Mirsadraee S, Weir N, Connolly S, Murchison J, Reid J, Hirani N, Connell M, van Beek E. Feasibility of radiation dose reduction using AIDR-3D in dynamic pulmonary CT perfusion. Clin Radiol 2015; 70:844-51. [DOI: 10.1016/j.crad.2015.04.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/20/2015] [Accepted: 04/17/2015] [Indexed: 01/05/2023]
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Geyer LL, Schoepf UJ, Meinel FG, Nance JW, Bastarrika G, Leipsic JA, Paul NS, Rengo M, Laghi A, De Cecco CN. State of the Art: Iterative CT Reconstruction Techniques. Radiology 2015. [PMID: 26203706 DOI: 10.1148/radiol.2015132766] [Citation(s) in RCA: 395] [Impact Index Per Article: 43.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Lucas L Geyer
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - U Joseph Schoepf
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Felix G Meinel
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - John W Nance
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Gorka Bastarrika
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Jonathon A Leipsic
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Narinder S Paul
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Marco Rengo
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Andrea Laghi
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Carlo N De Cecco
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
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The Impact of Different Levels of Adaptive Iterative Dose Reduction 3D on Image Quality of 320-Row Coronary CT Angiography: A Clinical Trial. PLoS One 2015; 10:e0125943. [PMID: 25945924 PMCID: PMC4422621 DOI: 10.1371/journal.pone.0125943] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 03/22/2015] [Indexed: 11/19/2022] Open
Abstract
Purpose The aim of this study was the systematic image quality evaluation of coronary CT angiography (CTA), reconstructed with the 3 different levels of adaptive iterative dose reduction (AIDR 3D) and compared to filtered back projection (FBP) with quantum denoising software (QDS). Methods Standard-dose CTA raw data of 30 patients with mean radiation dose of 3.2 ± 2.6 mSv were reconstructed using AIDR 3D mild, standard, strong and compared to FBP/QDS. Objective image quality comparison (signal, noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), contour sharpness) was performed using 21 measurement points per patient, including measurements in each coronary artery from proximal to distal. Results Objective image quality parameters improved with increasing levels of AIDR 3D. Noise was lowest in AIDR 3D strong (p≤0.001 at 20/21 measurement points; compared with FBP/QDS). Signal and contour sharpness analysis showed no significant difference between the reconstruction algorithms for most measurement points. Best coronary SNR and CNR were achieved with AIDR 3D strong. No loss of SNR or CNR in distal segments was seen with AIDR 3D as compared to FBP. Conclusions On standard-dose coronary CTA images, AIDR 3D strong showed higher objective image quality than FBP/QDS without reducing contour sharpness. Trial Registration Clinicaltrials.gov NCT00967876
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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: 3.8] [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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Utsunomiya D, Oda S, Yuki H, Yamamuro M, Tsujita K, Funama Y, Yoshida M, Kidoh M, Ogawa H, Yamashita Y. Evaluation of appropriateness of second-generation 320-row computed tomography for coronary artery disease. SPRINGERPLUS 2015; 4:109. [PMID: 25793150 PMCID: PMC4359191 DOI: 10.1186/s40064-015-0866-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 01/30/2015] [Indexed: 11/10/2022]
Abstract
The influence of newer-generation CT on the clinical indications and appropriateness of cardiac CT has not been adequately surveyed. We aimed to evaluate the distribution of appropriateness ratings and test the outcomes of cardiac CT using second-generation 320-row CT. The 2010 appropriate use criteria (AUC) were applied at the point of service to a consecutive series of patients (N = 309) who were referred for cardiac CT. The CT indication was determined based on interviews and medical records. The proportions of patients within the categories of appropriate (A), uncertain (U), inappropriate (I), and not covered were described. The prevalence of significant coronary artery disease (CAD) was also compared among the categories. The proportions were 49.2%, 25.9%, and 20.7% for appropriate, uncertain, and inappropriate indication, respectively. The indication that was not covered was only 4.2%. Significant CAD was more frequently observed for uncertain- than appropriate indication (42.5% vs 27.6%; P = 0.03), although the number of significant stenosed segments was not different (P = 0.13). The recent advancement of cardiac CT increased the proportion of uncertain scans, which were associated with a high prevalence of significant CAD.
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Affiliation(s)
- Daisuke Utsunomiya
- Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, 860-8556 Kumamoto-shi, Kumamoto, Chuo-ku Japan
| | - Seitaro Oda
- Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, 860-8556 Kumamoto-shi, Kumamoto, Chuo-ku Japan
| | - Hideaki Yuki
- Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, 860-8556 Kumamoto-shi, Kumamoto, Chuo-ku Japan
| | - Megumi Yamamuro
- Cardiovascular Medicine, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Kenichi Tsujita
- Cardiovascular Medicine, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Yoshinori Funama
- Medical Physics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Morikatsu Yoshida
- Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, 860-8556 Kumamoto-shi, Kumamoto, Chuo-ku Japan
| | - Masafumi Kidoh
- Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, 860-8556 Kumamoto-shi, Kumamoto, Chuo-ku Japan
| | - Hisao Ogawa
- Cardiovascular Medicine, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Yasuyuki Yamashita
- Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, 860-8556 Kumamoto-shi, Kumamoto, Chuo-ku Japan
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Liao YL, Chen YS, Lai NK, Chuang KS, Tsai HY. Overbeaming and overlapping of volume-scan CT with tube current modulation in a 320-detector row CT scanner. Radiat Phys Chem Oxf Engl 1993 2014. [DOI: 10.1016/j.radphyschem.2013.12.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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A new technique for noise reduction at coronary CT angiography with multi-phase data-averaging and non-rigid image registration. Eur Radiol 2014; 25:41-8. [PMID: 25113650 DOI: 10.1007/s00330-014-3381-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Revised: 07/09/2014] [Accepted: 07/29/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVES To investigate the feasibility of a newly developed noise reduction technique at coronary CT angiography (CTA) that uses multi-phase data-averaging and non-rigid image registration. METHODS Sixty-five patients underwent coronary CTA with prospective ECG-triggering. The range of the phase window was set at 70-80% of the R-R interval. First, three sets of consecutive volume data at 70%, 75% and 80% of the R-R interval were prepared. Second, we applied non-rigid registration to align the 70% and 80% images to the 75% image. Finally, we performed weighted averaging of the three images and generated a de-noised image. The image noise and contrast-to-noise ratio (CNR) in the proximal coronary arteries between the conventional 75% and the de-noised images were compared. Two radiologists evaluated the image quality using a 5-point scale (1, poor; 5, excellent). RESULTS On de-noised images, mean image noise was significantly lower than on conventional 75% images (18.3 HU ± 2.6 vs. 23.0 HU ± 3.3, P < 0.01) and the CNR was significantly higher (P < 0.01). The mean image quality score for conventional 75% and de-noised images was 3.9 and 4.4, respectively (P < 0.01). CONCLUSIONS Our method reduces image noise and improves image quality at coronary CTA. KEY POINTS • We introduce a new method for image noise reduction at cardiac CT. • Multiple data acquisitions of an object and their averaging yield lower noise. • Our method uses multi-phase images reconstructed from unused redundant imaging data. • It reduces image noise by averaging multi-phase images transformed by non-rigid registration. • This method achieves a 20% image noise reduction at cardiac CT.
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Funama Y, Utsunomiya D, Taguchi K, Oda S, Shimonobo T, Yamashita Y. Automatic exposure control at single- and dual-heartbeat CTCA on a 320-MDCT volume scanner: Effect of heart rate, exposure phase window setting, and reconstruction algorithm. Phys Med 2014; 30:385-90. [DOI: 10.1016/j.ejmp.2013.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 10/16/2013] [Accepted: 10/22/2013] [Indexed: 12/27/2022] Open
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Kim M, Lee JM, Yoon JH, Son H, Choi JW, Han JK, Choi BI. Adaptive iterative dose reduction algorithm in CT: effect on image quality compared with filtered back projection in body phantoms of different sizes. Korean J Radiol 2014; 15:195-204. [PMID: 24644409 PMCID: PMC3955785 DOI: 10.3348/kjr.2014.15.2.195] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 01/14/2014] [Indexed: 11/15/2022] Open
Abstract
Objective To evaluate the impact of the adaptive iterative dose reduction (AIDR) three-dimensional (3D) algorithm in CT on noise reduction and the image quality compared to the filtered back projection (FBP) algorithm and to compare the effectiveness of AIDR 3D on noise reduction according to the body habitus using phantoms with different sizes. Materials and Methods Three different-sized phantoms with diameters of 24 cm, 30 cm, and 40 cm were built up using the American College of Radiology CT accreditation phantom and layers of pork belly fat. Each phantom was scanned eight times using different mAs. Images were reconstructed using the FBP and three different strengths of the AIDR 3D. The image noise, the contrast-to-noise ratio (CNR) and the signal-to-noise ratio (SNR) of the phantom were assessed. Two radiologists assessed the image quality of the 4 image sets in consensus. The effectiveness of AIDR 3D on noise reduction compared with FBP were also compared according to the phantom sizes. Results Adaptive iterative dose reduction 3D significantly reduced the image noise compared with FBP and enhanced the SNR and CNR (p < 0.05) with improved image quality (p < 0.05). When a stronger reconstruction algorithm was used, greater increase of SNR and CNR as well as noise reduction was achieved (p < 0.05). The noise reduction effect of AIDR 3D was significantly greater in the 40-cm phantom than in the 24-cm or 30-cm phantoms (p < 0.05). Conclusion The AIDR 3D algorithm is effective to reduce the image noise as well as to improve the image-quality parameters compared by FBP algorithm, and its effectiveness may increase as the phantom size increases.
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Affiliation(s)
- Milim Kim
- College of Medicine, Seoul National University, Seoul 110-744, Korea
| | - Jeong Min Lee
- Department of Radiology, Seoul National University Hospital, Seoul 110-744, Korea. ; Research Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul 110-744, Korea
| | - Jeong Hee Yoon
- Department of Radiology, Seoul National University Hospital, Seoul 110-744, Korea
| | - Hyoshin Son
- College of Medicine, Seoul National University, Seoul 110-744, Korea
| | - Jin Woo Choi
- Department of Radiology, Seoul National University Hospital, Seoul 110-744, Korea
| | - Joon Koo Han
- Department of Radiology, Seoul National University Hospital, Seoul 110-744, Korea. ; Research Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul 110-744, Korea
| | - Byung Ihn Choi
- Department of Radiology, Seoul National University Hospital, Seoul 110-744, Korea. ; Research Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul 110-744, Korea
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Lee SK, Jung JI, Ko JM, Lee HG. Image quality and radiation exposure of coronary CT angiography in patients after coronary artery bypass graft surgery: influence of imaging direction with 64-slice dual-source CT. J Cardiovasc Comput Tomogr 2014; 8:124-30. [PMID: 24661825 DOI: 10.1016/j.jcct.2013.12.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 12/23/2013] [Accepted: 12/26/2013] [Indexed: 01/25/2023]
Abstract
BACKGROUND The evaluation of native coronary arteries (NCAs) as well as coronary artery bypass graft (CABG) patency after surgery is essential. However, NCAs are often blurred in the craniocaudal scan direction because of long scan time with 64-slice CT. OBJECTIVE The purpose of the study was to determine the effect of scan direction on image quality and radiation exposure in assessment of NCAs and CABGs. METHODS Retrospective analysis of 191 consecutive individuals undergoing coronary CT angiography to evaluate CABG patency using 64-slice dual source CT. A retrospectively ECG gated spiral acquisition protocol with ECG based tube current modulation and automatic adjustment of tube current to a reference of 320 mAs ("CareDose 4D") was used. Tube current was 120 kVp. Scan direction was either cranio-caudal (CRC, n = 98) or caudo-cranial (CRC, n = 93) and the scan volume covered the entire course of all bypass grafts. Independent investigators determined quantitative image quality of the coronary arteries by evaluating contrast-to-noise ratio (CNR), radiation exposure by comparing the effective dose, and qualitative image quality through a 5 point rating scale. RESULTS Quantitative image quality was not significantly different for the two groups except for the CNR of the right coronary artery which was significantly higher in patients with caudio-cranial scan direction (P = .0007). The qualitative image quality of the CaC group also was better for both NCAs and CABGs (P = .002 for NCAs and <.001 for CABGs), mostly because of the lower frequency of respiration artifacts on coronary arteries of the CaC group (P = .005). As an effect of automatic tube current adjustment, radiation dose was lower in patients with caudo-cranial scan direction (6.8 mSv vs. 9.6 mSv, p < 0.0001). CONCLUSION In patients with coronary bypass grafts imaged by 64-slice dual source CT with spiral acquisition and automated tube current adjustment, a caudo-cranial scan direction results in improved image quality and reduced radiation exposure.
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Affiliation(s)
- Seul Ki Lee
- Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222, Banpo-daero, Seocho-gu, Seoul, 137-701, South Korea
| | - Jung Im Jung
- Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222, Banpo-daero, Seocho-gu, Seoul, 137-701, South Korea.
| | - Jeong Min Ko
- Department of Radiology, St. Vincent Hospital, College of Medicine, The Catholic University of Korea, 93, Jungbu-daero, Paldal-gu, Suwon, Gyeonggi-do, 442-723, South Korea
| | - Hae Giu Lee
- Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222, Banpo-daero, Seocho-gu, Seoul, 137-701, South Korea
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Staniak HL, Sharovsky R, Pereira AC, de Castro CC, Benseñor IM, Lotufo PA, Bittencourt MS. Subcutaneous tissue thickness is an independent predictor of image noise in cardiac CT. Arq Bras Cardiol 2014; 102:86-92. [PMID: 24173136 PMCID: PMC3987400 DOI: 10.5935/abc.20130215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 06/27/2013] [Accepted: 08/07/2013] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Few data on the definition of simple robust parameters to predict image noise in cardiac computed tomography (CT) exist. OBJECTIVES To evaluate the value of a simple measure of subcutaneous tissue as a predictor of image noise in cardiac CT. METHODS 86 patients underwent prospective ECG-gated coronary computed tomographic angiography (CTA) and coronary calcium scoring (CAC) with 120 kV and 150 mA. The image quality was objectively measured by the image noise in the aorta in the cardiac CTA, and low noise was defined as noise < 30 HU. The chest anteroposterior diameter and lateral width, the image noise in the aorta and the skin-sternum (SS) thickness were measured as predictors of cardiac CTA noise. The association of the predictors and image noise was performed by using Pearson correlation. RESULTS The mean radiation dose was 3.5 ± 1.5 mSv. The mean image noise in CT was 36.3 ± 8.5 HU, and the mean image noise in non-contrast scan was 17.7 ± 4.4 HU. All predictors were independently associated with cardiac CTA noise. The best predictors were SS thickness, with a correlation of 0.70 (p < 0.001), and noise in the non-contrast images, with a correlation of 0.73 (p < 0.001). When evaluating the ability to predict low image noise, the areas under the ROC curve for the non-contrast noise and for the SS thickness were 0.837 and 0.864, respectively. CONCLUSION Both SS thickness and CAC noise are simple accurate predictors of cardiac CTA image noise. Those parameters can be incorporated in standard CT protocols to adequately adjust radiation exposure.
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Affiliation(s)
| | - Rodolfo Sharovsky
- Hospital Universitário - Universidade de São Paulo, São Paulo, SP -
Brazil
| | | | - Cláudio Campi de Castro
- Hospital Universitário - Universidade de São Paulo, São Paulo, SP -
Brazil
- Faculdade de Medicina - Universidade de São Paulo, São Paulo, SP -
Brazil
| | - Isabela M. Benseñor
- Hospital Universitário - Universidade de São Paulo, São Paulo, SP -
Brazil
- Faculdade de Medicina - Universidade de São Paulo, São Paulo, SP -
Brazil
| | - Paulo A. Lotufo
- Hospital Universitário - Universidade de São Paulo, São Paulo, SP -
Brazil
- Faculdade de Medicina - Universidade de São Paulo, São Paulo, SP -
Brazil
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Images Acquired Using 320-MDCT With Adaptive Iterative Dose Reduction With Wide-Volume Acquisition: Visual Evaluation of Image Quality by 10 Radiologists Using an Abdominal Phantom. AJR Am J Roentgenol 2014; 202:2-12. [DOI: 10.2214/ajr.12.10364] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Gervaise A, Osemont B, Louis M, Lecocq S, Teixeira P, Blum A. Standard dose versus low-dose abdominal and pelvic CT: Comparison between filtered back projection versus adaptive iterative dose reduction 3D. Diagn Interv Imaging 2014; 95:47-53. [DOI: 10.1016/j.diii.2013.05.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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CT angiography of the head-and-neck vessels acquired with low tube voltage, low iodine, and iterative image reconstruction: clinical evaluation of radiation dose and image quality. PLoS One 2013; 8:e81486. [PMID: 24339936 PMCID: PMC3855260 DOI: 10.1371/journal.pone.0081486] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 10/21/2013] [Indexed: 02/06/2023] Open
Abstract
Objectives We aimed to assess the effectiveness and feasibility of head-and-neck Computed Tomography Angiography (CTA) with low tube voltage and low concentration contrast media combined with iterative reconstruction algorithm. Methods 92 patients were randomly divided into group A and B: patients in group A received a conventional scan with 120 kVp and contrast media of 320 mgI/ml. Patients in group B, 80 kVp and contrast media of 270 mgI/ml were used along with iterative reconstruction algorithm techniques. Image quality, radiation dose and the effectively consumed iodine amount between two groups were analyzed and compared. Results Image quality of CTA of head-and-neck vessels obtained from patients in group B was significantly improved quantitatively and qualitatively. In addition, CT attenuation values in group B were also significantly higher than that in group A (p<0.001). Furthermore, compared with the protocol whereby 120 kVp and 320 mgI/dl were administrated, the mean radiation dose and consumed iodine amount in protocol B were also reduced by 50% and 15.6%, respectively (p<0.001). Conclusions With the help of iterative reconstruction algorithm techniques, the head-and-neck CTA with diagnostic quality can be adequately acquired with low tube voltage and low concentration contrast media. This method could be potentially extended to include any part of the body to reduce the risks related to ionizing radiation.
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Determining the Radiation Dose Reduction Potential for Coronary Calcium Scanning With Computed Tomography. Invest Radiol 2013; 48:857-62. [DOI: 10.1097/rli.0b013e31829e3932] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Chen CM, Chu SY, Hsu MY, Liao YL, Tsai HY. Low-tube-voltage (80 kVp) CT aortography using 320-row volume CT with adaptive iterative reconstruction: lower contrast medium and radiation dose. Eur Radiol 2013; 24:460-8. [PMID: 24081645 DOI: 10.1007/s00330-013-3027-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 08/14/2013] [Accepted: 09/08/2013] [Indexed: 01/03/2023]
Abstract
OBJECTIVES To evaluate CT aortography at reduced tube voltage and contrast medium dose while maintaining image quality through iterative reconstruction (IR). METHODS The Institutional Review Board approved a prospective study of 48 patients who underwent follow-up CT aortography. We performed intra-individual comparisons of arterial phase images using 120 kVp (standard tube voltage) and 80 kVp (low tube voltage). Low-tube-voltage imaging was performed on a 320-detector CT with IR following injection of 40 ml of contrast medium. We assessed aortic attenuation, aortic attenuation gradient, image noise, contrast-to-noise ratio (CNR), volume CT dose index (CTDIvol), and figure of merit (FOM) of image noise and CNR. Two readers assessed images for diagnostic quality, image noise, and artefacts. RESULTS The low-tube-voltage protocol showed 23-31% higher mean aortic attenuation and image noise (both P < 0.01) than the standard-tube-voltage protocol, but no significant difference in the CNR and aortic attenuation gradients. The low-tube-voltage protocol showed a 48% reduction in CTDIvol and an 80% increase in FOM of CNR. Subjective diagnostic quality was similar for both protocols, but low-tube-voltage images showed greater image noise (P = 0.01). CONCLUSIONS Application of IR to an 80-kVp CT aortography protocol allows radiation dose and contrast medium reduction without affecting image quality. KEY POINTS • CT aortography at 80 kVp allows a significant reduction in radiation dose. • Addition of iterative reconstruction reduces image noise and improves image quality. • The injected contrast medium dose can be substantially reduced at 80 kVp. • Aortic enhancement is uniform despite a reduced volume of contrast medium.
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Affiliation(s)
- Chien-Ming Chen
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital Linkou, College of Medicine, Chang Gung University, Taoyuan, Taiwan
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Nance JW, Schoepf UJ, Ebersberger U. The Role of Iterative Reconstruction Techniques in Cardiovascular CT. CURRENT RADIOLOGY REPORTS 2013. [DOI: 10.1007/s40134-013-0023-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Williams MC, Weir NW, Mirsadraee S, Millar F, Baird A, Minns F, Uren NG, McKillop G, Bull RK, van Beek EJR, Reid JH, Newby DE. Iterative reconstruction and individualized automatic tube current selection reduce radiation dose while maintaining image quality in 320-multidetector computed tomography coronary angiography. Clin Radiol 2013; 68:e570-7. [PMID: 23838086 PMCID: PMC3807656 DOI: 10.1016/j.crad.2013.05.098] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 05/13/2013] [Accepted: 05/29/2013] [Indexed: 01/22/2023]
Abstract
AIM To assess the effect of two iterative reconstruction algorithms (AIDR and AIDR3D) and individualized automatic tube current selection on radiation dose and image quality in computed tomography coronary angiography (CTCA). MATERIALS AND METHODS In a single-centre cohort study, 942 patients underwent electrocardiogram-gated CTCA using a 320-multidetector CT system. Images from group 1 (n = 228) were reconstructed with a filtered back projection algorithm (Quantum Denoising Software, QDS+). Iterative reconstruction was used for group 2 (AIDR, n = 379) and group 3 (AIDR3D, n = 335). Tube current was selected based on body mass index (BMI) for groups 1 and 2, and selected automatically based on scout image attenuation for group 3. Subjective image quality was graded on a four-point scale (1 = excellent, 4 = non-diagnostic). RESULTS There were no differences in age (p = 0.975), body mass index (p = 0.435), or heart rate (p = 0.746) between the groups. Image quality improved with iterative reconstruction and automatic tube current selection [1.3 (95% confidence intervals (CI): 1.2-1.4), 1.2 (1.1-1.2) and 1.1 (1-1.2) respectively; p < 0.001] and radiation dose decreased [274 (260-290), 242 (230-253) and 168 (156-180) mGy cm, respectively; p < 0.001]. CONCLUSION The application of the latest iterative reconstruction algorithm and individualized automatic tube current selection can substantially reduce radiation dose whilst improving image quality in CTCA.
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Affiliation(s)
- M C Williams
- University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Edinburgh, UK.
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Schultz K, George E, Mullen KM, Steigner ML, Mitsouras D, Bueno EM, Pomahac B, Rybicki FJ, Kumamaru KK. Reduced radiation exposure for face transplant surgical planning computed tomography angiography. PLoS One 2013; 8:e63079. [PMID: 23638180 PMCID: PMC3637203 DOI: 10.1371/journal.pone.0063079] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 03/28/2013] [Indexed: 12/21/2022] Open
Abstract
Objective To test the hypothesis that wide area detector face transplant surgical planning CT angiograms with simulated lower radiation dose and iterative reconstruction (AIDR3D) are comparable in image quality to those with standard tube current and filtered back projection (FBP) reconstruction. Materials and Methods The sinograms from 320-detector row CT angiography of four clinical candidates for face transplantation were processed utilizing standard FBP, FBP with simulated 75, 62, and 50% tube current, and AIDR3D with corresponding dose reduction. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured at muscle, fat, artery, and vein. Image quality for each reconstruction strategy was assessed by two independent readers using a 4-point scale. Results Compared to FBP, the median SNR and CNR for AIDR3D images were higher at all sites for all 4 different tube currents. The AIDR3D with simulated 50% tube current achieved comparable SNR and CNR to FBP with standard dose (median muscle SNR: 5.77 vs. 6.23; fat SNR: 6.40 vs. 5.75; artery SNR: 43.8 vs. 45.0; vein SNR: 54.9 vs. 55.7; artery CNR: 38.1 vs. 38.6; vein CNR: 49.0 vs. 48.7; all p-values >0.19). The interobserver agreement in the image quality score was good (weighted κ = 0.7). The overall score and the scores for smaller arteries were significantly lower when FBP with 50% dose reduction was used. The AIDR3D reconstruction images with 4 different simulated doses achieved a mean score ranging from 3.68 to 3.82 that were comparable to the scores from images reconstructed using FBP with original dose (3.68–3.77). Conclusions Simulated radiation dose reduction applied to clinical CT angiography for face transplant planning suggests that AIDR3D allows for a 50% reduction in radiation dose, as compared to FBP, while preserving image quality.
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Affiliation(s)
- Kurt Schultz
- Toshiba Medical Research Institute USA, Vernon Hills, Illinois, United States of America
| | - Elizabeth George
- Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Katherine M. Mullen
- Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Michael L. Steigner
- Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Dimitrios Mitsouras
- Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ericka M. Bueno
- Department of Surgery, Division of Plastic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Bohdan Pomahac
- Department of Surgery, Division of Plastic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Frank J. Rybicki
- Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| | - Kanako K. Kumamaru
- Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
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Kwan AC, Cater G, Vargas J, Bluemke DA. Beyond Coronary Stenosis: Coronary Computed Tomographic Angiography for the Assessment of Atherosclerotic Plaque Burden. CURRENT CARDIOVASCULAR IMAGING REPORTS 2013; 6:89-101. [PMID: 23524381 PMCID: PMC3601491 DOI: 10.1007/s12410-012-9183-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Coronary computed tomographic angiography (CCTA) is emerging as a key non-invasive method for assessing cardiovascular risk by measurement of coronary stenosis and coronary artery calcium (CAC). New advancements in CCTA technology have led to the ability to directly identify and quantify the so-called "vulnerable" plaques that have features of positive remodeling and low density components. In addition, CCTA presents a new opportunity for noninvasive measurement of total coronary plaque burden that has not previously been available. The use of CCTA needs also to be balanced by its risks and, in particular, the associated radiation exposure. We review current uses of CCTA, CCTA's ability to measure plaque quantity and characteristics, and new developments in risk stratification and CCTA technology. CCTA represents a quickly developing field that will play a growing role in the non-invasive management of cardiovascular disease.
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Affiliation(s)
- Alan C Kwan
- Radiology and Imaging Sciences - National Institutes of Health Clinical Center, Bethesda, MD, USA
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Chen MY, Steigner ML, Leung SW, Kumamaru KK, Schultz K, Mather RT, Arai AE, Rybicki FJ. Simulated 50 % radiation dose reduction in coronary CT angiography using adaptive iterative dose reduction in three-dimensions (AIDR3D). Int J Cardiovasc Imaging 2013; 29:1167-75. [PMID: 23404384 PMCID: PMC3701132 DOI: 10.1007/s10554-013-0190-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 01/28/2013] [Indexed: 11/06/2022]
Abstract
To compare the image quality of coronary CT angiography (CTA) studies between standard filtered back projection (FBP) and adaptive iterative dose reduction in three-dimensions (AIDR3D) reconstruction using CT noise additional software to simulate reduced radiation exposure. Images from 93 consecutive clinical coronary CTA studies were processed utilizing standard FBP, FBP with 50 % simulated dose reduction (FBP50 %), and AIDR3D with simulated 50 % dose reduction (AIDR50 %). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured within 5 regions-of-interest, and image quality for each reconstruction strategy was assessed by two independent readers using a 4-point scale. Compared to FBP, the SNR measured from the AIDR50 % images was similar or higher (airway: 38.3 ± 12.7 vs. 38.5 ± 14.5, p = 0.81, fat: 5.5 ± 1.9 vs. 5.4 ± 2.0, p = 0.20, muscle: 3.2 ± 1.2 vs. 3.1 ± 1.3, p = 0.38, aorta: 22.6 ± 9.4 vs. 20.2 ± 9.7, p < 0.0001, liver: 2.7 ± 1.0 vs. 2.3 ± 1.1, p < 0.0001), while the SNR of the FBP50 % images were all lower (p values < 0.0001). The CNR measured from AIDR50 % images was also higher than that from the FBP images for the aorta relative to muscle (20.5 ± 9.0 vs. 18.3 ± 9.2, p < 0.0001). The interobserver agreement in the image quality score was excellent (κ = 0.82). The quality score was significantly higher for the AIDR50 % images compared to the FBP images (3.6 ± 0.6 vs. 3.3 ± 0.7, p = 0.004). Simulated radiation dose reduction applied to clinical coronary CTA images suggests that a 50 % reduction in radiation dose can be achieved with adaptive iterative dose reduction software with image quality that is at least comparable to images acquired at standard radiation exposure and reconstructed with filtered back projection.
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Affiliation(s)
- Marcus Y Chen
- Advanced Cardiovascular Imaging Laboratory, Cardiovascular and Pulmonary Branch, Department of Health and Human Services, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
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Hosch W, Hofmann NP, Mueller D, Iwan J, Gitsioudis G, Siebert S, Giannitsis E, Kauczor HU, Katus HA, Korosoglou G. Body mass index-adapted prospective coronary computed tomography angiography. Determining the lowest limit for diagnostic purposes. Eur J Radiol 2013; 82:e232-9. [PMID: 23332891 DOI: 10.1016/j.ejrad.2012.12.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Revised: 12/17/2012] [Accepted: 12/22/2012] [Indexed: 10/27/2022]
Abstract
PURPOSE To investigate the value of 4 different protocols for prospectively triggered 256-slice coronary computed tomography angiography (coronary CTA). METHODS Two hundred and ten patients underwent prospectively triggered coronary CTA for suspected or known coronary artery disease (CAD). Patients with heart rate >75 bps before the scan despite ß-blocker administration and with arrhythmia were excluded. From January to September 2010, 60 patients underwent coronary CTA using a non-tailored protocol (120 kV; 200 mAs) and served as our 'control' group. From September 2010 to April 2012, based on the body mass index (BMI) of the examined patients (BMI subgroups of <25; 25-28; 28-30, and ≥ 30 kg/m(2)) current tube voltage and tube current were: (1) slightly, (2) moderately or (3) strongly reduced, resulting into the 3 following BMI-adapted acquisition groups: (1) a 'standard' (100/120 kV; 100-200 mAs; n=50), 2) a 'low dose' (100/120 kV; 75-150 mAs; n=50), and 3) an 'ultra-low dose' (100/120 kV; 50-100 mAs; n=50) protocol. RESULTS Patients examined using the non-tailored protocol exhibited the highest radiation exposure (3.2 ± 0.4 mSv), followed by the standard (1.6 ± 0.7 mSv), low-dose (1.2 ± 0.6 mSv) and ultra-low dose protocol (0.7 ± 0.3 mSv) (radiation savings of 50%, 63% and 78% respectively). Overall image quality was similar with standard dose (1.9 ± 0.6) and low-dose (2.0 ± 0.5) compared to the non-tailored group (1.9 ± 0.5) (p=NS for all). In the ultra-low dose group however, image quality was significant reduced (2.7 ± 0.6), p<0.05 versus all other groups). CONCLUSION Using BMI-adapted low dose acquisitions image quality can be maintained with simultaneous radiation savings of ∼65% (dose of ∼1 mSv). This appears to be the lower limit for diagnostic coronary CTA, whereas ultra-low dose acquisitions result in significant image degradation.
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Affiliation(s)
- Waldemar Hosch
- University of Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg, Germany.
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Dose reduction in chest CT: Comparison of the adaptive iterative dose reduction 3D, adaptive iterative dose reduction, and filtered back projection reconstruction techniques. Eur J Radiol 2012; 81:4185-95. [PMID: 22883532 DOI: 10.1016/j.ejrad.2012.07.013] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 07/10/2012] [Accepted: 07/11/2012] [Indexed: 11/20/2022]
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