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Camoni L, Santos A, Luporsi M, Grilo A, Pietrzak A, Gear J, Zucchetta P, Bar-Sever Z. EANM procedural recommendations for managing the paediatric patient in diagnostic nuclear medicine. Eur J Nucl Med Mol Imaging 2023; 50:3862-3879. [PMID: 37555902 PMCID: PMC10611649 DOI: 10.1007/s00259-023-06357-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/23/2023] [Indexed: 08/10/2023]
Abstract
PURPOSE The manuscript aims to characterize the principles of best practice in performing nuclear medicine procedures in paediatric patients. The paper describes all necessary technical skills that should be developed by the healthcare professionals to ensure the best possible care in paediatric patients, as it is particularly challenging due to psychological and physical conditions of children. METHODS We performed a comprehensive literature review to establish the most relevant elements of nuclear medicine studies in paediatric patients. We focused the attention to the technical aspects of the study, such as patient preparation, imaging protocols, and immobilization techniques, that adhere to best practice principles. Furthermore, we considered the psychological elements of working with children, including comforting and distraction strategies. RESULTS The extensive literature review combined with practical conclusions and recommendations presented and explained by the authors summarizes the most important principles of the care for paediatric patient in the nuclear medicine field. CONCLUSION Nuclear medicine applied to the paediatric patient is a very special and challenging area, requiring proper education and experience in order to be performed at the highest level and with the maximum safety for the child.
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Affiliation(s)
- Luca Camoni
- University of Brescia, 25123, Brescia, Italy.
- Nuclear Medicine Department, University of Brescia, ASST Spedali Civili Di Brescia, P.Le Spedali Civili 1, 25123, Brescia, Italy.
| | - Andrea Santos
- Nuclear Medicine Department, CUF Descobertas Hospital, Lisbon, Portugal
| | - Marie Luporsi
- Department of Nuclear Medicine, Institut Curie, PSL Research University, 75005, Paris, France
- LITO Laboratory INSERM U1288, Institut Curie, 91440, Orsay, France
| | - Ana Grilo
- H&TRC - Health and Technology Research Center, ESTeSL - Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal
- CICPSI, Faculdade de Psicologia, Universidade de Lisboa, Alameda da Universidade, Lisbon, Portugal
| | - Agata Pietrzak
- Electroradiology Department, Poznan University of Medical Sciences, Poznan, Poland
- Nuclear Medicine Department, Greater Poland Cancer Centre, Poznan, Poland
| | - Jonathan Gear
- Joint Department of Physics, Royal Marsden Hospital and Institute of Cancer Research, Sutton, UK
| | - Pietro Zucchetta
- Nuclear Medicine Department, Padova University Hospital, 35128, Padua, Italy
| | - Zvi Bar-Sever
- Department of Nuclear Medicine, Schneider Children's Medical Center, Tel-Aviv University, Petach Tikva, Israel
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Sato H, Fujimoto S, Tomizawa N, Inage H, Yokota T, Kudo H, Fan R, Kawamoto K, Honda Y, Kobayashi T, Minamino T, Kogure Y. Impact of a Deep Learning-based Super-resolution Image Reconstruction Technique on High-contrast Computed Tomography: A Phantom Study. Acad Radiol 2023; 30:2657-2665. [PMID: 36690564 DOI: 10.1016/j.acra.2022.12.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/17/2022] [Accepted: 12/24/2022] [Indexed: 01/23/2023]
Abstract
RATIONALE AND OBJECTIVES Deep-learning-based super-resolution image reconstruction (DLSRR) is a novel image reconstruction technique that is expected to contribute to improvement in spatial resolution as well as noise reduction through learning from high-resolution computed tomography (CT). This study aims to evaluate image quality obtained with DLSRR and assess its clinical potential. MATERIALS AND METHODS CT images of a Mercury CT 4.0 phantom were obtained using a 320-row multi-detector scanner at tube currents of 100, 200, and 300 mA. Image data were reconstructed by filtered back projection (FBP), hybrid iterative reconstruction (HIR), model-based iterative reconstruction (MBIR), deep-learning-based image reconstruction (DLR), and DLSRR at image reconstruction strength levels of mild, standard, and strong. Noise power spectrum (NPS), task transfer function (TTF), and detectability index were calculated. RESULTS The magnitude of the noise-reducing effect in comparison with FBP was in the order MBIR CONCLUSION The present results suggest that DLSRR can achieve greater noise reduction and improved spatial resolution in the high-contrast region compared with conventional DLR and iterative reconstruction techniques.
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Affiliation(s)
- Hideyuki Sato
- Department of Radiological Technology, Juntendo University Hospital, Tokyo, Japan
| | - Shinichiro Fujimoto
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
| | - Nobuo Tomizawa
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Hidekazu Inage
- Department of Radiological Technology, Juntendo University Hospital, Tokyo, Japan
| | - Takuya Yokota
- Department of Radiological Technology, Juntendo University Hospital, Tokyo, Japan
| | - Hikaru Kudo
- Department of Radiological Technology, Juntendo University Hospital, Tokyo, Japan
| | - Ruiheng Fan
- Department of Radiological Technology, Juntendo University Hospital, Tokyo, Japan
| | - Keiichi Kawamoto
- Department of Radiological Technology, Juntendo University Hospital, Tokyo, Japan
| | - Yuri Honda
- Department of Radiological Technology, Juntendo University Hospital, Tokyo, Japan
| | - Takayuki Kobayashi
- Department of Radiological Technology, Kitasato University Kitasato Institute Hospital, Tokyo, Japan
| | - Tohru Minamino
- Department of Cardiovascular Biology and Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yosuke Kogure
- Department of Radiological Technology, Juntendo University Hospital, Tokyo, Japan
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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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The Impact of Novel Reconstruction Algorithms on Calcium Scoring: Results on a Dedicated Cardiac CT Scanner. Diagnostics (Basel) 2023; 13:diagnostics13040789. [PMID: 36832277 PMCID: PMC9955482 DOI: 10.3390/diagnostics13040789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 01/27/2023] [Accepted: 02/10/2023] [Indexed: 02/22/2023] Open
Abstract
Contemporary reconstruction algorithms yield the potential of reducing radiation exposure by denoising coronary computed tomography angiography (CCTA) datasets. We aimed to assess the reliability of coronary artery calcium score (CACS) measurements with an advanced adaptive statistical iterative reconstruction (ASIR-CV) and model-based adaptive filter (MBAF2) designed for a dedicated cardiac CT scanner by comparing them to the gold-standard filtered back projection (FBP) calculations. We analyzed non-contrast coronary CT images of 404 consecutive patients undergoing clinically indicated CCTA. CACS and total calcium volume were quantified and compared on three reconstructions (FBP, ASIR-CV, and MBAF2+ASIR-CV). Patients were classified into risk categories based on CACS and the rate of reclassification was assessed. Patients were categorized into the following groups based on FBP reconstructions: 172 zero CACS, 38 minimal (1-10), 87 mild (11-100), 57 moderate (101-400), and 50 severe (400<). Overall, 19/404 (4.7%) patients were reclassified into a lower-risk group with MBAF2+ASIR-CV, while 8 additional patients (27/404, 6.7%) shifted downward when applying stand-alone ASIR-CV. The total calcium volume with FBP was 7.0 (0.0-133.25) mm3, 4.0 (0.0-103.5) mm3 using ASIR-CV, and 5.0 (0.0-118.5) mm3 with MBAF2+ASIR-CV (all comparisons p < 0.001). The concomitant use of ASIR-CV and MBAF2 may allow the reduction of noise levels while maintaining similar CACS values as FBP measurements.
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Xu J, Hu X, Zhang Y, Xu Z, Wu H, Luo K. Application of Different Levels of Advanced Modeling Iterative Reconstruction in Brain CT Scanning. Curr Med Imaging 2022; 18:1362-1368. [PMID: 35578865 DOI: 10.2174/1573405618666220516121722] [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: 11/04/2021] [Revised: 03/17/2022] [Accepted: 03/19/2022] [Indexed: 01/25/2023]
Abstract
BACKGROUND Advanced Modeling Iterative Reconstruction (ADMIRE) algorithm has five intensity levels; it is important to study which algorithm is better for brain CT scanning. OBJECTIVE The aim of the study is to compare the influence of different strength levels of ADMIRE and traditional Filtered Back Projection (FBP) on image quality in brain CT scanning. METHODS 60 patients were retrospectively selected, and the data from each of these patients' brains were reconstructed by four different reconstruction methods (FBP, ADMIRE1, ADMIRE3, and ADMIRE5). A five-point Likert Scale was implemented to evaluate the subjective image quality. Image noise, CT value of brain tissue , signal-to-noise ratio (SNR) of gray white matter, contrast-to-noise ratio (CNR), and beam hardening artifact index (AI) of the posterior fossa, were measured for evaluating the objective image quality. Finally, the differences between the subjective and objective evaluations were compared. RESULTS There were no statistical differences observed in CT values of gray matter and white matter between the four groups (all P >0.05). The image noise gradually decreased with the increase of ADMIRE algorithm level. The AI exhibited no statistical difference between the four groups (F =0.793, P =0.499), but it tended to decrease slightly with the increase of ADMIRE algorithm level. Compared to other groups (all p <0.001), the ADMIRE5 group demonstrated the best objective image quality. Nevertheless, the highest subjective score was observed in the ADMIRE3 group, which exhibited significant differences with other images (all P <0.001). CONCLUSION ADMIRE algorithm can clearly improve image quality, but it cannot significantly improve the linear sclerosis artifacts in the posterior cranial fossa. Based on the subjective evaluation of image quality, ADMIRE3 algorithm is recommended in brain CT scanning.
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Affiliation(s)
- Jun Xu
- Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.,Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, China
| | - Xiaoli Hu
- Department of Radiology, Wuhan Asian Heart Hospital, 430022 Wuhan, China
| | - Youxin Zhang
- Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.,Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, China
| | - Zhihan Xu
- Siemens Healthineers, 430022 Wuhan, China
| | - Hongying Wu
- Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.,Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, China
| | - Kun Luo
- Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.,Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, China
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Quintana-Ortí G, Chillarón M, Vidal V, Verdú G. High-performance reconstruction of CT medical images by using out-of-core methods in GPU. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 218:106725. [PMID: 35290900 DOI: 10.1016/j.cmpb.2022.106725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 02/18/2022] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND OBJECTIVE Since Computed Tomography (CT) is one of the most widely used medical imaging tests, it is essential to work on methods that reduce the radiation the patient is exposed to. Although there are several possible approaches to achieve this, we focus on reducing the exposure time through sparse sampling. With this approach, efficient algebraic methods are needed to be able to generate the images in real time, and since their computational cost is high, using high-performance computing is essential. METHODS In this paper we present a GPU (Graphics Processing Unit) software for solving the CT image reconstruction problem using the QR factorization performed with out-of-core (OOC) techniques. This implementation is optimized to reduce the data transfer times between disk, CPU, and GPU, as well as to overlap input/output operations and computations. RESULTS The experimental study shows that a block cache stored on main page-locked memory is more efficient than using a cache on GPU memory or mirroring it in both GPU and CPU memory. Compared to a CPU version, this implementation is up to 6.5 times faster, providing an improved image quality when compared to other reconstruction methods. CONCLUSIONS The software developed is an optimized version of the QR factorization for GPU that allows the algebraic reconstruction of CT images with high quality and resolution, with a performance that can be compared with state-of-the-art methods used in clinical practice. This approach allows reducing the exposure time of the patient and thus the radiation dose.
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Affiliation(s)
- Gregorio Quintana-Ortí
- Depto. de Ingeniería y Ciencia de Computadores, Universitat Jaume I, Castellón, 12.071, Spain.
| | - Mónica Chillarón
- Instituto de Seguridad Industrial, Radiofísica y Medioambiental, Universitat Politècnica de València, Valencia, 46.022, Spain.
| | - Vicente Vidal
- Depto. de Sistemas Informáticos y Computación, Universitat Politècnica de València, Valencia, 46.022, Spain.
| | - Gumersindo Verdú
- Instituto de Seguridad Industrial, Radiofísica y Medioambiental, Universitat Politècnica de València, Valencia, 46.022, Spain.
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Park HS, Jeon K, Lee J, You SK. Denoising of pediatric low dose abdominal CT using deep learning based algorithm. PLoS One 2022; 17:e0260369. [PMID: 35061701 PMCID: PMC8782418 DOI: 10.1371/journal.pone.0260369] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 11/08/2021] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVES To evaluate standard dose-like computed tomography (CT) images generated by a deep learning method, trained using unpaired low-dose CT (LDCT) and standard-dose CT (SDCT) images. MATERIALS AND METHODS LDCT (80 kVp, 100 mAs, n = 83) and SDCT (120 kVp, 200 mAs, n = 42) images were divided into training (42 LDCT and 42 SDCT) and validation (41 LDCT) sets. A generative adversarial network framework was used to train unpaired datasets. The trained deep learning method generated virtual SDCT images (VIs) from the original LDCT images (OIs). To test the proposed method, LDCT images (80 kVp, 262 mAs, n = 33) were collected from another CT scanner using iterative reconstruction (IR). Image analyses were performed to evaluate the qualities of VIs in the validation set and to compare the performance of deep learning and IR in the test set. RESULTS The noise of the VIs was the lowest in both validation and test sets (all p<0.001). The mean CT number of the VIs for the portal vein and liver was lower than that of OIs in both validation and test sets (all p<0.001) and was similar to those of SDCT. The contrast-to-noise ratio of portal vein and the signal-to-noise ratio (SNR) of portal vein and liver of VIs were higher than those of SDCT (all p<0.05). The SNR of VIs in test sets was the highest among three images. CONCLUSION The deep learning method trained by unpaired datasets could reduce noise of LDCT images and showed similar performance to SAFIRE. It can be applied to LDCT images of older CT scanners without IR.
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Affiliation(s)
- Hyoung Suk Park
- National Institute for Mathematical Sciences, Daejeon, Republic of Korea
| | - Kiwan Jeon
- National Institute for Mathematical Sciences, Daejeon, Republic of Korea
| | - JeongEun Lee
- Department of Radiology, Chungnam National University College of Medicine, Daejeon, Republic of Korea
- Department of Radiology, Chungnam National University Hospital, Daejeon, Republic of Korea
| | - Sun Kyoung You
- Department of Radiology, Chungnam National University College of Medicine, Daejeon, Republic of Korea
- Department of Radiology, Chungnam National University Hospital, Daejeon, Republic of Korea
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Muscogiuri G, Martini C, Gatti M, Dell'Aversana S, Ricci F, Guglielmo M, Baggiano A, Fusini L, Bracciani A, Scafuri S, Andreini D, Mushtaq S, Conte E, Gripari P, Annoni AD, Formenti A, Mancini ME, Bonfanti L, Guaricci AI, Janich MA, Rabbat MG, Pompilio G, Pepi M, Pontone G. Feasibility of late gadolinium enhancement (LGE) in ischemic cardiomyopathy using 2D-multisegment LGE combined with artificial intelligence reconstruction deep learning noise reduction algorithm. Int J Cardiol 2021; 343:164-170. [PMID: 34517017 DOI: 10.1016/j.ijcard.2021.09.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/05/2021] [Accepted: 09/07/2021] [Indexed: 01/04/2023]
Abstract
BACKGROUND Despite the low spatial resolution of 2D-multisegment late gadolinium enhancement (2D-MSLGE) sequences, it may be useful in uncooperative patients instead of standard 2D single segmented inversion recovery gradient echo late gadolinium enhancement sequences (2D-SSLGE). The aim of the study is to assess the feasibility and comparison of 2D-MSLGE reconstructed with artificial intelligence reconstruction deep learning noise reduction (NR) algorithm compared to standard 2D-SSLGE in consecutive patients with ischemic cardiomyopathy (ICM). METHODS Fifty-seven patients with known ICM referred for a clinically indicated CMR were enrolled in this study. 2D-MSLGE were reconstructed using a growing level of NR (0%,25%,50%,75%and 100%). Subjective image quality, signal to noise ratio (SNR) and contrast to noise ratio (CNR) were evaluated in each dataset and compared to standard 2D-SSLGE. Moreover, diagnostic accuracy, LGE mass and scan time were compared between 2D-MSLGE with NR and 2D-SSLGE. RESULTS The application of NR reconstruction ≥50% to 2D-MSLGE provided better subjective image quality, CNR and SNR compared to 2D-SSLGE (p < 0.01). The best compromise in terms of subjective and objective image quality was observed for values of 2D-MSLGE 75%, while no differences were found in terms of LGE quantification between 2D-MSLGE versus 2D-SSLGE, regardless the NR applied. The sensitivity, specificity, negative predictive value, positive predictive value and accuracy of 2D-MSLGE NR 75% were 87.77%,96.27%,96.13%,88.16% and 94.22%, respectively. Time of acquisition of 2D-MSLGE was significantly shorter compared to 2D-SSLGE (p < 0.01). CONCLUSION When compared to standard 2D-SSLGE, the application of NR reconstruction to 2D-MSLGE provides superior image quality with similar diagnostic accuracy.
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Affiliation(s)
| | - Chiara Martini
- Diagnostic Department, Azienda Ospedaliera-Universitaria di Parma, Parma, Italy
| | - Marco Gatti
- Department of Surgical Sciences, Radiology Institute, University of Turin, Turin, Italy
| | | | | | | | | | - Laura Fusini
- Centro Cardiologico Monzino, IRCCS, Milan, Italy
| | - Aurora Bracciani
- Institute of Radiology, Department of Medicine, University of Udine, Azienda Sanitaria Universitaria Integrata di Udine, Udine, Italy
| | | | - Daniele Andreini
- Centro Cardiologico Monzino, IRCCS, Milan, Italy; Department of Cardiovascular Sciences and Community Health, University of Milan, Italy
| | | | | | | | | | | | | | | | - Andrea Igoren Guaricci
- Institute of Cardiovascular Disease, Department of Emergency and Organ Transplantation, University Hospital "Policlinico Consorziale" of Bari, Bari, Italy
| | | | - Mark G Rabbat
- Loyola University of Chicago, Chicago, IL, United States of America; Edward Hines Jr. VA Hospital, Hines, IL, United States of America
| | - Giulio Pompilio
- Centro Cardiologico Monzino, IRCCS, Milan, Italy; Department of Cardiovascular Sciences and Community Health, University of Milan, Italy
| | - Mauro Pepi
- Centro Cardiologico Monzino, IRCCS, Milan, Italy
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Bos D, König B, Blex S, Zensen S, Opitz M, Maier S, Forsting M, Zylka W, Kühl H, Wetter A, Guberina N. EXPERIMENTAL EXAMINATION OF RADIATION DOSES OF DUAL- AND SINGLE-ENERGY COMPUTED TOMOGRAPHY IN CHEST AND UPPER ABDOMEN IN A PHANTOM STUDY. RADIATION PROTECTION DOSIMETRY 2021; 193:237-246. [PMID: 33893506 DOI: 10.1093/rpd/ncab052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 03/09/2021] [Accepted: 03/25/2021] [Indexed: 06/12/2023]
Abstract
The aim of this phantom study is to examine radiation doses of dual- and single-energy computed tomography (DECT and SECT) in the chest and upper abdomen for three different multi-slice CT scanners. A total of 34 CT protocols were examined with the phantom N1 LUNGMAN. Four different CT examination types of different anatomic regions were performed both in single- and dual-energy technique: chest, aorta, pulmonary arteries for suspected pulmonary embolism and liver. Radiation doses were examined for the CT dose index CTDIvol and dose-length product (DLP). Radiation doses of DECT were significantly higher than doses for SECT. In terms of CTDIvol, radiation doses were 1.1-3.2 times higher, and in terms of DLP, these were 1.1-3.8 times higher for DECT compared with SECT. The third-generation dual-source CT applied the lowest dose in 7 of 15 different examination types of different anatomic regions.
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Affiliation(s)
- Denise Bos
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Britta König
- Faculty of Physical Engineering, Westphalian University, Campus Gelsenkirchen, Neidenburger Str. 43, Gelsenkirchen 45897, Germany
| | - Sebastian Blex
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Sebastian Zensen
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Marcel Opitz
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Sandra Maier
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Michael Forsting
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Waldemar Zylka
- Faculty of Physical Engineering, Westphalian University, Campus Gelsenkirchen, Neidenburger Str. 43, Gelsenkirchen 45897, Germany
| | - Hilmar Kühl
- Department of Radiology, St. Bernhard-Hospital Kamp-Lintfort GmbH, Bürgermeister-Schmelzing-Str. 90, Kamp-Lintfort 47475, Germany
| | - Axel Wetter
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
- Department of Diagnostic and Interventional Radiology, Neuroradiology, Asklepios Klinikum Harburg, Eißendorfer Pferdeweg 52, Hamburg 21075, Germany
| | - Nika Guberina
- Department of Radiotherapy, West German Cancer Center, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
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Jin L, Gao Y, Jiang A, Li Z, Wang P, Li M. Can the Coronary Artery Calcium Score Scan Reduce the Radiation Dose in Coronary Computed Tomography Angiography? Acad Radiol 2021; 28:364-369. [PMID: 32209277 DOI: 10.1016/j.acra.2020.02.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/13/2020] [Accepted: 02/20/2020] [Indexed: 02/05/2023]
Abstract
RATIONALE AND OBJECTIVES Radiation exposure from coronary computed tomography angiography (CCTA) remains a cause for concern. The objective of this study was to investigate whether using the coronary artery calcium score scan (CACS) would reduce the radiation dose for CCTA scanning and the overall radiation exposure (ORE). MATERIALS AND METHODS In total, 256 patients were examined with a third-generation dual-source CT (n = 200) or 256-row CT (n = 56), among whom 105 (Group A) and 28 patients (Group B), respectively, underwent CCTA with CACS for field of view planning. The remaining patients, with the scout view for field of view planning, constituted Group A1 and B1. The scanning parameter settings were standardized between groups. RESULTS Shorter scan lengths were observed in Group A (9.98 ± 0.79 cm) compared to Group A1 (13.64 ± 1.79 cm; p < 0.001), which also resulted in a lower dose-length product (DLP) in Group A (115.04 ± 64.13) relative to Group A1 (138.67 ± 68.87; p < 0.05). Similarly, shorter scan lengths were found in Group B (14.92 ± 1.17 cm) compared to Group B1 (15.79 ± 0.63 cm; p = 0.001); this resulted in a lower DLP (322.07 ± 45.39) compared to Group B1 (354.34 ± 65.27; p = 0.036). The CACS resulted in an increase in ORE in both groups. CONCLUSION CACS may have a critical role in the reduction of radiation dose in CCTA scanning, but the potential effectiveness of CACS in reducing ORE is weak.
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Affiliation(s)
- Liang Jin
- Radiology Department, Huadong Hospital, Affiliated to Fudan University, Shanghai, China
| | - Yiyi Gao
- Radiology Department, Huadong Hospital, Affiliated to Fudan University, Shanghai, China
| | - An'qi Jiang
- Radiology Department, Huadong Hospital, Affiliated to Fudan University, Shanghai, China
| | - Zhenlin Li
- Radiology Department, West China Hospital, Affiliated to SiChuan University, Chengdu, China
| | - Peijun Wang
- Radiology Department, Tongji Hospital, Affiliated to Tongji University, Shanghai, China
| | - Ming Li
- Radiology Department, Huadong Hospital, Affiliated to Fudan University, Shanghai, China; Institute of Functional and Molecular Medical Imaging, Fudan University, Shanghai, China.
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11
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Impact of increasing levels of adaptive statistical iterative reconstruction on image quality in oil-based postmortem CT angiography in coronary arteries. Int J Legal Med 2021; 135:1869-1878. [PMID: 33629138 PMCID: PMC8354936 DOI: 10.1007/s00414-021-02530-1] [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: 07/08/2020] [Accepted: 02/03/2021] [Indexed: 01/03/2023]
Abstract
Introduction Postmortem multi-detector computed tomography (PMCT) has become an important part in forensic imaging. Modern reconstruction techniques such as iterative reconstruction (IR) are frequently used in postmortem CT angiography (PMCTA). The image quality of PMCTA depends on the strength of IR. For this purpose, we aimed to investigate the impact of different advanced IR levels on the objective and subjective PMCTA image quality. Material and methods We retrospectively analyzed the coronary arteries of 27 human cadavers undergoing whole-body postmortem CT angiography between July 2017 and March 2018 in a single center. Iterative reconstructions of the coronary arteries were processed in five different level settings (0%; 30%; 50%; 70%; 100%) by using an adaptive statistical IR method. We evaluated the objective (contrast-to-noise ratio (CNR)) and subjective image quality in several anatomical locations. Results Our results demonstrate that the increasing levels of an IR technique have relevant impact on the image quality in PMCTA scans in forensic postmortem examinations. Higher levels of IR have led to a significant reduction of image noise and therefore to a significant improvement of objective image quality (+ 70%). However, subjective image quality is inferior at higher levels of IR due to plasticized image appearance. Conclusion Objective image quality in PMCTA progressively improves with increasing level of IR with the best CNR at the highest IR level. However, subjective image quality is best at low to medium levels of IR. To obtain a “classic” image appearance with optimal image quality, PMCTAs should be reconstructed at medium levels of IR.
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Baldi D, Tramontano L, Alfano V, Punzo B, Cavaliere C, Salvatore M. Whole Body Low Dose Computed Tomography Using Third-Generation Dual-Source Multidetector With Spectral Shaping: Protocol Optimization and Literature Review. Dose Response 2020; 18:1559325820973131. [PMID: 33456411 PMCID: PMC7783892 DOI: 10.1177/1559325820973131] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/28/2020] [Accepted: 10/12/2020] [Indexed: 12/21/2022] Open
Abstract
For decades, the main imaging tool for multiple myeloma (MM) patient's management has been the conventional skeleton survey. In 2014 international myeloma working group defined the advantages of the whole-body low dose computed tomography (WBLDCT) as a gold standard, among imaging modalities, for bone disease assessment and subsequently implemented this technique in the MM diagnostic workflow. The aim of this study is to investigate, in a group of 30 patients with a new diagnosis of MM, the radiation dose (CT dose index, dose-length product, effective dose), the subjective image quality score and osseous/extra-osseous findings rate with a modified WBLDCT protocol. Spectral shaping and third-generation dual-source multidetector CT scanner was used for the assessment of osteolytic lesions due to MM, and the dose exposure was compared with the literature findings reported until 2020. Mean radiation dose parameters were reported as follows: CT dose index 0.3 ± 0.1 mGy, Dose-Length Product 52.0 ± 22.5 mGy*cm, effective dose 0.44 ± 0.19 mSv. Subjective image quality was good/excellent in all subjects. 11/30 patients showed osteolytic lesions, with a percentage of extra-osseous findings detected in 9/30 patients. Our data confirmed the advantages of WBLDCT in the diagnosis of patients with MM, reporting an effective dose for our protocol as the lowest among previous literature findings.
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Contrast medium administration with a body surface area protocol in step-and-shoot coronary computed tomography angiography with dual-source scanners. Sci Rep 2020; 10:16690. [PMID: 33028924 PMCID: PMC7541528 DOI: 10.1038/s41598-020-73915-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 04/21/2020] [Indexed: 11/08/2022] Open
Abstract
We evaluated the feasibility and image quality of prospective electrocardiography (ECG)-triggered coronary computed tomography angiography (CCTA) using a body surface area (BSA) protocol for contrast-medium (CM) administration on both second- and third-generation scanners (Flash and Force CT), without using heart rate control. One-hundred-and-eighty patients with suspected coronary heart disease undergoing CCTA were divided into groups A (BSA protocol for CM on Flash CT), B (body mass index (BMI)-matched patients; BMI protocol for CM on Flash CT), and C (BMI-matched patients; BSA protocol for CM on Force CT). Patient characteristics, quantitative and qualitative measures, and radiation dose were compared between groups A and B, and A and C. Of the 180 patients, 99 were male (median age, 62 years). Average BSA in groups A, B, and C was 1.80 ± 0.17 m2, 1.74 ± 0.16 m2, and 1.64 ± 0.17 m2, respectively, with groups A and C differing significantly (P < 0.001). Contrast volume (50.50 ± 8.57 mL vs. 45.00 ± 6.18 mL) and injection rate (3.90 ± 0.44 mL/s vs. 3.63 ± 0.22 mL/s) differed significantly between groups A and C (P < 0.001). Groups A and C (both: all CT values > 250 HU, average scores > 4) achieved slightly lower diagnostic image quality than group B. The BSA protocol for CM administration was feasible in both Flash and Force CT, and therefore may be valuable in clinical practice.
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Comparison of quantitative image quality of cardiac computed tomography between raw-data-based and model-based iterative reconstruction algorithms with an emphasis on image sharpness. Pediatr Radiol 2020; 50:1570-1578. [PMID: 32591981 DOI: 10.1007/s00247-020-04741-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 04/12/2020] [Accepted: 05/22/2020] [Indexed: 12/27/2022]
Abstract
BACKGROUND Image sharpness is commonly degraded on cardiac CT images reconstructed using iterative reconstruction algorithms. OBJECTIVE To compare the image quality of cardiac CT between raw-data-based and model-based iterative reconstruction algorithms developed by the same CT vendor in children and young adults with congenital heart disease. MATERIALS AND METHODS In 29 patients with congenital heart disease, we reconstructed 39 cardiac CT datasets using raw-data-based and model-based iterative reconstruction algorithms. We performed quantitative analysis of image sharpness using distance25-75% and angle25-75% on a line density profile across an edge of the descending thoracic aorta in addition to CT attenuation, image noise, signal-to-noise ratio and contrast-to-noise ratio. We compared these quantitative image-quality measures between the two algorithms. RESULTS CT attenuation did not show significant differences between the algorithms (P>0.05) except in the aorta. Image noise was small but significantly higher in the model-based algorithm than in the raw-data-based algorithm (4.8±2.3 Hounsfield units [HU] vs. 4.7±2.1 HU, P<0.014). Signal-to-noise ratio (110.2±50.9 vs. 108.4±50.4, P=0.050) and contrast-to-noise ratio (91.0±45.7 vs. 89.6±45.1, P=0.063) showed marginal significance between the two algorithms. The model-based algorithm showed a significantly smaller distance25-75% (1.4±0.4 mm vs. 1.6±0.3 mm, P<0.001) and a significantly higher angle25-75% (77.0±4.3° vs. 74.1±5.7°, P<0.001) than the raw-data-based algorithm. CONCLUSION Compared with the raw-data-based algorithm, the model-based iterative reconstruction algorithm demonstrated better image sharpness and higher image noise on cardiac CT in patients with congenital heart disease.
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15
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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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16
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Hong JH, Park EA, Lee W, Ahn C, Kim JH. Incremental Image Noise Reduction in Coronary CT Angiography Using a Deep Learning-Based Technique with Iterative Reconstruction. Korean J Radiol 2020; 21:1165-1177. [PMID: 32729262 PMCID: PMC7458859 DOI: 10.3348/kjr.2020.0020] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 03/19/2020] [Accepted: 03/20/2020] [Indexed: 12/11/2022] Open
Abstract
Objective To assess the feasibility of applying a deep learning-based denoising technique to coronary CT angiography (CCTA) along with iterative reconstruction for additional noise reduction. Materials and Methods We retrospectively enrolled 82 consecutive patients (male:female = 60:22; mean age, 67.0 ± 10.8 years) who had undergone both CCTA and invasive coronary artery angiography from March 2017 to June 2018. All included patients underwent CCTA with iterative reconstruction (ADMIRE level 3, Siemens Healthineers). We developed a deep learning based denoising technique (ClariCT.AI, ClariPI), which was based on a modified U-net type convolutional neural net model designed to predict the possible occurrence of low-dose noise in the originals. Denoised images were obtained by subtracting the predicted noise from the originals. Image noise, CT attenuation, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were objectively calculated. The edge rise distance (ERD) was measured as an indicator of image sharpness. Two blinded readers subjectively graded the image quality using a 5-point scale. Diagnostic performance of the CCTA was evaluated based on the presence or absence of significant stenosis (≥ 50% lumen reduction). Results Objective image qualities (original vs. denoised: image noise, 67.22 ± 25.74 vs. 52.64 ± 27.40; SNR [left main], 21.91 ± 6.38 vs. 30.35 ± 10.46; CNR [left main], 23.24 ± 6.52 vs. 31.93 ± 10.72; all p < 0.001) and subjective image quality (2.45 ± 0.62 vs. 3.65 ± 0.60, p < 0.001) improved significantly in the denoised images. The average ERDs of the denoised images were significantly smaller than those of originals (0.98 ± 0.08 vs. 0.09 ± 0.08, p < 0.001). With regard to diagnostic accuracy, no significant differences were observed among paired comparisons. Conclusion Application of the deep learning technique along with iterative reconstruction can enhance the noise reduction performance with a significant improvement in objective and subjective image qualities of CCTA images.
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Affiliation(s)
- Jung Hee Hong
- Department of Radiology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
| | - Eun Ah Park
- Department of Radiology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.
| | - Whal Lee
- Department of Radiology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
| | - Chulkyun Ahn
- Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea
| | - Jong Hyo Kim
- Department of Radiology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.,Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea
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Sinogram-Affirmed Iterative Reconstruction Negatively Impacts the Risk Category Based on Agatston Score: A Study Combining Coronary Calcium Score Measurement and Coronary CT Angiography. BIOMED RESEARCH INTERNATIONAL 2020; 2020:6909130. [PMID: 32733949 PMCID: PMC7376420 DOI: 10.1155/2020/6909130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 04/13/2020] [Accepted: 05/19/2020] [Indexed: 11/23/2022]
Abstract
Purpose To assess the impact of sinogram-affirmed iterative reconstruction (SAFIRE) on risk category for coronary artery disease by combining coronary calcium score measurement and coronary CT angiography (CCTA). Materials and Methods Eighty-nine patients (64.0% male) older than 18 years (64.4 ± 10.3 years) underwent coronary artery calcium scanning and prospectively ECG-triggered sequential CCTA examination. All raw data acquired in coronary artery calcium scanning were reconstructed by both filtered back projection (FBP) and SAFIRE algorithms with 5 different levels. Objective image quality and calcium quantification were evaluated and compared between FBP and all SAFIRE levels by the Sphericity Assumed test or Greenhouse-Geisser ε correction coefficient. Coronary artery stenosis was assessed in CCTA. Risk categories of all patients and of the patients with coronary artery stenosis in CCTA were compared between FBP and all SAFIRE levels by the Friedman test. Results The reconstruction protocol from traditional FBP to SAFIRE 5 was associated with a gradual reduction in CT value and image noise (P < 0.001) but associated with a gradual improvement in the signal-to-noise ratio (P < 0.001). There was a gradual reduction in coronary calcification quantification (Agatston score: from 73.5 in FBP to 38.1 in SAFIRE 5, P < 0.001) from traditional FBP to SAFIRE 5. There was a significant difference for the risk category between FBP and all levels of SAFIRE in all patients (from 3.5 in FBP to 3.2 in SAFIRE 5, P < 0.001) and in the patients with coronary artery stenosis in CCTA (from 4.0 in FBP to 3.6 in SAFIRE 5, P < 0.001). Conclusions SAFIRE significantly reduces coronary calcification quantification compared to FBP, resulting in the reduction of risk categories based on the Agatston score. The risk categories of the patients with coronary artery stenosis in CCTA may also decline. Thus, SAFIRE may lead risk categories to underestimate the existence of significant coronary artery stenosis.
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18
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Choi KS, Lee W, Jung JH, Park EA. Reproducibility of calcium scoring of the coronary arteries: comparison between different vendors and iterative reconstructions. Acta Radiol Open 2020; 9:2058460120922147. [PMID: 32426164 PMCID: PMC7218275 DOI: 10.1177/2058460120922147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 04/03/2020] [Indexed: 11/16/2022] Open
Abstract
Background The coronary artery calcium scoring (CCS) has been widely used for cardiac risk stratification for asymptomatic patients. Purpose To assess the reproducibility of CCS performed on four different computed tomography (CT) scanners, and compare the variability between two reconstruction algorithms, filtered back projection (FBP), and iterative reconstruction (IR). Material and Methods A CCS phantom was made from agar and contained 23 pieces of chicken bones. The phantom was repeatedly scanned using four different CT scanners: Toshiba; GE; Philips; and Siemens. Images were reconstructed using FBP and IR. Agatston and volume scores of total bone fragments were calculated and the overall differences between the instruments were evaluated using the Friedman test. Comparison of the Agatston and volume scores between the two reconstruction algorithms, for each instrument, was evaluated using the Wilcoxon signed rank test. Results The difference in the Agatston scores was significantly different between the four machines (P = 0.001). The Toshiba scanner yielded the highest score followed by Philips, GE, and Siemens scanners. There was no difference in the CCS evaluated using the two reconstruction algorithms, except in case of the Siemens scanner (P = 0.032). Conclusion CCS performed on different scanners varied significantly. In the Toshiba, Philips, and GE scanners, there was no significant difference in the CCS determined using either an IR or the FBP algorithm. In the Siemens scanner, applying the IR algorithm resulted in a slightly different scores, which might not be clinically significant.
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Affiliation(s)
- Kyu Sung Choi
- Graduate School of Medical Science and Engineering, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Whal Lee
- Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea.,Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
| | - Joon Hyung Jung
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Eun-Ah Park
- Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea.,Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
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Pediatric head computed tomography with advanced modeled iterative reconstruction: focus on image quality and reduction of radiation dose. Pediatr Radiol 2020; 50:242-251. [PMID: 31630218 DOI: 10.1007/s00247-019-04532-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 07/21/2019] [Accepted: 09/10/2019] [Indexed: 01/11/2023]
Abstract
BACKGROUND Iterative reconstruction has become the standard method for reconstructing computed tomography (CT) scans and needs to be verified for adaptation. OBJECTIVE To assess the image quality after adapting advanced modeled iterative reconstruction (ADMIRE) for pediatric head CT. MATERIALS AND METHODS We included image sets with filtered back projection reconstruction (the cFBP group, n=105) and both filtered back projection and ADMIRE reconstruction (the lower-dose group, n=109) after dose reduction. All five strength levels of ADMIRE and filtered back projection were adapted for the lower-dose group and compared with the cFBP group. Quantitative parameters including noise, signal-to-noise ratio and contrast-to-noise ratio and qualitative parameters including noise, white matter and gray matter differentiation of the supra- and infratentorial levels, sharpness, artifact, and diagnostic accuracy were also evaluated and compared with interobserver agreement. RESULTS There was a mean dose reduction of 30.6% in CT dose index volume, 32.1% in dose length product, and 32.1% in effective dose after tube current reduction. There was gradual reduction of noise in air, cerebrospinal fluid and white matter with strength levels of ADMIRE from 1 to 5 (P<0.001). Signal-to-noise ratio and contrast-to-noise ratio in all age groups increased among strength levels of ADMIRE, in sequence from 1 to 5, with statistical significance (P<0.001). Gradual reduction of qualitative parameters was noted among strength levels of ADMIRE in sequence from 1 to 5 (P<0.001). CONCLUSION Use of ADMIRE for pediatric head CT can reduce radiation dose without degrading image quality.
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Coronary computed tomography angiography using model-based iterative reconstruction algorithms in the detection of significant coronary stenosis: how the plaque type influences the diagnostic performance. Pol J Radiol 2019; 84:e522-e529. [PMID: 32082450 PMCID: PMC7016499 DOI: 10.5114/pjr.2019.91259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 11/04/2019] [Indexed: 01/14/2023] Open
Abstract
Purpose To evaluate the ability of coronary computed tomography angiography (CCTA) with model-based iterative reconstruction (MBIR) algorithm in detecting significant coronary artery stenosis compared with invasive coronary angiography (ICA). Material and methods We retrospectively identified 55 patients who underwent CCTA using the MBIR algorithm with evidence of at least one significant stenosis (≥ 50%) and an ICA within three months. Patients were stratified based on calcium score; stenoses were classified by type and by coronary segment involved. Dose-length-product was compared with the literature data obtained with previous reconstruction algorithms. Coronary artery stenosis was estimated on ICAs based on a qualitative method. Results CCTA data were confirmed by ICA in 89% of subjects, and in 73% and 94% of patients with CS < 400 and ≥ 400, respectively. ICA confirmed 81% of calcific stenoses, 91% of mixed, and 67% of soft plaques. Both the dose exposure of patients with prospective acquisition (34) and the exposure of the whole population were significantly lower than the standard of reference (p < 0.001 and p = 0.007). Conclusions CCTA with MBIR is valuable in detecting significant coronary artery stenosis with a solid reduction of radiation dose. Diagnostic performance was influenced by plaque composition, being lower compared with ICA for patients with lower CAC score and soft plaques; the visualisation of an intraluminal hypodensity could cause false positives, particularly in D1 and MO segments.
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Secinaro A, Curione D, Mortensen KH, Santangelo TP, Ciancarella P, Napolitano C, Del Pasqua A, Taylor AM, Ciliberti P. Dual-source computed tomography coronary artery imaging in children. Pediatr Radiol 2019; 49:1823-1839. [PMID: 31440884 DOI: 10.1007/s00247-019-04494-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 06/11/2019] [Accepted: 08/01/2019] [Indexed: 12/17/2022]
Abstract
Computed tomography (CT) has a well-established diagnostic role in the assessment of coronary arteries in adults. However, its application in a pediatric setting is still limited and often impaired by several technical issues, such as high heart rates, poor patient cooperation, and radiation dose exposure. Nonetheless, CT is becoming crucial in the noninvasive approach of children affected by coronary abnormalities and congenital heart disease. In some circumstances, CT might be preferred to other noninvasive techniques such as echocardiography and MRI for its lack of acoustic window influence, shorter acquisition time, and high spatial resolution. The introduction of dual-source CT has expanded the role of CT in the evaluation of pediatric cardiovascular anatomy and pathology. Furthermore, technical advances in the optimization of low-dose protocols represent an attractive innovation. Dual-source CT can play a key role in several clinical settings in children, namely in the evaluation of children with suspected congenital coronary artery anomalies, both isolated and in association with congenital heart disease. Moreover, it can be used to assess acquired coronary artery abnormalities, as in children with Kawasaki disease and after surgical manipulation, especially in case of transposition of the great arteries treated with arterial switch operation and in case of coronary re-implantation.
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Affiliation(s)
- Aurelio Secinaro
- Advanced Cardiovascular Imaging Unit - Department of Imaging, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
| | - Davide Curione
- Advanced Cardiovascular Imaging Unit - Department of Imaging, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - Teresa Pia Santangelo
- Advanced Cardiovascular Imaging Unit - Department of Imaging, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Paolo Ciancarella
- Advanced Cardiovascular Imaging Unit - Department of Imaging, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Carmela Napolitano
- Advanced Cardiovascular Imaging Unit - Department of Imaging, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Alessia Del Pasqua
- Pediatric Cardiology and Cardiac Surgery Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Andrew Mayall Taylor
- UCL Centre for Cardiovascular Imaging, Institute of Cardiovascular Science, University College of London, Great Ormond Street Hospital for Children, London, UK
| | - Paolo Ciliberti
- Pediatric Cardiology and Cardiac Surgery Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
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22
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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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Dual-energy computed tomography for evaluation of breast cancer: value of virtual monoenergetic images reconstructed with a noise-reduced monoenergetic reconstruction algorithm. Jpn J Radiol 2019; 38:154-164. [PMID: 31686294 DOI: 10.1007/s11604-019-00897-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 10/24/2019] [Indexed: 01/11/2023]
Abstract
PURPOSE To evaluate the image quality and lesion visibility of virtual monoenergetic images (VMIs) reconstructed using a new monoenergetic reconstruction algorithm (nMERA) for evaluation of breast cancer. MATERIALS AND METHODS Forty-two patients with 46 breast cancers who underwent 4-phasic breast contrast-enhanced computed tomography (CT) using dual-energy CT (DECT) were enrolled. We selected the peak enhancement phase of the lesion in each patient. The selected phase images were generated by 120-kVp-equivalent linear blended (M120) and monoenergetic reconstructions from 40 to 80 keV using the standard reconstruction algorithm (sMERA: 40, 50, 60, 70, 80) and nMERA (40 +, 50 +, 60 +, 70 +, 80 +). The contrast-to-noise ratio (CNR) was calculated and objectively analyzed. Two independent readers subjectively scored tumor visibility and image quality each on a 5-point scale. RESULTS The CNR at 40 + and tumor visibility scores at 40 + and 50 + were significantly higher than those on M120. The CNR at 50 + was not significantly different from that on M120. However, the overall image quality score at 40 + was significantly lower than that at 50 + and on M120 (40 + vs M120, P < 0.0001 and 40 + vs 50 +, P = 0.0001). CONCLUSIONS VMI reconstructed with nMERA at 50 keV is preferable for evaluation of patients with breast cancer.
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Tozakidou M, Yang SR, Kovacs BK, Szucs-Farkas Z, Studler U, Schindera S, Hirschmann A. Dose-optimized computed tomography of the cervical spine in patients with shoulder pull-down: Is image quality comparable with a standard dose protocol in an emergency setting? Eur J Radiol 2019; 120:108655. [PMID: 31542699 DOI: 10.1016/j.ejrad.2019.108655] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/07/2019] [Accepted: 08/15/2019] [Indexed: 11/19/2022]
Abstract
PURPOSE Superimposing soft tissue and bony structures in computed tomography (CT) of the cervical spine (C-spine) is a limiting factor in optimizing radiation exposure maintaining an acceptable image quality. Therefore, we assessed image quality of dose-optimized (DO) C-spine CT in patients capable of shoulder pull-down in an emergency setting. METHODS AND MATERIALS DO-CT (105mAs/120 kVp) of the C-spine in trauma settings was performed in patients with shoulder pull-down if C5 was not superimposed by soft tissue on the lateral topogram, otherwise standard-dose (SD)-CT (195 mAs/120 kVp) was performed. 34 DO (mean age, 68y ± 21; BMI, 24.2 kg/m2 ± 3.2) and 34 SD (mean age 70y ± 19; BMI 25.7 kg/m2 ± 4.4) iterative reconstructed CTs were evaluated at C2/3 and C6/7 by two musculoskeletal radiologists. Qualitative image noise and morphological characteristics of bony structures (cortex, trabeculae) were assessed on a Likert scale. Quantitative image noise was measured and effective dose (ED) was recorded. Parameters were compared using Mann-Whitney-U-test (p < 0.05). RESULTS At C2/3, DO-CT vs. SD-CT yielded comparable qualitative noise (mean, 1.3 vs. 1.0; p = 0.18) and morphological characteristics, but higher quantitative noise (27.2 ± 8.8HU vs. 19.6 ± 4.5HU; p < 0.001). At C6/7, DO-CT yielded lower subjective noise (1.9; SD-CT 2.2; p = 0.017) and better morphological characteristics with higher visibility scores for cortex (p = 0.001) and trabeculae (p = 0.03). Quantitative noise did not differ (p = 0.24). Radiation dose was 51% lower using DO-CT (EDDO-CT 0.80 ± 0.1 mSv; EDSD-CT 1.63 ± 0.2 mSv; p < 0.001). CONCLUSION C-spine CT with dose reduction of 51% showed no image quality impairment. Additional pull-down of both shoulders allowed better image quality at lower C-spine segments as compared to a standard protocol.
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Affiliation(s)
- Magdalini Tozakidou
- Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, University of Basel, Switzerland; Department of Radiology and Nuclear Medicine, Devision of Pediatric Radiology, University Hospital Eppendorf, Hamburg, Germany.
| | - Schu-Ren Yang
- Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, University of Basel, Switzerland.
| | - Balazs K Kovacs
- Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, University of Basel, Switzerland.
| | - Zsolt Szucs-Farkas
- Department of Diagnostic Radiology, Hospital Centre of Biel, Switzerland.
| | - Ueli Studler
- Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, University of Basel, Switzerland; Imamed, Radiology Northwest, Basel, Switzerland.
| | - Sebastian Schindera
- Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, University of Basel, Switzerland; Department of Diagnostic Radiology, cantonal hospital Aarau, Switzerland.
| | - Anna Hirschmann
- Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, University of Basel, Switzerland.
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Diagnosis of coronary artery disease in patients with atrial fibrillation using low tube voltage coronary CT angiography with isotonic low-concentration contrast agent. Int J Cardiovasc Imaging 2019; 35:2239-2248. [PMID: 31363878 DOI: 10.1007/s10554-019-01678-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 07/24/2019] [Indexed: 10/26/2022]
Abstract
This prospective study evaluated the image quality and accuracy of coronary computed tomography angiography (CCTA) for diagnosing coronary artery disease (CAD) in patients with atrial fibrillation (AF), in which CCTA used adaptive iterative dose reduction (AIDR) with a low tube voltage and low concentration of isotonic contrast agent. Sixty-eight consecutive patients with AF and suspected CAD were equally and randomly apportioned to two groups and underwent CCTA. In the experimental group, the contrast agent was iodixanol (270 mg I/mL), patients were scanned with 100 kV, and reconstruction was by AIDR. In the conventional scanning (control) group, the contrast agent was iopromide (370 mg I/mL), patients were scanned with 120 kV, and reconstruction was by filtered back projection. The image quality, effective radiation dose (E), and total iodine intake of the groups were compared. Thirty-nine patients with coronary artery stenosis later were given invasive coronary angiography (ICA). The groups were similar with regard to mean CT value, noise, and signal-to-noise and contrast-to-noise ratios. The figure of merit of the experimental group was significantly higher than that of the control group, while the E and total iodine were significantly lower. Using ICA as the diagnostic reference, the groups shared similar sensitivity, specificity, and false positive and false negative rates for diagnosing coronary artery stenosis. For determining CAD in patients with AF, CCTA with isotonic low-concentration contrast agent and low-voltage scanning is a feasible alternative that improves accuracy and reduces radiation dose and iodine intake.
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Mousavi Gazafroudi SS, Tavakkoli MB, Moradi M, Mousavi Gazafroudi SS, Yadegarfar G, Behjati M, Karimian M, Sajjadieh Khajouei A. Coronary CT angiography by modifying tube voltage and contrast medium concentration: Evaluation of image quality and radiation dose. Echocardiography 2019; 36:1391-1396. [PMID: 31215700 DOI: 10.1111/echo.14410] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/22/2019] [Accepted: 05/26/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Currently, there is an increasing interest in noninvasive imaging of cardiovascular system such as computed tomography coronary angiography (CCTA). The risks of radiation-induced cancer and contrast-induced nephropathy (CIN) have always been regarded as concerns which increased demand for CCTA using reduced radiation dose and iodine intake. We aimed to evaluate the image quality and radiation dose of CCTA by modifying tube voltage and concentration of contrast media. METHODS The present study includes 105 patients who underwent CCTA for clinical indications. Specific inclusion and exclusion criteria in terms of patient's weight, body mass index, calcium score, and stenting were used. First group of patients scanned by 120 kV and 370 mg I/mL contrast medium, compared with second and third groups for which scanning was performed using 100 kV and 370 mg I/mL and 100 kV and 300 mg I/mL, respectively. Image quality was evaluated both subjectively and objectively. The effective dose and iodine intake were also measured. RESULTS Using low kV protocols led to radiation dose reduction up to 38% and applying low contrast medium concentration with consequent reduced iodine intake up to 21%. Moreover, there were significant differences in image quality of new scanning protocols. CONCLUSION Reduction in tube voltage with lowering of contrast medium concentration can reduce radiation dose and iodine intake with acceptable image quality.
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Affiliation(s)
| | | | - Maryam Moradi
- Radiology Department, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | - Ghasem Yadegarfar
- Epidemiology Department, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohaddeseh Behjati
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Karimian
- Anatomical Sciences Research Center, Kashan University of Medical Sciences, Kashan, Iran
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Wu CC, Wolfe JM. Eye Movements in Medical Image Perception: A Selective Review of Past, Present and Future. Vision (Basel) 2019; 3:E32. [PMID: 31735833 PMCID: PMC6802791 DOI: 10.3390/vision3020032] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/09/2019] [Accepted: 06/18/2019] [Indexed: 12/21/2022] Open
Abstract
The eye movements of experts, reading medical images, have been studied for many years. Unlike topics such as face perception, medical image perception research needs to cope with substantial, qualitative changes in the stimuli under study due to dramatic advances in medical imaging technology. For example, little is known about how radiologists search through 3D volumes of image data because they simply did not exist when earlier eye tracking studies were performed. Moreover, improvements in the affordability and portability of modern eye trackers make other, new studies practical. Here, we review some uses of eye movements in the study of medical image perception with an emphasis on newer work. We ask how basic research on scene perception relates to studies of medical 'scenes' and we discuss how tracking experts' eyes may provide useful insights for medical education and screening efficiency.
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Affiliation(s)
- Chia-Chien Wu
- Visual Attention Lab, Department of Surgery, Brigham & Women’s Hospital, 65 Landsdowne St, Cambridge, MA 02139, USA
- Department of Radiology, Harvard Medical School, Boston, MA 02115, USA
| | - Jeremy M. Wolfe
- Visual Attention Lab, Department of Surgery, Brigham & Women’s Hospital, 65 Landsdowne St, Cambridge, MA 02139, USA
- Department of Radiology, Harvard Medical School, Boston, MA 02115, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA
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Tayal U, King L, Schofield R, Castellano I, Stirrup J, Pontana F, Earls J, Nicol E. Image reconstruction in cardiovascular CT: Part 2 - Iterative reconstruction; potential and pitfalls. J Cardiovasc Comput Tomogr 2019; 13:3-10. [PMID: 31014928 DOI: 10.1016/j.jcct.2019.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/04/2019] [Accepted: 04/15/2019] [Indexed: 12/22/2022]
Abstract
The use of IR in CT previously has been prohibitively complicated and time consuming, however improvements in computer processing power now make it possible on almost all CT scanners. Due to its potential to allow scanning at lower doses, IR has received a lot of attention in the medical literature and has become a successful commercial product. Its use in cardiovascular CT has been driven in part due to concerns about radiation dose and image quality. This manuscript discusses the various vendor permutations of iterative reconstruction (IR) in detail and critically appraises the current clinical research available on the various IR techniques used in cardiovascular CT.
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Affiliation(s)
- U Tayal
- Department of Cardiovascular CT, Royal Brompton Hospital, London, UK.
| | - L King
- Joint Department of Physics, The Royal Marsden, London, UK.
| | - R Schofield
- Department of Cardiovascular CT, Royal Brompton Hospital, London, UK.
| | - I Castellano
- Joint Department of Physics, The Royal Marsden, London, UK.
| | - J Stirrup
- Department of Cardiology, Royal Berkshire Hospital, Reading, UK.
| | - F Pontana
- Department of Cardiovascular Imaging, Lille University Hospital, France.
| | - J Earls
- George Washington University Hospital, Washington DC, USA.
| | - E Nicol
- Department of Cardiovascular CT, Royal Brompton Hospital, London, UK.
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Initial clinical experience of a prototype ultra-high-resolution CT for assessment of small intracranial arteries. Jpn J Radiol 2019; 37:283-291. [PMID: 30706382 DOI: 10.1007/s11604-019-00816-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 01/21/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE Diagnostic and neurosurgical procedures require the precise localization of small intracranial arteries, but this may be difficult using conventional computed tomography angiography (CTA). This study was conducted to evaluate the quality of CTA images acquired using a prototype ultra-high-resolution computed tomography (U-HRCT) system compared with those acquired using a conventional computed tomography (C-CT) system. MATERIALS AND METHODS From July through September 2015, 10 adult patients (6 women and 4 men) previously scanned by C-CT were examined using U-HRCT to locate and assess cerebral aneurysms. The bilateral ophthalmic artery (Opth A), anterior choroidal artery (Acho A), and thalamoperforating arteries (TPAs) were visually evaluated in randomly presented CTA images. Images were graded on a 5-point scale, and differences in scores between U-HRCT and C-CT were evaluated by the Wilcoxon signed-rank test. A p value < 0.05 was considered statistically significant. RESULTS Visual evaluation scores for images of the Opth A, Acho A, and TPAs were significantly higher for U-HRCT than for C-CT. U-HRCT images achieved good visualization (score > 3) for C-CT images with poor visualization (score < 3) in 66.7-100% of all the small arteries. CONCLUSION U-HRCT is superior to C-CT for detecting and evaluating clinically significant small intracranial arteries.
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Li J, Ma Z, Gao F, Ji Y. The measurement of dorsal radial tilt by x-ray and computed tomography. Rev Assoc Med Bras (1992) 2018; 64:1007-1011. [PMID: 30570052 DOI: 10.1590/1806-9282.64.11.1007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 02/25/2018] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE We conducted this study to define and measure the dorsal radial tilt, and to guide the reduction of distal radius fractures and the pre-bending of steel plates used in surgery. METHODS The dorsal radial tilt was measured using both computed tomography (CT) and x-ray from both left and right side. The differences and correlations of the data measured by those two methods and from two sides were analyzed. RESULTS The tilts measured by x-ray were significantly bigger than those measured by CT from the left side (t=55.51, p < 0.01) and from the right side (t=49.81, p < 0.01). The tilts measured by those two methods from the left and right sides were correlated (r=0.85, p < 0.01; r=0.81, p < 0.01). The dorsal radial tilts measured from the left side were not significantly different from those measured from the right side by CT (t=1.49, p > 0.05) and by x-ray (t=1.51, p > 0.05). The dorsal radial tilts measured from the left side by CT were significantly different from those measured from the right side by x-ray (t=43.07, p < 0.01), and these two sets of data were correlated (r=0.71, p < 0.01). The dorsal radial tilts measured from the left side by x-ray was significantly different from that measured from right side by CT (t=40.43, p < 0.01), and those two sets of data were also correlated (r=0.75, p < 0.01). CONCLUSIONS The dorsal radial tilts measured from one side by one method can be used to estimate the tilts measured from the other side / the same side by the same method / the other method.
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Affiliation(s)
- Jingning Li
- Department of Hand Surgery, Yantaishan Hospital, Yantai, Shangdong, China
| | - Zhenjie Ma
- Department of Hand Surgery, Yantaishan Hospital, Yantai, Shangdong, China
| | - Fei Gao
- Department of Hand Surgery, Yantaishan Hospital, Yantai, Shangdong, China
| | - Yuan Ji
- Department of Hand Surgery, Yantaishan Hospital, Yantai, Shangdong, China
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Radiation dose and image quality with new protocol in lower extremity computed tomography angiography. Radiol Med 2018; 124:184-190. [PMID: 30478814 DOI: 10.1007/s11547-018-0963-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/18/2018] [Indexed: 02/08/2023]
Abstract
PURPOSE To compare radiation dose and image quality of lower extremity computed tomography angiography (CTA) between cranio-caudal acquisition with single-source CT (SSCT) and flash caudo-cranial acquisition with dual-source CT (DSCT). MATERIALS AND METHODS In this prospective study, 60 patients were randomly assigned to Group A (control) or Group B (experimental) to undergo lower extremity CTA for peripheral obliterative arterial disease. Group A received protocol 1 (P1) with SSCT cranio-caudal acquisition. Group B received protocol (P2) with DSCT flash caudo-cranial acquisition. Intravascular attenuation (IVA), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image noise were compared. Two radiologists assessed the image quality. Computed tomography volume dose index (CTDIvol) and dose-length product (DLP) were also compared. RESULTS IVA with P2 was higher than with P1 (586.8 ± 140.3 vs. 496.1 ± 129.3 HU, p = 0.011), as was SNR (33.0 ± 11.3 vs. 27.4 ± 12.3; p = 0.042), CNR (30.1 ± 13.3 vs. 24.2 ± 10.3; p = 0.029) and image quality score of small arteries below the knee (3.8 ± 0.2 vs. 3.1 ± 0.2; p = 0.001). Radiation dose was significantly lower in P2 than in P1 with CTDIvol reduction of 40.9% (1.3 ± 0.1 vs. 2.2 ± 0.3 mGy; p = 0.006) and DLP reduction of 42.8% (148.7 ± 21.9 vs 260.2 ± 59.1 mGy * cm; p = 0.018). CONCLUSION Lower extremity CTA with DSCT flash caudo-cranial acquisition allows lower radiation dose with higher IVA, SNR, CNR and better image quality for small arteries below the knee than SSCT cranio-caudal acquisition.
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Richards CE, Dorman S, John P, Davies A, Evans S, Ninan T, Martin D, Kannoly S, Roberts-Davies G, Ramsey M, Obaid DR. Low-radiation and high image quality coronary computed tomography angiography in “real-world” unselected patients. World J Radiol 2018; 10:135-142. [PMID: 30386498 PMCID: PMC6205842 DOI: 10.4329/wjr.v10.i10.135] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 08/14/2018] [Accepted: 10/08/2018] [Indexed: 02/06/2023] Open
Abstract
AIM To determine the radiation dose and image quality in coronary computed tomography angiography (CCTA) using state-of-the-art dose reduction methods in unselected “real world” patients.
METHODS In this single-centre study, consecutive patients in sinus rhythm underwent CCTA for suspected coronary artery disease (CAD) using a 320-row detector CT scanner. All patients underwent the standard CT acquisition protocol at our institute (Morriston Hospital) a combination of dose saving advances including prospective electrocardiogram-gating, automated tube current modulation, tube voltage reduction, heart rate reduction, and the most recent novel adaptive iterative dose reconstruction 3D (AIDR3D) algorithm. The cohort comprised real-world patients for routine CCTA who were not selected on age, body mass index, or heart rate. Subjective image quality was graded on a 4-point scale (4 = excellent, 1 = non-diagnostic).
RESULTS A total of 543 patients were included in the study with a mean body weight of 81 ± 18 kg and a pre-scan mean heart rate of 70 ± 11 beats per minute (bpm). When indicated, patients received rate-limiting medication with an oral beta-blocker followed by additional intravenous beta-blocker to achieve a heart rate below 65 bpm. The median effective radiation dose was 0.88 mSv (IQR, 0.6-1.4 mSv) derived from a Dose Length Product of 61.45 mGy.cm (IQR, 42.86-100.00 mGy.cm). This also includes what we believe to be the lowest ever-reported radiation dose for a routine clinical CCTA (0.18 mSv). The mean image quality (± SD) was 3.65 ± 0.61, with a subjective image quality score of 3 (“good”) or above for 93% of patient CCTAs.
CONCLUSION Combining a low-dose scan protocol and AIDR3D with a 320-detector row CT scanner can provide high quality images at exceptionally low radiation dose in unselected patients being investigated for CAD.
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Affiliation(s)
- Caryl Elizabeth Richards
- Swansea University Medical School, Swansea University, Grove Building, Singleton Park, Sketty, Swansea SA2 8PP, United Kingdom
| | - Stephen Dorman
- Department of Cardiology, Morriston Hospital, Heol Maes Eglwys, Morriston, Cwmrhydyceirw, Swansea SA6 6NL, United Kingdom
| | - Patricia John
- Department of Radiology, Morriston Hospital, Heol Maes Eglwys, Morriston, Cwmrhydyceirw, Swansea SA6 6NL, United Kingdom
| | - Anthony Davies
- Department of Radiology, Morriston Hospital, Heol Maes Eglwys, Morriston, Cwmrhydyceirw, Swansea SA6 6NL, United Kingdom
| | - Sharon Evans
- Department of Radiology, Morriston Hospital, Heol Maes Eglwys, Morriston, Cwmrhydyceirw, Swansea SA6 6NL, United Kingdom
| | - Tishi Ninan
- Department of Radiology, Morriston Hospital, Heol Maes Eglwys, Morriston, Cwmrhydyceirw, Swansea SA6 6NL, United Kingdom
| | - David Martin
- Department of Radiology, Singleton Hospital, Sketty Ln, Sketty, Swansea SA2 8QA, United Kingdom
| | - Sriranj Kannoly
- Department of Cardiology, Singleton Hospital, Sketty Ln, Sketty, Swansea SA2 8QA, United Kingdom
| | - Gail Roberts-Davies
- Department of Radiology, Singleton Hospital, Sketty Ln, Sketty, Swansea SA2 8QA, United Kingdom
| | - Mark Ramsey
- Department of Cardiology, Morriston Hospital, Heol Maes Eglwys, Morriston, Cwmrhydyceirw, Swansea SA6 6NL, United Kingdom
| | - Daniel Rhys Obaid
- Swansea University Medical School, Swansea University, Grove Building, Singleton Park, Sketty, Swansea SA2 8PP, United Kingdom
- Department of Cardiology, Morriston Hospital, Heol Maes Eglwys, Morriston, Cwmrhydyceirw, Swansea SA6 6NL, United Kingdom
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Mann C, Ziegeler K, Mews J, Plaschke M, Issever AS. Bone mineral density assessment using iterative reconstruction compared with quantitative computed tomography as the standard of reference. Sci Rep 2018; 8:15095. [PMID: 30305658 PMCID: PMC6179993 DOI: 10.1038/s41598-018-33444-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/28/2018] [Indexed: 12/13/2022] Open
Abstract
This study examines the influence of iterative reconstruction on bone mineral density (BMD) measurement by comparison with standard quantitative computed tomography (QCT; reference) and two other protocols based on filtered back projection. Ten human cadaver specimens of the lumbar spine with a hydroxyapatite calibration phantom underneath, were scanned with 4 protocols: 1. standard QCT, 2. volume scan with FBP, 3. helical scan with FBP, and 4. helical scan with IR (Adaptive Iterative Dose Reduction 3D (AIDR3D)). Radiation doses were recorded as CT dose index (CTDIvol) and BMD, signal-to-noise and contrast-to-noise ratio were calculated. Mean hydroxyapatite concentration (HOA) did not differ significantly between protocols, ranging from 98.58 ± 31.09 mg cm3 (protocol 4) to 100.47 ± 30.82 mg cm3 (protocol 2). Paired sample correlations of HOA values for protocol 4 and protocols 1, 2 and 3 were nearly perfect with coefficients of 0.980, 0.979 and 0.982, respectively (p < 0.004). CTDIvol were 7.50, 5.00, 6.82 (±2.03) and 1.72 (±0.50) mGy for protocols 1, 2, 3 and 4 respectively. Objective image quality was highest for protocol 4. The use of IR for BMD assessment significantly lowers radiation exposure compared to standard QCT and protocols with FBP while not degrading BMD measurement.
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Affiliation(s)
- Constanze Mann
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
| | - Katharina Ziegeler
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jürgen Mews
- Canon Medical Systems Europe BV, Zoetermeer, Netherlands
| | - Martina Plaschke
- Department of Anatomy, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Ahi Sema Issever
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
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Noël PB, Engels S, Köhler T, Muenzel D, Franz D, Rasper M, Rummeny EJ, Dobritz M, Fingerle AA. Evaluation of an iterative model-based CT reconstruction algorithm by intra-patient comparison of standard and ultra-low-dose examinations. Acta Radiol 2018; 59:1225-1231. [PMID: 29320863 DOI: 10.1177/0284185117752551] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background The explosive growth of computer tomography (CT) has led to a growing public health concern about patient and population radiation dose. A recently introduced technique for dose reduction, which can be combined with tube-current modulation, over-beam reduction, and organ-specific dose reduction, is iterative reconstruction (IR). Purpose To evaluate the quality, at different radiation dose levels, of three reconstruction algorithms for diagnostics of patients with proven liver metastases under tumor follow-up. Material and Methods A total of 40 thorax-abdomen-pelvis CT examinations acquired from 20 patients in a tumor follow-up were included. All patients were imaged using the standard-dose and a specific low-dose CT protocol. Reconstructed slices were generated by using three different reconstruction algorithms: a classical filtered back projection (FBP); a first-generation iterative noise-reduction algorithm (iDose4); and a next generation model-based IR algorithm (IMR). Results The overall detection of liver lesions tended to be higher with the IMR algorithm than with FBP or iDose4. The IMR dataset at standard dose yielded the highest overall detectability, while the low-dose FBP dataset showed the lowest detectability. For the low-dose protocols, a significantly improved detectability of the liver lesion can be reported compared to FBP or iDose4 ( P = 0.01). The radiation dose decreased by an approximate factor of 5 between the standard-dose and the low-dose protocol. Conclusion The latest generation of IR algorithms significantly improved the diagnostic image quality and provided virtually noise-free images for ultra-low-dose CT imaging.
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Affiliation(s)
- Peter B Noël
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
- Physics Department & Munich School of BioEngineering, Technische Universität München, Garching, Germany
| | - Stephan Engels
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
| | | | - Daniela Muenzel
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
- Physics Department & Munich School of BioEngineering, Technische Universität München, Garching, Germany
| | - Daniela Franz
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
| | - Michael Rasper
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
| | - Ernst J Rummeny
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
| | - Martin Dobritz
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
| | - Alexander A Fingerle
- Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany
- Physics Department & Munich School of BioEngineering, Technische Universität München, Garching, Germany
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Gambre AS, Liew C, Hettiarachchi G, Lee SSG, MacDonald M, Kam CJW, Poh ACC. Accuracy and clinical outcomes of coronary CT angiography for patients with suspected coronary artery disease: a single-centre study in Singapore. Singapore Med J 2018; 59:413-418. [PMID: 30175374 DOI: 10.11622/smedj.2018096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
INTRODUCTION This study aimed to assess the accuracy and outcomes of coronary computed tomography angiography (CCTA) performed in a regional hospital in Singapore. METHODS The Changi General Hospital CCTA database was retrospectively analysed over a 24-month period. Electronic hospital records, catheter coronary angiography (CCA) and CCTA electronic databases were used to gather data on major adverse cardiovascular events (MACE) and CCA results. CCTA findings were deemed positive if coronary artery stenosis ≥ 50% was reported or if the stenosis was classified as moderate or severe. CCA findings were considered positive if coronary artery stenosis ≥ 50% was reported. RESULTS The database query returned 679 patients who had undergone CCTA for the evaluation of suspected coronary artery disease. Of the 101 patients in the per-patient accuracy analysis group, there were six true negatives, one false negative, 81 true positives and 13 false positives, resulting in a negative predictive value of 85.7% and positive predictive value of 86.2%. The mean age of the study sample was 53 ± 13 years and 255 (37.6%) patients were female. Mean duration of patient follow-up was 360 days. Of the 513 negative CCTA patients, none developed MACE during the follow-up period, and of the 164 positive CCTA patients, 19 (11.6%) developed MACE (p < 0.001). CONCLUSION Analysis of CCTA studies suggested accuracy and outcomes that were consistent with published clinical data. There was a one-year MACE-free warranty period following negative CCTA findings.
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Affiliation(s)
| | - Charlene Liew
- Department of Radiology, Changi General Hospital, Singapore
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Günther A, Aaberge L, Abildgaard A, Ragnarsson A, Edvardsen T, Jakobsen J, Andersen R. Coronary computed tomography in heart transplant patients: detection of significant stenosis and cardiac allograft vasculopathy, image quality, and radiation dose. Acta Radiol 2018; 59:1066-1073. [PMID: 29260577 DOI: 10.1177/0284185117748354] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Background Cardiac allograft vasculopathy (CAV) is an accelerated form of atherosclerosis unique to heart transplant (HTX) patients. Purpose To investigate the detection of significant coronary artery stenosis and CAV, determinants of image quality, and the radiation dose in coronary computed tomography angiography (CCTA) of HTX patients with 64-slice multidetector CT (64-MDCT). Material and Methods Fifty-two HTX recipients scheduled for invasive coronary angiography (ICA) were prospectively enrolled and underwent CCTA before ICA with intravascular ultrasound (IVUS). Results Interpretable CCTA images were acquired in 570 (95%) coronary artery segments ≥2 mm in diameter. Sensitivity, specificity, and positive and negative predictive values of CCTA for the detection of segments with significant stenosis (lumen reduction ≥50%) on ICA were 100%, 98%, 7.7%, and 100%, respectively. Twelve significant stenoses were located in segments with uninterpretable image quality or vessel diameter <2 mm; only one was eligible for intervention. IVUS detected CAV (maximal intimal thickness ≥0.5 mm) in 33/41 (81%) patients; CCTA and ICA identified CAV (any wall or luminal irregularity) in 18 (44%) and 14 (34%) of these 33 patients, respectively. The mean estimated radiation dose was 19.0 ± 3.4 mSv for CCTA and 5.7 ± 3.3 mSv for ICA ( P < 0.001). Conclusion CCTA with interpretable image quality had a high negative predictive value for ruling out significant stenoses suitable for intervention. The modest detection of CAV by CCTA implied a limited value in identifying subtle CAV. The high estimated radiation dose for 64-MDCT is of concern considering the need for repetitive examinations in the HTX population.
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Affiliation(s)
- Anne Günther
- Department of Radiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
- Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Lars Aaberge
- Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Andreas Abildgaard
- Department of Radiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Asgrimur Ragnarsson
- Department of Radiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Thor Edvardsen
- Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Jarl Jakobsen
- Department of Radiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
- Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Rune Andersen
- Department of Radiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
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Khobragade P, Fan J, Rupcich F, Crotty DJ, Schmidt TG. Application of fractal dimension for quantifying noise texture in computed tomography images. Med Phys 2018; 45:3563-3573. [PMID: 29885062 DOI: 10.1002/mp.13040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 05/22/2018] [Accepted: 05/28/2018] [Indexed: 12/16/2022] Open
Abstract
PURPOSE Evaluation of noise texture information in CT images is important for assessing image quality. Noise texture is often quantified by the noise power spectrum (NPS), which requires numerous image realizations to estimate. This study evaluated fractal dimension for quantifying noise texture as a scalar metric that can potentially be estimated using one image realization. METHODS The American College of Radiology CT accreditation phantom (ACR) was scanned on a clinical scanner (Discovery CT750, GE Healthcare) at 120 kV and 25 and 90 mAs. Images were reconstructed using filtered back projection (FBP/ASIR 0%) with varying reconstruction kernels: Soft, Standard, Detail, Chest, Lung, Bone, and Edge. For each kernel, images were also reconstructed using ASIR 50% and ASIR 100% iterative reconstruction (IR) methods. Fractal dimension was estimated using the differential box-counting algorithm applied to images of the uniform section of ACR phantom. The two-dimensional Noise Power Spectrum (NPS) and one-dimensional-radially averaged NPS were estimated using established techniques. By changing the radiation dose, the effect of noise magnitude on fractal dimension was evaluated. The Spearman correlation between the fractal dimension and the frequency of the NPS peak was calculated. The number of images required to reliably estimate fractal dimension was determined and compared to the number of images required to estimate the NPS-peak frequency. The effect of Region of Interest (ROI) size on fractal dimension estimation was evaluated. Feasibility of estimating fractal dimension in an anthropomorphic phantom and clinical image was also investigated, with the resulting fractal dimension compared to that estimated within the uniform section of the ACR phantom. RESULTS Fractal dimension was strongly correlated with the frequency of the peak of the radially averaged NPS curve, having a Spearman rank-order coefficient of 0.98 (P-value < 0.01) for ASIR 0%. The mean fractal dimension at ASIR 0% was 2.49 (Soft), 2.51 (Standard), 2.52 (Detail), 2.57 (Chest), 2.61 (Lung), 2.66 (Bone), and 2.7 (Edge). A reduction in fractal dimension was observed with increasing ASIR levels for all investigated reconstruction kernels. Fractal dimension was found to be independent of noise magnitude. Fractal dimension was successfully estimated from four ROIs of size 64 × 64 pixels or one ROI of 128 × 128 pixels. Fractal dimension was found to be sensitive to non-noise structures in the image, such as ring artifacts and anatomical structure. Fractal dimension estimated within a uniform region of an anthropomorphic phantom and clinical head image matched that estimated within the ACR phantom for filtered back projection reconstruction. CONCLUSIONS Fractal dimension correlated with the NPS-peak frequency and was independent of noise magnitude, suggesting that the scalar metric of fractal dimension can be used to quantify the change in noise texture across reconstruction approaches. Results demonstrated that fractal dimension can be estimated from four, 64 × 64-pixel ROIs or one 128 × 128 ROI within a head CT image, which may make it amenable for quantifying noise texture within clinical images.
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Affiliation(s)
- P Khobragade
- Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, WI, 53233, USA
| | | | | | | | - Taly Gilat Schmidt
- Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, WI, 53233, USA
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Tesche C, Duguay TM, Schoepf UJ, van Assen M, De Cecco CN, Albrecht MH, Varga-Szemes A, Bayer RR, Ebersberger U, Nance JW, Thilo C. Current and future applications of CT coronary calcium assessment. Expert Rev Cardiovasc Ther 2018; 16:441-453. [PMID: 29734858 DOI: 10.1080/14779072.2018.1474347] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
INTRODUCTION Computed tomographic (CT) coronary artery calcium scoring (CAC) has been validated as a well-established screening method for cardiovascular risk stratification and treatment management that is used in addition to traditional risk factors. The purpose of this review is to present an update on current and future applications of CAC. Areas covered: The topic of CAC is summarized from its introduction to current application with focus on the validation and clinical integration including cardiovascular risk prediction and outcome, cost-effectiveness, impact on downstream medical testing, and the technical advances in scanner and software technology that are shaping the future of CAC. Furthermore, this review aims to provide guidance for the appropriate clinical use of CAC. Expert commentary: CAC is a well-established screening test in preventive care that is underused in daily clinical practice. The widespread clinical implementation of CAC will be decided by future technical advances in CT image acquisition, cost-effectiveness, and reimbursement status.
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Affiliation(s)
- Christian Tesche
- a Division of Cardiovascular Imaging, Department of Radiology and Radiological Science , Medical University of South Carolina , Charleston , SC , USA.,b Department of Cardiology and Intensive Care Medicine , Heart Center Munich-Bogenhausen , Munich , Germany
| | - Taylor M Duguay
- a Division of Cardiovascular Imaging, Department of Radiology and Radiological Science , Medical University of South Carolina , Charleston , SC , USA
| | - U Joseph Schoepf
- a Division of Cardiovascular Imaging, Department of Radiology and Radiological Science , Medical University of South Carolina , Charleston , SC , USA.,c Division of Cardiology, Department of Medicine , Medical University of South Carolina , Charleston , SC , USA
| | - Marly van Assen
- a Division of Cardiovascular Imaging, Department of Radiology and Radiological Science , Medical University of South Carolina , Charleston , SC , USA.,d Center for Medical Imaging North East Netherlands , University Medical Center Groningen, University of Groningen , Groningen , The Netherlands
| | - Carlo N De Cecco
- a Division of Cardiovascular Imaging, Department of Radiology and Radiological Science , Medical University of South Carolina , Charleston , SC , USA
| | - Moritz H Albrecht
- a Division of Cardiovascular Imaging, Department of Radiology and Radiological Science , Medical University of South Carolina , Charleston , SC , USA.,e Department of Diagnostic and Interventional Radiology , University Hospital Frankfurt , Frankfurt , Germany
| | - Akos Varga-Szemes
- a Division of Cardiovascular Imaging, Department of Radiology and Radiological Science , Medical University of South Carolina , Charleston , SC , USA
| | - Richard R Bayer
- a Division of Cardiovascular Imaging, Department of Radiology and Radiological Science , Medical University of South Carolina , Charleston , SC , USA.,c Division of Cardiology, Department of Medicine , Medical University of South Carolina , Charleston , SC , USA
| | - Ullrich Ebersberger
- a Division of Cardiovascular Imaging, Department of Radiology and Radiological Science , Medical University of South Carolina , Charleston , SC , USA.,b Department of Cardiology and Intensive Care Medicine , Heart Center Munich-Bogenhausen , Munich , Germany
| | - John W Nance
- a Division of Cardiovascular Imaging, Department of Radiology and Radiological Science , Medical University of South Carolina , Charleston , SC , USA
| | - Christian Thilo
- f Department of Internal Medicine I - Cardiology , Central Hospital of Augsburg , Augsburg , Germany
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Fahlenkamp UL, Diaz Ramirez I, Wagner M, Schwenke C, Huppertz A, Hamm B, Lembcke A. Image quality of low-radiation dose left atrial CT using filtered back projection and an iterative reconstruction algorithm: intra-individual comparison in unselected patients undergoing pulmonary vein isolation. Acta Radiol 2018; 59:161-169. [PMID: 28513211 DOI: 10.1177/0284185117708472] [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] [Indexed: 12/20/2022]
Abstract
Background Computed tomography (CT) of the left atrium (LA) is performed prior to pulmonary vein isolation (PVI) to improve success of circumferential ablation for atrial fibrillation. The ablation procedure itself exposes patients to substantial radiation doses, therefore radiation dose reduction in pre-ablational imaging is of concern. Purpose To assess and compare diagnostic performance of low-radiation dose preprocedural CT in patients scheduled for PVI using two types of reconstruction algorithms. Material and Methods Forty-six patients (61 ± 10 years) scheduled for PVI were enrolled in this study irrespective of body-mass-index or cardiac rhythm at examination. An electrocardiographically triggered dual-source CT scan was performed. Filtered back projection (FBP) and iterative reconstruction (IR) algorithms were applied. Images were integrated into an electroanatomic mapping (EAM) system. Subjective image quality was scored independently by two readers on a five-point scale for both reconstruction algorithms (1 = excellent to 5 = non-diagnostic). Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and effective radiation dose were calculated. Results Data acquisition and EAM integration were successful in all patients. Median image quality score was 1 for both FBP (quartiles = 1, 1.62; range = 1-3) and IR (quartiles = 1, 1.5; range = 1-3). Mean SNR was 7.61 ± 2.14 for FBP and 9.02 ± 2.69 for IR. Mean CNR was 5.92 ± 1.80 for FBP and 6.95 ± 2.29 for IR. Mean effective radiation dose was 0.3 ± 0.1 mSv. Conclusion At a radiation dose of 0.3 ± 0.1 mSv, high-pitch dual-source CT yields LA images of consistently high quality using both FBP and IR. IR raises SNR and CNR without significantly improving subjective image quality.
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Affiliation(s)
- Ute Lina Fahlenkamp
- Department of Radiology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Ivan Diaz Ramirez
- Department of Cardiology, Charité – Universitätsmedizin, Berlin, Germany
| | - Moritz Wagner
- Department of Radiology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | | | - Alexander Huppertz
- Department of Radiology, Charité – Universitätsmedizin Berlin, Berlin, Germany
- Present address: Klinikum Ernst von Bergmann, Potsdam, Germany
| | - Bernd Hamm
- Department of Radiology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Alexander Lembcke
- Department of Radiology, Charité – Universitätsmedizin Berlin, Berlin, Germany
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Luhur R, Schuijf JD, Mews J, Blobel J, Hamm B, Lembcke A. Accuracy of coronary artery calcium scoring with tube current reduction by 75%, using an adaptive iterative reconstruction algorithm. Br J Radiol 2018; 91:20170678. [PMID: 29260893 DOI: 10.1259/bjr.20170678] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE To assess the accuracy of an iterative reconstruction (IR) technique for coronary artery calcium scoring with reduced radiation dose. METHODS 163 consecutive patients underwent twofold scanning by 320-row detector CT at 120 kVp. A low-dose scan at 25% tube current but with standard scan length (14 cm) was followed by a standard dose scan with routine tube current but reduced scan length (10 cm). Reduced dose images were constructed using filtered back-projection (FBP) and IR (adaptive iterative dose reduction in three dimensions). The standard dose scan reconstructed with FBP served as the gold standard for comparisons. Image noise and Agatston coronary calcium scores were determined and compared between the groups. RESULTS Compared with FBP at standard dose, noise at reduced dose increased markedly with FBP but remained low with IR. Mean Agatston score with FBP at reduced dose showed a significant increase as compared with FBP at standard dose. No significant difference was observed when applying IR at reduced dose. At reduced dose, 38 (23.3%) patients were reassigned to a different cardiovascular risk category with FBP but only 8 (4.9%) with IR. Out of 47 patients with a zero Agatston score, 15 patients (31.9%) were false-positive with FBP at reduced dose, but no false positives were found with IR. CONCLUSION IR allows accurate coronary artery calcium scoring with a radiation dose reduced by 75%. Advances in knowledge: The application of adaptive iterative dose reduction in three dimensions allows the maintenance of accurate Agatston scores and risk stratification at significantly reduced tube current, thus reducing the patient's exposure to ionizing radiation.
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Affiliation(s)
- Reny Luhur
- 1 Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Charité Mitte , Charité - Universitätsmedizin Berlin, Campus Charité Mitte , Berlin , Germany
| | - Joanne D Schuijf
- 2 Center for Medical Research & Development Europe,Toshiba Medical Systems Europe BV , Toshiba Medical Systems Europe BV , Zoetermeer , Netherlands
| | - Jürgen Mews
- 2 Center for Medical Research & Development Europe,Toshiba Medical Systems Europe BV , Toshiba Medical Systems Europe BV , Zoetermeer , Netherlands
| | - Jörg Blobel
- 2 Center for Medical Research & Development Europe,Toshiba Medical Systems Europe BV , Toshiba Medical Systems Europe BV , Zoetermeer , Netherlands
| | - Bernd Hamm
- 1 Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Charité Mitte , Charité - Universitätsmedizin Berlin, Campus Charité Mitte , Berlin , Germany
| | - Alexander Lembcke
- 1 Department of Radiology, Charité - Universitätsmedizin Berlin, Campus Charité Mitte , Charité - Universitätsmedizin Berlin, Campus Charité Mitte , Berlin , Germany
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Lee KB, Goo HW. Quantitative Image Quality and Histogram-Based Evaluations of an Iterative Reconstruction Algorithm at Low-to-Ultralow Radiation Dose Levels: A Phantom Study in Chest CT. Korean J Radiol 2018; 19:119-129. [PMID: 29354008 PMCID: PMC5768492 DOI: 10.3348/kjr.2018.19.1.119] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/28/2017] [Indexed: 01/17/2023] Open
Abstract
Objective To describe the quantitative image quality and histogram-based evaluation of an iterative reconstruction (IR) algorithm in chest computed tomography (CT) scans at low-to-ultralow CT radiation dose levels. Materials and Methods In an adult anthropomorphic phantom, chest CT scans were performed with 128-section dual-source CT at 70, 80, 100, 120, and 140 kVp, and the reference (3.4 mGy in volume CT Dose Index [CTDIvol]), 30%-, 60%-, and 90%-reduced radiation dose levels (2.4, 1.4, and 0.3 mGy). The CT images were reconstructed by using filtered back projection (FBP) algorithms and IR algorithm with strengths 1, 3, and 5. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were statistically compared between different dose levels, tube voltages, and reconstruction algorithms. Moreover, histograms of subtraction images before and after standardization in x- and y-axes were visually compared. Results Compared with FBP images, IR images with strengths 1, 3, and 5 demonstrated image noise reduction up to 49.1%, SNR increase up to 100.7%, and CNR increase up to 67.3%. Noteworthy image quality degradations on IR images including a 184.9% increase in image noise, 63.0% decrease in SNR, and 51.3% decrease in CNR, and were shown between 60% and 90% reduced levels of radiation dose (p < 0.0001). Subtraction histograms between FBP and IR images showed progressively increased dispersion with increased IR strength and increased dose reduction. After standardization, the histograms appeared deviated and ragged between FBP images and IR images with strength 3 or 5, but almost normally-distributed between FBP images and IR images with strength 1. Conclusion The IR algorithm may be used to save radiation doses without substantial image quality degradation in chest CT scanning of the adult anthropomorphic phantom, down to approximately 1.4 mGy in CTDIvol (60% reduced dose).
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Affiliation(s)
- Ki Baek Lee
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Hyun Woo Goo
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
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van der Werf NR, Willemink MJ, Willems TP, Greuter MJW, Leiner T. Influence of iterative reconstruction on coronary calcium scores at multiple heart rates: a multivendor phantom study on state-of-the-art CT systems. Int J Cardiovasc Imaging 2017; 34:947-957. [DOI: 10.1007/s10554-017-1292-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/19/2017] [Indexed: 10/18/2022]
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Tozakidou M, Reisinger C, Harder D, Lieb J, Szucs-Farkas Z, Müller-Gerbl M, Studler U, Schindera S, Hirschmann A. Systematic Radiation Dose Reduction in Cervical Spine CT of Human Cadaveric Specimens: How Low Can We Go? AJNR Am J Neuroradiol 2017; 39:385-391. [PMID: 29269403 DOI: 10.3174/ajnr.a5490] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 10/23/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE While the use of cervical spine CT in trauma settings has increased, the balance between image quality and dose reduction remains a concern. The purpose of our study was to compare the image quality of CT of the cervical spine of cadaveric specimens at different radiation dose levels. MATERIALS AND METHODS The cervical spine of 4 human cadavers (mean body mass index; 30.5 ± 5.2 kg/m2; range, 24-36 kg/m2) was examined using different reference tube current-time products (45, 75, 105, 135, 150, 165, 195, 275, 355 mAs) and a tube voltage of 120 kV(peak). Data were reconstructed with filtered back-projection and iterative reconstruction. Qualitative image noise and morphologic characteristics of bony structures were quantified on a Likert scale. Quantitative image noise was measured. Statistics included analysis of variance and the Tukey test. RESULTS Compared with filtered back-projection, iterative reconstruction provided significantly lower qualitative (mean noise score: iterative reconstruction = 2.10/filtered back-projection = 2.18; P = .003) and quantitative (mean SD of Hounsfield units in air: iterative reconstruction = 30.2/filtered back-projection = 51.8; P < .001) image noise. Image noise increased as the radiation dose decreased. Qualitative image noise at levels C1-4 was rated as either "no noise" or as "acceptable noise." Any shoulder position was at level C5 and caused more artifacts at lower levels. When we analyzed all spinal levels, scores for morphologic characteristics revealed no significant differences between 105 and 355 mAs (P = .555), but they were worse in scans at 75 mAs (P = .025). CONCLUSIONS Clinically acceptable image quality of cervical spine CTs for evaluation of bony structures of cadaveric specimens with different body habitus can be achieved with a reference mAs of 105 at 120 kVp with iterative reconstruction. Pull-down of shoulders during acquisition could improve image quality but may not be feasible in trauma patients with unknown injuries.
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Affiliation(s)
- M Tozakidou
- From the Clinic of Radiology and Nuclear Medicine (M.T., C.R., D.H., J.L., U.S., S.S., A.H.), University of Basel Hospital, Basel, Switzerland
| | - C Reisinger
- From the Clinic of Radiology and Nuclear Medicine (M.T., C.R., D.H., J.L., U.S., S.S., A.H.), University of Basel Hospital, Basel, Switzerland
| | - D Harder
- From the Clinic of Radiology and Nuclear Medicine (M.T., C.R., D.H., J.L., U.S., S.S., A.H.), University of Basel Hospital, Basel, Switzerland
| | - J Lieb
- From the Clinic of Radiology and Nuclear Medicine (M.T., C.R., D.H., J.L., U.S., S.S., A.H.), University of Basel Hospital, Basel, Switzerland
| | - Z Szucs-Farkas
- Department of Diagnostic Radiology (Z.S.-F.), Hospital Centre of Biel, Biel, Switzerland
| | - M Müller-Gerbl
- Institute of Anatomy (M.M.-G.), University of Basel, Basel, Switzerland
| | - U Studler
- From the Clinic of Radiology and Nuclear Medicine (M.T., C.R., D.H., J.L., U.S., S.S., A.H.), University of Basel Hospital, Basel, Switzerland
| | - S Schindera
- From the Clinic of Radiology and Nuclear Medicine (M.T., C.R., D.H., J.L., U.S., S.S., A.H.), University of Basel Hospital, Basel, Switzerland
| | - A Hirschmann
- From the Clinic of Radiology and Nuclear Medicine (M.T., C.R., D.H., J.L., U.S., S.S., A.H.), University of Basel Hospital, Basel, Switzerland
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Stellenwert der Herz-CT in der Diagnostik der koronaren Herzerkrankung. ZEITSCHRIFT FUR HERZ THORAX UND GEFASSCHIRURGIE 2017. [DOI: 10.1007/s00398-017-0190-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Nam S, Jeong D, Choo K, Nam K, Hwang JY, Lee J, Kim J, Lim S. Image quality of CT angiography in young children with congenital heart disease: a comparison between the sinogram-affirmed iterative reconstruction (SAFIRE) and advanced modelled iterative reconstruction (ADMIRE) algorithms. Clin Radiol 2017; 72:1060-1065. [DOI: 10.1016/j.crad.2017.07.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 06/20/2017] [Accepted: 07/06/2017] [Indexed: 01/21/2023]
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Diagnostic accuracy of low and high tube voltage coronary CT angiography using an X-ray tube potential-tailored contrast medium injection protocol. Eur Radiol 2017; 28:2134-2142. [PMID: 29181587 DOI: 10.1007/s00330-017-5150-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 09/07/2017] [Accepted: 10/18/2017] [Indexed: 12/12/2022]
Abstract
OBJECTIVES To compare the diagnostic accuracy between low-kilovolt peak (kVp) (≤ 100) and high-kVp (> 100) third-generation dual-source coronary CT angiography (CCTA) using a kVp-tailored contrast media injection protocol. METHODS One hundred twenty patients (mean age = 62.6 years, BMI = 29.0 kg/m2) who underwent catheter angiography and CCTA with automated kVp selection were separated into two cohorts (each n = 60, mean kVp = 84 and 117). Contrast media dose was tailored to the kVp level: 70 = 40 ml, 80 = 50 ml, 90 = 60 ml, 100 = 70 ml, 110 = 80 ml, and 120 = 90 ml. Contrast-to-noise ratio (CNR) was measured. Two observers evaluated image quality and the presence of significant coronary stenosis (> 50% luminal narrowing). RESULTS Diagnostic accuracy (sensitivity/specificity) with ≤ 100 vs. > 100 kVp CCTA was comparable: per patient = 93.9/92.6% vs. 90.9/92.6%, per vessel = 91.5/97.8% vs. 94.0/96.8%, and per segment = 90.0/96.7% vs. 90.7/95.2% (all P > 0.64). CNR was similar (P > 0.18) in the low-kVp vs. high-kVp group (12.0 vs. 11.1), as ws subjective image quality (P = 0.38). Contrast media requirements were reduced by 38.1% in the low- vs. high-kVp cohort (53.6 vs. 86.6 ml, P < 0.001) and radiation dose by 59.6% (4.3 vs. 10.6 mSv, P < 0.001). CONCLUSIONS Automated tube voltage selection with a tailored contrast media injection protocol allows CCTA to be performed at ≤ 100 kVp with substantial dose reductions and equivalent diagnostic accuracy for coronary stenosis detection compared to acquisitions at > 100 kVp. KEY POINTS • Low-kVp coronary CT angiography (CCTA) enables reduced contrast and radiation dose. • Diagnostic accuracy is comparable between ≤ 100 and > 100 kVp CCTA. • Image quality is similar for low- and high-kVp CCTA. • Low-kVp image acquisition is facilitated by automated tube voltage selection. • Tailoring contrast injection protocols to the automatically selected kVp-level is feasible.
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Halliburton SS, Tanabe Y, Partovi S, Rajiah P. The role of advanced reconstruction algorithms in cardiac CT. Cardiovasc Diagn Ther 2017; 7:527-538. [PMID: 29255694 DOI: 10.21037/cdt.2017.08.12] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Non-linear iterative reconstruction (IR) algorithms have been increasingly incorporated into clinical cardiac CT protocols at institutions around the world. Multiple IR algorithms are available commercially from various vendors. IR algorithms decrease image noise and are primarily used to enable lower radiation dose protocols. IR can also be used to improve image quality for imaging of obese patients, coronary atherosclerotic plaques, coronary stents, and myocardial perfusion. In this article, we will review the various applications of IR algorithms in cardiac imaging and evaluate how they have changed practice.
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Affiliation(s)
| | - Yuki Tanabe
- Cardiothoracic Imaging, Radiology Department, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sasan Partovi
- University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Prabhakar Rajiah
- Cardiothoracic Imaging, Radiology Department, UT Southwestern Medical Center, Dallas, TX, USA
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Iterative beam-hardening correction with advanced modeled iterative reconstruction in low voltage CT coronary calcium scoring with tin filtration: Impact on coronary artery calcium quantification and image quality. J Cardiovasc Comput Tomogr 2017; 11:354-359. [DOI: 10.1016/j.jcct.2017.07.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 07/06/2017] [Accepted: 07/23/2017] [Indexed: 11/23/2022]
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Iterative reconstruction improves detection of in-stent restenosis by high-pitch dual-source coronary CT angiography. Sci Rep 2017; 7:6956. [PMID: 28761180 PMCID: PMC5537291 DOI: 10.1038/s41598-017-07499-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 06/27/2017] [Indexed: 01/13/2023] Open
Abstract
Recent studies demonstrated that sinogram affirmed iterative reconstructions (SAFIRE) can produce higher-resolution images with greater robustness for the reduction of various imaging artefacts. Eighty-five patients were prospectively evaluated and underwent a high-pitch spiral acquisition CT scan. In-stent noise, signal-to-noise ratio(SNR), stent-lumen attenuation increase ratio (SAIR), and subjective image quality score were measured and compared between the SAFIRE and Filter back projection (FBP) reconstructions. Conventional coronary angiography served as the standard of reference. In 159 evaluated stents, SAFIRE was superior to FBP with regards to in-stent noise, SNR, SAIR, and image quality score. On per-stent analysis, SAFIRE vs. FBP reconstruction yielded 85% vs. 85%sensitivity, 89% vs. 78%specificity, 73% vs. 57%positive predictive value, 95% vs. 94%negative predictive value, and 0.87 vs. 0.82 area under curve, although these improvements did not reach statistical significance (P > 0.05). However, in the subgroup of small diameter stents (≤3 mm; n = 95), specificity(82% vs. 62%), positive predictive value(66% vs. 50%) and area under curve (0.81 vs. 0.70) improved significantly (P < 0.05) with SAFIRE. SAFIRE image reconstruction can thus improve the evaluation for ISR, especially in smaller stents.
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