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Mihailidis DN, Stratis A, Gingold E, Carlson R, DeForest W, Gray J, Lally MT, Pizzutiello R, Rong J, Spelic D, Hilohi MC, Massoth R. AAPM Task Group Report 261: Comprehensive quality control methodology and management of dental and maxillofacial cone beam computed tomography (CBCT) systems. Med Phys 2024; 51:3134-3164. [PMID: 38285566 DOI: 10.1002/mp.16911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 11/16/2023] [Accepted: 11/16/2023] [Indexed: 01/31/2024] Open
Abstract
Cone-beam computed tomography (CBCT) systems specifically designed and manufactured for dental, maxillofacial imaging (MFI) and otolaryngology (OLR) applications have been commercially available in the United States since 2001 and have been in widespread clinical use since. Until recently, there has been a lack of professional guidance available for medical physicists about how to assess and evaluate the performance of these systems and about the establishment and management of quality control (QC) programs. The owners and users of dental CBCT systems may have only a rudimentary understanding of this technology, including how it differs from conventional multidetector CT (MDCT) in terms of acceptable radiation safety practices. Dental CBCT systems differ from MDCT in several ways and these differences are described. This report provides guidance to medical physicists and serves as a basis for stakeholders to make informed decisions regarding how to manage and develop a QC program for dental CBCT systems. It is important that a medical physicist with experience in dental CBCT serves as a resource on this technology and the associated radiation protection best practices. The medical physicist should be involved at the pre-installation stage to ensure that a CBCT room configuration allows for a safe and efficient workflow and that structural shielding, if needed, is designed into the architectural plans. Acceptance testing of new installations should include assessment of mechanical alignment of patient positioning lasers and x-ray beam collimation and benchmarking of essential image quality performance parameters such as image uniformity, noise, contrast-to-noise ratio (CNR), spatial resolution, and artifacts. Several approaches for quantifying radiation output from these systems are described, including simply measuring the incident air-kerma (Kair) at the entrance surface of the image receptor. These measurements are to be repeated at least annually as part of routine QC by the medical physicist. QC programs for dental CBCT, at least in the United States, are often driven by state regulations, accreditation program requirements, or manufacturer recommendations.
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Affiliation(s)
- Dimitris N Mihailidis
- University of Pennsylvania, Perelman Center for Advanced Medicine, Philadelphia, Pennsylvania, USA
| | | | - Eric Gingold
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Ray Carlson
- Radiological Physics Services, Inc, Plymouth, Michigan, USA
| | | | | | - Mary T Lally
- Intersocietal Accreditation Commission, Ellicott City, Maryland, USA
| | | | - John Rong
- Department of Imaging Physics, UT MD Anderson Cancer Center, Houston, Texas, USA
| | - David Spelic
- Food and Drug Administration, Center for Device and Radiological Health, Silver Spring, Maryland, USA
| | - Mike C Hilohi
- Food and Drug Administration, Center for Device and Radiological Health, Silver Spring, Maryland, USA
| | - Richard Massoth
- Sunflower Medical Physics, LLC, Sioux Falls, South Dakota, USA
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Agostini A, Borgheresi A, Mariotti F, Ottaviani L, Carotti M, Valenti M, Giovagnoni A. New frontiers in oncological imaging with Computed Tomography: from morphology to function. Semin Ultrasound CT MR 2023; 44:214-227. [PMID: 37245886 DOI: 10.1053/j.sult.2023.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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Shehata S, Abdulmonaem G, Gamal A, Assy M. Spectrum of thoracic systemic venous abnormalities using multidetector computed tomography. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2022. [DOI: 10.1186/s43055-022-00756-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Anomalies of the thoracic systemic venous return vary widely and range from those with completely normal physiology to severe right to left shunting thus requiring surgical correction. The aim of the study is to enhance the awareness of multidetector computed tomography (MDCT) role in evaluation of systemic venous abnormalities, and be familiar with the imaging characteristics of even the extremely rare abnormalities.
Results
Among 270 examined patients, 15.19% had systemic venous abnormalities. Inferior vena cava (IVC) congenital anomalies accounted for (24.4%) of the detected abnormalities (prevalence: 3.7% among the studied population) where IVC interruption with azygos continuation was the most common detected IVC abnormality accounting for 17.7% of the detected abnormalities (prevalence: 2.6%), while IVC thrombosis accounted for 21.9% (prevalence: 3.3%). Persistent left sided superior vena cava (SVC) accounted for 14.6% of the detected abnormalities (prevalence: 2.2%), while SVC syndrome represented 19.5% (prevalence: 2.9%) and SVC aneurysm represented 2.4% (prevalence: 0.37%). Retroaortic brachiocephalic vein (BCV) and BCV thrombosis accounted for 7.3% each (prevalence: 1.1). Finally, persistent levo-atrial cardinal vein represented 2.4% of the detected abnormalities (prevalence: 0.37%).
Conclusions
MDCT is a non-invasive modality that can provide detailed information about the systemic thoracic veins before surgical or interventional procedures, especially in patients with congenital anomalies.
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Toia GV, Mileto A, Wang CL, Sahani DV. Quantitative dual-energy CT techniques in the abdomen. Abdom Radiol (NY) 2022; 47:3003-3018. [PMID: 34468796 DOI: 10.1007/s00261-021-03266-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 02/06/2023]
Abstract
Advances in dual-energy CT (DECT) technology and spectral techniques are catalyzing the widespread implementation of this technology across multiple radiology subspecialties. The inclusion of energy- and material-specific datasets has ushered overall improvements in CT image contrast and noise as well as artifacts reduction, leading to considerable progress in radiologists' ability to detect and characterize pathologies in the abdomen. The scope of this article is to provide an overview of various quantitative clinical DECT applications in the abdomen and pelvis. Several of the reviewed applications have not reached mainstream clinical use and are considered investigational. Nonetheless awareness of such applications is critical to having a fully comprehensive knowledge base to DECT and fostering future clinical implementation.
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Affiliation(s)
- Giuseppe V Toia
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, Mailbox 3252, Madison, WI, 53792, USA.
| | - Achille Mileto
- Department of Radiology, Mayo Clinic, 200 First Street, SW, Rochester, MN, 55905, USA
| | - Carolyn L Wang
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| | - Dushyant V Sahani
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Seattle, WA, 98195, USA
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van der Werf NR, Rodesch PA, Si-Mohamed S, van Hamersvelt RW, Greuter MJW, Leiner T, Boussel L, Willemink MJ, Douek P. Improved coronary calcium detection and quantification with low-dose full field-of-view photon-counting CT: a phantom study. Eur Radiol 2022; 32:3447-3457. [PMID: 34997284 DOI: 10.1007/s00330-021-08421-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 08/31/2021] [Accepted: 10/17/2021] [Indexed: 12/19/2022]
Abstract
OBJECTIVE The aim of the current study was to systematically assess coronary artery calcium (CAC) detection and quantification for spectral photon-counting CT (SPCCT) in comparison to conventional CT and, in addition, to evaluate the possibility of radiation dose reduction. METHODS Routine clinical CAC CT protocols were used for data acquisition and reconstruction of two CAC containing cylindrical inserts which were positioned within an anthropomorphic thorax phantom. In addition, data was acquired at 50% lower radiation dose by reducing tube current, and slice thickness was decreased. Calcifications were considered detectable when three adjacent voxels exceeded the CAC scoring threshold of 130 Hounsfield units (HU). Quantification of CAC (as volume and mass score) was assessed by comparison with known physical quantities. RESULTS In comparison with CT, SPCCT detected 33% and 7% more calcifications for the small and large phantoms, respectively. At reduced radiation dose and reduced slice thickness, small phantom CAC detection increased by 108% and 150% for CT and SPCCT, respectively. For the large phantom size, noise levels interfered with CAC detection. Although comparable between CT and SPCCT, routine protocols CAC quantification showed large deviations (up to 134%) from physical CAC volume. At reduced radiation dose and slice thickness, physical volume overestimations decreased to 96% and 72% for CT and SPCCT, respectively. In comparison with volume scores, mass score deviations from physical quantities were smaller. CONCLUSION CAC detection on SPCCT is superior to CT, and was even preserved at a reduced radiation dose. Furthermore, SPCCT allows for improved physical volume estimation. KEY POINTS • In comparison with conventional CT, increased coronary artery calcium detection (up to 156%) for spectral photon-counting CT was found, even at 50% radiation dose reduction. • Spectral photon-counting CT can more accurately measure physical volumes than conventional CT, especially at reduced slice thickness and for high-density coronary artery calcium. • For both conventional and spectral photon-counting CT, reduced slice thickness reconstructions result in more accurate physical mass approximation.
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Affiliation(s)
- N R van der Werf
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands. .,Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - P A Rodesch
- Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Lyon, France.,Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, Lyon, France
| | - S Si-Mohamed
- Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Lyon, France.,Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, Lyon, France
| | - R W van Hamersvelt
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - M J W Greuter
- Department of Radiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - T Leiner
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - L Boussel
- Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Lyon, France.,Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, Lyon, France
| | - M J Willemink
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - P Douek
- Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Lyon, France.,Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, Lyon, France
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Li K, Li Y, Qi Z, Garrett JW, Grist TM, Chen GH. Quantitative lung perfusion blood volume using dual energy CT-based effective atomic number (Z eff ) imaging. Med Phys 2021; 48:6658-6672. [PMID: 34520066 PMCID: PMC8595877 DOI: 10.1002/mp.15227] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 08/31/2021] [Accepted: 09/06/2021] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Iodine material images (aka iodine basis images) generated from dual energy computed tomography (DECT) have been used to assess potential perfusion defects in the pulmonary parenchyma. However, iodine material images do not provide the needed absolute quantification of the pulmonary blood pool, as materials with effective atomic numbers (Zeff ) different from those of basis materials may also contribute to iodine material images, thus confounding the quantification of perfusion defects. PURPOSE (i) To demonstrate the limitations of iodine material images in pulmonary perfusion defect quantification and (ii) to develop and validate a new quantitative biomarker using effective atomic numbers derived from DECT images. METHODS The quantitative relationship between the perfusion blood volume (PBV) in pulmonary parenchyma and the effective atomic number (Zeff ) spatial distribution was studied to show that the desired quantitative PBV maps are determined by the spatial maps of Zeff as PB V Z eff ( x ) = a Z eff β ( x ) + b , where a, b, and β are three constants. Namely, quantitative PB V Z eff is determined by Zeff images instead of the iodine basis images. Perfusion maps were generated for four human subjects to demonstrate the differences between conventional iodine material image-based PBV (PBViodine ) derived from two-material decompositions and the proposed PB V Z eff method. RESULTS Among patients with pulmonary emboli, the proposed PB V Z eff maps clearly show the perfusion defects while the PBViodine maps do not. Additionally, when there are no perfusion defects present in the derived PBV maps, no pulmonary emboli were diagnosed by an experienced thoracic radiologist. CONCLUSION Effective atomic number-based quantitative PBV maps provide the needed sensitive and specific biomarker to quantify pulmonary perfusion defects.
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Affiliation(s)
- Ke Li
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Yinsheng Li
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Zhihua Qi
- Department of Radiology, Henry Ford Health System, Detroit, Michigan, USA
| | - John W. Garrett
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Thomas M. Grist
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Guang-Hong Chen
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA
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van Praagh GD, van der Werf NR, Wang J, van Ommen F, Poelhekken K, Slart RHJA, Fleischmann D, Greuter MJW, Leiner T, Willemink MJ. Fully automated quantification method (FQM) of coronary calcium in an anthropomorphic phantom. Med Phys 2021; 48:3730-3740. [PMID: 33932026 PMCID: PMC8360117 DOI: 10.1002/mp.14912] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 02/19/2021] [Accepted: 04/15/2021] [Indexed: 12/23/2022] Open
Abstract
Objective Coronary artery calcium (CAC) score is a strong predictor for future adverse cardiovascular events. Anthropomorphic phantoms are often used for CAC studies on computed tomography (CT) to allow for evaluation or variation of scanning or reconstruction parameters within or across scanners against a reference standard. This often results in large number of datasets. Manual assessment of these large datasets is time consuming and cumbersome. Therefore, this study aimed to develop and validate a fully automated, open‐source quantification method (FQM) for coronary calcium in a standardized phantom. Materials and Methods A standard, commercially available anthropomorphic thorax phantom was used with an insert containing nine calcifications with different sizes and densities. To simulate two different patient sizes, an extension ring was used. Image data were acquired with four state‐of‐the‐art CT systems using routine CAC scoring acquisition protocols. For interscan variability, each acquisition was repeated five times with small translations and/or rotations. Vendor‐specific CAC scores (Agatston, volume, and mass) were calculated as reference scores using vendor‐specific software. Both the international standard CAC quantification methods as well as vendor‐specific adjustments were implemented in FQM. Reference and FQM scores were compared using Bland‐Altman analysis, intraclass correlation coefficients, risk reclassifications, and Cohen’s kappa. Also, robustness of FQM was assessed using varied acquisitions and reconstruction settings and validation on a dynamic phantom. Further, image quality metrics were implemented: noise power spectrum, task transfer function, and contrast‐ and signal‐to‐noise ratio among others. Results were validated using imQuest software. Results Three parameters in CAC scoring methods varied among the different vendor‐specific software packages: the Hounsfield unit (HU) threshold, the minimum area used to designate a group of voxels as calcium, and the usage of isotropic voxels for the volume score. The FQM was in high agreement with vendor‐specific scores and ICC’s (median [95% CI]) were excellent (1.000 [0.999‐1.000] to 1.000 [1.000‐1.000]). An excellent interplatform reliability of κ = 0.969 and κ = 0.973 was found. TTF results gave a maximum deviation of 3.8% and NPS results were comparable to imQuest. Conclusions We developed a fully automated, open‐source, robust method to quantify CAC on CT scans in a commercially available phantom. Also, the automated algorithm contains image quality assessment for fast comparison of differences in acquisition and reconstruction parameters.
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Affiliation(s)
- Gijs D van Praagh
- Department of Nuclear Medicine and Molecular Imaging, Medical Imaging Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Niels R van der Werf
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Radiology and Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Jia Wang
- Department of Environmental Health and Safety, Stanford University, Stanford, CA, USA
| | - Fasco van Ommen
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Keris Poelhekken
- Department of Radiology, Medical Imaging Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Riemer H J A Slart
- Department of Nuclear Medicine and Molecular Imaging, Medical Imaging Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Department of Biomedical Photonic Imaging, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Dominik Fleischmann
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Marcel J W Greuter
- Department of Radiology, Medical Imaging Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Department of Robotics and Mechatronics, University of Twente, Enschede, The Netherlands
| | - Tim Leiner
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Martin J Willemink
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
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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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Alikhani B, Werner M, Jamali L, Wacker F, Werncke T. Image Quality Performance of Virtual Single-Source CT Using Dual-Source Computed Tomography. Acad Radiol 2019; 26:1095-1101. [PMID: 30482627 DOI: 10.1016/j.acra.2018.09.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 09/03/2018] [Accepted: 09/24/2018] [Indexed: 10/28/2022]
Abstract
RATIONALE AND OBJECTIVES The aim of this study is to analyze the image quality provided by a dual-source (DS) data set and a single-source (SS) data set at the same radiation exposure, in order to evaluate a dose splitting method for dual-source scanning protocols. MATERIALS AND METHODS A 192-slice dual-source third generation CT (Somatom Force; Siemens Healthcare, Forchheim, Germany) was used to image a Catphan phantom (Catphan503; The Phantom Laboratory, Salem, New York) utilizing different X-ray tube voltages from 70 to 120 kVp with an organ-based tube-current modulation technique (X-CARE; Siemens Healthcare, Forchheim, Germany). In order to keep the radiation dose (given by volume computed tomography dose index) in a clinically relevant range, different X-ray tube time-current products ranging from 80 to 300 mAs were selected. The data sets by each X-ray tube voltage were collected using a single-source as well as a dual-source mode. The measurements in the dual-source mode were performed with five different tube currents of the X-ray tube A and B. Thereby, the tube current ratios were 50%|50% (DS 0.5), 60%|40% (DS 0.6), 70%|30% (DS 0.7), 80%|20% (DS 0.8), and 90%|10% (DS 0.9). The images were reconstructed by the use of a filter-back projection (Br40) and an advanced mode led iterative reconstruction algorithms (advanced modeled iterative reconstruction algorithms [ADMIRE]; Siemens Healthcare, Forchheim, Germany) with a strength range of 1-5. The image quality was evaluated in terms of noise, contrast-to-noise ratio (CNR), low-contrast detectability expressed as the structural similarity index (SSIM) and spatial resolution quantified by the full width at half maximum of the line-spread function. RESULTS Image noise decreased by the use of the dual-source mode, which led to improvement of their CNR compared to the single-source mode. SSIM showed an almost constant behavior by both modes. The spatial resolution indicated a lower trend by the dual-source mode in comparison to the single-source mode. However, the loss of the spatial resolution performance was lower than 5% for the dual-source modes. CONCLUSION The presented phantom study demonstrated that SSIM and spatial resolution performance obtained by dual-source CT protocols showed a negligible variation to those by the single-source CT. However, the noise and CNR displayed an improvement for the dual-source CT. Therefore, the use of the dual-source CT enables to split the radiation dose between X-ray tubes and to compare the data sets with different radiation dose levels without loss in the image quality.
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Affiliation(s)
- Babak Alikhani
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany; Center for Radiology and Nuclear Medicine, DIAKOVERE gGmbH, Hannover, Germany.
| | - Martin Werner
- Institute for Radiation Therapy and Special Oncology, Hannover Medical School, Hannover, Germany
| | - Leila Jamali
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Frank Wacker
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | - Thomas Werncke
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
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Zhang Y, Yang ZG, Yang MX, Shi K, Li R, Diao KY, Guo YK. Common atrium and the associated malformations: Evaluation by low-dose dual-source computed tomography. Medicine (Baltimore) 2018; 97:e12983. [PMID: 30431572 PMCID: PMC6257481 DOI: 10.1097/md.0000000000012983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Common atrium (CA) is a rare complex congenital heart disease. The studies of CA are mostly case reports, while few have been done regarding its morphological characteristics. We aimed to determine CA characteristics and diagnostic accuracy in assessing associated malformations in these patients with low-dose dual-source computed tomography (DSCT).Twenty-one pediatric and adolescent CA patients underwent low-dose DSCT. Different ventricular types and associated malformations were assessed. The diagnostic accuracy of DSCT and transthoracic echocardiography (TTE) in evaluating associated malformations were assessed. The effective doses of DSCT were calculated.Patients (n = 21) were divided into CA with biventricular physiology (n = 7) and CA with single ventricle (SV) (n = 14). There were 3 types of SV morphology: single left ventricle (n = 5), single right ventricle (n = 6), and undifferentiated ventricle (n = 3). In all, 22 associated malformations were seen in CA and 56 in CA with SV. DSCT was superior to TTE for detecting intracardiac anomalies (sensitivity: DSCT, 92.31% vs TTE, 76.92%), great vessels anomalies (sensitivity: DSCT, 100.00% vs TTE, 77.50%), and of collateral vessels (sensitivity: DSCT, 100% vs TTE, 20.00%). The estimated mean effective dose was 0.95 ± 0.44 mSv (<1 mSv).This study indicated that low-dose DSCT is an ideal alternative for pediatric and adolescent patients with CA, providing morphological details of CA and associated malformations with high accuracy.
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Affiliation(s)
- Yi Zhang
- Department of Radiology, National Key Laboratory of Biotherapy, West China Hospital
| | | | - Meng-xi Yang
- Department of Radiology, National Key Laboratory of Biotherapy, West China Hospital
| | | | | | | | - Ying-kun Guo
- Department of Radiology, Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, China
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11
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Vernuccio F, Meyer M, Mileto A, Marin D. Use of Dual-Energy Computed Tomography for Evaluation of Genitourinary Diseases. Urol Clin North Am 2018; 45:297-310. [PMID: 30031456 DOI: 10.1016/j.ucl.2018.03.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Since its clinical inception a decade ago, dual-energy computed tomography has expanded the array of computed tomography imaging tools available to the practicing abdominal radiologist. Of note, diagnostic solutions for imaging-based evaluation of genitourinary diseases, foremost kidney calculi and renal tumors characterization, represent the apogee applications of dual-energy computed tomography in abdominal imaging. This article reviews clinical applications of dual-energy computed tomography for the assessment of genitourinary diseases.
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Affiliation(s)
- Federica Vernuccio
- Department of Radiology, Duke University Medical Center, Box 3808 Erwin Road, Durham, NC 27710, USA; Section of Radiology -Di.Bi.Med., University Hospital "Paolo Giaccone", University of Palermo, Via del Vespro 129, 90127, Palermo, Italy
| | - Mathias Meyer
- Department of Radiology, Duke University Medical Center, Box 3808 Erwin Road, Durham, NC 27710, USA
| | - Achille Mileto
- Department of Radiology, University of Washington School of Medicine, Box 357115, 1959 Northeast Pacific Street, Seattle, WA 98195, USA
| | - Daniele Marin
- Department of Radiology, Duke University Medical Center, Box 3808 Erwin Road, Durham, NC 27710, USA.
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Hu BY, Shi K, Deng YP, Diao KY, Xu HY, Li R, Yang ZG, Guo YK. Assessment of tetralogy of Fallot-associated congenital extracardiac vascular anomalies in pediatric patients using low-dose dual-source computed tomography. BMC Cardiovasc Disord 2017; 17:285. [PMID: 29202750 PMCID: PMC5715549 DOI: 10.1186/s12872-017-0718-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 11/21/2017] [Indexed: 02/05/2023] Open
Abstract
Background To investigate the diagnostic value of dual-source computed tomography (DSCT) in the evaluation of tetralogy of Fallot (TOF)-associated extracardiac vascular abnormalities in pediatric patients compared with transthoracic echocardiography (TTE). Methods One hundred and twenty-three pediatric patients diagnosed with TOF were included in this retrospective study. All patients underwent DSCT and TTE preoperatively. All associated extracardiac vascular abnormalities and their percentages were recorded. The diagnostic performances of DSCT and TTE were compared based on the surgical results. The image quality of DSCT was rated, and the effective radiation dose (ED) was calculated. Results A total of 159 associated extracardiac vascular deformities were confirmed by surgery. Patent ductus arteriosus (36, 22.64%), right-sided aortic arch (29, 18.24%), and pulmonary valve stenosis (23, 14.47%) were the most common associated extracardiac vascular abnormalities. DSCT was superior to TTE in demonstrating associated extracardiac anomalies (diagnostic accuracy: 99.13% vs. 97.39%; sensitivity: 92.45% vs. 77.07%; specificity: 99.81% vs. 99.42%). The agreement on grading the image quality of DSCT was excellent (κ = 0.80), and the mean score of the image quality was 3.39 ± 0.50. The mean ED of DSCT was 0.86 ± 0.47 mSv. Conclusions Compared to TTE, low-dose DSCT has high diagnostic accuracy in the depiction of associated extracardiac vascular anomalies in pediatric patients with TOF, and could provide more morphological details for surgeons.
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Affiliation(s)
- Bi-Yue Hu
- Department of Radiology, West China Hospital, Sichuan University, 37# Guo Xue Xiang, Chengdu, Sichuan, 610041, China
| | - Ke Shi
- Department of Radiology, West China Hospital, Sichuan University, 37# Guo Xue Xiang, Chengdu, Sichuan, 610041, China
| | - Yu-Ping Deng
- Department of Radiology, The Medical Centre Hospital of Qionglai City, 172# Xinlin Road, Qionglai, Chengdu, Sichuan, 611530, China
| | - Kai-Yue Diao
- Department of Radiology, West China Hospital, Sichuan University, 37# Guo Xue Xiang, Chengdu, Sichuan, 610041, China
| | - Hua-Yan Xu
- Department of Radiology, West China Hospital, Sichuan University, 37# Guo Xue Xiang, Chengdu, Sichuan, 610041, China
| | - Rui Li
- Department of Radiology, West China Hospital, Sichuan University, 37# Guo Xue Xiang, Chengdu, Sichuan, 610041, China
| | - Zhi-Gang Yang
- Department of Radiology, West China Hospital, Sichuan University, 37# Guo Xue Xiang, Chengdu, Sichuan, 610041, China.
| | - Ying-Kun Guo
- Department of Radiology, West China Second University Hospital, Sichuan University, 20# Section 3 South Renmin Road, Chengdu, Sichuan, 610041, China
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Marino MA, Silipigni S, Barbaro U, Mazziotti S, Sofia C, Mazzei MA, Ascenti G. Dual Energy CT Scanning in Evaluation of the Urinary Tract. CURRENT RADIOLOGY REPORTS 2017. [DOI: 10.1007/s40134-017-0243-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Xue Y, Ruan R, Hu X, Kuang Y, Wang J, Long Y, Niu T. Statistical image-domain multimaterial decomposition for dual-energy CT. Med Phys 2017; 44:886-901. [PMID: 28060999 DOI: 10.1002/mp.12096] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 12/12/2016] [Accepted: 12/27/2016] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Dual-energy CT (DECT) enhances tissue characterization because of its basis material decomposition capability. In addition to conventional two-material decomposition from DECT measurements, multimaterial decomposition (MMD) is required in many clinical applications. To solve the ill-posed problem of reconstructing multi-material images from dual-energy measurements, additional constraints are incorporated into the formulation, including volume and mass conservation and the assumptions that there are at most three materials in each pixel and various material types among pixels. The recently proposed flexible image-domain MMD method decomposes pixels sequentially into multiple basis materials using a direct inversion scheme which leads to magnified noise in the material images. In this paper, we propose a statistical image-domain MMD method for DECT to suppress the noise. METHODS The proposed method applies penalized weighted least-square (PWLS) reconstruction with a negative log-likelihood term and edge-preserving regularization for each material. The statistical weight is determined by a data-based method accounting for the noise variance of high- and low-energy CT images. We apply the optimization transfer principles to design a serial of pixel-wise separable quadratic surrogates (PWSQS) functions which monotonically decrease the cost function. The separability in each pixel enables the simultaneous update of all pixels. RESULTS The proposed method is evaluated on a digital phantom, Catphan©600 phantom and three patients (pelvis, head, and thigh). We also implement the direct inversion and low-pass filtration methods for a comparison purpose. Compared with the direct inversion method, the proposed method reduces noise standard deviation (STD) in soft tissue by 95.35% in the digital phantom study, by 88.01% in the Catphan©600 phantom study, by 92.45% in the pelvis patient study, by 60.21% in the head patient study, and by 81.22% in the thigh patient study, respectively. The overall volume fraction accuracy is improved by around 6.85%. Compared with the low-pass filtration method, the root-mean-square percentage error (RMSE(%)) of electron densities in the Catphan©600 phantom is decreased by 20.89%. As modulation transfer function (MTF) magnitude decreased to 50%, the proposed method increases the spatial resolution by an overall factor of 1.64 on the digital phantom, and 2.16 on the Catphan©600 phantom. The overall volume fraction accuracy is increased by 6.15%. CONCLUSIONS We proposed a statistical image-domain MMD method using DECT measurements. The method successfully suppresses the magnified noise while faithfully retaining the quantification accuracy and anatomical structure in the decomposed material images. The proposed method is practical and promising for advanced clinical applications using DECT imaging.
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Affiliation(s)
- Yi Xue
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang, 310009, China.,Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, Zhejiang, 310009, China
| | - Ruoshui Ruan
- University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiuhua Hu
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang, 310009, China
| | - Yu Kuang
- Department of Medical Physics, University of Nevada, 4505 S Maryland Pkwy Box 453037, Las Vegas, NV, 89154-3037, USA
| | - Jing Wang
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang, 310009, China
| | - Yong Long
- University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Tianye Niu
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang, 310009, China.,Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, Zhejiang, 310009, China
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15
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Abstract
Reignited by innovations in scanner engineering and software design, dual-energy computed tomography (CT) has come back into the clinical radiology arena in the last decade. Possibilities for noninvasive in vivo characterization of genitourinary disease, especially for renal stones and renal masses, have become the pinnacle offerings of dual-energy CT for body imaging in clinical practice. This article renders a state-of-the-art review on clinical applications of dual-energy CT in genitourinary imaging.
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Affiliation(s)
- Achille Mileto
- Department of Radiology, University of Washington School of Medicine, Box 357115, 1959 Northeast Pacific Street, Seattle, WA 98195, USA
| | - Daniele Marin
- Department of Radiology, Duke University Medical Center, Box 3808 Erwin Road, Durham, NC 27710, USA.
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Evaluation of High-Pitch Ungated Pediatric Cardiovascular Computed Tomography for the Assessment of Cardiac Structures in Neonates. J Thorac Imaging 2017; 31:177-82. [PMID: 27007667 DOI: 10.1097/rti.0000000000000201] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE We evaluated a high-pitch, non-electrocardiogram-gated cardiac computed tomographic protocol, designed to image both cardiac and extracardiac structures, including coronary arteries, in a neonatal population (less than 1 year old) that was referred for congenital heart disease assessment and compared it with an optimized standard-pitch protocol in an equivalent cohort. MATERIALS AND METHODS Twenty-nine high-pitch scans were compared with 31 age-matched, sex-matched, and weight-matched standard-pitch, dosimetrically equivalent scans. The visualization and subjective quality of both cardiac and extracardiac structures were scored by consensus between 2 trained blinded observers. Image noise, signal-to-noise and contrast-to-noise ratios, and radiation doses were also compared. RESULTS The high-pitch protocol better demonstrated the pulmonary veins (P=0.03) and all coronary segments (all P<0.05), except the distal right coronary artery (P=0.10), with no significant difference in the visualization of the remaining cardiac or extracardiac structures. Both contrast-to-noise and signal-to-noise ratios improved due to greater vessel opacity, with significantly fewer streak (P<0.01) and motion (P<0.01) artifacts. Image noise and computed tomographic dose index were comparable across the 2 techniques; however, the high-pitch acquisition resulted in a small, but statistically significant, increase in dose-length product [13.0 mGy.cm (9.0 to 17.3) vs. 11.0 mGy.cm (9.0 to 13.0), P=0.05] due to greater z-overscanning. CONCLUSIONS In neonates, a high-pitch protocol improves coronary artery and pulmonary vein delineation compared with the standard-pitch protocol, allowing a more comprehensive assessment of cardiovascular anatomy while obviating the need for either patient sedation or heart rate control.
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Strategies to Lessen the Radiation Risk from CT: A Multination Perspective. CURRENT RADIOLOGY REPORTS 2016. [DOI: 10.1007/s40134-016-0186-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Dankerl P, Hammon M, Seuss H, Tröbs M, Schuhbaeck A, Hell MM, Cavallaro A, Achenbach S, Uder M, Marwan M. Computer-aided evaluation of low-dose and low-contrast agent third-generation dual-source CT angiography prior to transcatheter aortic valve implantation (TAVI). Int J Comput Assist Radiol Surg 2016; 12:795-802. [PMID: 27604759 DOI: 10.1007/s11548-016-1470-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 08/04/2016] [Indexed: 11/24/2022]
Abstract
PURPOSE To evaluate the performance of computer-aided evaluation software for a comprehensive workup of patients prior to transcatheter aortic valve implantation (TAVI) using low-contrast agent and low radiation dose third-generation dual-source CT angiography. METHODS We evaluated 30 consecutive patients scheduled for TAVI. All patients underwent ECG-triggered high-pitch dual-source CT angiography of the aortic root and aorta with a standardized contrast agent volume (30 ml Imeron350, flow rate 4 ml/s) and low-dose (100 kv/350 mAs) protocol. An expert (10 years of experience) manually evaluated aortic root and iliac access dimensions (distance between coronary ostia and aortic annulus, minimal/maximal diameters and area-derived diameter of the aortic annulus) and best CT-predicted fluoroscopic projection angle as the reference standard. Utilizing computer-aided software (syngo.via), the same pre-TAVI workup was performed and compared to the reference standard. RESULTS Mean CTDI[Formula: see text] was 3.46 mGy and mean DLP 217.6 ± 12.1 mGy cm, corresponding to a mean effective dose of 3.7 ± 0.2 mSv. Computer-aided evaluation was successful in all but one patient. Compared to the reference standard, Bland-Altman analysis indicated very good agreement for the distances between aortic annulus and coronary ostia (RCA: mean difference 0.8 mm; 95 % CI 0.4-1.2 mm; LM: mean difference 0.9 mm; 95 % CI 0.5-1.3 mm); however, we demonstrated a systematic overestimation of annulus- derived diameter using the software (mean difference 44.4 mm[Formula: see text]; 95 % CI 30.4-58.3 mm[Formula: see text]). Based on respective annulus dimensions, the recommended prosthesis size (Edwards SAPIEN 3) matched in 26 out of the 29 patients (90 %). CT-derived fluoroscopic projection angles showed an excellent agreement for both methods. Out of 58 iliac arteries, 15 (25 %) arteries could not be segmented by the software. Preprocessing time of the software was 71 ± 11 s (range 51-96 s), and reading time with the software was 118 ± 31 s (range 68-201 s). CONCLUSION In the workup of pre-TAVI CT angiography, computer-aided evaluation of low-contrast, low-dose examinations is feasible with good agreement and quick reading time. However, a systematic overestimation of the aortic annulus area is observed.
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Affiliation(s)
- Peter Dankerl
- Department of Radiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Maximiliansplatz 1, 91054, Erlangen, Germany
| | - Matthias Hammon
- Department of Radiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Maximiliansplatz 1, 91054, Erlangen, Germany.
| | - Hannes Seuss
- Department of Radiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Maximiliansplatz 1, 91054, Erlangen, Germany
| | - Monique Tröbs
- Department of Cardiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Ulmenweg 18, 91054, Erlangen, Germany
| | - Annika Schuhbaeck
- Department of Cardiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Ulmenweg 18, 91054, Erlangen, Germany
| | - Michaela M Hell
- Department of Cardiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Ulmenweg 18, 91054, Erlangen, Germany
| | - Alexander Cavallaro
- Department of Radiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Maximiliansplatz 1, 91054, Erlangen, Germany
| | - Stephan Achenbach
- Department of Cardiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Ulmenweg 18, 91054, Erlangen, Germany
| | - Michael Uder
- Department of Radiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Maximiliansplatz 1, 91054, Erlangen, Germany
| | - Mohamed Marwan
- Department of Cardiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Ulmenweg 18, 91054, Erlangen, Germany
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Khalique OK, Pulerwitz TC, Halliburton SS, Kodali SK, Hahn RT, Nazif TM, Vahl TP, George I, Leon MB, D'Souza B, Einstein AJ. Practical considerations for optimizing cardiac computed tomography protocols for comprehensive acquisition prior to transcatheter aortic valve replacement. J Cardiovasc Comput Tomogr 2016; 10:364-74. [PMID: 27475972 DOI: 10.1016/j.jcct.2016.07.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 07/03/2016] [Indexed: 01/07/2023]
Abstract
Transcatheter aortic valve replacement (TAVR) is performed frequently in patients with severe, symptomatic aortic stenosis who are at high risk or inoperable for open surgical aortic valve replacement. Computed tomography angiography (CTA) has become the gold standard imaging modality for pre-TAVR cardiac anatomic and vascular access assessment. Traditionally, cardiac CTA has been most frequently used for assessment of coronary artery stenosis, and scanning protocols have generally been tailored for this purpose. Pre-TAVR CTA has different goals than coronary CTA and the high prevalence of chronic kidney disease in the TAVR patient population creates a particular need to optimize protocols for a reduction in iodinated contrast volume. This document reviews details which allow the physician to tailor CTA examinations to maximize image quality and minimize harm, while factoring in multiple patient and scanner variables which must be considered in customizing a pre-TAVR protocol.
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Affiliation(s)
- Omar K Khalique
- Columbia University Medical Center/New York Presbyterian Hospital, New York, NY, USA.
| | - Todd C Pulerwitz
- Columbia University Medical Center/New York Presbyterian Hospital, New York, NY, USA
| | | | - Susheel K Kodali
- Columbia University Medical Center/New York Presbyterian Hospital, New York, NY, USA
| | - Rebecca T Hahn
- Columbia University Medical Center/New York Presbyterian Hospital, New York, NY, USA
| | - Tamim M Nazif
- Columbia University Medical Center/New York Presbyterian Hospital, New York, NY, USA
| | - Torsten P Vahl
- Columbia University Medical Center/New York Presbyterian Hospital, New York, NY, USA
| | - Isaac George
- Columbia University Medical Center/New York Presbyterian Hospital, New York, NY, USA
| | - Martin B Leon
- Columbia University Medical Center/New York Presbyterian Hospital, New York, NY, USA
| | - Belinda D'Souza
- Columbia University Medical Center/New York Presbyterian Hospital, New York, NY, USA
| | - Andrew J Einstein
- Columbia University Medical Center/New York Presbyterian Hospital, New York, NY, USA
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Andreini D, Martuscelli E, Guaricci AI, Carrabba N, Magnoni M, Tedeschi C, Pelliccia A, Pontone G. Clinical recommendations on Cardiac-CT in 2015. J Cardiovasc Med (Hagerstown) 2016; 17:73-84. [DOI: 10.2459/jcm.0000000000000318] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Roy S, Sharma J. Role of CT Coronary Angiography in Recanalization of Chronic Total Occlusion. Curr Cardiol Rev 2015; 11:317-322. [PMID: 26354516 PMCID: PMC4774636 DOI: 10.2174/1573403x11666150909105616] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 03/10/2015] [Accepted: 09/04/2015] [Indexed: 11/22/2022] Open
Abstract
Chronic total occlusion (CTO) is considered as the most challenging frontier in interventional cardiology and the last one to be conquered. With availability of state of the art hardware, wires and catheters in particular and increased skills of the operators, the success rate for recanalization of CTO by percutaneous catheter intervention (PCI) has improved. Yet the complications rate and longterm adverse events are high, mostly due to failure in tracking or navigation of hardware through the occluded CTO segment, prolonged exposure to radiation and high doses of contrast used. Therefore, proper selection of patient is of utmost importance. One of the major challenges for successful CTO recanalization is satisfactory visualization of the occluded CTO segment. Conventional invasive catheterization fails to fill the gap and the shortcomings and handicaps of such invasive imaging can be resolved with the use of non-invasive CT coronary angiography (CTCA). CTCA helps to better define the morphological features of the occluded CTO segment, which are established predictors of success, like the actual length of the occluded segment and any calcification or tortuosity in its course. Integration of reconstructed three-dimensional CT coronary images with twodimensional fluoroscopic images, offers directional guide to select the best angiographic plane for visualization of angiographically “missing segment”. With advances in CT technology, CTCA has now become an established technology for pre-procedure evaluation of CTO segment, thereby help in planning and execution of successful PCI.
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Affiliation(s)
- Sanjeeb Roy
- Department of Cardiology, Fortis Escorts Hospital, Jaipur, India
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Shi K, Yang ZG, Chen J, Zhang G, Xu HY, Guo YK. Assessment of Double Outlet Right Ventricle Associated with Multiple Malformations in Pediatric Patients Using Retrospective ECG-Gated Dual-Source Computed Tomography. PLoS One 2015; 10:e0130987. [PMID: 26115034 PMCID: PMC4482600 DOI: 10.1371/journal.pone.0130987] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 05/26/2015] [Indexed: 02/05/2023] Open
Abstract
Purpose To evaluate the feasibility and diagnostic accuracy of retrospective electrocardiographically (ECG)-gated dual-source computed tomography (DSCT) for the assessment of double outlet right ventricle (DORV) and associated multiple malformations in pediatric patients. Materials and Methods Forty-seven patients <10 years of age with DORV underwent retrospective ECG-gated DSCT. The location of the ventricular septal defect (VSD), alignment of the two great arteries, and associated malformations were assessed. The feasibility of retrospective ECG-gated DSCT in pediatric patients was assessed, the image quality of DSCT and the agreement of the diagnosis of associated malformations between DSCT and transthoracic echocardiography (TTE) were evaluated, the diagnostic accuracies of DSCT and TTE were referred to surgical results, and the effective doses were calculated. Results Apart from DORV, 109 associated malformations were confirmed postoperatively. There was excellent agreement (κ = 0.90) for the diagnosis of associated malformations between DSCT and TTE. However, DSCT was superior to TTE in demonstrating paracardiac anomalies (sensitivity, coronary artery anomalies: 100% vs. 80.00%, anomalies of great vessels: 100% vs. 88.57%, separate thoracic and abdominal anomalies: 100% vs. 76.92%, respectively). Combined with TTE, DSCT can achieve excellent diagnostic performance in intracardiac anomalies (sensitivity, 91.30% vs. 100%). The mean image quality score was 3.70 ± 0.46 (κ = 0.76). The estimated mean effective dose was < 1 mSv (0.88 ± 0.34 mSv). Conclusions Retrospective ECG-gated DSCT is a better diagnostic tool than TTE for pediatric patients with complex congenital heart disease such as DORV. Combined with TTE, it may reduce or even obviate the use of invasive cardiac catheterization, and thus expose the patients to a much lower radiation dose.
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Affiliation(s)
- Ke Shi
- Department of Radiology, West China Hospital, Sichuan University, 37# Guo Xue Xiang, Chengdu, Sichuan 610041, China
| | - Zhi-gang Yang
- Department of Radiology, West China Hospital, Sichuan University, 37# Guo Xue Xiang, Chengdu, Sichuan 610041, China
- National Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 17# Section 3 South Renmin Road, Chengdu, Sichuan 610041, China
- * E-mail: (ZGY); (YKG)
| | - Jing Chen
- Department of Radiology, West China Hospital, Sichuan University, 37# Guo Xue Xiang, Chengdu, Sichuan 610041, China
| | - Ge Zhang
- Department of Radiology, West China Hospital, Sichuan University, 37# Guo Xue Xiang, Chengdu, Sichuan 610041, China
| | - Hua-yan Xu
- Department of Radiology, West China Hospital, Sichuan University, 37# Guo Xue Xiang, Chengdu, Sichuan 610041, China
- National Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 17# Section 3 South Renmin Road, Chengdu, Sichuan 610041, China
| | - Ying-kun Guo
- Department of Radiology, West China Second University Hospital, Sichuan University, 20# Section 3 South Renmin Road, Chengdu, Sichuan 610041, China
- * E-mail: (ZGY); (YKG)
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Abazid R, Smettei O, Sayed S, Harby FA, Habeeb AA, Saqqa HA, Mergania S, Selvanayagam JB. Objective and subjective image quality with prospectively gated versus ECG-controlled tube current modulation using 256-slice computed tomographic angiography. J Saudi Heart Assoc 2015; 27:256-63. [PMID: 26557743 PMCID: PMC4614896 DOI: 10.1016/j.jsha.2015.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Revised: 03/24/2015] [Accepted: 03/26/2015] [Indexed: 11/23/2022] Open
Abstract
Introduction Radiation exposure is one of the major limitations of computed tomographic coronary angiography (CTA). The purpose of this study was to compare the objective and subjective image quality and radiation dose using prospective ECG gating (PGA) versus ECG-controlled tube current modulation (ECTCM) scanning techniques. Methods A prospective, single-center study was performed at Prince Sultan Cardiac Centre, Qassim, Saudi Arabia. A total of 104 patients with low-to- intermediate probability of coronary artery disease (CAD) underwent CTA with either PGA or ECTCM acquisition. PGA was performed during the study period and compared with the last 50 CTAs previously done using ECTCM. A 4-point scale was used to assess the image quality subjectively. Objective image quality was assessed using image signal, noise, and signal-to-noise ratio (SNR). Results Patient‘s Baseline characteristics were not different between the two scanning protocols. The 4-point score of subjective image quality showed no significant differences between the PGA and ECTCM scans (2.9 ± 0.7, 2.96 ± 0.7, respectively; p = 0.87). The objective image quality showed significantly higher noise and lower SNR with PGA compared with ECTCM (31 ± 9, 27 ± 9, respectively; p < 0.001 for noise) and (15 ± 5, 17 ± 7, respectively; p < 0.001 for SNR), with no statistical difference in the image signal (434 ± 123, 425 ± 103 HU, respectively, p = 0.7). Radiation exposure was significantly lower with PGA than with ECTCM. The dose-length product (DLP) for PGA was 334 ± 130 mGy, compared with 822 ± 286 mGy for the ECTCM. This corresponds to a 59% reduction in radiation exposure (p < 0.0001). Conclusions Although prospective ECG-triggered axial scanning increased image noise, it maintained subjective image quality and was associated with a 59% reduction in radiation exposure when compared with ECTCM.
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Key Words
- BMI, body mass index
- CAD, coronary artery disease
- CTA, computed tomographic coronary angiography
- Coronary angiography
- DLP, dose-length product
- ECTCM, ECG-controlled tube current modulation
- HR, heart rate
- HU, Hounsfield unit
- Image noise
- MPR, multi-planar reconstruction
- PGA, prospective gated axial
- RGH, retrospectively-gated helical
- Radiation exposure
- SNR, signal-to-noise ratio
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Affiliation(s)
- Rami Abazid
- Prince Sultan Cardiac Center, Qassim, PSCCQ, Buraydah
| | - Osama Smettei
- Prince Sultan Cardiac Center, Qassim, PSCCQ, Buraydah
| | - Sawsan Sayed
- Prince Sultan Cardiac Center, Qassim, PSCCQ, Buraydah
| | | | | | | | | | - Joseph B Selvanayagam
- Department of Cardiovascular Medicine, Flinders Medical Centre, Flinders University of South Australia, Flinders Drive, Bedford Park, Adelaide 5042, Australia
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Leng S, Hruska CB, McCollough CH. Use of ionizing radiation in screening examinations for coronary artery calcium and cancers of the lung, colon, and breast. Semin Roentgenol 2015; 50:148-60. [PMID: 25770345 DOI: 10.1053/j.ro.2014.10.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Shuai Leng
- Department of Radiology, Mayo Clinic, Rochester, MN.
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Half-dose abdominal CT with sinogram-affirmed iterative reconstruction technique in children - comparison with full-dose CT with filtered back projection. Pediatr Radiol 2015; 45:188-93. [PMID: 25030221 DOI: 10.1007/s00247-014-3105-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 04/16/2014] [Accepted: 06/18/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Iterative reconstruction can be helpful to reduce radiation dose while maintaining image quality. However, this technique has not been fully evaluated in children during abdominal CT. OBJECTIVE To compare objective and subjective image quality between half-dose images reconstructed with iterative reconstruction at iteration strength levels 1 to 5 (half-S1 to half-S5 studies) and full-dose images reconstructed with filtered back projection (full studies) in pediatric abdominal CT. MATERIALS AND METHODS Twenty-one children (M:F = 13:8; mean age 8.2 ± 5.7 years) underwent dual-source abdominal CT (mean effective dose 4.8 ± 2.1 mSv). The objective image quality was evaluated as noise. Subjective image quality analysis was performed comparing each half study to the full study for noise, sharpness, artifact and diagnostic acceptability. RESULTS Both objective and subjective image noise decreased with increasing iteration strength. Half-S4 and -S5 studies showed objective image noise similar to or lower than that of full studies. The half-S2 and -S3 studies produced the greatest sharpness and the half-S5 studies were the worst from a blocky appearance. Full and half studies did not differ in artifacts. Half-S3 studies showed the best diagnostic acceptability. CONCLUSION Half-S4 and -S5 studies objectively and half-S3 studies subjectively showed comparable image quality to full studies in pediatric abdominal CT.
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Rubin GD. Computed tomography: revolutionizing the practice of medicine for 40 years. Radiology 2015; 273:S45-74. [PMID: 25340438 DOI: 10.1148/radiol.14141356] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Computed tomography (CT) has had a profound effect on the practice of medicine. Both the spectrum of clinical applications and the role that CT has played in enhancing the depth of our understanding of disease have been profound. Although almost 90 000 articles on CT have been published in peer-reviewed journals over the past 40 years, fewer than 5% of these have been published in Radiology. Nevertheless, these almost 4000 articles have provided a basis for many important medical advances. By enabling a deepened understanding of anatomy, physiology, and pathology, CT has facilitated key advances in the detection and management of disease. This article celebrates this breadth of scientific discovery and development by examining the impact that CT has had on the diagnosis, characterization, and management of a sampling of major health challenges, including stroke, vascular diseases, cancer, trauma, acute abdominal pain, and diffuse lung diseases, as related to key technical advances in CT and manifested in Radiology.
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Affiliation(s)
- Geoffrey D Rubin
- From the Duke Clinical Research Institute and Department of Radiology, Duke University School of Medicine, PO Box 17969, 2400 Pratt St, Durham, NC 27715
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Pushing CT and MR imaging to the molecular level for studying the "omics": current challenges and advancements. BIOMED RESEARCH INTERNATIONAL 2014; 2014:365812. [PMID: 24738056 PMCID: PMC3971568 DOI: 10.1155/2014/365812] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 12/26/2013] [Accepted: 01/24/2014] [Indexed: 12/24/2022]
Abstract
During the past decade, medical imaging has made the transition from anatomical imaging to functional and even molecular imaging. Such transition provides a great opportunity to begin the integration of imaging data and various levels of biological data. In particular, the integration of imaging data and multiomics data such as genomics, metabolomics, proteomics, and pharmacogenomics may open new avenues for predictive, preventive, and personalized medicine. However, to promote imaging-omics integration, the practical challenge of imaging techniques should be addressed. In this paper, we describe key challenges in two imaging techniques: computed tomography (CT) and magnetic resonance imaging (MRI) and then review existing technological advancements. Despite the fact that CT and MRI have different principles of image formation, both imaging techniques can provide high-resolution anatomical images while playing a more and more important role in providing molecular information. Such imaging techniques that enable single modality to image both the detailed anatomy and function of tissues and organs of the body will be beneficial in the imaging-omics field.
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Yang S, Li X, Chao B, Wu L, Cheng Z, Duan Y, Wu D, Zhan Y, Chen J, Liu B, Ji X, Nie P, Wang X. Abdominal aortic intimal flap motion characterization in acute aortic dissection: assessed with retrospective ECG-gated thoracoabdominal aorta dual-source CT angiography. PLoS One 2014; 9:e87664. [PMID: 24503676 PMCID: PMC3913653 DOI: 10.1371/journal.pone.0087664] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 12/27/2013] [Indexed: 11/23/2022] Open
Abstract
Objectives To evaluate the feasibility of dose-modulated retrospective ECG-gated thoracoabdominal aorta CT angiography (CTA) assessing abdominal aortic intimal flap motion and investigate the motion characteristics of intimal flap in acute aortic dissection (AAD). Materials and Methods 49 patients who had thoracoabdominal aorta retrospective ECG-gated CTA scan were enrolled. 20 datasets were reconstructed in 5% steps between 0 and 95% of the R-R interval in each case. The aortic intimal flap motion was assessed by measuring the short axis diameters of the true lumen and false lumen 2 cm above of celiac trunk ostium in different R-R intervals. Intimal flap motion and configuration was assessed by two independent observers. Results In these 49 patients, 37 had AAD, 7 had intramural hematoma, and 5 had negative result for acute aortic disorder. 620 datasets of 31 patients who showed double lumens in abdominal aorta were enrolled in evaluating intimal flap motion. The maximum and minimum true lumen diameter were 12.2±4.1 mm (range 2.6∼17.4) and 6.7±4.1 mm (range 0∼15.3) respectively. The range of intimal flap motion in all patients was 5.5±2.6 mm (range 1.8∼10.2). The extent of maximum true lumen diameter decreased during a cardiac cycle was 49.5%±23.5% (range 12%∼100%). The maximum motion phase of true lumen diameter was in systolic phase (5%∼40% of R-R interval). Maximum and minimum intimal flap motion was at 15% and 75% of the R-R interval respectively. Intimal flap configuration had correlation with the phase of cardiac cycle. Conclusions Abdominal intimal flap position and configuration varied greatly during a cardiac cycle. Retrospective ECG-gated thoracoabdominal aorta CTA can reflect the actual status of the true lumen and provide more information about true lumen collapse. This information may be helpful to diagnosis and differential diagnosis of dynamic abstraction.
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Affiliation(s)
- Shifeng Yang
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P.R. China
| | - Xia Li
- Departments of Ultrasound, Shandong Provincial Hospital, Jinan, Shandong, P. R. China
| | - Baoting Chao
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P.R. China
| | - Lebin Wu
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P.R. China
| | - Zhaoping Cheng
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P.R. China
| | - Yanhua Duan
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P.R. China
| | - Dawei Wu
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P.R. China
| | - Yiqiang Zhan
- Unit of Periodontology, University of Greifswald, Greifswald, Germany
| | - Jiuhong Chen
- CT Research Collaboration, Siemens Ltd., China, Beijing, P.R. China
| | - Bo Liu
- Healthcare Sector, Siemens Ltd., China, Shanghai, P.R. China
| | - Xiaopeng Ji
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P.R. China
| | - Pei Nie
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P.R. China
| | - Ximing Wang
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, P.R. China
- * E-mail:
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Influence of image acquisition on radiation dose and image quality: full versus narrow phase window acquisition using 320 MDCT. ScientificWorldJournal 2014; 2013:731590. [PMID: 24453899 PMCID: PMC3884853 DOI: 10.1155/2013/731590] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 10/07/2013] [Indexed: 12/29/2022] Open
Abstract
Purpose. To compare radiation dose and image quality using predefined narrow phase window versus complete phase window with dose modulation during R-R using 320-row MDCTA. Methods. 114 patients underwent coronary CTA study using 320-row MDCT scanner. 87 patients with mean age (61 + 13 years), mean BMI (29 + 6), and mean heart rate (HR) (58 + 7 bpm) were imaged at predefined 66–80% R-R interval and then reconstructed at 75% while 27 patients with mean age (63 + 16 years), mean BMI (28 + 5), and mean HR (57 + 7 bpm) were scanned throughout the complete R-R interval with tube current modulation. The effective dose (ED) was calculated from dose length product (DLP) and conversion k (0.014 mSv/mGy/cm). Image quality was assessed using a three-point ordinal scale (1 = excellent, 2 = good, and 3 = nondiagnostic). Results. Both groups were statistically similar to each other with reference of HR (P = 0.59), BMI (P = 0.17), and tube current mAs (P = 0.68). The median radiation dose was significantly higher in those scanned with complete R-R phase window versus narrow phase window (P < 0.0001). Independently of patient and scan parameters, increased phase window was associated with higher radiation dose (P < 0.001). Image quality was better among those scanned with narrow phase window versus complete phase window (P < 0.0001). Conclusion. Our study supports that good HR control and predefined narrow window acquisition result in lower radiation dose without compromising diagnostic image quality for coronary disease evaluation.
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Small GR, Chow BJW, Ruddy TD. Low-dose cardiac imaging: reducing exposure but not accuracy. Expert Rev Cardiovasc Ther 2014; 10:89-104. [DOI: 10.1586/erc.11.173] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Dankerl P, Hammon M, Tsymbal A, Cavallaro A, Achenbach S, Uder M, Janka R. Evaluation of novice reader diagnostic performance in coronary CT angiography using an advanced cardiac software package. Int J Comput Assist Radiol Surg 2013; 9:609-15. [PMID: 24203574 PMCID: PMC4082650 DOI: 10.1007/s11548-013-0953-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 10/14/2013] [Indexed: 11/25/2022]
Abstract
Purpose The purpose of this research was to evaluate whether a commercially available advanced cardiac software package for coronary CT angiography (CTA) interpretation may reliably assist inexperienced readers to screen for significant coronary artery stenoses. Methods Coronary CTA data sets of 61 consecutive patients with suspected coronary artery disease were evaluated by three novice readers with no experience in cardiac CT interpretation. In the first 15 patients, the novice readers were trained to use the advanced cardiac software package (includes automatic detection of coronary vessels, curved MPR and VRT reconstructions and a measurement too) knowing the results of an expert read. In the next 46 patients, the novice readers had to state whether there is a significant coronary artery stenosis (\documentclass[12pt]{minimal}
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\begin{document}$$>$$\end{document}>50 %) and if they are confident with their diagnosis. The results of the novice readers were compared to the expert read. Results The 46 coronary CTA data sets contained 184 vessels with 15 stenoses in 9 patients. On a per-vessel analysis, novice reader 1/2/3 demonstrated 60 %/100 %/ 93% sensitivity, and 98 %/90 %/86 % specificity. Per patient, the readers diagnosed 36/28/29 cases correctly as free of stenoses, 6/9/8 correctly as having at least one stenosis, missed 3/0/1 cases with a stenosis and overdiagnosed 1/9/8 patients. Cohen’s kappa values for the three readers versus the expert were 0.60, 0.61 and 0.54. The three novice readers felt confident in the diagnosis of 36/33/30 patients. In these patients, they missed one significant stenosis, showed a sensitivity of 100 %/100 %/75 % and a specificity of 100 %/92 %/88 %. Conclusions The evaluated advanced cardiac software package successfully assists novice readers in interpreting coronary CTA data sets especially in ruling out significant coronary artery stenosis.
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Affiliation(s)
- Peter Dankerl
- Department of Radiology, University Hospital Erlangen, Maximiliansplatz 1, 91054 Erlangen, Germany
| | - Matthias Hammon
- Department of Radiology, University Hospital Erlangen, Maximiliansplatz 1, 91054 Erlangen, Germany
| | - Alexey Tsymbal
- Corporate Technology, Imaging and Computer Vision Department, Siemens AG, San-Carlos Str. 7, 91054 Erlangen, Germany
| | - Alexander Cavallaro
- Department of Radiology, University Hospital Erlangen, Maximiliansplatz 1, 91054 Erlangen, Germany
| | - Stephan Achenbach
- Department of Cardiology, University Hospital Erlangen, Ulmenweg 18, 91054 Erlangen, Germany
| | - Michael Uder
- Department of Radiology, University Hospital Erlangen, Maximiliansplatz 1, 91054 Erlangen, Germany
| | - Rolf Janka
- Department of Radiology, University Hospital Erlangen, Maximiliansplatz 1, 91054 Erlangen, Germany
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Matsuzaki Y, Fujii K, Kumagai M, Tsuruoka I, Mori S. Effective and organ doses using helical 4DCT for thoracic and abdominal therapies. JOURNAL OF RADIATION RESEARCH 2013; 54:962-970. [PMID: 23603303 PMCID: PMC3766296 DOI: 10.1093/jrr/rrt024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 02/23/2013] [Accepted: 02/28/2013] [Indexed: 06/02/2023]
Abstract
The capacity of 4DCT to quantify organ motion is beyond conventional 3DCT capability. Local control could be improved. However we are unaware of any reports of organ dose measurements for helical 4DCT imaging. We therefore quantified the radiation doses for helical 4DCT imaging. Organ and tissue dose was measured for thoracic and abdominal 4DCT in helical mode using an adult anthropomorphic phantom. Radiation doses were measured with thermoluminescence dosimeter chips inserted at various anatomical sites on the phantom. For the helical thoracic 4DCT, organ doses were 57.2 mGy for the lung, 76.7 mGy for the thyroids, 48.1 mGy for the breasts, and 10.86 mGy for the colon. The effective doses for male and female phantoms were very similar, with a mean value of 33.1 mSv. For abdominal 4DCT imaging, organ doses were 14.4 mGy for the lung, 0.78 mGy for the thyroids, 9.83 mGy for breasts, and 58.2 mGy for the colon (all obtained by using ICRP 103). We quantified the radiation exposure for thoracic and abdominal helical 4DCT. The doses for helical 4DCT were approximately 1.5 times higher than those for cine 4DCT, however the stepwise image artifact was reduced. 4DCT imaging should be performed with care in order to minimize radiation exposure, but the advantages of 4DCT imaging mandates its incorporation into routine treatment protocols.
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MESH Headings
- Abdominal Neoplasms/diagnostic imaging
- Abdominal Neoplasms/radiotherapy
- Humans
- Imaging, Three-Dimensional/instrumentation
- Imaging, Three-Dimensional/methods
- Phantoms, Imaging
- Radiation Dosage
- Radiography, Abdominal/instrumentation
- Radiography, Abdominal/methods
- Radiography, Thoracic/instrumentation
- Radiography, Thoracic/methods
- Radiotherapy, Image-Guided/methods
- Relative Biological Effectiveness
- Reproducibility of Results
- Respiratory-Gated Imaging Techniques/methods
- Sensitivity and Specificity
- Thoracic Neoplasms/diagnostic imaging
- Thoracic Neoplasms/radiotherapy
- Tomography, X-Ray Computed/instrumentation
- Tomography, X-Ray Computed/methods
- Viscera/diagnostic imaging
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Affiliation(s)
| | | | | | | | - Shinichiro Mori
- Corresponding author. Tel: +81-43-251-2111; Fax: +81-43-284-0198;
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Paul J, Jacobi V, Bazrafshan B, Farshid P, Vogl T. Effect of contrast material on radiation dose in an adult cardiac dual-energy CT using retrospective ECG-gating. HEALTH PHYSICS 2013; 105:156-164. [PMID: 23799500 DOI: 10.1097/hp.0b013e31828d814c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The purpose of this study was to determine the effect of contrast material and retrospective ECG-gating on radiation dose in an adult cardiac dual-energy computed tomography (DECT). Sixty-two patients underwent CT cardiac examination with a Somatom Definition Flash DECT using tube voltages of 100 kV without filter and 140 kV with a tin filter (mean effective mA s: arterial 72.39 and 62.94, venous 93.21 and 78.45, and late phase 134.5 and 118.2). The arterial and late phases were examined with retrospective ECG-gating, but gating was not used for the venous phase. Seventy milliliters (70 ml) iodinated contrast material (CM) was injected into the patient during examination. The effective doses (ED) were calculated from dose-length-product (DLP) and computed tomographic dose index volume (CTDIvol) using the latest k-factor (0.028). Pearson's correlation coefficient was used for statistical tests on continuous variables. Mean CTDIvol and DLP were lower in the late phase (10.15 ± 1.5 mGy and 202.9 ± 23 mGy cm) compared to the arterial phase (19.69 ± 3 mGy and 394 ± 90 mGy cm). Differences between the arterial and late phase were statistically significant (p = 0.005), and mean values for the late phase were 48.5% lower than mean values for the arterial phase. Mean CTDIvol and DLP were lower in venous (7.72 ± 1 mGy and 154.3 ± 17 mGy cm) compared to late phase (10.15 ± 1.5 mGy and 202.9 ± 23 mGy cm). The difference between venous and late phase was statistically significant (p < 0.001). The mean results for the venous phase were 24% lower than those for the late phase. This study shows that contrast material (CM) absorbs radiation significantly and increases dose by 48.5% in an adult cardiac dual-energy CT with retrospective ECG-gating. Care must be taken to determine the type, concentration, and volume of CM used for the scan. The dual-energy non-ECG-gated technique decreased radiation dose by 24% compared to the ECG-gated technique. ECG-gated cardiac examination should be limited to patients with strong clinical indications. SNR and HU increased with decreasing energy. The image noise values showed a negligible difference in the arterial and late phase datasets, and this did not affect the diagnostic quality of the image evaluation.
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Affiliation(s)
- Jijo Paul
- J.W Goethe-University Hospital, Diagnostic and Interventional Radiology, Theodor-Stern-Kai-7, 60590, Frankfurt/Main, Germany.
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Krissak R, Henzler T, Prechel A, Reichert M, Gruettner J, Sueselbeck T, Schoenberg SO, Fink C. Triple-rule-out dual-source CT angiography of patients with acute chest pain: Dose reduction potential of 100kV scanning. Eur J Radiol 2012; 81:3691-6. [PMID: 21163600 DOI: 10.1016/j.ejrad.2010.11.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Accepted: 11/17/2010] [Indexed: 10/18/2022]
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Ogawa M, Hara M, Imafuji A, Ozawa Y, Arakawa T, Kobayashi S, Shibamoto Y. Dual-energy CT can evaluate both hilar and mediastinal lymph nodes and lesion vascularity with a single scan at 60 seconds after contrast medium injection. Acad Radiol 2012; 19:1003-10. [PMID: 22621917 DOI: 10.1016/j.acra.2012.03.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 03/23/2012] [Accepted: 03/25/2012] [Indexed: 11/24/2022]
Abstract
RATIONALE AND OBJECTIVES The aim of this study was to investigate whether 80-kVp and weighted-average 120-kVp computed tomographic (CT) images scanned at 60 seconds after contrast material injection using a dual-source CT scanner could substitute for conventional 120-kVp images obtained at 30 and 100 seconds. MATERIALS AND METHODS Eighty-three consecutive patients with suspected lung cancer were enrolled. Images were obtained in dual-energy mode (80 and 140 kVp) at 60 seconds and conventional 120-kVp mode at 30 and 100 seconds after contrast injection. The CT numbers of the pulmonary artery, pulmonary vein, hilar zone lymph nodes, and pulmonary lesions were measured. Contrasts between the pulmonary artery/pulmonary vein and lymph nodes and beam-hardening artifacts were visually evaluated using five-point and four-point scales, respectively. The degree of enhancement was evaluated on 30-second 120-kVp, 100-second 120-kVp, and 60-second weighted-average 120-kVp images. RESULTS The mean differences in attenuation between the pulmonary artery/pulmonary vein and lymph nodes on the 30-second 120-kVp, 60-second 80-kVp, and 60-second weighted-average 120-kVp images were 184/155, 130/140, and 84/92 Hounsfield units, respectively (all P values <.001). The mean contrast scores for the hilar/mediastinal lymph nodes were 4.5/4.7, 3.7/4.2, 3.3/3.6, and 2.4/2.5 for these three and for 100-second 120-kVp images, respectively (all P values <.01). The mean artifact scores of the four images were 1.2, 3.4, 3.6, and 4.0, respectively. On 60-second weighted-average 120-kVp images, 55 of 60 lesions (92%) showed higher enhancement than on 100-second conventional 120-kVp images. CONCLUSIONS Dual-energy CT images scanned 60 seconds after contrast injection show excellent vessel-lymph node contrast and enhancement of lesions and can replace dual-phase scan protocols.
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Kim T, Choi BJ, Kang DK, Sun JS. Assessment of myocardial viability using multidetector computed tomography in patients with reperfused acute myocardial infarction. Clin Radiol 2012; 67:754-65. [PMID: 22749383 DOI: 10.1016/j.crad.2011.12.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 10/03/2011] [Accepted: 12/14/2011] [Indexed: 11/18/2022]
Abstract
AIM To assess the prognostic value of 64-section multidetector computed tomography (MDCT) to predict follow-up myocardial dysfunction and functional recovery after reperfusion therapy in patients with acute myocardial infarction (MI) as defined by echocardiography. MATERIALS AND METHODS After reperfusion therapy for acute MI, 71 patients underwent two-phase contrast-enhanced MDCT and follow-up echocardiography. MDCT findings were compared with echocardiographic findings using kappa statistics. The areas under the receiver operating characteristic curves (AUCs) and the odds ratios (ORs) of early perfusion defects (EPD), delayed enhancement (DE), and residual perfusion defects (RPD) for predicting follow-up myocardial dysfunction and functional recovery were calculated on a segmental basis. RESULTS The presence of transmural EPD (EPD(TM)) or RPD showed good agreement (k = 0.611 and 0.658, respectively) with follow-up myocardial dysfunction, while subendocardial EPD (EPD(sub)) or subendocardial DE (DE(sub)) showed fair agreement with follow-up myocardial dysfunction (k = 0.235 and 0.234, respectively). The AUC of RPD (0.796) was superior (p < 0.001 and 0.031, respectively) to those of EPD(TM) (0.761) and DE(TM) (0.771). The presence of EPD(TM), DE(TM), and RPD were significant, independent positive predictors of follow-up myocardial dysfunction (OR = 6.4, 1.9, and 9.8, respectively). EPD(TM) was a significant, independent negative predictor of myocardial functional recovery (OR = 0.13). CONCLUSION Abnormal myocardial attenuation on two-phase MDCT after reperfusion therapy may provide promising information regarding myocardial viability in patients with acute MI.
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Affiliation(s)
- T Kim
- Department of Radiology, Ajou University School of Medicine, Suwon, South Korea
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Lee AM, Engel LC, Shah B, Liew G, Sidhu MS, Kalra M, Abbara S, Brady TJ, Hoffmann U, Ghoshhajra BB. Coronary computed tomography angiography during arrhythmia: Radiation dose reduction with prospectively ECG-triggered axial and retrospectively ECG-gated helical 128-slice dual-source CT. J Cardiovasc Comput Tomogr 2012; 6:172-183.e2. [DOI: 10.1016/j.jcct.2012.04.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2012] [Revised: 03/02/2012] [Accepted: 04/03/2012] [Indexed: 10/28/2022]
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Ramirez-Giraldo JC, Yu L, Kantor B, Ritman EL, McCollough CH. A strategy to decrease partial scan reconstruction artifacts in myocardial perfusion CT: phantom and in vivo evaluation. Med Phys 2012; 39:214-23. [PMID: 22225290 DOI: 10.1118/1.3665767] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Partial scan reconstruction (PSR) artifacts are present in myocardial perfusion imaging using dynamic multidetector computed tomography (MDCT). PSR artifacts appear as temporal CT number variations due to inconsistencies in the angular data range used to reconstruct images and compromise the quantitative value of myocardial perfusion when using MDCT. The purpose of this work is to present and evaluate a technique termed targeted spatial frequency filtration (TSFF) to reduce CT number variations due to PSR when applied to myocardial perfusion imaging using MDCT. METHODS The TSFF algorithm requires acquiring enough X-ray projections to reconstruct both partial (π + fan angle α) and full (2π) scans. Then, using spatial linear filters, the TSFF-corrected image data are created by superimposing the low spatial frequency content of the full scan reconstruction (containing no PSR artifacts, but having low spatial resolution and worse temporal resolution) with the high spatial frequency content of the partial scan reconstruction (containing high spatial frequencies and better temporal resolution). The TSFF method was evaluated both in a static anthropomorphic thoracic phantom and using an in vivo porcine model and compared with a previously validated reference standard technique that avoids PSR artifacts by pacing the animal heart in synchrony with the gantry rotation. CT number variations were quantified by measuring the range and standard deviation of CT numbers in selected regions of interest (ROIs) over time. Myocardial perfusion parameters such as blood volume (BV), mean transit time (MTT), and blood flow (BF) were quantified and compared in the in vivo study. RESULTS Phantom experiments demonstrated that TSFF reduced PSR artifacts by as much as tenfold, depending on the location of the ROI. For the in vivo experiments, the TSFF-corrected data showed two- to threefold decrease in CT number variations. Also, after TSFF, the perfusion parameters had an average difference of 13.1% (range 4.5%-25.6%) relative to the reference method, in contrast to an average difference of 31.8% (range 0.3%-54.0%) between the non-TSFF processed data with the reference method. CONCLUSIONS TSFF demonstrated consistent reduction in CT number variations due to PSR using controlled phantom and in vivo experiments. TSFF-corrected data provided quantitative measures of perfusion (BV, MTT, and BF) with better agreement to a reference method compared to noncorrected data. Practical implementation of TSFF is expected to incur in an additional radiation exposure of 14%, when tube current is modulated to 20% of its maximum, to complete the needed full scan reconstruction.
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Affiliation(s)
- Juan C Ramirez-Giraldo
- Department of Radiology, CT Clinical Innovation Center, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA
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Goo HW. CT radiation dose optimization and estimation: an update for radiologists. Korean J Radiol 2011; 13:1-11. [PMID: 22247630 PMCID: PMC3253393 DOI: 10.3348/kjr.2012.13.1.1] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Accepted: 10/18/2011] [Indexed: 11/29/2022] Open
Abstract
In keeping with the increasing utilization of CT examinations, the greater concern about radiation hazards from examinations has been addressed. In this regard, CT radiation dose optimization has been given a great deal of attention by radiologists, referring physicians, technologists, and physicists. Dose-saving strategies are continuously evolving in terms of imaging techniques as well as dose management. Consequently, regular updates of this issue are necessary especially for radiologists who play a pivotal role in this activity. This review article will provide an update on how we can optimize CT dose in order to maximize the benefit-to-risk ratio of this clinically useful diagnostic imaging method.
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Affiliation(s)
- Hyun Woo Goo
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
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Park EA, Lee W, Kim KW, Kim KG, Thomas A, Chung JW, Park JH. Iterative reconstruction of dual-source coronary CT angiography: assessment of image quality and radiation dose. Int J Cardiovasc Imaging 2011; 28:1775-86. [PMID: 22187198 DOI: 10.1007/s10554-011-0004-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 12/14/2011] [Indexed: 11/30/2022]
Abstract
To assess the image quality and radiation dose of low-dose dual-source CT (DSCT) coronary angiography reconstructed using iterative reconstruction in image space (IRIS), in comparison with routine-dose CT using filtered back projection (FBP). Eighty-one patients underwent low-dose coronary DSCT using IRIS with two protocols: (a)100 kVp and 200 mAs per rotation for body mass index (BMI) < 25 (group I), (b)100 kVp and 320 mAs for BMI ≥ 25 (II). For comparison, two sex-and BMI-matched groups using standard protocols with FBP were selected: (a)100 kVp and 320 mAs for BMI < 25 (III), (b)120 kVp and 320 mAs for BMI ≥ 25 (IV). Image noise, signal to noise ratio (SNR) and modulation transfer function (MTF) 50% were objectively calculated. Two blinded readers then subjectively graded the image quality. Radiation dose was also measured. Image noise tended to be lower in IRIS of low-dose protocols: 22.0 ± 4.5 for group I versus 24.8 ± 4.0 for III (P < 0.001); 20.9 ± 4.5 for II versus 21.6 ± 4.9 for IV (P = 0.6). SNR was better with IRIS: 25.8 ± 4.4 for I versus 22.7 ± 4.6 for III (P < 0.001); 24.6 ± 5.4 for II versus 18.7 ± 4.5 for IV (P < 0.001). No differences in MTF 50% or image quality scores were seen between each two groups (P > 0.05). Radiation reduction was 40% for I and 51% for II, compared to standard protocols. Compared with routine-dose CT using FBP, low-dose coronary angiography using IRIS provides significant radiation reduction without impairment to image quality.
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Affiliation(s)
- Eun-Ah Park
- Department of Radiology, Seoul National University Hospital, Seoul 110-744, Korea
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Usefulness of dual-energy CT scanning at 80 kVp for identifying hilar and mediastinal structures: evaluation of contrast enhancement of the pulmonary vessels and lymph nodes. Jpn J Radiol 2011; 30:69-77. [DOI: 10.1007/s11604-011-0014-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 08/31/2011] [Indexed: 11/24/2022]
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Kerl JM, Bauer RW, Renker M, Weber E, Weisser P, Korkusuz H, Schell B, Larson MC, Kromen W, Jacobi V, Vogl TJ. Triphasic contrast injection improves evaluation of dual energy lung perfusion in pulmonary CT angiography. Eur J Radiol 2011; 80:e483-7. [DOI: 10.1016/j.ejrad.2010.09.030] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 09/23/2010] [Indexed: 10/18/2022]
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Tsai CJ, Chen LK, Mok GS, Wu TH, Lee JJ. Dose reduction in 256-slice triple rule-out CT angiography. RADIAT MEAS 2011. [DOI: 10.1016/j.radmeas.2011.06.070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Salavati A, Radmanesh F, Heidari K, Dwamena BA, Kelly AM, Cronin P. Dual-source computed tomography angiography for diagnosis and assessment of coronary artery disease: systematic review and meta-analysis. J Cardiovasc Comput Tomogr 2011; 6:78-90. [PMID: 22226727 DOI: 10.1016/j.jcct.2011.10.018] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 08/22/2011] [Accepted: 10/20/2011] [Indexed: 01/01/2023]
Abstract
BACKGROUND Development of an accurate test for noninvasive assessment of coronary arteries has been highly desirable. OBJECTIVES We performed a systematic review of diagnostic accuracy of the dual-source computed tomography (DSCT) in the diagnosis of coronary artery disease (CAD). METHODS Eight medical databases were searched for articles published from January 2005 through March 2011. Studies compared DSCT coronary angiography (DSCT-CA) and invasive coronary angiography, as the reference standard, in consecutive patients with suspected or known CAD, and relevant data were extracted by 2 independent reviewers. Summary diagnostic accuracies were calculated, and the effect of covariates on the diagnostic performance was evaluated by meta-regression. RESULTS Twenty-five studies were included. In per-patient analysis (n = 2303), pooled sensitivity was 99% [95% confidence interval (CI), 97%-99%] with specificity of 89% (95% CI, 84%-92%). The summary positive (+LR) and negative (-LR) likelihood ratios were 8.6 (95% CI, 6.4-11.6) and 0.02 (95% CI, 0.01-0.03), respectively. In per-segment analysis (n = 32,615), pooled sensitivity was 94% (95% CI, 92%-96%) with specificity of 97% (95% CI, 96%--98%). Summary +LR and -LR were 30.2 (95% CI, 22.1-43.5) and 0.06 (95% CI, 0.04-0.08), respectively. CONCLUSIONS DSCT-CA seems to be robust to elevate heart rates while maintaining a high level of diagnostic performance.
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Affiliation(s)
- Ali Salavati
- Department of Nuclear Medicine, Center for PET/CT, Zentralklinik Bad Berka, Bad Berka 99437, Germany.
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Ghoshhajra BB, Maurovich-Horvat P, Techasith T, Medina HM, Verdini D, Sidhu MS, Blankstein R, Brady TJ, Cury RC. Infarct detection with a comprehensive cardiac CT protocol. J Cardiovasc Comput Tomogr 2011; 6:14-23. [PMID: 22210535 DOI: 10.1016/j.jcct.2011.10.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 09/01/2011] [Accepted: 10/21/2011] [Indexed: 11/30/2022]
Abstract
BACKGROUND Cardiac CT has the potential to offer comprehensive infarct detection by assessing regional wall motion abnormalities (RWMAs), rest perfusion defects (RPDs), and delayed contrast enhancement (DCE). However, the diagnostic accuracy of these techniques for the detection of myocardial infarction (MI) is unknown. METHODS Forty-eight patients with intermediate-to-high probability for coronary artery disease after single-photon emitting CT myocardial perfusion imaging were prospectively enrolled for a research comprehensive 64-detector row dual-source cardiac CT protocol that included cine images for RWMA, first-pass images for RPD, and delayed images for DCE. Blinded readers independently assessed each technique. Subsequently, a final combined analysis (cine + rest + DCE) was performed. The universal definition for MI by the 2007 American Heart Association task force was used as the "gold standard." RESULTS Twenty-four of 48 patients (50%) had infarct by the universal definition. The combined CT analysis was most accurate (90%) with the highest per-patient sensitivity (88%) and specificity (92%) versus individual assessments (RWMA, 79% and 88%; RPD, 67% and 92%; DCE, 79% and 88%). Similar findings were observed on a per-vessel basis analysis. A combination of DCE and cine showed a good accuracy (85%) and high sensitivity (92%). CONCLUSIONS Infarct detection with CT is feasible with overall good diagnostic accuracy compared with the universal definition. A combined evaluation that included all techniques (cine, RPD, and DCE) had the highest diagnostic accuracy. These findings may have implications when designing future clinical and research CT protocols for optimal infarct detection.
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Affiliation(s)
- Brian B Ghoshhajra
- Cardiac MR PET CT Program, Department of Radiology and Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, 165 Cambridge Street, Suite 400, Boston, MA 02114, USA
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Abstract
Cardiac multidetector computed tomography (MDCT) for congenital heart disease is a useful, rapid, and noninvasive imaging technique bridging the gaps between echocardiography, cardiac catheterization, and cardiac MRI. Fast scan speed and greater anatomic coverage, combined with flexible ECG-synchronized scans and a low radiation dose, are critical for improving the image quality of cardiac MDCT and minimizing patient risk. Current MDCT techniques can accurately evaluate extracardiac great vessels, lungs, and airways, as well as coronary arteries and intracardiac structures. Radiologists who perform cardiac MDCT in children should be familiarized with optimal cardiac computed tomography (CT) scan techniques and characteristic cardiac CT scan imaging findings.
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Affiliation(s)
- Hyun Woo Goo
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, South Korea.
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May MS, Deak P, Kuettner A, Lell MM, Wuest W, Scharf M, Keller AK, Häberle L, Achenbach S, Seltmann M, Uder M, Kalender WA. Radiation dose considerations by intra-individual Monte Carlo simulations in dual source spiral coronary computed tomography angiography with electrocardiogram-triggered tube current modulation and adaptive pitch. Eur Radiol 2011; 22:569-78. [PMID: 21984448 DOI: 10.1007/s00330-011-2300-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Revised: 09/09/2011] [Accepted: 09/13/2011] [Indexed: 11/24/2022]
Abstract
OBJECTIVES To evaluate radiation dose levels in patients undergoing spiral coronary computed tomography angiography (CTA) on a dual-source system in clinical routine. METHODS Coronary CTA was performed for 56 patients with electrocardiogram-triggered tube current modulation (TCM) and heart-rate (HR) dependent pitch adaptation. Individual Monte Carlo (MC) simulations were performed for dose assessment. Retrospective simulations with constant tube current (CTC) served as reference. Lung tissue was segmented and used for organ and effective dose (ED) calculation. RESULTS Estimates for mean relative ED was 7.1 ± 2.1 mSv/100 mAs for TCM and 12.5 ± 5.3 mSv/100 mAs for CTC (P < 0.001). Relative dose reduction at low HR (≤60 bpm) was highest (49 ± 5%) compared to intermediate (60-70 bpm, 33 ± 12%) and high HR (>70 bpm, 29 ± 12%). However lowest ED is achieved at high HR (5.2 ± 1.5 mSv/100 mAs), compared with intermediate (6.7 ± 1.6 mSv/100 mAs) and low (8.3 ± 2.1 mSv/100 mAs) HR when automated pitch adaptation is applied. CONCLUSIONS Radiation dose savings up to 52% are achievable by TCM at low and regular HR. However lowest ED is attained at high HR by pitch adaptation despite inferior radiation dose reduction by TCM. KEY POINTS • Monte Carlo simulations allow for individual radiation dose calculations. • ECG-triggered tube current modulation (TCM) can effectively reduce radiation dose. • Slow and regular heart rates allow for highest dose reductions by TCM. • Adaptive pitch accounts for lowest radiation dose at high heart rates. • Women receive higher effective dose than men undergoing spiral coronary CT-angiography.
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Affiliation(s)
- Matthias S May
- Department of Radiology, University of Erlangen, Maximiliansplatz 1, 91054 Erlangen, Germany.
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Moscariello A, Takx RAP, Schoepf UJ, Renker M, Zwerner PL, O'Brien TX, Allmendinger T, Vogt S, Schmidt B, Savino G, Fink C, Bonomo L, Henzler T. Coronary CT angiography: image quality, diagnostic accuracy, and potential for radiation dose reduction using a novel iterative image reconstruction technique-comparison with traditional filtered back projection. Eur Radiol 2011; 21:2130-8. [PMID: 21611758 DOI: 10.1007/s00330-011-2164-9] [Citation(s) in RCA: 232] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 04/07/2011] [Accepted: 04/09/2011] [Indexed: 12/30/2022]
Abstract
OBJECTIVES To compare image noise, image quality and diagnostic accuracy of coronary CT angiography (cCTA) using a novel iterative reconstruction algorithm versus traditional filtered back projection (FBP) and to estimate the potential for radiation dose savings. METHODS Sixty five consecutive patients (48 men; 59.3 ± 7.7 years) prospectively underwent cCTA and coronary catheter angiography (CCA). Full radiation dose data, using all projections, were reconstructed with FBP. To simulate image acquisition at half the radiation dose, 50% of the projections were discarded from the raw data. The resulting half-dose data were reconstructed with sinogram-affirmed iterative reconstruction (SAFIRE). Full-dose FBP and half-dose iterative reconstructions were compared with regard to image noise and image quality, and their respective accuracy for stenosis detection was compared against CCA. RESULTS Compared with full-dose FBP, half-dose iterative reconstructions showed significantly (p = 0.001 - p = 0.025) lower image noise and slightly higher image quality. Iterative reconstruction improved the accuracy of stenosis detection compared with FBP (per-patient: accuracy 96.9% vs. 93.8%, sensitivity 100% vs. 100%, specificity 94.6% vs. 89.2%, NPV 100% vs. 100%, PPV 93.3% vs. 87.5%). CONCLUSIONS Iterative reconstruction significantly reduces image noise without loss of diagnostic information and holds the potential for substantial radiation dose reduction from cCTA.
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Affiliation(s)
- Antonio Moscariello
- Heart & Vascular Center, Medical University of South Carolina, Charleston, SC 29425-2260, USA
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