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Ghigo N, Ramos-Palacios G, Bourquin C, Xing P, Wu A, Cortés N, Ladret H, Ikan L, Casanova C, Porée J, Sadikot A, Provost J. Dynamic Ultrasound Localization Microscopy Without ECG-Gating. ULTRASOUND IN MEDICINE & BIOLOGY 2024; 50:1436-1448. [PMID: 38969526 DOI: 10.1016/j.ultrasmedbio.2024.05.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 05/04/2024] [Accepted: 05/22/2024] [Indexed: 07/07/2024]
Abstract
OBJECTIVE Dynamic Ultrasound Localization Microscopy (DULM) has first been developed for non-invasive Pulsatility measurements in the rodent brain. DULM relies on the localization and tracking of microbubbles (MBs) injected into the bloodstream, to obtain highly resolved velocity and density cine-loops. Previous DULM techniques required ECG-gating, limiting its application to specific datasets, and increasing acquisition time. The objective of this study is to eliminate the need for ECG-gating in DULM experiments by introducing a motion-matching method for time registration. METHODS We developed a motion-matching algorithm based on tissue Doppler that leverages the cyclic tissue motion within the brain. Tissue Doppler was estimated for each group of frames in the acquisitions, at multiple locations identified as local maxima in the skin above the skull. Subsequently, each group of frames was time-registered to a reference group by delaying it based on the maximum correlation value between their respective tissue Doppler signals. This synchronization ensured that each group of frames aligned with the brain tissue motion of the reference group, and consequently, with its cardiac cycle. As a result, velocities of MBs could be averaged to retrieve flow velocity variations over time. RESULTS Initially validated in ECG-gated acquisitions in a rat model (n = 1), the proposed method was successfully applied in a mice model in 2D (n = 3) and in a feline model in 3D (n = 1). Performing time-registration with the proposed motion-matching method or by using ECG-gating leads to similar results. For the first time, dynamic velocity and density cine-loops were extracted without the need for any information on the animal ECG, and complex dynamic markers such as the Pulsatility index were estimated. CONCLUSION Results suggest that DULM can be performed without external gating, enabling the use of DULM on any ULM dataset where enough MBs are detectable. Time registration by motion-matching represents a significant advancement in DULM techniques, making DULM more accessible by simplifying its experimental complexity.
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Affiliation(s)
- Nin Ghigo
- Department of Engineering Physics, Polytechnique Montréal, Montréal, Quebec, Canada.
| | | | - Chloé Bourquin
- Department of Engineering Physics, Polytechnique Montréal, Montréal, Quebec, Canada
| | - Paul Xing
- Department of Engineering Physics, Polytechnique Montréal, Montréal, Quebec, Canada
| | - Alice Wu
- Department of Engineering Physics, Polytechnique Montréal, Montréal, Quebec, Canada
| | - Nelson Cortés
- School of Optometry, University of Montreal, Montréal, Quebec, Canada
| | - Hugo Ladret
- School of Optometry, University of Montreal, Montréal, Quebec, Canada; Institut de Neurosciences de la Timone, UMR 7289, CNRS and Aix-Marseille Université, Marseille, France
| | - Lamyae Ikan
- School of Optometry, University of Montreal, Montréal, Quebec, Canada
| | | | - Jonathan Porée
- Department of Engineering Physics, Polytechnique Montréal, Montréal, Quebec, Canada
| | - Abbas Sadikot
- Montreal Neurological Institute, McGill University, Montréal, Quebec, Canada
| | - Jean Provost
- Department of Engineering Physics, Polytechnique Montréal, Montréal, Quebec, Canada; Montreal Heart Institute, Montréal, Quebec, Canada
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Assessing Agreement When Agreement Is Hard to Assess-The Agatston Score for Coronary Calcification. Diagnostics (Basel) 2022; 12:diagnostics12122993. [PMID: 36553000 PMCID: PMC9777110 DOI: 10.3390/diagnostics12122993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/22/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022] Open
Abstract
Method comparison studies comprised simple scatterplots of paired measurements, a 45-degree line as benchmark, and correlation coefficients up to the advent of Bland-Altman analysis in the 1980s. The Agatston score for coronary calcification is based on computed tomography of the heart, and it originated in 1990. A peculiarity of the Agatston score is the often-observed skewed distribution in screening populations. As the Agatston score has manifested itself in preventive cardiology, it is of interest to investigate how reproducibility of the Agatston score has been established. This review is based on literature findings indexed in MEDLINE/PubMed before 20 November 2021. Out of 503 identified articles, 49 papers were included in this review. Sample sizes were highly variable (10-9761), the main focus comprised intra- and interrater as well as intra- and interscanner variability assessments. Simple analysis tools such as scatterplots and correlation coefficients were successively supplemented by first difference, later Bland-Altman plots; however, only very few publications were capable of deriving Limits of Agreement that fit the observed data visually in a convincing way. Moreover, several attempts have been made in the recent past to improve the analysis and reporting of method comparison studies. These warrant increased attention in the future.
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van Velzen SGM, de Vos BD, Noothout JMH, Verkooijen HM, Viergever MA, Išgum I. Generative models for reproducible coronary calcium scoring. J Med Imaging (Bellingham) 2022; 9:052406. [PMID: 35664539 DOI: 10.1117/1.jmi.9.5.052406] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 05/12/2022] [Indexed: 11/14/2022] Open
Abstract
Purpose: Coronary artery calcium (CAC) score, i.e., the amount of CAC quantified in CT, is a strong and independent predictor of coronary heart disease (CHD) events. However, CAC scoring suffers from limited interscan reproducibility, which is mainly due to the clinical definition requiring application of a fixed intensity level threshold for segmentation of calcifications. This limitation is especially pronounced in non-electrocardiogram-synchronized computed tomography (CT) where lesions are more impacted by cardiac motion and partial volume effects. Therefore, we propose a CAC quantification method that does not require a threshold for segmentation of CAC. Approach: Our method utilizes a generative adversarial network (GAN) where a CT with CAC is decomposed into an image without CAC and an image showing only CAC. The method, using a cycle-consistent GAN, was trained using 626 low-dose chest CTs and 514 radiotherapy treatment planning (RTP) CTs. Interscan reproducibility was compared to clinical calcium scoring in RTP CTs of 1662 patients, each having two scans. Results: A lower relative interscan difference in CAC mass was achieved by the proposed method: 47% compared to 89% manual clinical calcium scoring. The intraclass correlation coefficient of Agatston scores was 0.96 for the proposed method compared to 0.91 for automatic clinical calcium scoring. Conclusions: The increased interscan reproducibility achieved by our method may lead to increased reliability of CHD risk categorization and improved accuracy of CHD event prediction.
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Affiliation(s)
- Sanne G M van Velzen
- Amsterdam UMC location University of Amsterdam, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands.,Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands.,University of Amsterdam, Informatics Institute, Faculty of Science, Amsterdam, The Netherlands.,Utrecht University, University Medical Center Utrecht, Image Sciences Institute, Utrecht, The Netherlands
| | - Bob D de Vos
- Amsterdam UMC location University of Amsterdam, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands.,Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands.,University of Amsterdam, Informatics Institute, Faculty of Science, Amsterdam, The Netherlands
| | - Julia M H Noothout
- Amsterdam UMC location University of Amsterdam, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands.,Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands.,University of Amsterdam, Informatics Institute, Faculty of Science, Amsterdam, The Netherlands
| | - Helena M Verkooijen
- University Medical Center Utrecht, Imaging Division, Utrecht, The Netherlands
| | - Max A Viergever
- Utrecht University, University Medical Center Utrecht, Image Sciences Institute, Utrecht, The Netherlands
| | - Ivana Išgum
- Amsterdam UMC location University of Amsterdam, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands.,Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands.,University of Amsterdam, Informatics Institute, Faculty of Science, Amsterdam, The Netherlands.,Amsterdam UMC location University of Amsterdam, Department of Radiology and Nuclear Medicine, Amsterdam, The Netherlands
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Patel N, Li D, Nakanishi R, Fatima B, Andreini D, Pontone G, Conte E, O'Rourke R, Jayawardena E, Hamilton-Craig C, Nimmagadda M, Budoff MJ. Comparison of Whole Heart Computed Tomography Scanners for Image Quality Lower Radiation Dosing in Coronary Computed Tomography Angiography: The CONVERGE Registry. Acad Radiol 2019; 26:1443-1449. [PMID: 30683612 DOI: 10.1016/j.acra.2019.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 12/31/2018] [Accepted: 01/02/2019] [Indexed: 11/30/2022]
Abstract
RATIONALE AND OBJECTIVES Novel technology in coronary computed tomographic angiography allows assessment of coronary artery disease with high image quality (IQ). There are currently two wide detector "whole heart" coverage scanners available, which avoid misregistration artifacts. However, there are no data directly comparing IQ between the two scanners. The aim of the current study is to investigate if IQ is different between the most scanners of GE and Toshiba broad detector scanners. MATERIALS AND METHODS Prospective, observational, multicenter international cohort study comparing 236 consecutive patients who underwent coronary computed tomographic angiography using whole-heart scanners; 126 patients on scanner S1 ( Aquilion ONE Vision, Toshiba), and 110 patients on scanner S2 (Revolution CT, GE Healthcare). Hounsfield units were measured using regions of interest in the descending aorta at 6 points (cranial slice, level of the visualized first, second, third, and fourth spines, and the caudal slice). We also compared the coverage length (z-axis) of the full width field of view between a single rotation of the two scanners. RESULTS Evaluating mean CT attenuation values Hounsfield units through the scan range, are progressively reduced across the descending aorta in the S1 group, resulting in the larger difference of contrast brightness between the cranial and caudal slices compared to the S2 group (absolute difference: S2 13.0 ± 4.4 vs S1 141.9 ± 16.4, p < 0.0001; Percent difference: 19.3 ± 2.1 vs -3.4 ± 1.2, <0.0001). The standard deviation (SD) is similar at the cranial slice between the two scanners, however, the S1 group demonstrated higher SD-differential from cranial to caudal than S2 group. Median radiation exposure was significantly lower for the S2 scanner 1.50 ± 0.75 mSv vs the S1 system 1.9 mSv (IQR 1.7-2.7 mSv) (p = 0.01). Z-axis coverage was larger for the S2 scanner 152.5 mm (244 slices × 0.625 mm/slice) than 133 mm for S1 (266 slices × 0.5 mm/slice). CONCLUSION Although both "volume" scanners cover the whole heart z-axis with one beat, scans using the S1 scanner have a larger variability in attenuation values throughout the scan range, resulting in 20% increase in nonuniformity from cranial to caudal slice. Additionally, SD variation across the field of view, a metric of noise, is larger when using the S1 scanner vs the S2 scanner. These results indicate that the GE Revolution CT has more uniform contrast enhancement and more coverage, lower radiation and lower image noise compared to the Toshiba Aquilion ONE Vision system.
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Affiliation(s)
- Nirali Patel
- Department of Medicine, Los Angeles Biomedical Research Institute, Torrance, CA
| | - Dong Li
- Department of Medicine, Los Angeles Biomedical Research Institute, Torrance, CA
| | - Rine Nakanishi
- Department of Medicine, Los Angeles Biomedical Research Institute, Torrance, CA; Department of Cardiovascular Medicine, Toho University Graduate School of Medicine, Tokyo, Japan
| | - Badiha Fatima
- Department of Medicine, Los Angeles Biomedical Research Institute, Torrance, CA
| | - Daniele Andreini
- Centro Cardiologico Monzino, IRCCS, Milan, Italy; Department of Clinical Sciences and Community Health, Cardiovascular Section, University of Milan, Italy
| | | | | | - Rachael O'Rourke
- Department of Medical Imaging, The Prince Charles Hospital, Brisbane, Queensland Australia; University of Queensland, Brisbane, Queensland, Australia
| | - Eranthi Jayawardena
- Department of Medicine, Los Angeles Biomedical Research Institute, Torrance, CA
| | - Christian Hamilton-Craig
- Department of Medical Imaging, The Prince Charles Hospital, Brisbane, Queensland Australia; University of Queensland, Brisbane, Queensland, Australia
| | - Manojna Nimmagadda
- Department of Medicine, Los Angeles Biomedical Research Institute, Torrance, CA
| | - Matthew J Budoff
- Department of Medicine, Los Angeles Biomedical Research Institute, Torrance, CA.
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Šprem J, de Vos BD, Lessmann N, van Hamersvelt RW, Greuter MJW, de Jong PA, Leiner T, Viergever MA, Išgum I. Coronary calcium scoring with partial volume correction in anthropomorphic thorax phantom and screening chest CT images. PLoS One 2018; 13:e0209318. [PMID: 30571729 PMCID: PMC6301689 DOI: 10.1371/journal.pone.0209318] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 12/04/2018] [Indexed: 11/24/2022] Open
Abstract
INTRODUCTION The amount of coronary artery calcium determined in CT scans is a well established predictor of cardiovascular events. However, high interscan variability of coronary calcium quantification may lead to incorrect cardiovascular risk assignment. Partial volume effect contributes to high interscan variability. Hence, we propose a method for coronary calcium quantification employing partial volume correction. METHODS Two phantoms containing artificial coronary artery calcifications and 293 subject chest CT scans were used. The first and second phantom contained nine calcifications and the second phantom contained three artificial arteries with three calcifications of different volumes, shapes and densities. The first phantom was scanned five times with and without extension rings. The second phantom was scanned three times without and with simulated cardiac motion (10 and 30 mm/s). Chest CT scans were acquired without ECG-synchronization and reconstructed using sharp and soft kernels. Coronary calcifications were annotated employing the clinically used intensity value thresholding (130 HU). Thereafter, a threshold separating each calcification from its background was determined using an Expectation-Maximization algorithm. Finally, for each lesion the partial content of calcification in each voxel was determined depending on its intensity and the determined threshold. RESULTS Clinical calcium scoring resulted in overestimation of calcium volume for medium and high density calcifications in the first phantom, and overestimation of calcium volume for high density and underestimation for low density calcifications in the second phantom. With induced motion these effects were further emphasized. The proposed quantification resulted in better accuracy and substantially lower over- and underestimation of calcium volume even in presence of motion. In chest CT, the agreement between calcium scores from the two reconstructions improved when proposed method was used. CONCLUSION Compared with clinical calcium scoring, proposed quantification provides a better estimate of the true calcium volume in phantoms and better agreement in calcium scores between different subject scan reconstructions.
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Affiliation(s)
- Jurica Šprem
- Image Sciences Institute, University Medical Center Utrecht and Utrecht University, Utrecht, The Netherlands
| | - Bob D de Vos
- Image Sciences Institute, University Medical Center Utrecht and Utrecht University, Utrecht, The Netherlands
| | - Nikolas Lessmann
- Image Sciences Institute, University Medical Center Utrecht and Utrecht University, Utrecht, The Netherlands
| | - Robbert W van Hamersvelt
- Department of Radiology, University Medical Center Utrecht and Utrecht University, Utrecht, The Netherlands
| | - Marcel J W Greuter
- Department of Radiology, University Medical Center Groningen, Groningen, the Netherlands
| | - Pim A de Jong
- Department of Radiology, University Medical Center Utrecht and Utrecht University, Utrecht, The Netherlands
| | - Tim Leiner
- Department of Radiology, University Medical Center Utrecht and Utrecht University, Utrecht, The Netherlands
| | - Max A Viergever
- Image Sciences Institute, University Medical Center Utrecht and Utrecht University, Utrecht, The Netherlands
| | - Ivana Išgum
- Image Sciences Institute, University Medical Center Utrecht and Utrecht University, Utrecht, The Netherlands
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Šprem J, de Vos BD, Lessmann N, de Jong PA, Viergever MA, Išgum I. Impact of automatically detected motion artifacts on coronary calcium scoring in chest computed tomography. J Med Imaging (Bellingham) 2018; 5:044007. [PMID: 30840743 DOI: 10.1117/1.jmi.5.4.044007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 11/16/2018] [Indexed: 11/14/2022] Open
Abstract
The amount of coronary artery calcification (CAC) quantified in computed tomography (CT) scans enables prediction of cardiovascular disease (CVD) risk. However, interscan variability of CAC quantification is high, especially in scans made without ECG synchronization. We propose a method for automatic detection of CACs that are severely affected by cardiac motion. Subsequently, we evaluate the impact of such CACs on CAC quantification and CVD risk determination. This study includes 1000 baseline and 585 one-year follow-up low-dose chest CTs from the National Lung Screening Trial. About 415 baseline scans are used to train and evaluate a convolutional neural network that identifies observer determined CACs affected by severe motion artifacts. Therefore, 585 paired scans acquired at baseline and follow-up were used to evaluate the impact of severe motion artifacts on CAC quantification and risk categorization. Based on the CAC amount, the scans were categorized into four standard CVD risk categories. The method identified CACs affected by severe motion artifacts with 85.2% accuracy. Moreover, reproducibility of CAC scores in scan pairs is higher in scans containing mostly CACs not affected by severe cardiac motion. Hence, the proposed method enables identification of scans affected by severe cardiac motion, where CAC quantification may not be reproducible.
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Affiliation(s)
- Jurica Šprem
- University Medical Center Utrecht, Image Sciences Institute, Utrecht, The Netherlands
| | - Bob D de Vos
- University Medical Center Utrecht, Image Sciences Institute, Utrecht, The Netherlands
| | - Nikolas Lessmann
- University Medical Center Utrecht, Image Sciences Institute, Utrecht, The Netherlands
| | - Pim A de Jong
- Utrecht University and University Medical Center Utrecht, Department of Radiology, Utrecht, The Netherlands
| | - Max A Viergever
- Utrecht University and University Medical Center Utrecht, Image Sciences Institute, Utrecht, The Netherlands
| | - Ivana Išgum
- University Medical Center Utrecht, Image Sciences Institute, Utrecht, The Netherlands
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Abstract
The ability to follow changes in atherosclerotic plaque burden over time should provide an accurate measure of efficacy for different cardiovascular therapies. Coronary calcifications are associated with atherosclerotic coronary artery plaque, and the amount of coronary calcifications has been shown to correlate with the overall coronary plaque burden. The presence and extent of coronary calcifications can be assessed noninvasively by monitoring the progression of coronary calcification with electron beam tomography. With annual progression rates of 22% to 52% and a median interscan variability of only 5% to 8%, this technology provides an opportunity to monitor patients to assess the clinical efficacy of medical therapies in studies as short as 1 year. Several studies have demonstrated that the successful pharmacologic reduction of low-density lipoprotein cholesterol significantly mitigated the progression of the calcium score. Studies using serial computed tomographic scans indicate that the annual progression of coronary calcium varies between 30% and 50% in symptomatic or high-risk individuals and from 0% to 20% in patients treated effectively with lipid-lowering medication. An increased rate of progression of coronary calcium seems to indicate a substantially increased risk for adverse cardiac events, suggesting that this modality can be used to monitor the efficacy of therapy.
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Affiliation(s)
- Matthew J Budoff
- Division of Cardiology, Harbor-UCLA Medical Center Research and Education Institute, Torrance, CA 90502, USA.
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Quantification of Right Ventricular Volume and Function Using Single-Beat Three-Dimensional Echocardiography: A Validation Study with Cardiac Magnetic Resonance. J Am Soc Echocardiogr 2016; 29:392-401. [DOI: 10.1016/j.echo.2016.01.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Indexed: 11/22/2022]
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Radiation dose reduction at coronary artery calcium scoring by using a low tube current technique and hybrid iterative reconstruction. J Comput Assist Tomogr 2015; 39:119-24. [PMID: 25319604 DOI: 10.1097/rct.0000000000000168] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this study was to compare the accuracy of coronary artery calcium scoring (CACS) on cardiac computed tomographic images using hybrid iterative reconstruction (hIR) and a low tube current as well as on images acquired with a filtered back projection (FBP) algorithm and a normal tube current. SUBJECTS AND METHODS Patients (N = 77) with suspected coronary artery disease were subjected to 2 CACS evaluations based on their Agatston, volume, and mass scores. One CACS evaluation was performed on images obtained with a 364-mA tube current and reconstructed with FBP; the other was performed on images obtained with a 73-mA tube current and reconstructed with hIR at iDose4. All scans were performed with the prospective electrocardiogram-triggered method using a 256-slice computed tomographic scanner (Brilliance iCT; Philips). We assessed agreement between calcium scores obtained with FBP and with IR using the percentage difference and Bland-Altman analysis. RESULTS The effective radiation doses for CACS at 80 mA s with FBP and at 16 mA s with IR were 1.20 and 0.24 mSv, respectively (k = 0.014). The mean Agatston, volume, and mass scores at 80 mA s with FBP as well as at 16 mA s with IR were 390.7, 146.5, and 63.2 as well as 377.7, 142.5, and 62.2, respectively. The percentage difference between FBP and hIR for the Agatston, volume, and mass score was 20.7%, 20.7%, and 27.1%, respectively. Bland-Altman analysis showed that there was no systemic bias. CONCLUSIONS The radiation dose for CACS can be reduced at a low tube current and hIR without affecting the calcium score.
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Computed Tomograph Cardiovascular Imaging. Coron Artery Dis 2015. [DOI: 10.1007/978-1-4471-2828-1_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Eilot D, Goldenberg R. Fully automatic model-based calcium segmentation and scoring in coronary CT angiography. Int J Comput Assist Radiol Surg 2013; 9:595-608. [PMID: 24203575 DOI: 10.1007/s11548-013-0955-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2013] [Accepted: 10/16/2013] [Indexed: 12/12/2022]
Abstract
PURPOSE The paper presents new methods for automatic coronary calcium detection, segmentation and scoring in coronary CT angiography (cCTA) studies. METHODS Calcium detection and segmentation are performed by modeling image intensity profiles of coronary arteries. The scoring algorithm is based on a simulated unenhanced calcium score (CS) CT image, constructed by virtually removing the contrast media from cCTA. The methods are implemented as part of a fully automatic system for CS assessment from cCTA. RESULTS The system was tested in two independent clinical trials on 263 studies and demonstrated 0.95/0.91 correlation between the CS computed from cCTA and the standard Agatston score derived from unenhanced CS CT. The mean absolute percent difference (MAPD) of 36/39 % between the two scores lies within the error range of the standard CS CT (15-65 %). CONCLUSIONS High diagnostic performance, combined with the benefits of the fully automatic solution, suggests that the proposed technique can be used to eliminate the need in a separate CS CT scan as part of the cCTA examination, thus reducing the radiation exposure and simplifying the procedure.
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Affiliation(s)
- Dov Eilot
- Rcadia Medical Imaging, 157 Yafo Str., 35251 , Haifa, Israel,
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Budoff MJ. Screening for Ischemic Heart Disease with Cardiac CT: Current Recommendations. SCIENTIFICA 2012; 2012:812046. [PMID: 24278742 PMCID: PMC3820482 DOI: 10.6064/2012/812046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 09/16/2012] [Indexed: 06/02/2023]
Abstract
Cardiovascular disease remains the leading cause of mortality in the US and worldwide, and no widespread screening for this number one killer has been implemented. Traditional risk factor assessment does not fully account for the coronary risk and underestimates the prediction of risk even in patients with established risk factors for atherosclerosis. Coronary artery calcium (CAC) represents calcified atherosclerosis in the coronary arteries. It has been shown to be the strongest predictor of adverse future cardiovascular events and provides incremental information to the traditional risk factors. CAC consistently outperforms traditional risk factors, including models such as Framingham risk to predict future CV events. It has been incorporated into both the European and American guidelines for risk assessment. CAC is the most robust test today to reclassify individuals based on traditional risk factor assessment and provides the opportunity to better strategize the treatments for these subjects (converting patients from intermediate to high or low risk). CAC progression has also been identified as a risk for future cardiovascular events, with markedly increased events occurring in those patients exhibiting increases in calcifications over time. The exact intervals for rescanning is still being evaluated.
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Affiliation(s)
- Matthew J. Budoff
- Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center, 1124 West Carson Street, Torrance, CA 90502, USA
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McEvoy JW, Blaha MJ, DeFilippis AP, Budoff MJ, Nasir K, Blumenthal RS, Jones SR. Coronary Artery Calcium Progression: An Important Clinical Measurement? J Am Coll Cardiol 2010; 56:1613-22. [DOI: 10.1016/j.jacc.2010.06.038] [Citation(s) in RCA: 185] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Revised: 06/14/2010] [Accepted: 06/15/2010] [Indexed: 11/29/2022]
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Sharma RK, Sharma RK, Voelker DJ, Singh VN, Pahuja D, Nash T, Reddy HK. Cardiac risk stratification: role of the coronary calcium score. Vasc Health Risk Manag 2010; 6:603-11. [PMID: 20730016 PMCID: PMC2922321 DOI: 10.2147/vhrm.s8753] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2010] [Indexed: 11/23/2022] Open
Abstract
Coronary artery calcium (CAC) is an integral part of atherosclerotic coronary heart disease (CHD). CHD is the leading cause of death in industrialized nations and there is a constant effort to develop preventative strategies. The emphasis is on risk stratification and primary risk prevention in asymptomatic patients to decrease cardiovascular mortality and morbidity. The Framingham Risk Score predicts CHD events only moderately well where family history is not included as a risk factor. There has been an exploration for new tests for better risk stratification and risk factor modification. While the Framingham Risk Score, European Systematic Coronary Risk Evaluation Project, and European Prospective Cardiovascular Munster study remain excellent tools for risk factor modification, the CAC score may have additional benefit in risk assessment. There have been several studies supporting the role of CAC score for prediction of myocardial infarction and cardiovascular mortality. It has been shown to have great scope in risk stratification of asymptomatic patients in the emergency room. Additionally, it may help in assessment of progression or regression of coronary artery disease. Furthermore, the CAC score may help differentiate ischemic from nonischemic cardiomyopathy.
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Affiliation(s)
- Rakesh K Sharma
- Medical Center of South Arkansas, University of Arkansas for Medical Sciences, Little Rock, AR 71730, USA.
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Rutten A, Isgum I, Prokop M. Calcium scoring with prospectively ECG-triggered CT: using overlapping datasets generated with MPR decreases inter-scan variability. Eur J Radiol 2010; 80:83-8. [PMID: 20599336 DOI: 10.1016/j.ejrad.2010.06.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 06/03/2010] [Accepted: 06/09/2010] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To examine the feasibility of reducing the inter-scan variability of prospectively ECG-triggered calcium-scoring scans by using overlapping 3-mm datasets generated from multiplanar reformation (MPR) instead of non-overlapping 3-mm or 1.5-mm datasets. PATIENTS AND METHODS Seventy-five women (59-79 years old) underwent two sequential prospectively ECG-triggered calcium-scoring scans with 16 mm×1.5mm collimation in one session. Between the two scans patients got off and on the table. We performed calcium scoring (Agatston and mass scores) on the following datasets: contiguous 3-mm sections reconstructed from the raw data (A), contiguous 3-mm sections from MPR (B), overlapping 3-mm sections from MPR (C) and contiguous 1.5-mm sections from the raw data (D). To determine the feasibility of the MPR approach, we compared MPR (B) with direct raw data reconstruction (A). Inter-scan variability was calculated for each type of dataset (A-D). RESULTS Calcium scores ranged from 0 to 1455 (Agatston) and 0 to 279 mg (mass) for overlapping 3-mm sections (C). Calcium scores (both Agatston and mass) were nearly identical for MPR (B) and raw data approaches (A), with inter-quartile ranges of 0-1% for inter-scan variability. Median inter-scan variability with contiguous 3-mm sections (B) was 13% (Agatston) and 11% (mass). Median variability was reduced to 10% (Agatston and mass) with contiguous 1.5-mm sections (D) and to 8% (Agatston) and 7% (mass) with overlapping 3-mm MPR (A). CONCLUSION Calcium scoring on MPR yields nearly identical results to calcium scoring on images directly reconstructed from raw data. Overlapping MPR from prospectively ECG-triggered scans improve inter-scan variability of calcium scoring without increasing patient radiation dose.
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Affiliation(s)
- A Rutten
- Department of Radiology, Room E01.132, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
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Coronary artery calcification scoring in low-dose ungated CT screening for lung cancer: interscan agreement. AJR Am J Roentgenol 2010; 194:1244-9. [PMID: 20410410 DOI: 10.2214/ajr.09.3047] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE In previous studies detection of coronary artery calcification (CAC) with low-dose ungated MDCT performed for lung cancer screening has been compared with detection with cardiac CT. We evaluated the interscan agreement of CAC scores from two consecutive low-dose ungated MDCT examinations. SUBJECTS AND METHODS The subjects were 584 participants in the screening segment of a lung cancer screening trial who underwent two low-dose ungated MDCT examinations within 4 months (mean, 3.1 +/- 0.6 months) of a baseline CT examination. Agatston score, volume score, and calcium mass score were measured by two observers. Interscan agreement of stratification of participants into four Agatston score risk categories (0, 1-100, 101-400, > 400) was assessed with kappa values. Interscan variability and 95% repeatability limits were calculated for all three calcium measures and compared by repeated measures analysis of variance. RESULTS An Agatston score > 0 was detected in 443 baseline CT examinations (75.8%). Interscan agreement of the four risk categories was good (kappa = 0.67). The Agatston scores were in the same risk category in both examinations in 440 cases (75.3%); 578 participants (99.0%) had scores differing a maximum of one category. Furthermore, mean interscan variability ranged from 61% for calcium volume score to 71% for Agatston score (p < 0.01). A limitation of this study was that no comparison of CAC scores between low-dose ungated CT and the reference standard ECG-gated CT was performed. CONCLUSION Cardiovascular disease risk stratification with low-dose ungated MDCT is feasible and has good interscan agreement of stratification of participants into Agatston score risk categories. High mean interscan variability precludes the use of this technique for monitoring CAC scores for individual patients.
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Goh VK, Lau CP, Mohlenkamp S, Rumberger JA, Achenbach S, Budoff MJ. Outcome of coronary plaque burden: a 10-year follow-up of aggressive medical management. Cardiovasc Ultrasound 2010; 8:5. [PMID: 20226020 PMCID: PMC2850323 DOI: 10.1186/1476-7120-8-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Accepted: 03/12/2010] [Indexed: 11/26/2022] Open
Abstract
Background The effect of aggressive medical therapy on quantitative coronary plaque burden is not generally known, especially in ethnic Chinese. Aims We reasoned that Cardiac CT could conveniently quantify early coronary atherosclerosis in our patient population, and hypothesized that serial observation could differentiate the efficacy of aggressive medical therapy regarding progression and regression of the atherosclerotic process, as well as evaluating the additional impact of life-style modification and the relative effects of the application of statin therapy. Methods We employed a standardized Cardiac CT protocol to serially scan 113 westernized Hong Kong Chinese individuals (64 men and 49 women) with Chest Pain and positive coronary risk factors. In all cases included for this serial investigation, subsequent evaluation showed no significantly-obstructive coronary disease by functional studies and angiography. After stringent risk factor modification, including aggressive statin therapy to achieve LDL-cholesterol lowering conforming to N.C.E.P. ATP III guidelines, serial CT scans were performed 1-12 years apart for changes in coronary artery calcification (CAC), using the Agatston Score (AS) for quantification. Results At baseline, the mean AS was 1413.6 for males (mean age 54.4 years) and 2293.3 for females (mean age 62.4 years). The average increase of AS in the entire study population was 24% per year, contrasting with 16.4% per year on strict risk factor modification plus statin therapy, as opposed to 33.2% per year for historical control patients (p < 0.001). Additionally, 20.4% of the 113 patients demonstrated decreasing calcium scores. Medical therapy also yielded a remarkably low adverse event rate during the follow-up period --- 2 deaths, 2 strokes and only 1 case requiring PCI. Conclusions This study revealed that aggressive medical therapy can positively influence coronary plaque aiding in serial regression of calcium scores.
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Affiliation(s)
- Victor K Goh
- Imaging Centre, Matilda International Hospital, 41 Mount Kellett Road, The Peak, Hong Kong, SAR China.
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Barrett-Connor E, Bergstrom J, Wright M, Kramer CK. Heart disease risk factors in midlife predict subclinical coronary atherosclerosis more than 25 years later in survivors without clinical heart disease: the Rancho Bernardo Study. J Am Geriatr Soc 2009; 57:1041-4. [PMID: 19507296 DOI: 10.1111/j.1532-5415.2009.02268.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To determine which of the classic modifiable coronary heart disease (CHD) risk factors, measured in midlife, are associated with subclinical coronary atherosclerosis in older age. DESIGN Prospective study. SETTING Community based. PARTICIPANTS Participants were 400 community-dwelling middle-aged adults who had no history of CHD at baseline (1972-1974), when CHD risk factors were measured, and who were still free of known CHD in 2000 to 2002. MEASUREMENTS Coronary artery plaque burden was assessed according to coronary artery calcium (CAC) score using computed tomography in 2000 to 2002. RESULTS Ordinal logistic regression analysis was used to compare baseline risk factors with severity of CAC. Mean age was 42 at baseline and 69 at the time of CAC assessment; 46.5% were male. In analyses adjusted for age, sex, and all other risk factors, one standard deviation increase in body mass index (odds ratio (OR)=1.24, 95%confidence interval (CI)=1.02-1.51; P=.03), cholesterol (OR=1.28, 95% CI=1.03-1.58; P=.020, pulse pressure (OR=1.24, 95% CI=1.03-1.50; P=.03), and log triglycerides (OR=1.22, 95% CI=0.99-1.50; P=.06) each independently predicted the presence and severity of coronary artery atherosclerosis. CONCLUSION Modifiable risk factors measured more than 25 years earlier influence plaque burden in elderly survivors without clinical heart disease.
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Affiliation(s)
- Elizabeth Barrett-Connor
- Division of Epidemiology, Department of Family & Preventive Medicine, School of Medicine, University of California, San Diego, 9500 Gilman Drive, MC 0607, La Jolla, CA 92093, USA.
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Reproducibility of coronary artery calcified plaque with cardiac 64-MDCT: the Multi-Ethnic Study of Atherosclerosis. AJR Am J Roentgenol 2009; 192:613-7. [PMID: 19234254 DOI: 10.2214/ajr.08.1242] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The Multi-Ethnic Study of Atherosclerosis is a longitudinal study evaluating determinants of future cardiac events and progression of atherosclerosis. Emerging data are showing that coronary artery calcification (CAC) is a robust independent predictor of future cardiac events and that measurement of progression depends on reproducibility of the measure. Reproducibility previously was reported on baseline scans obtained with both electron-beam tomography (EBT) and MDCT. The aim of this study was to compare the interscan variability for both Agatston and volume scores derived with newer (16- and 64-MDCT) scanners with that derived with older scanners in the Multi-Ethnic Study of Atherosclerosis. SUBJECTS AND METHODS The participants in this study were 4,054 persons who underwent dual scanning with EBT (n = 1,716), 4-MDCT (n = 370), 16-MDCT (n = 1,245), or 64-MDCT (n = 723). Agreement on the presence or absence of CAC was assessed with logistic regression models adjusted for age, sex, body mass index, and scanner type. Among participants with CAC, the log-transformed interscan difference was regressed on log-transformed amount of CAC, age, sex, and body mass index. RESULTS The percentage agreement for the presence or absence of CAC was high and similar across scanner groups (EBT, 16-MDCT, and 64-MDCT). The greatest adjusted average absolute CAC differences between scans were found with the Aquilion 64 (24%; 95% CI, 20.9-27.6) and LightSpeed Pro 16 (19%; 95% CI, 17.4-21.0) scanners, both differences being significantly greater than with the EBT scanner (16%; 95% CI, 15.4-17.5) (p < 0.05). No differences were found between the EBT, Sensation 16, and Sensation 64 scanners. For volume score, the Aquilion 64 was the only scanner with significantly greater average absolute interscan differences than the EBT scanner (p < 0.001). Volume scoring resulted in lower rescan differences for all scanners. CONCLUSION For CAC scoring, interscan variability with newer-generation MDCT scanners was similar to but not superior to that with the EBT scanner.
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Mazzaferro S, Pasquali M, Taggi F, Baldinelli M, Conte C, Muci ML, Pirozzi N, Carbone I, Francone M, Pugliese F. Progression of coronary artery calcification in renal transplantation and the role of secondary hyperparathyroidism and inflammation. Clin J Am Soc Nephrol 2009; 4:685-90. [PMID: 19211668 DOI: 10.2215/cjn.03930808] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND OBJECTIVES Transplantation should favorably affect coronary calcification (CAC) progression in dialysis; however, changes in CAC score in the individual patient are not reliably evaluated. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS The authors used special tables of reproducibility limits for each score level to study, by multislice computed tomography and biochemistries, the 2-year changes in CAC in 41 transplant patients (age 48 +/- 13 yr, 25 men, dialysis vintage 4.8 +/- 4.3 yr, underwent transplant 6.2 +/- 5.5 yr prior). Thirty balanced dialysis patients served as controls. RESULTS In the study group, Agatston score was stable, and C-reactive protein decreased, whereas fetuin and osteoprotegerin increased. In the control group, Agatston score increased, parathyroid hormone and phosphate decreased, and inflammation markers were persistently twice as high as in the study group. With regard to individual changes, 12.2% transplant patients worsened, compared with 56.6% of patients in dialysis (P < 0.0001). Patients without calcification at entry showed slower progression in transplantation (8.3%) than in dialysis (44.4%; P < 0.034), and the difference was similar to that observed in cases with CAC (17.6% versus 61.9%; P < 0.007). Discriminant analysis indicated parathyroid hormone, the modality of therapy (dialysis or transplantation), and erythrocyte sedimentation rate as the variables most associated with worsening. CONCLUSIONS Renal transplantation lowers but does not halt CAC progression. Inflammation and hyperparathyroidism are associated with progression in the populations studied.
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Affiliation(s)
- Sandro Mazzaferro
- Department of Clinical Science, University of Rome La Sapienza, Rome, Italy.
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Oudkerk M, Stillman AE, Halliburton SS, Kalender WA, Möhlenkamp S, McCollough CH, Vliegenthart R, Shaw LJ, Stanford W, Taylor AJ, van Ooijen PMA, Wexler L, Raggi P. Coronary artery calcium screening: current status and recommendations from the European Society of Cardiac Radiology and North American Society for Cardiovascular Imaging. Eur Radiol 2008; 18:2785-807. [DOI: 10.1007/s00330-008-1095-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 05/05/2008] [Accepted: 05/19/2008] [Indexed: 01/07/2023]
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Coronary artery calcium screening: current status and recommendations from the European Society of Cardiac Radiology and North American Society for Cardiovascular Imaging. Int J Cardiovasc Imaging 2008; 24:645-71. [PMID: 18504647 PMCID: PMC2493606 DOI: 10.1007/s10554-008-9319-z] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Accepted: 05/06/2008] [Indexed: 01/07/2023]
Abstract
Current guidelines and literature on screening for coronary artery calcium for cardiac risk assessment are reviewed for both general and special populations. It is shown that for both general and special populations a zero score excludes most clinically relevant coronary artery disease. The importance of standardization of coronary artery calcium measurements by multi-detector CT is discussed.
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Budoff MJ, Kessler P, Gao YL, Qunibi W, Moustafa M, Mao SS. The interscan variation of CT coronary artery calcification score: analysis of the Calcium Acetate Renagel Comparison (CARE)-2 study. Acad Radiol 2008; 15:58-61. [PMID: 18078907 DOI: 10.1016/j.acra.2007.08.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 08/18/2007] [Accepted: 08/18/2007] [Indexed: 11/27/2022]
Abstract
RATIONALE AND OBJECTIVES In the Calcium Acetate Renagel Evaluation (CARE)-2 study, the effects of calcium acetate plus atorvastatin (Lipitor) on the progression of coronary artery calcifications (CACs) are evaluated versus those of Renagel, monitored using dual electron beam tomography (EBT) scans (two scans at study initiation and two at follow up). The aim of this study is to estimate the interscan variation for the Agatston score and for the volume score determined in patients with end-stage renal disease (ESRD) in the CARE-2 study. MATERIALS AND METHODS CAC score and volume were measured at study initiation in 463 ESRD subjects (mean age: 59.4 +/- 12.5 years, 48.3% female). All patients underwent dual scanning using an EBT, as first scan of two needed to measure the progression of CAC when treated with sevelamer (Renagel) compared with calcium acetate with or without atorvastatin. All scans in all participants were completed by using an EBT system (GE Imatron, South San Francisco, CA). Interscan variability was defined by the following formula: abs (scan A - scan B) / (0.5 x scan A + 0.5 x scan B) x 100%, where A and B denote the first and second scan, respectively, of the dual scan procedure performed before treatment. We evaluated the reproducibility of the cutpoints commonly used for calcium scores clinically, namely 1-30, 31-100, 101-400, and >400. RESULTS The CAC interscan variability was 11.8% using the Agatston score and 10.3% using the volume score. The reproducibility was then assessed using cutpoints 1-30, 31-100, 101-400, and >400. Agatston score variability for the four subgroups was 61.3%, 23%, 16.1%, and 8.2%, respectively (mean variability, 11.8%). Volume score variability was 60.0%, 14.4%, 14.6%, and 7.7%, respectively (mean variability, 10.3%). The correlation coefficient for scan A to scan B goes up significantly with increasing calcium scores and reaches 0.99 for scores greater than 400 (P < .0001). CONCLUSION Interscan variability was sufficiently small for patients with calcium scores greater than 30. Our study thus demonstrates a sufficient reproducibility of the calcium score using EBT. This score allows for accurate serial assessment of these patients and for comparing different therapies.
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Rutten A, Isgum I, Prokop M. Coronary calcification: effect of small variation of scan starting position on Agatston, volume, and mass scores. Radiology 2007; 246:90-8. [PMID: 18024437 DOI: 10.1148/radiol.2461070006] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To retrospectively evaluate the effect of a small variation of scan starting position on coronary artery calcium scores based on nonoverlapping 3-mm multidetector computed tomographic (CT) data sets. MATERIALS AND METHODS Informed consent and institutional review board approval were obtained. A retrospective study was performed by using prospective unenhanced electrocardiographically triggered cardiac multidetector CT scans in 228 women (mean age, 67 years +/- 5 [standard deviation]). From the original 1.5-mm data set, two sets of adjacent images with a section thickness of 3 mm and a variation in starting point of 1.5 mm were obtained. Calcium scoring was performed to acquire Agatston, volume, and mass scores. Subjects were assigned to one of five risk categories (I-V) according to the Agatston score of each 3-mm data set and the average score. Kappa value was calculated to assess agreement in risk category assignment. Differences and relative differences between scores obtained for both 3-mm data sets were calculated overall and according to risk category. The effect of scoring algorithm on the relative differences between scores was analyzed with the Wilcoxon signed rank test. RESULTS Categories I-V contained 102, 35, 48, 31, and 12 subjects, respectively. For all scoring algorithms, median relative differences decreased from more than 130% in category II to less than 10% in category V. In the three highest categories, relative differences were significantly smaller for volume and mass scores than for Agatston scores (P < .05). Twenty-one subjects were assigned to different risk categories between the two data sets (kappa = 0.87). Eleven patients were assigned a nonzero score in one and a zero score in the other data set. CONCLUSION A small variation in scan starting position can substantially influence calcium measurements and poses an inherent limit to calcium scoring with contiguous 3-mm sections. Mass and volume scores are slightly less affected than are Agatston scores.
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Affiliation(s)
- Annemarieke Rutten
- Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, Room E01.132, 3584 CX Utrecht, The Netherlands.
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CT-Based Calcium Scoring to Screen for Coronary Artery Disease: Why Aren't We There Yet? AJR Am J Roentgenol 2007; 189:1061-3. [DOI: 10.2214/ajr.07.2591] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Budoff MJ, Katz R, Wong ND, Nasir K, Mao SS, Takasu J, Kronmal R, Detrano RC, Shavelle DM, Blumenthal RS, O'brien KD, Carr JJ. Effect of scanner type on the reproducibility of extracoronary measures of calcification: the multi-ethnic study of atherosclerosis. Acad Radiol 2007; 14:1043-9. [PMID: 17707311 DOI: 10.1016/j.acra.2007.05.021] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Revised: 05/28/2007] [Accepted: 05/30/2007] [Indexed: 11/24/2022]
Abstract
RATIONALE AND OBJECTIVES Cardiac computed tomography (CT) has been used extensively to measure coronary artery calcification. However, extracoronary calcifications, such as aortic valve calcification (AVC), may have independent clinical significance as well. The ability to track calcification is dependent on the reproducibility of the original measurement, and the variability of extracoronary calcification measurements still is unknown. Accurate quantification of calcification of the aortic valve, mitral annulus (MAC), and thoracic aortic (TAC) may be possible by using cardiac CT. METHODS A total of 1,729 randomly chosen participants (ages 45-84, 53% female, 28% African-American, 36% Caucasian, 11% Chinese, 25% Hispanic) of the Multi-Ethnic Study of Atherosclerosis underwent dual scanning by electron beam CT (EBT) or multidetector CT (MDCT) to assess coronary and extra-coronary calcifications. Two calcium measurement methods--Agatston score (AS) and volume score (VS)--were measured for each scan. Concordance for calcium positivity was assessed among all scans. Mean absolute and relative differences between calcium measures on scans 1 and 2, excluding cases for which both scans had a measure of zero, was modeled by using linear regression to compare variability between scanner types. A repeated measures analysis of variance test was used to compare variability across calcium measures, with mean percentage absolute difference as the outcome measure. RESULTS Concordances for the presence of calcium between duplicate scans were high and similar for both EBT and MDCT. Concordance was high for all three extracoronary measures, with a kappa statistic of kappa = 0.94-0.96. For all three extracoronary sites, Bland-Altman plots demonstrated excellent agreement, with almost all measures falling within the boundaries of the 95% confidence limits of reproducibility. AVC interscan variability was approximately 8% for both AS and VS, with improved variability for EBT as compared with MDCT. Mitral annular calcification demonstrated slightly lower variability than AVC for both scanner types (approximately 6%), with no significant differences between MDCT and EBT. Of the three extracoronary sites, TAC had the highest variability (10%), with MDCT variability slightly lower than EBT variability (9.3 vs. 10.2%, respectively, P = NS). Agatson and volume scores for each of the three extracoronary sites were similar. CONCLUSIONS Overall rescan measurement variabilities for extracoronary calcification are low and should not be an impediment to the use of this test for studying progression of extracoronary calcification over time.
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Affiliation(s)
- Matthew J Budoff
- Division of Cardiology, Los Angeles Biomedical Research Institute at Harbor-UCLA, 1124 W. Carson Street, RB2, Torrance, CA 90502, USA.
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Greenland P, Bonow RO, Brundage BH, Budoff MJ, Eisenberg MJ, Grundy SM, Lauer MS, Post WS, Raggi P, Redberg RF, Rodgers GP, Shaw LJ, Taylor AJ, Weintraub WS. ACCF/AHA 2007 clinical expert consensus document on coronary artery calcium scoring by computed tomography in global cardiovascular risk assessment and in evaluation of patients with chest pain: a report of the American College of Cardiology Foundation Clinical Expert Consensus Task Force (ACCF/AHA Writing Committee to Update the 2000 Expert Consensus Document on Electron Beam Computed Tomography) developed in collaboration with the Society of Atherosclerosis Imaging and Prevention and the Society of Cardiovascular Computed Tomography. J Am Coll Cardiol 2007; 49:378-402. [PMID: 17239724 DOI: 10.1016/j.jacc.2006.10.001] [Citation(s) in RCA: 683] [Impact Index Per Article: 40.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Greenland P, Bonow RO, Brundage BH, Budoff MJ, Eisenberg MJ, Grundy SM, Lauer MS, Post WS, Raggi P, Redberg RF, Rodgers GP, Shaw LJ, Taylor AJ, Weintraub WS, Harrington RA, Abrams J, Anderson JL, Bates ER, Grines CL, Hlatky MA, Lichtenberg RC, Lindner JR, Pohost GM, Schofield RS, Shubrooks SJ, Stein JH, Tracy CM, Vogel RA, Wesley DJ. ACCF/AHA 2007 Clinical Expert Consensus Document on Coronary Artery Calcium Scoring by Computed Tomography in Global Cardiovascular Risk Assessment and in Evaluation of Patients With Chest Pain. Circulation 2007; 115:402-26. [PMID: 17220398 DOI: 10.1161/circulationaha..107.181425] [Citation(s) in RCA: 362] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Computed Tomographic Cardiovascular Imaging. CARDIOVASCULAR MEDICINE 2007. [DOI: 10.1007/978-1-84628-715-2_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Budoff MJ, Achenbach S, Blumenthal RS, Carr JJ, Goldin JG, Greenland P, Guerci AD, Lima JAC, Rader DJ, Rubin GD, Shaw LJ, Wiegers SE. Assessment of coronary artery disease by cardiac computed tomography: a scientific statement from the American Heart Association Committee on Cardiovascular Imaging and Intervention, Council on Cardiovascular Radiology and Intervention, and Committee on Cardiac Imaging, Council on Clinical Cardiology. Circulation 2006; 114:1761-91. [PMID: 17015792 DOI: 10.1161/circulationaha.106.178458] [Citation(s) in RCA: 998] [Impact Index Per Article: 55.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Horiguchi J, Yamamoto H, Hirai N, Akiyama Y, Fujioka C, Marukawa K, Fukuda H, Ito K. Variability of Repeated Coronary Artery Calcium Measurements on Low-Dose ECG-Gated 16-MDCT. AJR Am J Roentgenol 2006; 187:W1-6. [PMID: 16794121 DOI: 10.2214/ajr.05.0052] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE High reproducibility on coronary artery calcium (CAC) scoring is a key requirement in monitoring the progression of coronary atherosclerosis. Retrospective ECG-gated helical CT has been shown to be superior to prospective gating helical CT in the reproducibility of CAC measurements. However, it brings with it a high level of radiation exposure. The purpose of this study was to compare low- and standard-dose protocols in the variability of CAC scores and in image quality, thereby assessing the feasibility of low-dose retrospective ECG-gated helical CT in CAC measurements. SUBJECTS AND METHODS Eighty-six patients with CAC were scanned using a tube current setting of 100 mA once and then a tube current setting equivalent to the patient's body weight twice. CAC scores (Agatston and volume) and interscan variability were evaluated. The mean and SD of the CT attenuation values in regions of interest in the aorta were measured, and the value (mean + 2 x SD) was obtained. RESULTS A high correlation of log(10) (Agatston score + 1) was observed between sequential helical CT scans (r = 0.998). The variability in CAC measurements ranged from 11% to 12% for both the Agatston and volume scores. With the tube current equivalent to body weight, the value (mean + 2 x SD) did not exceed a CT attenuation value of 130 H. CONCLUSION Low-dose retrospective ECG-gated helical CT-yielding low variability and achieving the level of image quality needed to measure CAC-can be used to monitor patients with coronary atherosclerosis.
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Affiliation(s)
- Jun Horiguchi
- Department of Clinical Radiology, Hiroshima University Hospital, 1-2-3, Kasumi-cho, Minami-ku, Hiroshima 734-8551, Japan.
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Horiguchi J, Fukuda H, Yamamoto H, Hirai N, Alam F, Kakizawa H, Hieda M, Tachikake T, Marukawa K, Ito K. The impact of motion artifacts on the reproducibility of repeated coronary artery calcium measurements. Eur Radiol 2006; 17:81-6. [PMID: 16718452 DOI: 10.1007/s00330-006-0278-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2005] [Revised: 03/17/2006] [Accepted: 04/03/2006] [Indexed: 10/24/2022]
Abstract
The purpose of this study is, using a 16-section multidetector-row helical computed tomography (MDCT) scanner with retrospective reconstruction, to compare variability in repeated coronary calcium scoring and qualitative scores of the motion artifacts. One hundred forty-four patients underwent two subsequent scans using MDCT. According to Agatston and volume algorithms, the coronary calcium scores during mid-diastole (the center corresponding to 70% of the R-R cycle) were calculated and the inter-scan variability was obtained. Motion artifacts from coronary artery calcium were subjectively evaluated and classified using a 5-point scale: 1, excellent; no motion artifacts; 2, fine, minor motion artifacts; 3, moderate, mild motion artifacts; 4, bad, severe motion artifacts; 5, poor, doubling or discontinuity. Each reading was done by vessels (left main, left descending, left circumflex and right coronary arteries) and the motion artifact score (mean of the scales) was determined per patient. The variability in the low (1.2+/-0.2) and high (2.4+/-0.6) motion artifact score groups was 7+/-6 (median, 6)% and 19+/-15 (16)% on the Agatston score (P<0.01) and 7+/-7 (6)% and 16+/-13 (14)% on the volume score (P<0.01), respectively. In conclusion, motion has a significant impact on the reproducibility of coronary calcium scoring.
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Affiliation(s)
- Jun Horiguchi
- Department of Clinical Radiology, Hiroshima University Hospital, Hiroshima 734-8551, Japan.
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Abstract
Prospective epidemiologic studies have identified several risk factors for heart disease, and most can be the target of risk reduction interventions. The most widely recognized risk factors for atherosclerotic cardiovascular disease (ASCVD) include age, gender, cigarette smoking, sedentary lifestyle, elevated LDL, reduced HDL, hypertension, and diabetes. The consistency of associations between these factors and ASCVD risk across populations is substantial. Our understanding of the pathogenesis and etiology of coronary ASCVD, as well as its clinical implications, has grown tremendously over the past 20 y. The role garlic might play in treating ASCVD has been postulated for many years, but until recently no studies on garlic's ability to inhibit the atherosclerotic process have been reported. A pilot study evaluating coronary artery calcification and the effect of garlic therapy in a group of patients who were also on statin therapy suggested incremental benefits. The implications of this study must be put in context of the potential importance of early atherosclerosis detection and prevention.
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Affiliation(s)
- Matthew Budoff
- Division of Cardiology, Harbor-UCLA Medical Center, Torrance, CA, USA
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Abstract
Over the last decade, there has been increased recognition that atherosclerosis imaging adds greatly to the ability to identify patients at high risk for cardiac events. Technologies such as electron beam computed tomography and carotid intimal media thickness have contributed significantly to our understanding of the prevalence of preclinical atherosclerosis and its consequences. Current data suggest that elevated calcium scores are predictive of future cardiac events, independently and incrementally to traditional cardiac risk factors. The approximate predictive power is 10-fold for scores > 100, based upon current studies now reported. Guidelines and policy toward these modalities have shifted, with increased recognition of the importance among experts in cardiology, lipidology, and preventive medicine. Because most adverse events related to atherosclerosis occur in individuals at an intermediate risk, data suggest that it will be most cost-effective to concentrate screening efforts on this group of patients. This article reviews the current understanding of the value of coronary artery calcium screening in asymptomatic and symptomatic patients. Accurate measurement of subclinical coronary atherosclerosis should significantly improve the accuracy of global cardiovascular risk prediction, and allow for tracking of atherosclerosis burden, as well as better prediction of future cardiovascular events. Finally, by identifying high-risk patients, CAC may help select those patients who would benefit most from additional testing (e.g., non-invasive stress imaging) and intensification of medical therapy; CAC should have a significant impact on early detection and management of CAD.
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Affiliation(s)
- Matthew J Budoff
- Division of Cardiology, Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, CA 90502, USA.
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Sevrukov AB, Bland JM, Kondos GT. Serial electron beam CT measurements of coronary artery calcium: Has your patient's calcium score actually changed? AJR Am J Roentgenol 2006; 185:1546-53. [PMID: 16304011 DOI: 10.2214/ajr.04.1589] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The objective of our study was to develop a model for determining the smallest statistically significant change in the coronary artery calcium score (CAC) between serial measurements in a given subject. MATERIALS AND METHODS We assembled a convenience sample of 2,217 pairs of repeated electron beam CT coronary calcium scans acquired in quick succession. Each scan consisted of forty 100-msec, 3-mm sections obtained at 60% of the ECG R-R interval. A single observer quantified calcium in each scan independent of knowledge of calcium quantity in the repeated scan. We then modeled a relationship between the variation of the differences between repeated measurements of calcium and the magnitude of the calcium score and formulated 95% repeatability coefficient equations for the Agatston and volumetric CAC score. The equations allow determining the smallest statistically significant interval change in the calcium score between two serial measurements in a given subject. RESULTS In a subject with measurable CAC at baseline, the smallest statistically significant interval change is +/- (4.930 x square root of baseline Agatston CAC score) or +/- (3.445 x square root of baseline volumetric CAC score). In a subject with no measurable CAC at baseline, a follow-up CAC score exceeding 11.6 Agatston units or 9.5 mm3 qualifies for statistically significant progression. The results were similar in men and women. CONCLUSION By examining repeatability of quantitative electron beam CT measurements of coronary calcium as a function of the magnitude of the calcium score, we developed a model to determine the smallest statistically significant change between serial measurements in a given subject.
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Affiliation(s)
- Alexander B Sevrukov
- Department of Medicine, Section of Cardiology (M/C 715), University of Illinois at Chicago College of Medicine, Chicago, IL 60612, USA.
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Affiliation(s)
- Melvin E Clouse
- Beth Israel Deaconess Medical Center, Harvard Medical School, 1 Deaconess Rd, Room 302, Boston, MA 02215, USA.
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Sandstede JJW, Stoffels J, Wendel F, Ritter C, Beer M, Hahn D. Different Reconstruction Intervals for Exclusion of Coronary Artery Calcifications by Retrospectively Gated MDCT. AJR Am J Roentgenol 2006; 186:193-7. [PMID: 16357401 DOI: 10.2214/ajr.04.0793] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Exclusion of coronary artery calcifications has a high negative predictive value for the diagnosis of coronary artery disease. However, it is known that significant differences in calcium scoring can occur because of the ECG trigger interval. Thus, the aim of the study was to evaluate the influence of different reconstruction intervals on detection of any coronary calcium by using MDCT and retrospective cardiac gating. CONCLUSION For a true exclusion of coronary artery calcifications, different reconstruction intervals have to be evaluated.
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Budoff MJ, Nasir K, Mao S, Tseng PH, Chau A, Liu ST, Flores F, Blumenthal RS. Ethnic differences of the presence and severity of coronary atherosclerosis. Atherosclerosis 2005; 187:343-50. [PMID: 16246347 DOI: 10.1016/j.atherosclerosis.2005.09.013] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2005] [Revised: 08/20/2005] [Accepted: 09/10/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND Although cardiovascular risk factor levels are substantially different in Caucasians, African-American, Hispanics, and Asians, the relative rates of coronary heart disease in these groups are not consistent with these differences. The objective of the study is to assess the differences in the prevalence and severity of coronary artery calcification, as a measure of atherosclerosis, in these different ethnic groups. METHODS Electron-beam tomography was performed in 16,560 asymptomatic men and women (Asians=1336, African-Americans=610, Hispanics=1256) aged >or=35 years referred by their physician for cardiovascular risk evaluation. The study population encompassed 70% males, aged 52+/-8 years. RESULTS Caucasians were more likely to present with dyslipidemia (p<0.0001), while African-Americans and Hispanics had a higher prevalence of smoking, diabetes, and hypertension (all p<0.001). After adjustment for age, gender, risk factors, and treatment for hypercholesterolemia, compared with Caucasians, the relative risks for men having coronary calcification were 0.64 (95% CI: 0.48-0.86) in African-Americans, 0.88 (95% CI: 0.67-1.15) in Hispanics, and 0.66 (95% CI: 0.55-0.80) in Asians. After similar adjustments, the relative risks for women having coronary calcification, were 1.58 (95% CI: 1.13-2.19) for African-Americans, 0.84 (95% CI: 0.66-1.06) in Hispanics, and 0.71 (95% CI: 0.56-0.89) in Asian women. After adjusting for age and risk factors using multivariable analysis, African-American men were least likely to have any coronary calcium while African-American women had significantly higher OR of any calcification. Asian men and women had significantly lower OR of any calcification. There was no significant difference in prevalence or severity of atherosclerosis between Hispanics and Caucasians, in men or women. CONCLUSIONS Our study results demonstrate significant difference in the presence as well as severity of calcification according to ethnicity, independent of atherosclerotic risk factors. Results from this study (physician referred) closely parallel the results from MESA (population based, measured risk factors). Ethnic specific data on the predictive value of differing coronary calcium scores are needed.
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Affiliation(s)
- Matthew J Budoff
- Division of Cardiology, Los Angeles Biomedical Research Institute at Harbor-UCLA, 1124 W Carson Street, Bldg RB-2, Torrance, CA, USA.
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Horiguchi J, Shen Y, Akiyama Y, Hirai N, Sasaki K, Ishifuro M, Nakanishi T, Ito K. Electron Beam CT Versus 16-MDCT on the Variability of Repeated Coronary Artery Calcium Measurements in a Variable Heart Rate Phantom. AJR Am J Roentgenol 2005; 185:995-1000. [PMID: 16177422 DOI: 10.2214/ajr.04.1057] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE High reproducibility of coronary artery calcium (CAC) scoring is a key requirement for monitoring the progression of coronary atherosclerosis. The purposes of this study were to compare electron beam CT and 16-MDCT scanners in the variability of repeated CAC measurements and to assess the factors influencing this variability. MATERIALS AND METHODS CAC models of different sizes attached to a cardiac phantom with a programmable variable heart rate were scanned three times, and interscan variability of the CAC measurement was calculated each time. For helical CT, different slice-thickness images of either retrospective ECG-gated or prospective ECG-triggering reconstruction were obtained. The detection of small amounts of calcium, variability of the Agatston score, and CAC measurement algorithms (Agatston, volume, and mass scores) were compared between CT scanners and protocols. RESULTS All 1-mm-sized calcium models were detected on 0.625- and 1.25-mm helical CT, whereas some were missed on electron beam CT and 2.5-mm helical CT. Retrospective ECG-gated thin-slice helical CT showed the lowest variability. Reduction of variability by volume and mass scoring algorithms was less effective on 0.625- and 1.25-mm-thickness CT. CONCLUSION Retrospective ECG-gated thin-slice helical CT has the potential to be a useful tool for monitoring coronary atherosclerosis.
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Affiliation(s)
- Jun Horiguchi
- Department of Clinical Radiology, Hiroshima University Hospital, 1-2-3, Kasumi-cho, Minami-ku, Hiroshima 734-8551, Japan.
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Horiguchi J, Shen Y, Akiyama Y, Hirai N, Sasaki K, Ishifuro M, Ito K. Electron beam CT versus 16-slice spiral CT: how accurately can we measure coronary artery calcium volume? Eur Radiol 2005; 16:374-80. [PMID: 16175352 DOI: 10.1007/s00330-005-2904-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2005] [Revised: 06/28/2005] [Accepted: 08/18/2005] [Indexed: 10/25/2022]
Abstract
The purpose of this study was to investigate how accurately CAC volume we can be measured using electron beam computed tomography (CT) and 16-slice spiral CT. CAC models with known volume attached to a cardiac phantom were scanned. The error of measurement, variability between measured and real volumes, and inter-scan measurement variability were obtained. For spiral CT, seven different parameters were included: (1) slice thickness (0.625 mm, 1.25 mm and 2.5 mm), (2) retrospective spiral electrocardiograph (ECG)-gated or prospective axial ECG-triggering, (3) overlapping or non-overlapping. The error of measurement was 15% on electron beam CT and 8-20% on spiral CT. CAC volumes were underestimated in 92% and overestimated in 8% of the electron beam CT scans. Volumes were underestimated in 79%, correct in 5% and overestimated in 16% of the spiral CT scans. The best measurement and the least variability was observed on 0.625-mm retrospective spiral ECG-gated CT (error of 8%), a significant result (t-test: P<0.01) when compared with electron beam CT. CAC volume measurement on CT scanners may be significantly different and often underestimates the real volume of CAC. For precise evaluation of CAC volume, thin-slice retrospective spiral ECG-gated scan using a spiral CT scanner is desirable.
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Affiliation(s)
- Jun Horiguchi
- Department of Clinical Radiology, Hiroshima University Hospital, 1-2-3, Kasumi-cho, Minami-ku, Hiroshima, 734-8551, Japan.
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Rasouli ML, Nasir K, Blumenthal RS, Park R, Aziz DC, Budoff MJ. Plasma homocysteine predicts progression of atherosclerosis. Atherosclerosis 2005; 181:159-65. [PMID: 15939068 DOI: 10.1016/j.atherosclerosis.2005.01.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2004] [Revised: 12/28/2004] [Accepted: 01/10/2005] [Indexed: 11/26/2022]
Abstract
UNLABELLED MINI ABSTRACT: Three emerging risk factors potentially useful in predicting future cardiac events are electron-beam computed tomography (EBT), homocysteine(HCY), and C-reactive Protein (CRP). We evaluated a cohort of 133 serial asymptomatic patients, who underwent two consecutive EBT scans (8-84 months apart) and a comprehensive cardiac risk factor assessment, including measurements for lipids, ultrasensitive CRP and homocysteine. Individuals with elevated HCY (> or =12 micromol/L) demonstrated a mean increase in CC progression of 35% per year, while those with HCY <12 micromol/L (median) progressed at 17% per year (p = 0.0008). Patients with a level equal to or lower than the median value of CRP (0.8 mg/L) had a median yearly progression of 22%, compared to 21% for those with CRP value = 0.9-11 mg/L (p = ns). Presence of elevated HCY (>12 micromol/L) strongly and independently predicts progression of coronary plaque burden. BACKGROUND Despite the availability of effective preventive therapies, coronary artery disease (CAD) remains the leading cause of morbidity and mortality. Use of traditional cardiovascular risk factors is imprecise and predicts less than one half of future cardiovascular events. Three 'emerging risk factors', as potential means of identifying subclinical atherosclerosis and predicting future cardiovascular events, are electron-beam computed tomography, homocysteine, and C-reactive protein. Given the evidence that HCY and CRP are involved in atherogenesis, we hypothesized that significant progression of EBT calcium score (a measure of atherosclerotic plaque burden) is associated with higher levels of these markers. METHODS We evaluated 133 asymptomatic patients (100 men, 33 women; mean age was 61 +/- 9 years) who underwent previous EBT calcium score testing at Harbor-UCLA 8-80 months prior to enrollment (mean follow-up 20 months). Exclusion criteria included those with known or symptomatic CAD and chronic renal disease. During enrollment, we measured risk factors, serum HCY, serum lipids, ultrasensitive-CRP, and repeat EBT calcium scan. Statistical analysis was performed using probable Chi square method, and Student's t-test. RESULTS Individuals with elevated HCY (> or =12 micromol/L) demonstrated a mean increase in CC progression of 35% per year, while those with HCY <12 micromol/L (median) progressed at 17% per year (p = 0.0008). Patients with a level equal to or lower than the median value of CRP (0.8 mg/L) had a median yearly progression of 22%, compared to 21% for those with CRP value = 0.9-11 mg/L (p = ns). Neither cholesterol values, body mass index, gender, age nor presence of individual risk factors predicted progression of coronary calcium. CONCLUSION Presence of elevated HCY (>12 micromol/L) strongly and independently predicts progression of coronary plaque burden.
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Affiliation(s)
- M Leila Rasouli
- Division of Cardiology, Harbor-UCLA Medical Center Research and Education Institute, Torrance, CA 90502, USA
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Detrano RC, Anderson M, Nelson J, Wong ND, Carr JJ, McNitt-Gray M, Bild DE. Coronary calcium measurements: effect of CT scanner type and calcium measure on rescan reproducibility--MESA study. Radiology 2005; 236:477-84. [PMID: 15972340 DOI: 10.1148/radiol.2362040513] [Citation(s) in RCA: 236] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To evaluate the effect of scanner type and calcium measure on the reproducibility of calcium measurements. MATERIALS AND METHODS This investigation was approved by the institutional review boards of each study site and by the Institutional Review Board of the Los Angeles Biomedical Research Institute. Informed consent for scanning and participation was obtained from all participants. The study was Health Insurance Portability and Accountability Act compliant. The Multi-Ethnic Study of Atherosclerosis (MESA) is a multicenter observational study of 6814 participants undergoing demographic, risk factor, and subclinical disease evaluations. Coronary artery calcium was measured by using duplicate CT scans. Three study centers used electron-beam computed tomography (CT), and three used multi-detector row CT. Coronary artery calcium was detected in 3355 participants. Three calcium measurement methods-Agatston score, calcium volume, and interpolated volume score-were evaluated. Mean absolute differences between calcium measures on scans 1 and 2, excluding cases for which both scans had a measure of zero, was modeled by using linear regression to compare reproducibility between scanner types. A repeated measures analysis of variance test was used to compare reproducibility across calcium measures, with mean percentage absolute difference as the outcome measure. Rescan reproducibility in relation to misregistrations, noise, and motion artifacts was also examined. Variables were log transformed to create a more normal distribution. RESULTS Concordance for presence of calcium between duplicate scans was high and similar for both electron-beam and multi-detector row CT (96%, kappa = 0.92). Mean absolute difference between calcium scores for the two scans was 15.8 for electron-beam and 16.9 for multi-detector row CT scanners (P = .06). Mean relative differences were 20.1 for Agatston score, 18.3 for calcium volume, and 18.3 for interpolated volume score (P < .01). Reproducibility was lower for scans with versus those without image misregistrations or motion artifacts (P < .01 for both). CONCLUSION Electron-beam and multi-detector row CT scanners have equivalent reproducibility for measuring coronary artery calcium. Calcium volumes and interpolated volume scores are slightly more reproducible than Agatston scores. Reproducibility is lower for scans with misregistrations or motion artifacts.
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Affiliation(s)
- Robert C Detrano
- Div of Cardiology, Los Angeles Biomedical Research Inst, 1124 W Carson St, Bldg E-5, Torrance, CA 90502, USA.
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Horiguchi J, Yamamoto H, Akiyama Y, Hirai N, Marukawa K, Fukuda H, Ito K. Variability of Repeated Coronary Artery Calcium Measurements by 16-MDCT with Retrospective Reconstruction. AJR Am J Roentgenol 2005; 184:1917-23. [PMID: 15908554 DOI: 10.2214/ajr.184.6.01841917] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE High reproducibility on coronary calcium scoring is an important factor in monitoring the progression of coronary atherosclerosis. The purposes of this study were, using a 16-MDCT scanner with retrospective reconstruction, to compare the effects of thin-slice images and overlapping image reconstruction on the reproducibility of coronary calcium scoring and to compare 16-MDCT with electron beam CT (EBCT). MATERIALS AND METHODS Fifty patients underwent two sequential examinations using both EBCT and MDCT. For MDCT, images were reconstructed from the same raw data using the following thicknesses and increments (thickness/increment): 1.25 mm/1.25 mm, 2.5 mm/2.5 mm, and 2.5 mm/1.25 mm. The Agatston, volume, and mass scores were calculated on four pairs of image sets. Statistical analysis was performed to determine significant differences in interscan variability among image acquisition protocols and among measurement algorithms. RESULTS Overlapping reconstructed images (thickness/increment, 2.5 mm/1.25 mm) obtained on a 16-MDCT scanner showed the lowest variability (mean, 13%; median, 10%) when compared with the Agatston score. CONCLUSION The use of 16-MDCT with overlapping reconstruction by retrospective reconstruction, yielding low variability of coronary artery calcium measurement on two sequential scans, has an advantage over EBCT in monitoring the progression of atherosclerosis.
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Affiliation(s)
- Jun Horiguchi
- Department of Clinical Radiology, Hiroshima University Hospital, 1-2-3, Kasumi-cho, Minami-ku, Hiroshima 734-8551, Japan.
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Chiles C, Carr JJ. Vascular Diseases of the Thorax: Evaluation with Multidetector CT. Radiol Clin North Am 2005; 43:543-69, viii. [PMID: 15847815 DOI: 10.1016/j.rcl.2005.02.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The list of vascular diseases in the thorax has been narrowed to three, which are considered essential information for radiologists interpreting CT scans of the thorax: (1) aortic dissection and its variants, intramural hematoma and penetrating atherosclerotic ulcer; (2) acute pulmonary embolism; and (3) coronary artery disease. The spatial resolution of multidetector CT is such that CT has become the imaging modality of choice for aortic dissection and pulmonary embolism. This move away from angiography has transpired over the last decade; perhaps the next decade will see the same occur for evaluation of coronary artery disease.
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Affiliation(s)
- Caroline Chiles
- Division of Radiological Sciences, Department of Radiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
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Manzke R, Köhler T, Nielsen T, Hawkes D, Grass M. Automatic phase determination for retrospectively gated cardiac CT. Med Phys 2005; 31:3345-62. [PMID: 15651618 DOI: 10.1118/1.1791351] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The recent improvements in CT detector and gantry technology in combination with new heart rate adaptive cone beam reconstruction algorithms enable the visualization of the heart in three dimensions at high spatial resolution. However, the finite temporal resolution still impedes the artifact-free reconstruction of the heart at any arbitrary phase of the cardiac cycle. Cardiac phases must be found during which the heart is quasistationary to obtain outmost image quality. It is challenging to find these phases due to intercycle and patient-to-patient variability. Electrocardiogram (ECG) information does not always represent the heart motion with an adequate accuracy. In this publication, a simple and efficient image-based technique is introduced which is able to deliver stable cardiac phases in an automatic and patient-specific way. From low-resolution four-dimensional data sets, the most stable phases are derived by calculating the object similarity between subsequent phases in the cardiac cycle. Patient-specific information about the object motion can be determined and resolved spatially. This information is used to perform optimized high-resolution reconstructions at phases of little motion. Results based on a simulation study and three real patient data sets are presented. The projection data were generated using a 16-slice cone beam CT system in low-pitch helical mode with parallel ECG recording.
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Affiliation(s)
- R Manzke
- Philips Research Laboratories, Sector Technical Systems, Roentgenstrasse, 24-26, D-22335 Hamburg, Germany.
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Takasu J, Shavelle DM, O'Brien KD, Babaei A, Rosales J, Mao S, Fischer H, Budoff MJ. Association between progression of aortic valve calcification and coronary calcification: assessment by electron beam tomography. Acad Radiol 2005; 12:298-304. [PMID: 15766689 DOI: 10.1016/j.acra.2004.12.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2004] [Revised: 12/27/2004] [Accepted: 12/28/2004] [Indexed: 11/26/2022]
Abstract
RATIONALE AND OBJECTIVES It has been demonstrated that aortic valve calcification (AVC) shares many similarities with coronary atherosclerosis, including risk factors and pathologic characteristics. We sought to examine the relationship of AVC to coronary artery calcification (CC), to assess whether similar risk factors affect the process in a similar way. MATERIALS AND METHODS The study included 620 asymptomatic persons (513 men and 107 women, mean age 59 years range [30-82]) who underwent two consecutive electron beam tomography (EBT) scans at least 1 year apart (mean 3.3 years). Calcification scores were obtained by summation of Agatston and volumetric scores. Stabilization of calcium was defined as no increase in score per year or positive percent change in score </=1%/year. Progression was defined as a positive percent change in score >1%/year. Of 106 with AVC, 105 (99%) had CC. Sixty-five patients had an AVC >10 on initial scan, and 50 (77%) demonstrated progression on the follow-up scan. Of 394 participants with CC >10 on initial scan, follow-up scans showed CC stabilization in 64 (16.2%) and CC progression in 330 (83.8%). Patients with AVC were significantly older than those with only CC (64.5 versus 56.5 years, P < .0001). The average age of the patient with AVC was 7 years older than the average age with CC. AVC (by volumetric score) progressed more rapidly in patients with diabetes (P = .036) and smoking (P = .042) than those without. RESULTS We found no difference in the degree of change in the CC scores (by Agatston or volumetric methods) over time between men and women, or in any baseline cardiac risk factor (P > .05 for all measures). In 65 patients with both AVC and CC >10, there was a significant association between progression of AVC and CC (P = .047); the absolute rate of change of AVC was 24.5 +/- 43.2 %/year, and CC was 28.0 +/- 49.1 %/year. CONCLUSION Virtually all patients with AVC had CC, potentially explaining the coronary risk associated with AVC. There is substantially parallel development between rates of progression of EBT-assessed AVC and CC.
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Affiliation(s)
- Junichiro Takasu
- Division of Cardiology, Harbor-UCLA Research and Education Institute, 1124 W. Carson Street, RB2, Torrance, CA 90502
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Budoff MJ, Shinbane JS, Oudiz RJ, Child J, Carson S, Chau A, Tseng P, Gao Y, Mao S. Comparison of coronary artery calcium screening image quality between C-150 and e-Speed electron beam scanners. Acad Radiol 2005; 12:309-12. [PMID: 15766691 DOI: 10.1016/j.acra.2004.09.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2004] [Revised: 09/15/2004] [Accepted: 09/16/2004] [Indexed: 11/22/2022]
Abstract
RATIONALE AND OBJECTIVE The newest generation of electron beam tomographic scanner (e-Speed) has increased spatial and temporal resolution compared with the C-150 XP scanner. The aim of this study was to evaluate coronary artery calcium screening image quality between the e-Speed and C-150 scanners (GE Imatron, San Francisco, CA). MATERIALS AND METHODS Studies from 41 patients (14 women and 27 men) who underwent serial coronary artery calcium screening with the C-150 (first study) and the e-Speed (second study) were analyzed. Individual computed tomography (CT) slices were assessed for coronary artery motion artifacts, and CT Hounsfield units (HU) and noise values (CT HU standard deviation) at 16 discrete cardiac sites were measured and averaged. RESULTS With the e-Speed scanner, there were significant decreases in right coronary artery motion artifacts compared with the C-150 scanner (0.3% versus 1.8%, P < .001) as well as decreased noise values (24.3 versus 32.0 HU, P < .001). CONCLUSION Image quality is significantly improved with use of the e-Speed scanner, due to its improved temporal and spatial resolution, compared with the C-150 scanner.
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Affiliation(s)
- Matthew J Budoff
- Division of Cardiology, Harbor-UCLA Research and Education Institute, 1124 W. Carson Street, RB2, Torrance, California 90502, USA.
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Budoff MJ, Lu B, Shinbane JS, Chen L, Child J, Carson S, Mao S. Methodology for improved detection of coronary stenoses with computed tomographic angiography. Am Heart J 2004; 148:1085-90. [PMID: 15632897 DOI: 10.1016/j.ahj.2004.04.043] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Noninvasive angiography is a promising technique for visualization of the coronary lumen; however, current methodologies lead to limited accuracy. We assessed the accuracy of electron beam computed tomographic angiography (EBA) for detection of coronary stenoses, using improved triggering techniques and thinner slice collimation. METHODS Eighty-six patients with suspected coronary disease were studied with EBA and conventional invasive coronary angiography. Electrocardiographic triggering was performed at a fixed time in end systole to reduce cardiac motion. Thin (1.5 mm) slices were obtained with 1.5 mm table incrementation. In axial (2-dimensional) EBA images and 3-dimensional reconstructions, all coronary arteries and side branches with a diameter of >or=1.5 mm were assessed for the presence of stenoses with >50% diameter reduction. Both EBA and invasive angiographic images were assessed in a blinded manner. RESULTS In comparison to invasive coronary angiography, EBA correctly classified 49 of 53 patients (92%) as having at least 1 coronary stenosis. Overall, 103 stenoses with >50% diameter reduction were present, and 93 of these lesions were correctly detected by EBA (sensitivity 90%, specificity 93%, positive predictive value 84%, and negative predictive value 96%). Only 5% of vessels could not be assessed, predominantly due to significant calcification. CONCLUSIONS Thinner slice collimation and end-systolic electrocardiographic triggering improves accuracy and assessment of coronary EBA for the detection of obstructive coronary artery disease, making this study clinically useful in the evaluation of obstructive coronary artery disease.
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Lu B, Zhuang N, Mao SS, Child J, Carson S, Budoff MJ. Baseline Heart Rate–adjusted Electrocardiographic Triggering for Coronary Artery Electron-Beam CT Angiography. Radiology 2004; 233:590-5. [PMID: 15459327 DOI: 10.1148/radiol.2332030953] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Conventional electrocardiographic (ECG) triggering (group 1, 53 patients) was compared with baseline heart rate-adjusted ECG triggering (group 2, 54 patients) for coronary artery electron-beam computed tomographic (CT) angiography. CT angiographic data sets were compared blindly with conventional angiograms according to segment. Nonassessability of coronary artery segments was reduced from 35% in group 1 to 13% in group 2 (P < .001). More motion-free coronary artery images were obtained in group 2 than in group 1, especially in the right coronary artery (95% vs 67%, P < .001). Overall sensitivity and specificity for luminal stenosis (> or =50%) were 69% and 82% (group 1) and 76% and 92% (group 2) (P > .05 and P < .001, respectively). Baseline heart rate-adjusted ECG triggering improves image quality at coronary artery CT angiography for detection of coronary artery disease.
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Affiliation(s)
- Bin Lu
- Department of Radiology, Cardiovascular Institute and FuWai Hospital, Peking Union Medical College, and Chinese Academy of Medical Sciences, 167 Bei-Li-Shi St, Beijing 100037, China.
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