PubMed Health⌕ Search

Biomedical subjects

Matthew J Budoff

Publications and source records attributed to Matthew J Budoff.

88 records · Page 5Linked to original sources
PubMed2002

Causes of interscan variability of coronary artery calcium measurements at electron-beam CT.

RATIONALE AND OBJECTIVES: The authors performed this study to investigate the causes of interscan variability of coronary artery calcium measurements at electron-beam computed tomography (CT). MATERIALS AND METHODS: Two sets of electron-beam CT scans were obtained in 298 consecutive patients who underwent electron-beam CT to screen for coronary artery calcium. Interscan variations of coronary artery calcium characteristics and the effects of heart rate, electrocardiographic (ECG) triggering method, image noise, and coronary motion on interscan variability were analyzed. RESULTS: The interscan mean variabilities were 21.6% (median, 11.7%) and 17.8% (median, 10.8%) with the Agatston and volumetric score, respectively (P < .01). Variability decreased with increasing calcification score (34.6% for a score of 11-50 and 9.4% for a score of 400-1,000, P < .0001). The absolute difference in Agatston score between scans was 44.1 +/- 95.6. The correlation coefficient between the first and second sets of scans was 0.99 (P < .0001). Lower interscan variability was found in younger patients (<60 years), patients with stable heart rates (heart rate changing less than 10 beats per minute during scanning), patients with no visible coronary motion, and those with an optimal ECG triggering method (P < .05 for all). Results of multivariate logistic analysis showed that changes in calcium volume, mean attenuation, and peak attenuation were significant predictors of interscan variability and caused the interscan variations of the coronary artery calcium measurements (r2 = 0.83, P < .0001). CONCLUSION: Coronary calcification at electron-beam CT varies from scan to scan. Volumetric scoring and optimal ECG triggering should be used to reduce interscan variability. Baseline calcium score and interscan variability must be considered in the evaluation of calcium progression.

Adult↗
PubMed2002

Reproducibility of electron-beam CT measures of aortic valve calcification.

RATIONALE AND OBJECTIVES: The authors performed this study to establish the interscan, interobserver, and intraobserver reproducibility of aortic valve calcification (AVC) measurements obtained with electron-beam computed tomography (CT). MATERIALS AND METHODS: The authors evaluated electron-beam CT scans from all patients who had undergone two serial examinations on the same day as part of a study of coronary artery calcification reproducibility. In patients in whom aortic valve calcium was identified at electron-beam CT, AVC scores were measured with both the Agatston and the volumetric methods, which were developed previously to quantify coronary calcium. RESULTS: Forty-four asymptomatic patients (mean age, 66 years +/- 9) with AVC at electron-beam CT were included in the analyses. AVC score reproducibility was excellent with both the Agatston and the volumetric methods (R2 = 0.99, P = .0001 for both), with median interscan variabilities of 7% and 6.2%, respectively. Interscan reproducibility was similar, whether the analysis included all scans or was restricted to those with scores greater than 10 or greater than 30. For the volumetric method, the median interobserver variability was 5% and the median intraobserver variability was 1%. CONCLUSION: The low interscan, interobserver, and intraobserver variabilities at electron-beam CT suggest that this method should be useful for the noninvasive monitoring of AVC changes over time and for assessing the efficacy of therapies aimed at slowing AVC accumulation.

Aged↗
PubMed2002

Reproducibility of three different scoring systems for measurement of coronary calcium.

BACKGROUND: There is great interest in measuring and tracking atherosclerosis using electron beam tomography (EBT). We sought to assess the reproducibility of two new software systems, InSight and AccuImage, and the console workstation of an EBT scanner for measuring coronary calcification. METHODS: Two sets of non-contrast EBT scans were obtained in 85 subjects. The calcium volume (CV) score and the Agatston score (AS) were analyzed and the relative differences were compared on three workstations. RESULTS: The intra- and inter-observer variabilities by InSight and AccuImage were both significantly better than variabilities on the console workstation. Both intra- and inter-observer differences for the AS were significantly smaller than those for the CV on each workstation. However, inter-scan variability was lower for the volume method (13.3%) as compared to the AS (17%). Scores were divided into tertiles (T), and the relative inter-scan differences for the AS in T-I (scores < 66) were higher than those in others (T-I 21.0%, T-II 11.9%, T-III 6.8%, p < 0.01). However, there were no significant differences for the CV method (T-I 19.9%, T-II 9.4%, and T-III 5.3%). Thus, while intra- and inter-observer differences with the AS method was lower than volume scoring, the CV inter-scan variability was significantly better. CONCLUSIONS: Both workstations using volumetric and Agatston methods have higher reliability than the console workstation. Inter- and intra-observer reproducibility was excellent (> 98%). There is minimal inter-scan variability for subjects with higher scores (> 65) for both scoring methods.

Aged↗
PubMed2002

Coronary calcium and cardiovascular event risk: evaluation by age- and sex-specific quartiles.

BACKGROUND: Wide differences in risks for cardiovascular disease (CVD) events associated with coronary artery calcium (CAC) have been reported. We evaluated the relationship of the coronary calcium quartile, on the basis of age-sex cut points from a large sample of asymptomatic patients, to CVD events as a possible standardized means for reporting event risks associated with CAC, in comparison with quartiles of absolute CAC scores. METHODS: We applied age/sex-stratified cut points to 928 asymptomatic men and women (mean age 54 years) followed up for an average of 3.3 years, during which 28 CVD events were confirmed. Cox regression was used to evaluate the relation of the 2nd, 3rd, and 4th quartiles (compared with the 1st), with and without age/sex stratification, to the risk of future CVD events. RESULTS: The number of events (and percent incidence) that occurred in the 1st, 2nd, 3rd, and 4th quartiles of coronary calcium was 4 (0.9%), 2 (2.0%), 9 (4.5%), and 13 (6.4%) events (P =.001) for the age/sex-stratified quartiles and 4 (1.0%), 0 (0%), 7 (3.0%), and 17 (7.3%) for the absolute score quartiles (P =.001). In multivariable analysis adjusted for other risk factors, there was a modest increase in CVD events seen among those in the 3rd quartile (relative risk [RR] 4.3, P =.02), with a greater risk seen among those in the 4th quartile (RR 6.0, P <.01) (compared with the 1st quartile). This did not differ from use of absolute CAC scores, where RR = 2.6 (P =.14) for the 3rd quartile and RR = 6.4 (P <.01) for the 4th quartile. CONCLUSIONS: Our results suggest that age-sex stratification by percentile rank of CAC is as accurate as absolute CAC scores for predicting CVD events in asymptomatic persons. Ongoing longitudinal population-based studies will provide more definitive data.

Adult↗
PubMed2002

Coronary calcium scanning adds incremental value to patients with positive stress tests.

BACKGROUND: The sensitivity of coronary calcification by electron beam tomography (EBT) for the detection of coronary atherosclerosis is well-established. Combining the anatomic information of EBT with the functional information of stress testing might reduce the high false-positive result rate seen with treadmill stress test (TMST) alone. No studies have reported the additive value of a negative EBT result (no coronary calcium) for excluding obstructive coronary artery disease (OCAD) in patients with a positive TMST result. This study evaluated the negative predictive value and potential clinical utility of EBT to identify patients with a falsely abnormal TMST. METHODS: A coronary calcium score was determined by EBT for 153 symptomatic patients who underwent coronary angiography because of a positive TMST. The sensitivity, specificity, and predictive values of EBT were determined. A multiple logistic regression analysis compared conventional cardiac risk factors with coronary calcification by EBT for predicting OCAD. A receiver operating characteristic curve was generated plotting sensitivity versus false-positive rate. RESULTS: The false-positive rate of the TMST compared with angiography was 27% (41 of 153). The sensitivity of a nonzero coronary calcium score for OCAD was 98% (110 of 112), with a negative predictive value of 93%. According to multiple logistic regression, coronary calcification by EBT was a stronger predictor of OCAD than any conventional cardiac risk factor. EBT calcium added incremental value to the results of the TMST. Receiver operating characteristic curve analysis found an area under the curve of 0.91 (P <.001). CONCLUSIONS: The absence of coronary calcification by EBT reliably identified patients with a false-positive TMST result. The combination of EBT with TMST is a potentially useful diagnostic strategy to reduce the number of false-positive test results.

Area Under Curve↗
PubMed2002

Electron beam tomography and angiography: sex differences.

BACKGROUND: We sought to study a large cohort of symptomatic women to determine the clinical use of electron beam tomography (EBT), with evaluation of the sensitivity and specificity of obstructive coronary disease and the differences between premenopausal and postmenopausal cohorts. METHODS: Patients who underwent angiography for evaluation of coronary artery disease (CAD) and EBT within 3 months were enrolled. Receiver operating characteristic curves were used to establish relationships between EBT calcium scores and angiographic disease. RESULTS: We studied 1120 symptomatic patients, 387 women and 733 men. We found no significant differences with respect to sensitivity for obstructive disease (96% in men and women). However, women had a significantly higher specificity (46% in men versus 57% in women; P =.01). The area under the curves for coronary calcium score predicting angiographic disease was 0.85 for all patients and 0.84 in women. Evaluation of scores on the basis of age revealed a 14.4-year lag between men and women. One hundred thirty-five women had negative EBT study results (score, zero; no calcium present), with 6 with single-vessel disease and 129 with normal coronaries or nonobstructive disease only (negative predictive value, 96%). CONCLUSION: EBT may have a great value in evaluation of women with possible CAD. The high sensitivity and high negative predictive value may serve as the basis for a new diagnostic approach to filter symptomatic women with suspected CAD before coronary angiography.

Calcinosis↗
PubMed2002

EKG-triggered CT data acquisition to reduce variability in coronary arterial calcium score.

PURPOSE: To test the hypothesis that computed tomographic (CT) scanning during optimal electrocardiographic (EKG) triggering can minimize image motion artifact and reduce interexamination variation of coronary arterial calcification (CAC) score at electron-beam CT. MATERIALS AND METHODS: Two hundred patients underwent electron-beam CT once and again 5 minutes later to evaluate interexamination variability of CAC score. Group 1 (104 patients) underwent scanning with use of an optimal EKG-triggering protocol (EKG triggering performed individually at the time of least coronary arterial motion during the cardiac cycle); group 2 (96 patients) underwent scanning with use of conventional 80% R-R interval triggering (the most common protocol with the electron-beam CT scanner). Interexamination, intraobserver, and interobserver variations of CAC measurements were compared between groups by using unpaired t tests for both Agatston and volumetric scores (in square millimeters). RESULTS: Coronary arterial motion artifacts were found in 26% (27 of 104) versus 80% (77 of 96) of patients in groups 1 and 2, respectively (P <.0001). Intraobserver, interobserver, and interexamination variabilities in volumetric score were derived, with values of 1.2%, 9.2%, and 15.9% in group 1 and 2.1%, 11.3%, and 25.9% in group 2, respectively. Interexamination variabilities in both Agatston and volumetric score were significantly reduced with individualized EKG triggering, as compared with conventional triggering (P <.05), but intra- and interobserver variabilities were not (P >.05). CONCLUSION: Optimal EKG triggering improves the reproducibility of CAC measurement by reducing coronary arterial motion artifacts.

Arteries↗
PubMed2002

Noninvasive assessment of coronary artery bypass graft patency and flow characteristics by electron-beam tomography.

OBJECTIVE: To evaluate the flow characteristics and accuracy for the detection of patent or occluded coronary artery bypass grafts (CABG) with multi-slice flow study of electron-beam tomography (EBT). METHODS: One hundred and twenty-three patients who had undergone CABG surgery were enrolled in this study. Flow datasets were assessed with time-density curves by EBT. The EBT results were blindly compared with post-operative cardiac catheterizations in 26 patients. RESULTS: Image quality was adequate to evaluate in 111 patients (90.2%). Flow curves of bypass grafts were technically adequate in 265 of 309 (85.8%) saphenous-vein grafts (SVG) and 35 of 56 (62.5%) internal mammary artery (IMA) grafts (p < 0.05). In comparison to conventional angiographic results, EBT correctly identified 14 of 16 occluded grafts (sensitivity, 87.5%) and 68 of 75 patent grafts (specificity, 90.7%), yielding an accuracy of 90.1%. The intra-graft flows of the IMA and SVG were 4.9 +/- 2.2 ml/min/g and 6.9 +/- 2.8 ml/min/g, respectively (p < 0.001), which was 31.6 +/- 20.4% and 39.4 +/- 21.9% of the ascending aorta's flow (16.7 +/- 5.0 ml/min/g) (p < 0.001). CONCLUSION: EBT flow study can be used in the assessment of CABG patency and quantification of intra-graft flow of patent CABG vessels.

Adult↗
PubMedDate not supplied

Utility of stress testing and coronary calcification measurement for detection of coronary artery disease in women.

Accurate and safe diagnostic testing provides the crucial link between detection and optimal management of coronary artery disease (CAD). Noninvasive diagnostic testing for CAD may be less accurate in women than in men. Many noninvasive diagnostic modalities are available for this purpose. An exercise tolerance test provides an assessment of functional capacity and has the advantages of wide availability and low initial cost. However, exercise echocardiography may be the most cost-effective method for the initial assessment of coronary artery disease in intermediate-risk women owing to its higher sensitivity and specificity. Recent studies with electron-beam computed tomography reveal that women with no coronary calcification are very unlikely to have obstructive CAD. In symptomatic women with an intermediate likelihood of CAD, either an exercise treadmill test or exercise echocardiography is appropriate for initial screening and can provide useful prognostic information. Alternatively, an electron-beam computed tomographic scan with a 0 calcium score may spare many women with atypical chest pain or equivocal findings on an exercise tolerance test from undergoing more expensive stress imaging studies or coronary angiography. For high-risk symptomatic women, a more aggressive approach involving coronary angiography appears to be the preferred initial diagnostic strategy.

Algorithms↗
PubMedDate not supplied

Atherosclerosis imaging and calcified plaque: coronary artery disease risk assessment.

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. 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. The validity of measuring coronary artery calcium with new multislice computed tomography scanners is also reviewed. 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.

Calcinosis↗
PubMedDate not supplied

Image quality of three-dimensional electron beam coronary angiography.

PURPOSE: This study identifies reasons for poor image quality and nonassessability of coronary artery segments and compares results between early and late diastolic triggering on coronary electron beam angiography (EBA). METHOD: One hundred patients referred for EBA were studied. Contrast-enhanced transaxial coronary images were acquired using electrocardiographic (ECG) triggering and reconstructed three dimensionally using volume-rendering techniques. The image quality of coronary segments and image artifacts were analyzed statistically. RESULTS: Volume rendering failed in seven patients (7%) owing to cardiac and breathing motions. Image quality was the best with the left main (LM) and worst with the left circumflex (LCX) coronary arteries (p < 0.001). The image quality decreased systematically from proximal to distal within each coronary artery (p < 0.001). Forty percent R-R interval triggering on ECG was better than 80% for image quality. The nonassessable segments occurred in 3% of LM, 2, 8, and 5% of proximal, 24, 22, and 12% of mid, and 64, 45, and 20% of distal segments of the left anterior descending, LCX, and right coronary arteries, respectively (p < 0.05). CONCLUSION: The major limitations of coronary EBA were suboptimal spatial resolution and image artifacts. The image quality could be improved by using optimal ECG triggering.

Aged↗
PubMedDate not supplied

Ability of calibration phantom to reduce the interscan variability in electron beam computed tomography.

OBJECTIVE: To test the hypothesis that a calibration phantom would improve interpatient and interscan variability in coronary artery calcium (CAC) studies. METHODS: We scanned 144 patients twice with or without the calibration phantom and then scanned 93 patients with a single calcific lesion twice and, finally, scanned a cork heart with calcific foci. RESULTS: There were no linear correlations in computed tomography Hounsfield unit (CT HU) and CT HU interscan variation between blood pool and phantom plugs at any slice level in patient groups (p > 0.05). The CT HU interscan variation in phantom plugs (2.11 HU) was less than that of the blood pool (3.47 HU; p < 0.05) and CAC lesion (20.39; p < 0.001). Comparing images with and without a calibration phantom, there was a significant decrease in CT HU as well as an increase in noise and peak values in patient studies and the cork phantom study. CONCLUSION: The CT HU attenuation variations of the interpatient and interscan blood pool, calibration phantom plug, and cork coronary arteries were not parallel. Therefore, the ability to adjust the CT HU variation of calcific lesions by a calibration phantom is problematic and may worsen the problem.

Artifacts↗
PubMedDate not supplied

Assessment of cardiac function using multidetector row computed tomography.

In patients with suspected or documented heart disease, a precise quantitative and qualitative assessment of cardiac function is critical for clinical diagnosis, risk stratification, management and prognosis. Cardiac CT is increasingly being used in diagnosis of coronary artery disease. Initially multi-detector row computed tomography (MDCT) was used chiefly for detecting coronary artery stenosis and assessment of cardiac morphology. Electron beam computed tomography has been shown to provide a highly accurate ejection fraction (+/-1%), with 50 ms image acquisition per image. Retrospective electrocardiographic gating allows for image reconstruction in any phase of the cardiac cycle. Thus, end systolic and end diastolic images can be produced to assess ventricular volumes and function. Despite lower temporal resolution than electron beam computed tomography, the ability of MDCT to assess ejection fraction is preserved. In the assessment of cardiac function, MDCT has been shown to be in good agreement with echocardiography, cineventriculography, single photon emission computed tomography and magnetic resonance imaging. The fast technical development of scanner hardware along with multisegmental image reconstruction has led to rapid improvement of spatial and temporal resolution and significantly faster cardiac scans. The same data that is acquired for MDCT angiography can also be used for evaluation of cardiac function. Considering contrast media application, radiation exposure, and limited temporal resolution, MDCT solely for analysis of cardiac function parameters seems not reasonable at the present time. However, because the data is already obtained during coronary evaluation, the combination of noninvasive coronary artery imaging and assessment of cardiac function with MDCT is a suitable approach to a conclusive cardiac workup in patients with suspected coronary artery disease. MDCT seems suitable for assessment of cardiac function by MDCT when results are held in comparison to magnetic resonance imaging as the reference standard. Given the radiation dose and contrast requirement, referring a patient to MDCT only for evaluation of function is not warranted, but rather adds important clinical information to the already acquired data during retrospective triggering for MDCT angiography.

Contrast Media↗
PubMedDate not supplied

Electron beam tomography in women. Is it a valuable test?

Cardiovascular disease (CVD) is the leading cause of mortality in women and a major cause of morbidity. Coronary artery disease (CAD) accounts for nearly half of all CVD deaths. Traditional risk factors are very helpful in predicting the development of CAD in women; however, many women suffer events in the absence of established risk factors for atherosclerosis. To meet the challenge of CAD, several tools have been developed to identify atherosclerotic disease in its preclinical stages, with the hope of modifying its natural history. In this article, we review the current literature on utilization of electron beam tomography (EBT) for detection of CAD as a tool to conduct risk stratification in the general asymptomatic female population as well as among asymptomatic women. In conclusion, EBT can be used to estimate the overall coronary atherosclerotic plaque burden in women. It can also be used to diagnose its presence and determine its extent; furthermore, information from the coronary artery calcium scores can be used to assess the likelihood of obstructive disease and to provide prognostic information. Finally, EBT has the potential to determine the consequences of therapeutic interventions regarding progression, stabilization, or regression of coronary atherosclerotic disease.

Calcinosis↗
PubMedDate not supplied

Comparison of electron beam computed tomography and technetium stress testing in differentiating cause of dilated versus ischemic cardiomyopathy.

OBJECTIVE: The current reference standard for differentiating between nonischemic versus ischemic cardiomyopathy (CM) is angiography. The diagnostic accuracy of nuclear stress testing and electron beam tomography (EBT) was evaluated to differentiate between nonischemic and ischemic CM, using coronary angiography as the reference standard. METHODS: A total of 56 patients who underwent technetium stress testing and coronary angiography for the evaluation of CM were enrolled. Patients then underwent EBT coronary scanning for coronary calcification (CC). RESULTS: Of the 56 patients, 34 (61%) had angiographically significant disease. Using the criteria of ischemia (reversible defect) or infarct (fixed defect) to define a patient with ischemic CM, nuclear stress testing had a sensitivity of 97% (33 of 34 patients) but a specificity of only 18% (4 of 22 patients). Using the criteria of reversible ischemia only, the specificity of nuclear stress testing improved to 50% (P < 0.001); however, the sensitivity decreased to 56%. An EBT score >0 had a sensitivity of 97% (33 of 34 patients) and a specificity of 68% (15 of 22 patients) for defining ischemia. Overall diagnostic accuracy was significantly higher with EBT as compared with nuclear stress testing in this study of patients with reduced ejection fractions (84% vs. 64%; P = 0.009). CONCLUSION: Given the high sensitivity of nuclear testing and EBT, these tests may prove to be an effective screen before angiography in patients with congestive heart failure of unclear cause.

Adult↗