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1.
J Comput Assist Tomogr ; 48(1): 49-54, 2024.
Article in English | MEDLINE | ID: mdl-37531634

ABSTRACT

OBJECTIVE: Nonalcoholic fatty liver disease not only shares multiple risk factors with cardiovascular disease but also independently predicts its increased risk and related outcomes. Here, we evaluate reproducibility of 3-dimensional (3D) liver volume segmentation method to identify fatty liver on noncontrast cardiac computed tomography (CT) and compare measures with previously validated 2-dimensional (2D) segmentation CT criteria for the measurement of liver fat. METHODS: The study included 68 participants enrolled in the EVAPORATE trial and underwent serial noncontrast cardiac CT. Liver attenuation < 40 Hounsfield units (HU) was used for diagnosing fatty liver, as done in the MESA study. Two-dimensional and 3D segmentation of the liver were performed by Philips software. Bland-Altman plot analysis was used to assess reproducibility. RESULTS: Interreader reproducibility of 3D liver mean HU measurements was 96% in a sample of 111 scans. Reproducibility of 2D and 3D liver mean HU measurements was 93% in a sample of 111 scans. Reproducibility of change in 2D and 3D liver mean HU was 94% in 68 scans. Kappa, a measure of agreement in which the 2D and 3D measures both identified fatty liver, was excellent at 96.4% in 111 scans. CONCLUSIONS: Fatty liver can be reliably diagnosed and measured serially in a stable and reproducible way by 3D liver segmentation of noncontrast cardiac CT scans. Future studies need to explore the sensitivity and stability of measures for low liver fat content by 3D segmentation, over the current 2D methodology. This measure can serve as an imaging biomarker to understand mechanistic correlations between atherosclerosis, fatty liver, and cardiovascular disease risk.


Subject(s)
Cardiovascular Diseases , Non-alcoholic Fatty Liver Disease , Humans , Cardiovascular Diseases/diagnostic imaging , Non-alcoholic Fatty Liver Disease/diagnostic imaging , Reproducibility of Results , Tomography, X-Ray Computed/methods , Clinical Trials as Topic
2.
Nutr Metab Cardiovasc Dis ; 31(6): 1767-1773, 2021 06 07.
Article in English | MEDLINE | ID: mdl-33934946

ABSTRACT

BACKGROUND AND AIMS: Obesity and osteoporosis are two important and growing public health problems worldwide. Body mass index (BMI) has been found to be inversely related to the risk of osteoporotic fracture. We aimed to assess the association of BMI with thoracic vertebral bone mineral density (BMD) measured from a quantitative computed tomography (QCT). METHODS AND RESULTS: We retrospectively evaluated the data from 15,758 consecutive patients (5675 females and 10,083 males) between age 20-90 years, who underwent Coronary Artery Calcium (CAC) scoring. Quantitative data analyses of thoracic trabecular BMD (mg/cm3) was performed with a phantom system or phantomless using validated software. The gender-specific subgroup was divided based on age (<45, 45-55, 55-65, >65 yrs in females; <40,40-60,>60 yrs in Males) and weight by BMI (kg/m2) as < 25 (normal or low weight), >25 - <30 (overweight) and >30 (obesity). Analysis of variance (ANOVA) and Scheffe's post hoc procedure tested the association of body weight/BMI on BMD. A significant positive association between the body weight and BMD existed in obese population in elder groups in both genders (p < 0.05). There was no significant difference in BMD in 40-60 years in men and <55 years in women with normal or low weight compared to overweight or obese cohorts. CONCLUSIONS: We concluded that the effect of weight on BMD is age-specific and the BMD should be monitored routinely with a cardiac CT scan in the senile population.


Subject(s)
Body Mass Index , Bone Density , Obesity/physiopathology , Osteoporosis/physiopathology , Thoracic Vertebrae/physiopathology , Adult , Age Factors , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Multidetector Computed Tomography , Obesity/complications , Obesity/diagnosis , Osteoporosis/diagnostic imaging , Osteoporosis/etiology , Retrospective Studies , Risk Assessment , Risk Factors , Sex Factors , Thoracic Vertebrae/diagnostic imaging , Young Adult
3.
Acad Radiol ; 20(2): 202-8, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23099239

ABSTRACT

RATIONALE AND OBJECTIVES: Few data were available regarding the underlying burden of specific plaque types with increasing ages. The aim of this study was to assess the relationship of coronary artery calcium (CAC) score with total coronary plaque burden and the difference of underlying coronary plaque composition across differing aging groups using 64-slice multidetector computed tomography. MATERIALS AND METHODS: Multidetector computed tomographic images of 781 consecutive patients were evaluated using a 15-coronary segment model. Segment involvement score (the total number of segments with any plaque), segment stenosis score (the sum of maximal stenosis score per segment), total plaque score (the sum of the plaque amount per segment), and plaque composition were measured to compare with total CAC scores stratified by age tertile (lowest [n = 274], <55 years; middle [n = 242], 55-65 years; highest [n = 265], >65 years). RESULTS: The mean age of the study population was 59 ± 13 years (481 men [62%]). With increasing age, higher segment involvement scores, segment stenosis scores, and total plaque scores were noted. Plaque burden was correlated significantly with total CAC scores in all tertiles. The percentage of partially calcified (P < .001) and calcified (P < .001) plaque increased with age, and in the highest age tertile, 87% of plaque contained calcium (calcified or mixed), compared to only 63% in the younger patients (P < .001). Those aged >65 years were highly unlikely to have isolated noncalcified plaque (in the setting of a calcium score of 0). Younger patients were 10 times more likely to have isolated noncalcified plaque (P < .001). CONCLUSIONS: The absence of CAC strongly excludes obstructive disease, and CAC predicts the presence of coronary atherosclerotic plaque. However, the absence of any CAC does not exclude the presence of coronary atherosclerotic plaque, especially in patients aged <55 years. Plaque composition shifted from noncalcified to calcified plaque with increasing age, which may affect the vulnerability of these lesions over time.


Subject(s)
Calcinosis/diagnostic imaging , Calcinosis/epidemiology , Coronary Angiography/statistics & numerical data , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/epidemiology , Tomography, X-Ray Computed/statistics & numerical data , Age Distribution , California/epidemiology , Comorbidity , Female , Humans , Male , Prevalence , Reproducibility of Results , Risk Assessment , Sensitivity and Specificity
5.
Coron Artery Dis ; 22(6): 380-7, 2011.
Article in English | MEDLINE | ID: mdl-21666441

ABSTRACT

OBJECTIVE: Ventricular dysfunction in asymptomatic patients is directly linked to the eventual development of symptomatic congestive heart failure. This study investigates whether subclinical left ventricular (LV) and right ventricular (RV) dysfunctions measured by computed tomography angiography is associated with the severity of coronary artery disease (CAD). METHODS AND RESULTS: We studied 1608 consecutive patients with suspected CAD (age 62 ± 10 years, 64% male), who underwent coronary artery calcium (CAC) scanning and computed tomography angiography. RV and LV volumes at end systole and end diastole were measured, and stroke volume and ejection fraction were calculated using the Simpson method and piecewise smooth subdivision surface (PSSS) method. Analysis by Simpson was performed on short axis and apical four-chamber views. Axial images were used to measure RV and LV volumes by the PSSS method. CAD was defined as normal, nonobstructive, and obstructive (0% stenosis, luminal stenosis 1-49 and 50%+, respectively). There was a strong agreement between PSSS and Simpson method RV ejection fraction (RVEF) and LV ejection fraction (LVEF) measurement. RVEF and LVEF decreased proportionally from CAC 0 to CAC 100+, also from normal-to-diseased coronaries (P=0.001). After adjustment for cardiovascular risk factors, the mean LVEF and RVEF decreased 2.8 and 2.4%, respectively in CAC 100+ compared with CAC 0. Similarly, LVEF and RVEF decreased significantly in nonobstructive CAD (-3.5 and -3.1%, respectively) and obstructive CAD (-5.9 and -4.5%, respectively) compared with normal coronaries, respectively (P<0.05). The relative risk of each 5% decrease in LVEF and RVEF was 1.33 and 1.29 for nonobstructive CAD and 1.54 and 1.33 for obstructive CAD, respectively. CONCLUSION: The presence and severity of coronary atherosclerosis is significantly associated with subclinical RV and LV dysfunctions.


Subject(s)
Calcinosis/diagnostic imaging , Coronary Angiography/methods , Coronary Artery Disease/diagnostic imaging , Tomography, X-Ray Computed , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Right/diagnostic imaging , Aged , Asymptomatic Diseases , Calcinosis/complications , California , Coronary Artery Disease/complications , Female , Humans , Linear Models , Logistic Models , Male , Middle Aged , Predictive Value of Tests , Risk Assessment , Risk Factors , Severity of Illness Index , Stroke Volume , Ventricular Dysfunction, Left/etiology , Ventricular Dysfunction, Left/physiopathology , Ventricular Dysfunction, Right/etiology , Ventricular Dysfunction, Right/physiopathology , Ventricular Function, Left , Ventricular Function, Right
6.
Int J Cardiovasc Imaging ; 27(3): 459-69, 2011 Mar.
Article in English | MEDLINE | ID: mdl-20711815

ABSTRACT

Impaired aortic distensibility index (ADI) is associated with cardiovascular risk factors. This study evaluates the relation of ADI measured by computed tomographic angiography (CTA) with the severity of coronary atherosclerosis in subjects with suspected coronary artery disease (CAD). Two hundred and twenty-nine subjects,age 63 ± 9 years, 42% female, underwent coronary artery calcium (CAC) scanning and CTA, and their ADI and Framingham risk score (FRS) were measured. End-systolic and end-diastolic (ED) cross-sectional-area(CSA) of ascending-aorta (AAo) was measured 15-mm above the left-main coronary ostium. ADI was defined as: [(Δlumen-CSA)/(lumen-CSA in ED × systemic-pulse-pressure) × 10(3)]. ADI measured by 2D-trans-thoracic echocardiography (TTE) was compared with CTA-measured ADI in 26 subjects without CAC. CAC was defined as 0, 1-100, 101-400 and 400+. CAD was defined as luminal stenosis 0, 1-49% and 50%+. There was an excellent correlation between CTA- and TTE-measured ADI (r(2)=0.94, P=0.0001). ADI decreased from CAC 0 to CAC 400+; similarly from FRS 1-9% to FRS 20% + (P<0.05). After adjustment for risk factors, the relative risk for each standard deviation decrease in ADI was 1.66 for CAC 1-100, 2.26 for CAC 101-400 and 2.32 for CAC 400+ as compared to CAC 0; similarly, 2.36 for non-obstructive CAD and 2.67 for obstructive CAD as compared to normal coronaries. The area under the ROC-curve to predict significant CAD was 0.68 for FRS, 0.75 for ADI, 0.81 for CAC and 0.86 for the combination (P<0.05). Impaired aortic distensibility strongly correlates with the severity of coronary atherosclerosis. Addition of ADI to CAC and traditional risk factors provides incremental value to predict at-risk individuals.


Subject(s)
Aorta/physiopathology , Coronary Angiography/methods , Coronary Stenosis/diagnostic imaging , Tomography, X-Ray Computed , Aged , Analysis of Variance , Aorta/diagnostic imaging , California , Compliance , Coronary Stenosis/physiopathology , Female , Humans , Male , Middle Aged , Predictive Value of Tests , ROC Curve , Regression Analysis , Risk Assessment , Risk Factors , Severity of Illness Index , Ultrasonography
7.
Am J Cardiol ; 107(1): 10-6, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21146679

ABSTRACT

It was previously reported that event-free survival rates of symptomatic patients with coronary artery disease (CAD) diagnosed by computed tomographic angiography decreased incrementally from normal coronary arteries to obstructive CAD. The aim of this study was to investigate the clinical outcomes of symptomatic patients with nonobstructive CAD with luminal stenoses of 1% to 49% on the basis of coronary plaque morphology in an outpatient setting. Among 3,499 consecutive symptomatic subjects who underwent computed tomographic angiography, 1,102 subjects with nonobstructive CAD (mean age 59 ± 14 years, 69.9% men) were prospectively followed for a mean of 78 ± 12 months. Coronary plaques were defined as noncalcified, mixed, and calcified per patient. Multivariate Cox proportional-hazards models were developed to predict all-cause mortality. The death rate of patients with nonobstructive CAD was 3.1% (34 deaths). The death rate increased incrementally from calcified plaque (1.4%) to mixed plaque (3.3%) to noncalcified plaque (9.6%), as well as from single- to triple-vessel disease (p <0.001). In subjects with mixed or calcified plaques, the death rate increased with the severity of coronary artery calcium from 1 to 9 to ≥ 400. The risk-adjusted hazard ratios of all-cause mortality in patients with nonobstructive CAD were 3.2 (95% confidence interval 1.3 to 8.0, p = 0.001) for mixed plaques and 7.4 (95% confidence interval 2.7 to 20.1, p = 0.0001) for noncalcified plaques compared with calcified plaques. The areas under the receiver-operating characteristic curve to predict all-cause mortality were 0.75 for mixed and 0.86 for noncalcified coronary lesions. In conclusion, this study demonstrates that the presence of noncalcified and mixed coronary plaques provided incremental value in predicting all-cause mortality in symptomatic subjects with nonobstructive CAD independent of age, gender, and conventional risk factors.


Subject(s)
Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/mortality , Coronary Angiography/methods , Coronary Artery Disease/pathology , Female , Follow-Up Studies , Humans , Incidence , Male , Middle Aged , Risk Factors , Tomography, X-Ray Computed
8.
Int J Cardiovasc Imaging ; 27(7): 1015-23, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21063782

ABSTRACT

In this study, we define the correlation between LV volumes (both LV end-diastolic volume [LVEDV] and LV end-systolic volume [LVESV]) and ejection fraction (EF) on 64 slice multi-detector computed tomography (MDCT). We also determine the accuracy of all the LV volume (LVV) parameters to detect LV systolic dysfunction (LVSD) and investigate the feasibility of using LVV as a surrogate of LVSD on prospectively gated imaging to prevent the radiation exposure of retrospective imaging. 568 patients undergoing 64-detector MDCT were divided into 2 groups: Group 1-subjects without any heart disease and LVEF ≥ 50%; and Group 2-patients with coronary artery disease and LVEF < 50% (defined as LVSD). The LVV (LV cavity only) and Total LV volume (cavity + LV mass) at end-systole and end-diastole (LVESV, Total LVESV, LVEDV and Total LVEDV) were measured. The upper limit values (mean + 2 SD) of all LVV parameters in Group 1 were used as the reference criterion to diagnose LVSD in Group 2. An exponential correlation was found between LVEF and all the LVV parameters. The specificity to detect LVSD in Group 2 was >90% and the sensitivity was 88.9, 83.3, 61.3 and 74.9% by using LVESV, Total LVESV, LVEDV and Total LVEDV, respectively. Systolic and diastolic LV volumes had a high correlation with LVEF and a high accuracy to detect LVSD. Thus, on prospectively triggered imaging, ventricular volumes can predict patients with reduced LVEF, and appropriate referrals can be made.


Subject(s)
Stroke Volume , Tomography, X-Ray Computed , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Function, Left , California , Case-Control Studies , Diastole , Feasibility Studies , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Prognosis , Radiation Dosage , Tomography, X-Ray Computed/adverse effects , Ventricular Dysfunction, Left/physiopathology
9.
J Cardiovasc Comput Tomogr ; 4(5): 322-9, 2010.
Article in English | MEDLINE | ID: mdl-20947042

ABSTRACT

BACKGROUND: Test phantoms with simulated micro-calcifications of true calcium hydroxyapatite (CaHA) density were not available to validate advanced calcium scoring methods or plaque density measurements. OBJECTIVES: We evaluated a coronary calcium scoring (CCS) test phantom containing very small CaHA microspheres and validated a new scoring method for measurements of plaque densities. METHODS: The semianthropomorphic CCS phantom was constructed with CaHA microspheres (volumes, 0.05-3.1 mm(3)) with the approximate density of biologic calcifications. QRM and CCS phantoms were scored with a new calibrated and automated calcium scoring method (N-vivo; Image Analysis). The densities of the microspheres and 609 individual patient plaques were measured. RESULTS: The range of measured densities of the CaHA microspheres was approximately equivalent to that measured in the patient coronary calcifications. The smallest microspheres scored with the calibrated/automated and the Agatston methods had volumes of 0.075 mm(3) and 0.27 mm(3), respectively. The standard deviations of the mass scores of the microspheres ranged from 0.02 to 0.17 mg with regression slope of 0.962 and R(2) = 0.997. The relationship of measured density to measured mass of the patient plaques was similar to that of the microspheres, suggesting that vascular calcifications are CaHA density. CONCLUSIONS: The CaHA microspheres of the CCS test phantom were found to be representative in density and size of coronary calcifications. The measurements show that CT calcium scoring underestimates plaque density and greatly overestimates volume. The heterogeneity of calcium concentration densities measured in the patient plaques was due largely to CT scanner measurement errors.


Subject(s)
Calcinosis/diagnostic imaging , Coronary Artery Disease/diagnostic imaging , Durapatite/chemistry , Phantoms, Imaging , Tomography, X-Ray Computed/instrumentation , Automation, Laboratory , Calibration , Equipment Design , Humans , Microspheres , Predictive Value of Tests , Reproducibility of Results , Severity of Illness Index , Tomography, X-Ray Computed/standards
10.
Med Phys ; 37(7): 3621-32, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20831070

ABSTRACT

PURPOSE: Development and verification of peak signal-to-noise ratio (SNR(P)) equations for determining optimum CT scanning and scoring parameters for a new automated coronary calcium scoring program (N-vivo). Experimental evaluation of the new program for scoring small calcium hydroxyapatite (CaHA) microspheres with small voxel CT images. METHODS: Theoretical SNR(P) equations were developed using measures of noise, resolution, contrast, scatter, and x-ray photon energy. A coronary calcium scoring test phantom containing very small CaHA microspheres was scanned simultaneously with a calibration phantom at three kVps, three voxel sizes, and three phantom sizes. Agatston and calibrated mass scores, noise standard deviations, peak noise, and peak signal voxel intensities were measured by the N-vivo method for individual microspheres and in patient CT scans. RESULTS: The SNR(P) equation was predictive of the optimum voxel size, kVp, and phantom size, and allowed automated computation of mass scoring thresholds specific to each patient and CT scan. The smallest microcalcification scored in the full sized phantom with the N-vivo method by calibrated mass score (volume 0.075 mm3, mass 0.17 mg) was approximately four times smaller than that scored with the Agatston method (0.27 mm3, mass 0.63 mg). CONCLUSIONS: The SNR(P) equation can be used to model and optimize calcium scoring and CT scan parameters. The common assumptions that noise is too high in thin slice CT or requires high radiation dose for CAC scoring are shown to be misleading. The N-vivo method showed higher detection sensitivity for small microspheres and more consistent mass scores at different beam energies than the conventional Agatston method. Advanced calcium scoring methods with higher sensitivity may allow improved monitoring of plaque changes and provide earlier detection of atherosclerosis.


Subject(s)
Calcium/metabolism , Heart/diagnostic imaging , Myocardium/metabolism , Tomography, X-Ray Computed/methods , Automation , Female , Humans , Male , Phantoms, Imaging
11.
J Cardiovasc Comput Tomogr ; 4(2): 119-26, 2010.
Article in English | MEDLINE | ID: mdl-20430343

ABSTRACT

BACKGROUND: Atherosclerotic changes within the coronary artery wall can affect vessel distensibility. OBJECTIVE: This study evaluated the relationship between the coronary distensibility index (CDI) and the severity of coronary artery disease (CAD) measured by computed tomographic angiography (CTA). METHODS: One hundred thirteen subjects, age 63 +/- 10 years, 32% women, who underwent coronary artery calcium (CAC) scanning and CTA, were studied. Early diastolic and mid diastolic (MD) cross-section area (CSA) of the left anterior descending (LAD) artery were measured 5 mm distal to the left main bifurcation. CDI was defined as Deltalumen CSA/[lumen CSA in MD x estimated central pulse pressure (eCPP)] x 10(3) {eCPP = 0.77 x peripheral pulse pressure}. LAD diameter measured by CTA and quantitative coronary angiography (QCA) was compared in 19 subjects without CAD. CAD was defined as normal (no stenosis and CAC 0), mild (stenosis or= 70%) on CTA. RESULTS: Excellent correlation was observed between CTA and QCA measured by CDI (r(2) = 0.96, P = 0.0001). CDI decreased from normal coronaries (6.75 +/- 1.43) to arteries with mild (5.78 +/- 1.45), moderate (3.96 +/- 1.06), and severe (3.31 +/- 1.06) disease (P = 0.004). The risk factor adjusted odds ratio of lowest versus 2 upper tertiles of CDI was 1.28 for mild, 8.47 for moderate, and 10.59 for severe CAD compared with the normal cohort. The area under the ROC curve to predict obstructive CAD (stenosis >or= 50%) increased significantly from 0.71 to 0.84 by addition of CDI to CAC (P < 0.05). CONCLUSION: CTA-measured CDI is inversely related to the severity of CAD independent of age, sex, cardiovascular risk factors, and CAC.


Subject(s)
Calcinosis/diagnostic imaging , Coronary Angiography/methods , Coronary Artery Disease/diagnostic imaging , Severity of Illness Index , Tomography, X-Ray Computed/methods , Aged , Blood Pressure , Calcinosis/epidemiology , Coronary Angiography/standards , Coronary Artery Disease/epidemiology , Diastole , Female , Humans , Logistic Models , Male , Middle Aged , Reproducibility of Results , Risk Factors , Tomography, X-Ray Computed/standards
12.
Int J Cardiovasc Imaging ; 25(7): 717-23, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19633998

ABSTRACT

Type 2 diabetes mellitus (DM) is associated with a higher risk of cardiovascular disease and atherosclerotic burden. However little data exists in regards to plaque distribution and plaque composition in these patients. To assess for differences in the coronary plaques burden and composition among symptomatic patients with and without type 2 DM using multidetector computed tomography angiography (MDCTA). The 416 symptomatic patients (64% males, mean age: 61 +/- 13 years) with 61 (15%) reporting type 2 DM, who underwent contrast-enhanced MDCTA were studied. Enrolled patients had an intermediate to high pre-test probability of obstructive coronary artery disease. Multivariate analysis was used to correct for differences in age and gender. Patients with type 2 DM were more likely to have significant stenosis >or=70% in at least one coronary segments (33% in type 2 DM vs. 18% in non diabetic, P = 0.013), whereas 11% of both type 2 DM and non diabetics had stenosis of 50-70% (P = NS). Also type 2 DM patients had a higher number of coronary segments with mixed plaques compared to nondiabetic patients (1.67 +/- 2.01 vs. 1.23 +/- 1.61, P = 0.05), whereas no such differences were observed for non-calcified or calcified plaques. Nearly half (43%) of type 2 DM had coronary artery calcium scores (CACS) >or=400 vs. 29% in non diabetic patients (P = 0.03). Patients with type 2 DM tend to have atherosclerotic plaques which are more likely to be mixed in nature. Future studies need to elucidate the prognostic value of differences in plaque characteristics observed according to type 2 diabetic status.


Subject(s)
Calcinosis/diagnostic imaging , Coronary Angiography/methods , Coronary Stenosis/diagnostic imaging , Diabetes Mellitus, Type 2/complications , Diabetic Angiopathies/diagnostic imaging , Tomography, X-Ray Computed , Aged , Calcinosis/etiology , Contrast Media , Coronary Stenosis/etiology , Diabetes Mellitus, Type 2/diagnostic imaging , Diabetic Angiopathies/etiology , Female , Humans , Linear Models , Male , Middle Aged , Odds Ratio , Predictive Value of Tests , Radiographic Image Enhancement , Risk Assessment , Risk Factors , Severity of Illness Index
13.
Acad Radiol ; 16(6): 726-32, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19427981

ABSTRACT

RATIONALE AND OBJECTIVES: Left ventricular hypertrophy (LVH) is associated with an increased risk of cardiac death. The present study evaluates whether using computed tomographic (CT)-derived criteria for normal myocardial mass can improve detection of LVH on CT angiography (CTA). MATERIALS AND METHODS: A total of 2238 subjects (63 +/- 9 years, 27% female) who underwent CTA were studied. To identify normal limits for CT-derived myocardial mass, we studied normal subjects (those without diabetes, hypertension, congestive heart failure, or coronary artery disease). Left ventricular mass (LVM) was measured manually using two different workstations. The CT criteria of LVH was defined as LVM above the 97th percentile per gender and compared to echocardiographic criteria (110 g/m(2) in women; 124 g/m(2) in men), and specificity and sensitivity of both models to detect LVH were calculated. RESULTS: The LVM was higher in men than women in normal cohorts (75.5 +/- 14.0 vs. 63.1 +/- 12.8 g/m(2), P = .001 with electron beam CTA and 78.5 +/- 11.9 vs. 65.0 +/- 9.2 g/m(2), P = .001 with 64 multidetector [MD] CT, respectively). The coefficient of variation between electron beam CTA and 64 MDCT for measuring LVM was 3.1%. Comparing the new CTA/64 MDCT criteria of LVH (103.0 g/m(2) in men; 89.0 g/m(2) in women) to the previous echocardiographic criteria of LVH, the specificity in women and men decreased from 100% in both genders by echocardiography to 91.8% and 92.6%, respectively, but the sensitivity increased from 42.0% to 100% and from 41.1% to 100%. CONCLUSION: This study suggests that CT-measured LVM has low variability and normal values based on CT criteria will potentially increase the early detection of LVH.


Subject(s)
Coronary Angiography/methods , Hypertrophy, Left Ventricular/complications , Hypertrophy, Left Ventricular/diagnostic imaging , Tomography, X-Ray Computed/methods , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Left/etiology , Female , Humans , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity
14.
J Comput Assist Tomogr ; 33(2): 175-8, 2009.
Article in English | MEDLINE | ID: mdl-19346841

ABSTRACT

OBJECTIVE: Because almost all data currently available with coronary calcium scanning are from electron beam tomography (EBT), we assessed whether scores obtained with 64-multidetector computed tomography (CT; MDCT) are similar. We evaluated the interscan variation in coronary artery calcium (CAC), Agatston score (AS), and volume score (VS) between EBT and 64-MDCT (VCT; GE, Milwaukee, Wis). MATERIALS AND METHODS: One hundred two patients (mean age, 61.1 years; 27 women) underwent dual CAC scanning with both EBT and 64-MDCT. The AS and VS were measured with the Aquarius workstation (TeraRecon, Inc, San Mateo, Calif). The correlation coefficient, Bland-Altman analysis, interscanner variation, and agreement in AS and VS scores between EBT and 64-MDCT were computed. RESULTS: Interscan agreement for presence of CAC was 99%. Median values were 286 and 268 mm for AS and 243 and 213 mm for VS with EBT and 64-MDCT, respectively (P > 0.05). There was significant linear relationship between scores from the 2 scanners (R = 0.98 in AS and R = 0.99 in VS; P < 0.001). The interscanner variability between EBT and 64-MDCT was 20.9% and 17.6% in AS and VS, respectively (P = NS). Bland-Altman analysis demonstrated a mean difference in scores of 8.3% for AS and 7.8% by VS. When compared with EBT, there were larger and more prevalent motion artifacts (P < 0.001) and larger mean Hounsfield units using 64-MDCT (P < 0.001). CONCLUSIONS: At CAC scanning, 64-MDCT and EBT were comparable in AS and VS. The interscan variability between scanners is similar to interscan variability of 2 calcium scores done on the same equipment. However, heart rate control was achieved for this study for calcium scores. Whether these results are repeatable without heart rate control needs to be further assessed.


Subject(s)
Calcinosis/diagnostic imaging , Calcium/analysis , Coronary Angiography/instrumentation , Coronary Angiography/statistics & numerical data , Coronary Disease/diagnostic imaging , Tomography, X-Ray Computed/instrumentation , Tomography, X-Ray Computed/statistics & numerical data , Artifacts , Female , Heart Rate , Humans , Male , Middle Aged , Observer Variation , Reproducibility of Results , Tomography Scanners, X-Ray Computed/statistics & numerical data
15.
J Cardiovasc Comput Tomogr ; 3(2): 90-5, 2009.
Article in English | MEDLINE | ID: mdl-19269915

ABSTRACT

BACKGROUND: Cardiac computed tomographic angiography (CTA) provides for accurate noninvasive diagnosis of coronary artery disease (CAD). OBJECTIVES: We analyzed the clinical outcomes over 40 months in patients with and without CAD as determined by CTA in an outpatient setting. METHODS: Consecutive symptomatic patients (n = 493; mean age, 58 +/- 15 years; 70% men) with an intermediate likelihood of CAD referred for outpatient CTA evaluation were prospectively followed for a mean of 40 +/- 9 months. RESULTS: Results of CTA included as normal (defined as normal coronary lumen), found in 32% (157), nonobstructive disease (<50% luminal stenosis) in 41% (204), obstructive disease (>or=50% luminal stenosis) in 19% (93). Eight percent (n = 39) had >or=1 major nondiagnostic coronary artery segment. Follow-up identified 21 patients with myocardial infarction (MI) in the significant obstructive CAD and nondiagnostic group. No patients with either normal coronary arteries or nonobstructive disease experienced an MI during follow-up. The 40-month event-free survival was 100% for both the normal and nonobstructive disease groups, 97.5% for the nondiagnostic study group, and 79% for the group with obstructive CAD. After adjustment for age, sex, diabetes mellitus, hypertension, hypercholesterolemia, and baseline coronary artery calcium (CAC), a stepwise multivariable model (Cox regression) showed that obstructive CAD was an independent predictor of cardiac events and had significant incremental value over clinical risk factors and CAC (HR = 16.6; 95% CI, 4.9-55.2; P = 0.0001). CONCLUSION: In symptomatic patients with an intermediate likelihood of CAD referred for CTA, normal coronary arteries or nonobstructive CAD portends an excellent prognosis. The finding of obstructive CAD identifies patients at higher risk of subsequent MI, independent of cardiovascular risk factors and coronary artery calcium.


Subject(s)
Ambulatory Care , Coronary Angiography/methods , Coronary Artery Disease/diagnostic imaging , Myocardial Infarction/etiology , Tomography, X-Ray Computed , Adolescent , Adult , Aged , Aged, 80 and over , Coronary Artery Disease/complications , Coronary Artery Disease/mortality , Coronary Artery Disease/therapy , Disease-Free Survival , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Myocardial Infarction/diagnostic imaging , Myocardial Infarction/mortality , Myocardial Infarction/prevention & control , Predictive Value of Tests , Prevalence , Prognosis , Proportional Hazards Models , Prospective Studies , Risk Assessment , Risk Factors , Severity of Illness Index , Time Factors , Young Adult
16.
Int J Cardiovasc Imaging ; 25(4): 405-16, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19051055

ABSTRACT

Current 64-multidetector Computed Tomographic scanners (MDCT) utilize retrospective overlapping helical acquisition (RS-OHA) which imparts a higher than desired radiation dose. Although the radiation burden of computed tomographic angiography (CTA) can be efficiently reduced by dose modulation and limiting field of view, a further decrease in radiation without compromising diagnostic image quality would be indeed very desirable. An alternative imaging mode is the axial prospective ECG-triggering acquisition (prospective gating). This study was done to compare the effective radiation dose and the image quality with two techniques to reduce radiation doses with CTA studies utilizing 64-MDCT scanners. The study included 149 consecutive patients (48 females and 101 males) 64-MDCT (mean age = 67 +/- 11 years, 72.2% male). Patients underwent CT coronary angiography using one of three algorithms: retrospective triggering with dose modulation; prospective triggering with padding (step and shoot acquisition with additional adjacent phases); and prospective triggering without padding (single phase acquisition only). Based on body habitus, two different voltages were utilized: 100 kVp (<85 kg) or 120 kVp (>85 kg). Radiation doses and image quality (signal to noise ratio) was measured for each patient, and compared between different acquisition protocols. The signal to-noise ratio of the ascending aorta (SNR-AA) was calculated from the mean pixel values of the contrast-filled left ventricular chamber divided by the standard deviation of these pixel values. Use of 100 kVp reduced radiation dose 41.5% using prospective triggering and 39.6% using retrospective imaging as compared to 120 kVp (P < 0.001). Use of prospective imaging reduced radiation exposure by 82.6% as compared to retrospective imaging (P < 0.001). Using both prospective imaging and 100 kVp without padding (single phase data, no other phases obtained), radiation dose was reduced by 90% (P < 0.001). In terms of image quality, the coefficient of variation of ascending aortic contrast enhancement between kVp of 120 and kVp of 100 was 6% (1.05, 95 CI 0.93-1.17), and 7.8% (0.9, 95% CI 0.7-1.2) at the pulmonary artery. The prospective ECG-Triggered acquisition and 100 kVp images were of diagnostic quality, allowing adequate assessment in all patients. CTA using PA and 100 kVp reduced the radiation dose by up to 90% without compromising the image quality.


Subject(s)
Coronary Angiography/methods , Coronary Disease/diagnostic imaging , Tomography, Spiral Computed/methods , Aged , Algorithms , Chi-Square Distribution , Electrocardiography , Female , Humans , Male , Middle Aged , Radiation Dosage , Radiographic Image Interpretation, Computer-Assisted , Retrospective Studies , Risk Reduction Behavior
17.
J Am Coll Cardiol ; 52(16): 1335-43, 2008 Oct 14.
Article in English | MEDLINE | ID: mdl-18929245

ABSTRACT

OBJECTIVES: This study investigated whether cardiac computed tomography angiography (CTA) can predict all-cause mortality in symptomatic patients. BACKGROUND: Noninvasive coronary angiography is being increasingly performed by CTA to assess for obstructive coronary artery disease (CAD), and minimal outcome data exist for coronary CTA. We have utilized a cohort of symptomatic patients who underwent electron beam tomography to allow for longer follow-up (up to 12 years) than currently available with newer 64-slice multidetector-row computed tomography studies. METHODS: In all, 2,538 consecutive patients who underwent CTA by electron beam tomography (age 59 +/- 14 years, 70% males) without known CAD were studied. Computed tomographic angiography results were categorized as significant CAD (> or =50% luminal narrowing), mild CAD (<50% stenosis), and normal coronary arteries. Multivariable Cox proportional hazards models were developed to predict all-cause mortality. Risk-adjusted models incorporated traditional risk factors for coronary disease and coronary artery calcification (CAC). RESULTS: During a mean follow-up of 78 +/- 12 months, the death rate was 3.4% (86 deaths). The CTA-diagnosed CAD was an independent predictor of mortality in a multivariable model adjusted for age, gender, cardiac risk factors, and CAC (p < 0.0001). The addition of CAC to CTA-diagnosed CAD increased the concordance index significantly (0.69 for risk factors, 0.83 for the CTA-diagnosed CAD, and 0.89 for the addition of CAC to CAD, p < 0.0001). Risk-adjusted hazard ratios for CTA-diagnosed CAD were 1.7-, 1.8-, 2.3-, and 2.6-fold for 3-vessel nonobstructive, 1-vessel obstructive, 2-vessel obstructive, and 3-vessel obstructive CAD, respectively (p < 0.0001), when compared with the group who did not have CAD. CONCLUSIONS: The primary results of our study reveal that the burden of angiographic disease detected by CTA provides both independent and incremental value in predicting all-cause mortality in symptomatic patients independent of age, gender, conventional risk factors, and CAC.


Subject(s)
Cause of Death , Coronary Angiography/methods , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/mortality , Radiographic Image Enhancement , Tomography, X-Ray Computed/methods , Adult , Age Factors , Aged , Aged, 80 and over , Cohort Studies , Confidence Intervals , Contrast Media/pharmacology , Coronary Artery Disease/physiopathology , Female , Humans , Incidence , Kaplan-Meier Estimate , Male , Middle Aged , Predictive Value of Tests , Prognosis , Proportional Hazards Models , ROC Curve , Risk Assessment , Sensitivity and Specificity , Severity of Illness Index , Sex Factors , Survival Analysis
18.
Acad Radiol ; 15(1): 58-61, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18078907

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.


Subject(s)
Calcinosis/diagnostic imaging , Coronary Artery Disease/diagnostic imaging , Tomography, X-Ray Computed/methods , Acetates/therapeutic use , Atorvastatin , Calcium Compounds/therapeutic use , Chelating Agents/therapeutic use , Coronary Artery Disease/drug therapy , Coronary Artery Disease/etiology , Disease Progression , Drug Therapy, Combination , Female , Heptanoic Acids/therapeutic use , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Kidney Failure, Chronic/complications , Male , Middle Aged , Polyamines/therapeutic use , Prospective Studies , Pyrroles/therapeutic use , Reproducibility of Results , Sevelamer , Treatment Outcome
19.
Int J Cardiol ; 129(1): 32-6, 2008 Sep 16.
Article in English | MEDLINE | ID: mdl-17651836

ABSTRACT

PURPOSE: To determine the prevalence of significant obstructive disease and non-diagnostic studies using coronary computed tomographic angiography (CTA) in an outpatient environment, to establish if CTA could help avoid unnecessary diagnostic cardiac catheterizations. METHODS: We evaluated all cases consecutively performed in our outpatient CTA laboratory seen over one year with an indication that could warrant a cardiac catheterization to establish the presence or absence of coronary artery disease (CAD). Excluded were patients without established indications for cardiac catheterization and those with known CAD (i.e.- prior myocardial infarction, revascularization). Four hundred and ninety-three (493) CTA case studies were included for the analysis. Patients were classified as normal (no luminal irregularities seen), non-obstructive coronary disease (<50% stenosis), significant obstructive coronary disease (>50% stenosis), or a non-diagnostic study. We assumed that all patients assigned to the obstructive CAD group and the non-diagnostic study group would require a cardiac catheterization. In the remaining two groups, a cardiac catheterization would not be necessary for diagnosis or treatment. RESULTS: Of the 493 index cases evaluated, 157 (32%) cases were reported to be normal, 204 patients were classified as having non-obstructive disease (41%), 93 patients were defined to have obstructive CAD (19%), and 39 cases were inconclusive (8%). Thus, in 27% of the study population, a conventional coronary angiography would be indicated to clarify the diagnosis or provide definitive disease severity for subsequent revascularization. CONCLUSION: Among ambulatory patients referred for CT angiography with symptoms or positive (or equivocal) cardiac stress tests, 73% of patients were found to have either normal coronary arteries or non-obstructive disease. Given the high negative predictive power of cardiac CTA (93-99%), these patients most likely would not require subsequent invasive coronary angiography. A strategy of selective cardiac catheterization may substantially decrease unnecessary diagnostic cardiac catheterizations and reduce health care expenses.


Subject(s)
Ambulatory Care/methods , Coronary Angiography/methods , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/epidemiology , Tomography, X-Ray Computed/methods , Adolescent , Adult , Aged , Aged, 80 and over , Cardiac Catheterization , Female , Humans , Male , Middle Aged , Prevalence
20.
Acad Radiol ; 14(3): 252-7, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17307657

ABSTRACT

RATIONALE AND OBJECTIVES: Endowed with sufficient diagnostic accuracy, electron beam computed tomography angiography (CTA) is being increasingly used to evaluate coronary arteries. However, data on direct comparisons with nuclear myocardial perfusion studies are limited. In this study, we sought to compare the accuracies of CTA and myocardial perfusion imaging (MPI) for identifying symptomatic patients with hemodynamically significant obstructive coronary artery disease (CAD). MATERIALS AND METHODS: In a single-center study, symptomatic outpatients who were scheduled for cardiac catheterization were prospectively enrolled. Only patients with exertional angina or dyspnea were included. After fulfilling the inclusion criteria, 30 patients were enrolled in the study (mean age 54 +/- 9 years and 70% males). Patients underwent MPI, CTA including coronary artery calcification (CAC) measure, and invasive coronary angiography for evaluation of obstructive coronary artery disease. Significant CAD was defined as >50% left main artery stenosis or >70% stenosis of any other epicardial vessel by invasive angiography. The sensitivities, specificities and predictive values of MPI, CAC, and CTA were analyzed per patient RESULTS: CTA demonstrated significant higher sensitivity than MPI (95% vs. 81%, P < .05). CTA demonstrated significantly higher specificity than both MPI (89% versus 78%, P = .04) and CAC (56%, P = .002). CTA also performed better in a per-vessel analysis (sensitivity 94%, specificity 96%) than both nuclear and CAC. There were no significant differences between the sensitivities and specificities of MPI and CAC. CONCLUSION: CTA accurately detects obstructive CAD in symptomatic patients and may be more accurate than MPI or CAC assessment. Larger studies in a more diverse population are needed.


Subject(s)
Coronary Angiography/methods , Coronary Disease/diagnosis , Tomography, X-Ray Computed , Calcium/analysis , Coronary Disease/diagnostic imaging , Coronary Vessels/chemistry , Female , Humans , Male , Middle Aged , Radionuclide Imaging , Radiopharmaceuticals , Sensitivity and Specificity , Technetium Tc 99m Sestamibi
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