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1.  Evaluation of left ventricular ejection fraction using through-time radial GRAPPA 
The determination of left ventricular ejection fraction using cardiovascular magnetic resonance (CMR) requires a steady cardiac rhythm for electrocardiogram (ECG) gating and multiple breathholds to minimize respiratory motion artifacts, which often leads to scan times of several minutes. The need for gating and breathholding can be eliminated by employing real-time CMR methods such as through-time radial GRAPPA. The aim of this study is to compare left ventricular cardiac functional parameters obtained using current gold-standard breathhold ECG-gated functional scans with non-gated free-breathing real-time imaging using radial GRAPPA, and to determine whether scan time or the occurrence of artifacts are reduced when using this real-time approach.
63 patients were scanned on a 1.5T CMR scanner using both the standard cardiac functional examination with gating and breathholding and the real-time method. Total scan durations were noted. Through-time radial GRAPPA was employed to reconstruct images from the highly accelerated real-time data. The blood volume in the left ventricle was assessed to determine the end systolic volume (ESV), end diastolic volume (EDV), and ejection fraction (EF) for both methods, and images were rated for the presence of artifacts and quality of specific image features by two cardiac readers. Linear regression analysis, Bland-Altman plots and two-sided t-tests were performed to compare the quantitative parameters. A two-sample t-test was performed to compare the scan durations, and a two-sample test of proportion was used to analyze the presence of artifacts. For the reviewers´ ratings the Wilcoxon test for the equality of the scores’ distributions was employed.
The differences in EF, EDV, and ESV between the gold-standard and real-time methods were not statistically significant (p-values of 0.77, 0.82, and 0.97, respectively). Additionally, the scan time was significantly shorter for the real-time data collection (p<0.001) and fewer artifacts were reported in the real-time images (p<0.01). In the qualitative image analysis, reviewers marginally preferred the standard images although some features including cardiac motion were equivalently rated.
Real-time functional CMR with through-time radial GRAPPA performed without ECG-gating under free-breathing can be considered as an alternative to gold-standard breathhold cine imaging for the evaluation of ejection fraction in patients.
PMCID: PMC4180954  PMID: 25315256
Real-time imaging; Left ventricular ejection fraction; Cardiovascular magnetic resonance; Cardiac function
2.  Soluble CD14 is independently associated with coronary calcification and extent of subclinical vascular disease in treated HIV infection 
AIDS (London, England)  2014;28(7):969-977.
To use multimodality imaging to explore the relationship of biomarkers of inflammation, T-cell activation and monocyte activation with coronary calcification and subclinical vascular disease in a population of HIV-infected patients on antiretroviral therapy (ART).
A panel of soluble and cellular biomarkers of inflammation and immune activation was measured in 147 HIV-infected adults on ART with HIV RNA less than 1000 copies/ml and low-density lipoprotein cholesterol (LDL-C) 130 mg/dl or less. We examined the relationship of biomarkers to coronary calcium (CAC) score and multiple ultrasound measures of subclinical vascular disease.
Overall, median (interquartile range, IQR) age was 46 (40–53) years; three-quarters of participants were male and two-thirds African-American. Median 10-year Framingham risk score was 6%. Participants with CAC more than 0 were older, less likely to be African-American and had higher current and lower nadir CD4+ T-cell counts. Most biomarkers were similar between those with and without CAC; however, soluble CD14 was independently associated with CAC after adjustment for traditional risk factors. Among those with a CAC score of zero, T-cell activation and systemic inflammation correlated with carotid intima–media thickness and brachial hyperemic velocity, respectively. Compared with normal participants and those with CAC only, participants with increasing degrees of subclinical vascular disease had higher levels of sCD14, hs-CRP and fibrinogen (all P<0.05).
Soluble CD14 is independently associated with coronary artery calcification, and, among those with detectable calcium, predicts the extent of subclinical disease in other vascular beds. Future studies should investigate the utility of multimodality imaging to characterize vascular disease phenotypes in this population.
PMCID: PMC4097603  PMID: 24691204
carotid intima–media thickness; coronary artery calcium; endothelial function; HIV; inflammation; microbial translocation; soluble CD14
3.  Psoriasis and cardiovascular risk factors: increased serum myeloperoxidase and corresponding immunocellular overexpression by Cd11b+ CD68+ macrophages in skin lesions 
Background: Recent studies report independent associations between psoriasis, cardiovascular (CV) events and risk factors. Blood Myeloperoxidase (MPO) from activated myeloid cells is associated with CV risk mainly through lipid oxidation, induction of endothelial dysfunction and release of IL-12 from macrophages. Objectives: To elucidate associations between psoriasis and conventional CV risk factors. Methods: We performed a cross-sectional study of 100 psoriasis patients and 53 controls, group matched on age, gender and body mass index, to assess levels of MPO in serum, as well as immunohistochemical staining from psoriasis skin lesions, psoriasis uninvolved skin, and normal skin. Results: Although the groups did not differ on waist circumference, glucose, cholesterol, triglycerides, creatinine or personal history of CV events, psoriasis patients had significantly higher waist-to-hip ratios, blood pressures, proportion of current smokers, and lower high density lipoprotein level than controls. Serum MPO level was elevated 2.5 fold (P<0.001) in psoriasis patients, even after adjusting for the CV risk factors on which the groups differed. MPO did correlate with coronary artery calcification, carotid plaque, carotid intima media thickness and flow mediated dilation, but did not correlate with psoriasis severity. However, MPO was highly expressed in lesional psoriatic skin and colocalized predominantly with CD45+ CD11b+ leukocytes. CD11b+ cell density correlated with circulation MPO levels. Conclusion: Lesional skin CD11b+ leukocytes activated to generate MPO may contribute to serum levels of MPO. Lesional CD11b+ cell activity may be an alternative measure of disease burden to PASI that underlies the MPO biomarker for systemic inflammation related to Cardiovascular Disease.
PMCID: PMC3853421  PMID: 24349618
Myeloperoxidase; psoriasis; cardiovascular disease; immunofluorescence; immunohistochemistry
4.  Assessment of Coronary Artery Calcium Using Dual-Energy Subtraction Digital Radiography 
Journal of Digital Imaging  2011;25(1):129-136.
Cardiovascular disease is the leading cause of global mortality, yet its early detection remains a vexing problem of modern medicine. Although the computed tomography (CT) calcium score predicts cardiovascular risk, relatively high cost ($250–400) and radiation dose (1–3 mSv) limit its universal utility as a screening tool. Dual-energy digital subtraction radiography (DE; <$60, 0.07 mSv) enables detection of calcified structures with high sensitivity. In this pilot study, we examined DE radiography’s ability to quantify coronary artery calcification (CAC). We identified 25 patients who underwent non-contrast CT and DE chest imaging performed within 12 months using documented CAC as the major inclusion criteria. A DE calcium score was developed based on pixel intensity multiplied by the area of the calcified plaque. DE scores were plotted against CT scores. Subsequently, a validation cohort of 14 additional patients was independently evaluated to confirm the accuracy and precision of CAC quantification, yielding a total of 39 subjects. Among all subjects (n = 39), the DE score demonstrated a correlation coefficient of 0.87 (p < 0.0001) when compared with the CT score. For the 13 patients with CT scores of <400, the correlation coefficient was −0.26. For the 26 patients with CT scores of ≥400, the correlation coefficient yielded 0.86. This pilot study demonstrates the feasibility of DE radiography to identify patients at the highest cardiovascular risk. DE radiography’s accuracy at lower scores remains unclear. Further evaluation of DE radiography as an inexpensive and low-radiation imaging tool to diagnose cardiovascular disease appears warranted.
PMCID: PMC3264713  PMID: 21557030
Calcification detection; Cardiac imaging; Chest CT; Chest radiographs; Computed tomography; Coronary arteries; Coronary calcifications; Coronary disease; Digital radiography; Digital subtraction radiography; Dual-energy subtraction; Radiography; Dual-energy scanned projection; ROC-based analysis
6.  Stroke Severity Predicted by Aortic Atheroma Detected by Ultra-Fast and Cardiac-Gated Chest Tomography† 
Background and Purpose: The presence of aortic atherosclerosis is an independent risk factor for secondary stroke. The present study was designed to have an initial exploration of the correlation between the load and extent of aortic atheroma (AA) and initial stroke severity or clinical outcome 3 months after stroke. Methods: Cardiac-gated chest tomography (CGCT) was used to detect and measure AA in patients with acute ischemic stroke as shown by our group in prior prospective studies and this is part four sub-exploratory study of the same cohort. The National Institute of Health Stroke Scale (NIHSS) was used to assess the initial stroke severity, and the modified Rankin Scale (mRS) was used to assess 3-month outcome. Results: Thirty-two patients underwent CGCT for evaluation of AA, and 21 were found to have AA. AA was more prevalent in patient with NIHSS >6 (14/17 versus 7/15, p-value 0.03). Applying the multiple logistic regression and propensity score adjustment (using the propensity of having AA given the baseline features as covariates) showed a non-significant trend that AA is three times more likely to be associated with NIHSS >6 (p = 0.08, OR 3.08, 95% CI 0.94–13.52). There was no evidence of association of AA with 3-month functional outcome (mRS): 11/14 (78.6%) mRS >1 had AA, and 10/18 (55.5%) of those with mRS ≤1 had AA (p = 0.27). Conclusion: In our current study with limited sample number and exploratory nature, the presence of AA on CGCT with acute ischemic stroke patients may be associated with worse neurological deficit at presentation. There was no evidence of association with 3-month functional outcome using the mRS.
PMCID: PMC3066465  PMID: 21472030
stroke; outcome; aortic atheroma; cardiac-gated CT; TEE; stroke severity; atherosclerosis
7.  The Relationship Between Race, Cigarette Smoking and Carotid Intimal Medial Thickness in Systemic Lupus 
Lupus  2009;18(14):1289-1297.
Racial differences are known to account for a higher incidence of systemic lupus erythematosus (SLE), as well as increased disease severity and mortality. The purpose of this study was to determine if there are any race-specific risk factors that affect measures of subclinical atherosclerosis in SLE patients.
Traditional and SLE-related cardiovascular disease (CVD) risk factors were assessed in 106 female SLE patients. Carotid medial intimal medial thickness (mIMT) and coronary artery calcification (CAC) were measured on all subjects. Differences were evaluated between races for all clinical, serologic, and CVD risk factors and the racial interactions with all covariables. Outcomes included mIMT and CAC.
There were no significant differences between races with regard to mIMT or CAC. Significant covariables in the final model for mIMT included age, triglycerides, glucose, and race-age and race-smoking interactions. A prediction model with fixed significant covariables demonstrated that Black subjects with a smoking history had a significantly higher mIMT than Blacks who had never smoked, an effect not seen in Whites. There were no differences between having CAC or with the CAC scores between the races. In the final model for CAC, age and SLE disease duration were significant covariables impacting CAC.
When controlling for other significant CVD covariables and interactions, Black women, but not White, with SLE with a history of smoking have higher mIMT measurements than those who have never smoked. This is the first report documenting the race-specific effect of smoking on subclinical measures of CVD in SLE.
PMCID: PMC2804892  PMID: 19861342
lupus; cardiovascular; smoking; race
8.  Automatic Registration of CT Volumes and Dual-Energy Digital Radiography for Detection of Cardiac and Lung Diseases 
We are investigating image processing and analysis techniques to improve the ability of dual-energy digital radiography (DR) for the detection of cardiac calcification. Computed tomography (CT) is an established tool for the diagnosis of coronary artery diseases. Dual-energy digital radiography could be a cost-effective alternative. In this study, we use three-dimensional (3D) CT images as the “gold standard” to evaluate the DR X-ray images for calcification detection. To this purpose, we developed an automatic registration method for 3D CT volumes and two-dimensional (2D) X-ray images. We call this 3D-to-2D registration. We first use a 3D CT image volume to simulate X-ray projection images and then register them with X-ray images. The registered CT projection images are then used to aid the interpretation dual-energy X-ray images for the detection of cardiac calcification. We acquired both CT and X-ray images from patients with coronary artery diseases. Experimental results show that the 3D-to-2D registration is accurate and useful for this new application.
PMCID: PMC2743908  PMID: 17945687
9.  Automatic 3D-to-2D registration for CT and dual-energy digital radiography for calcification detection 
Medical physics  2007;34(12):4934-4943.
We are investigating three-dimensional (3D) to two-dimensional (2D) registration methods for computed tomography (CT) and dual-energy digital radiography (DEDR). CT is an established tool for the detection of cardiac calcification. DEDR could be a cost-effective alternative screening tool. In order to utilize CT as the “gold standard” to evaluate the capability of DEDR images for the detection and localization of calcium, we developed an automatic, intensity-based 3D-to-2D registration method for 3D CT volumes and 2D DEDR images. To generate digitally reconstructed radiography (DRR) from the CT volumes, we developed several projection algorithms using the fast shear-warp method. In particular, we created a Gaussian-weighted projection for this application. We used normalized mutual information (NMI) as the similarity measurement. Simulated projection images from CT values were fused with the corresponding DEDR images to evaluate the localization of cardiac calcification. The registration method was evaluated by digital phantoms, physical phantoms, and clinical data sets. The results from the digital phantoms show that the success rate is 100% with a translation difference of less than 0.8 mm and a rotation difference of less than 0.2°. For physical phantom images, the registration accuracy is 0.43±0.24 mm. Color overlay and 3D visualization of clinical images show that the two images registered well. The NMI values between the DRR and DEDR images improved from 0.21±0.03 before registration to 0.25±0.03 after registration. Registration errors measured from anatomic markers decreased from 27.6±13.6 mm before registration to 2.5±0.5 mm after registration. Our results show that the automatic 3D-to-2D registration is accurate and robust. This technique can provide a useful tool for correlating DEDR with CT images for screening coronary artery calcification. © 2007 American Association of Physicists in Medicine. [DOI: 10.1118/1.2805994]
PMCID: PMC2743028  PMID: 18196818
3D-to-2D registration; dual-energy digital radiography (DEDR); computed tomography (CT); cardiac calcification; coronary artery diseases (CADs)
10.  Gadolinium-Enhanced Magnetic Resonance Angiography in Scimitar Syndrome: Diagnosis and Postoperative Evaluation 
Texas Heart Institute Journal  2000;27(3):309-311.
We report the 1st magnetic resonance demonstration of both an anomalous pulmonary venous drainage and systemic arterial supply in a patient with scimitar syndrome. With its superior imaging capabilities, gadolinium-enhanced magnetic resonance angiography provides a powerful diagnostic tool for this complex congenital lesion and offers the possibility of surgical repair and follow-up without conventional cardiac catheterization.
PMCID: PMC101089  PMID: 11093422
Gadolinium/diagnostic use; lung/abnormalities; magnetic resonance angiography; pulmonary veins/abnormalities; scimitar syndrome/diagnosis

Results 1-10 (10)