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A standardized, holistic artificial intelligence (AI) curriculum is necessary to meet trainee demand and prepare them for effective AI tool use in their future practice.

Introduction: Cardiomyopathy is a common complication in muscular dystrophy (MD) patients, though the mechanism is not clear. Retrospective data from adults with Duchenne muscular dystrophy suggest they have reduced LV mass compared to adults with other forms of non-ischemic cardiomyopathy. This raises the question whether pathologic hypertrophy contributes to the development of neuromuscular-associated cardiomyopathies. In this study, we hypothesized that MD patients have lower LV mass and associated changes in cardiac function as compared to healthy individuals. Methods: Utilizing cardiac magnetic resonance imaging (cMRI) data, a retrospective study was undertaken to compare LV mass, structure, and function between adults with MD and healthy age-, sex-, weight-matched controls from the Dallas Heart Study (DHS). Types of MD included dystrophinopathies, facioscapulohumeral MD, Freidreich ataxia, limb-girdle MD, myotonic dystrophy, and other rare MD. Approximately 50% of the MD patients were able to ambulate. MD patients were stratified into normal and reduced LVEF, defined as < 62% on cMRI, for further comparison. Statistical analysis was done using a two-sample, two-tailed t-test. Results: There were 339 MD patients (221 male) of mean age 40 and 417 DHS patients (187 male) of mean age 42. MD patients had a significantly lower LV mass, LV mass index, and LVEF than DHS adults. They also had significantly higher absolute and indexed volumes. In those with normal LVEF, all variables except LVESVi were significantly different from DHS. In those with reduced LVEF, all variables were significantly different from DHS. The results are summarized in Table 1. Conclusions: Collectively, MD patients have a reduced LV mass compared to healthy adults. In addition, MD patients with normal LVEF have lower LV mass than those patients with reduced LV function. Whether this observed decrease in LV mass represents cardiac hypoplasia or atrophy warrants further investigation.

Introduction: Duchenne muscular dystrophy (DMD) is a rare X-linked neuromuscular disorder affecting 1:5,000 males that results in terminal injury to the skeletal muscle and the heart. Recent evidence suggests that DMD female carriers are also at increased risk of developing cardiomyopathy. Renin-angiotensin-aldosterone system (RAAS) antagonists reduce morbidity and mortality and inhibit adverse left ventricular remodeling in patients with heart failure with reduced ejection fraction. The benefit of RAAS inhibition in DMD carriers has not been studied to date. Hypothesis: We hypothesize that RAAS inhibition will improve left ventricular function and induce favorable left ventricular structural changes in DMD carriers over time. Methods: A retrospective, single-center cohort study was undertaken to compare cardiac magnetic resonance imaging (cMRI) parameters in DMD carriers at the time of RAAS inhibitor initiation and after treatment with RAAS inhibitors for at least 12 months. RAAS inhibitors included angiotensin converting enzyme inhibitors, angiotensin receptor blockers, or angiotensin receptor neprilysin inhibitors. Through EMR review, demographic data and cMRI parameters were collected retrospectively on 20 consecutive DMD carriers. Results: The average time elapsed between cMRIs was 39 months. Overall, left ventricular ejection fraction (LVEF) increased in DMD carriers over time, though the improvement in LVEF did not reach significance (57% + 8 vs 59% + 6, p=0.2). However, subgroup analysis of 16 DMD carriers with reduced LVEF (defined as LVEF + 6 vs 58% + 7; p= 0.004). DMD carriers with reduced LVEF additionally demonstrated a significant decrease in left ventricular end systolic volume index (LVESVi) after RAAS inhibition (38 + 10 vs 32 + 10 ml/m2; p= 0.013). Conclusions: DMD carriers with reduced LVEF showed significant improvement in LVEF and LVESVi following RAAS inhibition. Collectively, the data suggest that RAAS inhibition significantly improves left ventricular systolic function and significantly reduces maladaptive left ventricular remodeling and dilation in this population.

Value-based imaging requires appropriate utilization and the delivery of consistently high-quality imaging at an acceptable cost. Challenges include developing standardized imaging protocols, ensuring consistent application by technologists, and monitoring quality. These challenges increase as enterprises grow in geographical extent and complexity through mergers or partnerships. Our imaging enterprise includes a university hospital and clinic system, a large county hospital and healthcare system, and a pediatric hospital and health system. Studies across the three systems are interpreted by one large academic radiology group with expertise in various subspecialties. Our goals were as follows: (1) Standardize imaging protocols; (2) adapt the imaging protocols to specific modalities and available equipment; and (3) disseminate this knowledge across all of the sites of care. Our approach involved three components: (1) facilitation of imaging protocol definition across subspecialty radiologist teams; (2) creation of a database which links the clinical imaging protocols to the scanner/machine specific acquisition protocols; and (3) delivery of a protocol library and updates to all users regardless of location. We successfully instituted a process for the development, implementation, and delivery of standardized imaging protocols in a complex, multi-institutional healthcare system. Key elements for success include (1) a Project Champion who is able to articulate the importance of protocol standardization in improving the quality of patient care, (2) strong, effective modality-specific operational committees, (3) a Project Lead to manage the process efficiently, and (4) an electronic publishing of the protocol database to facilitate ease of access and use.

Background: Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disorder characterized by progressive muscle degeneration. The leading cause of death is complications from the development of DMD-associated cardiomyopathy. The majority of DMD patients have skeletal abnormalities that limit the quality of echocardiograms (ECHO). Although cardiac magnetic resonance imaging (cMRI) is the gold standard cardiac imaging tool, the vast majority of DMD patients are evaluated by ECHO rather than cMRI. We hypothesized that when compared to ECHO, cMRI more accurately assesses cardiac function and provides more valuable data for the diagnosis of DMD-associated cardiomyopathy. Methods: We undertook a retrospective study of 20 DMD patients referred to the UT Southwestern Adult Neuromuscular Cardiomyopathy Clinic who had undergone both an ECHO and cMRI within 15 months of each other. We assessed the proportion of studies demonstrating reduced left ventricular (LV) function [cMRI LVEF Results: Amongst these patients, 10% of cMRIs and 85% of ECHOs were technically difficult. By cMRI, 30% of the studies were normal (LVEF 64±2 %), while 70% showed reduced function (LVEF: 44±12%). By ECHO, 75% of the studies were normal (FS 32±5), while 25% showed reduced function (FS: 15±8). Of the patients with truly reduced function by cMRI, 64% were considered normal by ECHO. Finally, 61% of cMRI studies showed LGE (50% with normal LVEF and 67% with reduced LVEF). Conclusions: In summary, cMRI is superior to ECHO in assessing cardiac function in DMD. ECHO underestimates left ventricular dysfunction, likely due to the poor quality of studies obtained in this patient population. In addition, cMRI identifies LGE, a marker associated with increased mortality, irrespective of cardiac function. Earlier utilization of cMRI will expedite the diagnosis of DMD-associated cardiomyopathy and enable the cardiologist to initiate aggressive guideline-directed medical therapy at an earlier age.

Introduction: Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disorder. DMD-associated cardiomyopathy is the primary mode of premature death in the majority of male DMD patients, but the prevalence of cardiomyopathy and its clinical significance in female DMD carriers is less well characterized. Hypothesis: We hypothesized that a significant proportion of DMD carriers develop maladaptive left ventricular (LV) structural remodeling and cardiomyopathy over time. Methods: A cross-sectional study was undertaken comparing cardiac magnetic resonance imaging (cMRI) and cardiopulmonary stress test (CPX) parameters between DMD carriers and healthy age- and sex-matched controls from the Dallas Heart Study (DHS). Demographic data, cMRI parameters, and CPX parameters were collected retrospectively on 30 consecutive DMD carriers and 26 control DHS subjects. Results: Overall, DMD carriers had a significantly lower LVEF compared to DHS controls (58+8% vs 70+7%, p< 0.0001). The overall prevalence of reduced LVEF in DMD carriers (defined as LVEF 2 vs 58+7, p< 0.0001; 31+10 ml/m 2 vs 17+5, p< 0.0001; respectively). LV concentricity was also significantly lower among all DMD carriers compared to DHS controls (3.10+0.65 g/mL 0.67 vs 3.73+0.79, p =0.002). LV concentricity was significantly lower in DMD carriers with reduced EF compared to controls (3.09+0.51 g/mL 0.67 vs 3.73+0.79, p = 0.012), while DMD carriers with preserved EF also had reduced concentricity compared to controls (3.12+0.86 vs 3.73+0.79, p = 0.054). Finally, peak VO 2 was lower in DMD carriers compared to DHS controls (23+6 ml/kg/min vs 25+4, p =0.076), though this difference did not reach statistical significance. Conclusions: Collectively, the data suggest that middle-aged female DMD carriers are at greater risk of developing left ventricular systolic dysfunction and cardiomyopathy associated with decreased exercise capacity. A possible mechanism driving the development of this cardiomyopathy is progressive, maladaptive left ventricular dilatation and cardiac atrophy.

Background: Muscular dystrophies (MD) are genetic disorders that cause progressive peripheral skeletal myopathies. The majority of MD patients will develop atrial and ventricular arrhythmias and/or an associated cardiomyopathy with a high degree of morbidity and mortality. However, it remains unknown the degree of atrial remodeling that may also occur in MD patients. We hypothesize maladaptive atrial remodeling occurs in MD patients. Methods: Utilizing the UT Southwestern Cardiomyopathy Clinic, MD [total: 79 patients (34 females, 45 males)] and non-ischemic cardiomyopathy (NICM) [total: 81 patients (29 females, 52 males)] patients were identified who underwent a cardiac MRI (cMRI) between 2011 and 2015. A matched, healthy control cohort from the Dallas Heart Study (DHS) [total: 101 patients (40 females, 61 males)] were identified. Most MD patients had Duchenne/Becker MD, Limb-Girdle MD or myotonic MD. Two blinded, independent readers made volumetric measurements from cMRIs to assess right atrial (RA) and left atrial (LA) dimensions with low inter-reader variability. A third independent investigator analyzed the RA and LA data with aggregate data presented in the Table. The statistical significance of the data (p Results: Analysis of the cMRI data revealed significant differences in both the structure and function of the RA and the LA between MD and NICM patients. In addition, the data revealed significant differences in the LA but not the RA emptying fraction in MD patients as compared to the DHS patients. Conclusion: Collectively, the data suggests MD patients develop significant maladaptive remodeling of the LA but not the RA, predisposing these patients to atrial arrhythmias. Investigation into differences in atrial remodeling as a function of gender and the type of MD need to be explored.

PURPOSE: To explore the safety and clinical utility of MRI in participants with non–MRI-conditional cardiac implantable electronic devices, by establishing the Patient Registry of Magnetic Resonance Imaging in Non-Approved DEvices (PROMeNADe). MATERIALS AND METHODS: From September 2015 to June 2019, 532 participants (211 women) with a mean age of 69 years ± 14 (standard deviation) were enrolled prospectively in the PROMeNADe registry (ClinicalTrials.gov identifier: NCT03081364) and underwent a total of 608 MRI examinations (61 cardiac MRI examinations). All participants had device interrogations performed before and after each MRI. Pacemaker-dependent patients received asynchronous pacing. Patients with an implantable cardioverter defibrillator (ICD) had tachycardia therapies disabled during the MRI. An electrophysiology nurse monitored participants for any hemodynamic or rhythm abnormalities. Referring physicians were surveyed regarding the clinical utility of the MRI. Standard descriptive analyses included summary statistics with percentages and means. RESULTS: Cardiac devices included pacemakers (46%), ICDs (30%), cardiac resynchronization therapy (CRT) pacemakers (4%), and CRT defibrillators (17%), as well as abandoned leads (2%). Pacemaker-dependent patients comprised 27% of all MRI examinations. There were no patient- or device-related complications. Clinical utility surveys of MRI examinations were completed by 150 physicians. According to the survey responses, these MRI examinations changed the suspected diagnosis 25% of the time and changed suspected prognosis in 26% of participants, with planned medical or surgical treatment being changed 42% of the time. CONCLUSION: This registry demonstrates that MRI examinations, including thoracic MRI examinations, can be performed safely in patients who have non–MRI-conditional devices, in pacemaker-dependent patients with ICDs, and in patients with abandoned leads. These MRI examinations can have a substantial impact on patient care, justifying the extensive resources used to perform them. Supplemental material is available for this article. © RSNA, 2020 See also the commentary by Peshock in this issue.

Background: Coronary artery calcium scoring only represents a small fraction of all information available in noncontrast cardiac computed tomography (CAC-CT). We hypothesized that an automated pipeline using radiomics and machine learning could identify phenotypic information about high-risk left ventricular hypertrophy (LVH) embedded in CAC-CT. Methods: This was a retrospective analysis of 1982 participants from the DHS (Dallas Heart Study) who underwent CAC-CT and cardiac magnetic resonance. Two hundred twenty-four participants with high-risk LVH were identified by cardiac magnetic resonance. We developed an automated adaptive atlas algorithm to segment the left ventricle on CAC-CT, extracting 107 radiomics features from the volume of interest. Four logistic regression models using different feature selection methods were built to predict high-risk LVH based on CAC-CT radiomics, sex, height, and body surface area in a random training subset of 1587 participants. Results: The respective areas under the receiver operating characteristics curves for the cluster-based model, the logistic regression model after exclusion of highly correlated features, and the penalized logistic regression models using least absolute shrinkage and selection operators with minimum or one SE λ values were 0.74 (95% CI, 0.67–0.82), 0.74 (95% CI, 0.67–0.81), 0.76 (95% CI, 0.69–0.83), and 0.73 (95% CI, 0.66–0.80) for detecting high-risk LVH in a distinct validation subset of 395 participants. Conclusions: Ventricular segmentation, radiomics features extraction, and machine learning can be used in a pipeline to automatically detect high-risk phenotypes of LVH in participants undergoing CAC-CT, without the need for additional imaging or radiation exposure. Registration: URL http://www.clinicaltrials.gov . Unique identifier: NCT00344903.

Determining the clinical impact of imaging exams at the enterprise level is problematic, as radiology reports historically have been created with the content meant primarily for the referring provider. Structured reporting can establish the foundation for enterprise monitoring of imaging outcomes without manual review providing the framework for assessment of utilization and quality. Ultrasound (US) for deep vein thrombosis evaluation (DVT) is an ideal testbed for assessing this functionality. The system standard template for Doppler US for extremity venous evaluation for DVT was updated with a discrete fixed picklist of impression options and implemented system wide. Template utilization and interpretive outcomes were actively monitored and use reinforced as part of standard clinical practice. From January 1, 2017 to December 31, 2017, 9111 US exams for DVT were performed with 8997 utilizing structured reporting (98.75%). Of those in the structured reporting group, 1074 (11.79%) were positive for any type of DVT with 732 (8.03%) reported as Acute/New above the knee. Positive rates for any type of DVT were 10.29% emergency department, 14.17% inpatient, and 13.20% outpatient. While being the lowest positive rate, the emergency department had the highest overall volume of exams. Structured reporting for DVT US assessment outcomes can be implemented with a very high rate of radiologist adoption and adherence providing accurate determination of positive rates, month by month, in differing patient locations. Structured elements can be used to automatically trigger downstream processes; in our institution, this will alert providers in the EHR if the patient does not receive anticoagulation within 2 h of a positive test. This lays the foundation for effective enterprise assessment of imaging outcomes forming the basis of future quality and safety initiatives on optimizing health system resource utilization.

Background Development and change of coronary artery calcium (CAC) are associated with coronary heart disease. Interpretation of serial CAC measurements will require better understanding of changes in CAC beyond the variability in the test itself. Methods Dallas Heart Study participants (2888) with duplicate CAC scans obtained minutes apart were analyzed to determine interscan concordance and 95% confidence bounds (ie: repeatability limits) for each discrete CAC value. These data derived cutoffs were then used to define change above measurement variation and determine the frequency of CAC development and change among 1779 subjects with follow up CAC scans performed 6.9 years later. Results Binary concordance (0 vs. >0) was 91%. The value of CAC denoting true development of CAC by exceeding the 95% confidence bounds for a single score of 0 was 2.7 Agatston units (AU). Among those with scores >0, the 95% confidence bounds for CAC change were determined by the following formulas: for CAC≤100AU: 5.6√CAC + 0.3*CAC – 3.1; for CAC>100AU: 12.4√CAC – 67.7. Using these parameters, CAC development occurred in 15.0% and CAC change occurred in 48.9%. Although 225 individuals (24.9%) had a decrease in CAC over follow up, only 1 (0.1%) crossed the lower confidence bound. Compared with prior reported definition of CAC development (ie: >0), the novel threshold of 2.7AU resulted in better measures of model performance. In contrast, for CAC change, no consistent differences in performance metrics were observed compared with previously reported definitions. Conclusion There is significant interscan variability in CAC measurement, including around scores of 0. Incorporating repeatability estimates may help discern true differences from those due to measurement variability, an approach that may enhance determination of CAC development and change.

The aim of this study was to assess characteristic impedance (Z c ) of the proximal aorta in young and middle-aged individuals with isolated systolic hypertension (ISH). Z c is an index of aortic stiffness relative to aortic size. In the Dallas Heart Study, 2001 untreated participants 18 to 64 years of age (mean age: 42.3 years; 44% black race) were divided into the following groups based on office blood pressure (BP) measurements: (1) optimal BP (systolic BP [SBP] c , aortic arch pulse wave velocity, and minimum ascending aortic size were quantified using cardiovascular magnetic resonance. In multivariable-adjusted linear models, Z c was highest in the ISH group compared with the optimal BP, isolated diastolic hypertension, or systolic–diastolic hypertension groups (103.2±4.0 versus 68.3±2.1, 75.4±6.0, and 88.9±4.8 dyne*seconds/cm 5 , respectively; all P c –ISH association did not differ by race. Aortic pulse wave velocity was highest in the ISH group compared with the optimal BP, isolated diastolic hypertension, or systolic–diastolic hypertension groups (6.3±0.3 versus 4.3±0.1, 4.4±0.4 and 5.5±0.3 m/s, respectively; all P P >0.2). Results were similar in a subgroup of 1551 participants 18 to 49 years of age. In a multiracial population-based sample, we found evidence of a mismatch between proximal aortic stiffness and diameter in young and middle-aged adults with ISH.

Objectives This study aims to compare ethnic difference in proximal aortic pulse wave velocity (PWV) and characteristic impedance (Zc). Background Increased aortic stiffness is an independent predictor of target organ damage, incident hypertension, and all-cause mortality. However, previous studies have not directly assessed proximal aortic function in Blacks, the ethnic population with disproportionately high risk for incident hypertension and target organ complications. Methods We evaluated the multiethnic, population-based DHS (Dallas Heart Study) participants (N = 2,544, 54.2% women, 49.7% Black) who underwent cardiac magnetic resonance at 1.5-T. Aortic stiffness and Zc were determined from aortic arch PWV and lumen area measurements. Linear regression was used to evaluate ethnic differences in proximal aortic wall stiffness using aortic arch PWV and Zc as dependent variables with and without adjustment for traditional cardiovascular risk factors. Because cardiac output was significantly higher in Blacks compared to Whites and Hispanics, additional comparisons of PWV and Zc were performed after adjustment for cardiac output and peripheral vascular resistance. Results Compared with Whites, both Blacks and Hispanics had higher levels of aortic arch PWV (4.25, 95% confidence interval [CI]: 4.15 to 4.35 m/s, vs. 4.72, 95% CI: 4.64 to 4.81 m/s, vs. 4.48, 95% CI: 4.33 to 4.63 m/s, respectively, both p 5 , vs. 75.6, 95% CI: 74.0 to 77.2 dyne·s/cm 5 , vs. 70.1, 95% CI: 67.6 to 72.8 dyne·s/cm 5 , respectively, both p Conclusions In a multiethnic population-based-sample, Blacks and Hispanics had higher proximal aortic stiffness compared with Whites independent of blood pressure and relevant risk factors.

This chapter is an overview of methods and strategies to visualize and quantify anatomy and function of the heart and great vessels. Common causes of artifacts degrading image quality, and methods for mitigating such artifacts, are described.

To determine how to optimize the delivery of machine learning techniques in a clinical setting to detect intracranial hemorrhage (ICH) on non-contrast-enhanced CT images to radiologists to improve workflow.In this study, a commercially available machine learning algorithm that flags abnormal noncontrast CT examinations for ICH was implemented in a busy academic neuroradiology practice between September 2017 and March 2019. The algorithm was introduced in three phases:Notification with a widget or flagging the examination had no effect on queue-adjusted image wait (The approach used to present flags from artificial intelligence and machine learning algorithms to the radiologist can reduce image wait time and turnaround times.© RSNA, 2021See also the commentary by O'Connor and Bhalla in this issue.

To determine in a large multiethnic cohort the cardiovascular and genetic risk factors associated with smaller volume in the hippocampus, precuneus, and posterior cingulate, and their association with preclinical deficits in cognitive performance in patients younger and older than 50 years.The institutional review board approved the study and all participants provided written informed consent. Eligible for this study were 1629 participants (700 men and 929 women; mean age, 50.0 years ± 10.2 [standard deviation]) drawn from the population-based Dallas Heart Study who underwent laboratory and clinical analysis in an initial baseline visit and approximately 7 years later underwent brain magnetic resonance imaging with automated volumetry and cognitive assessment with the Montreal Cognitive Assessment (MoCA). Regression analysis showed associations between risk factors and segmental volumes, and associations between these volumes with cognitive performance in participants younger and older than 50 years.Lower hippocampal volume was associated with previous alcohol consumption (standardized estimate, -0.04; P = .039) and smoking (standardized estimate, -0.04; P = .048). Several risk factors correlated with lower total brain, posterior cingulate, and precuneus volumes. Higher total (standardized estimate, 0.06; P = .050), high-density lipoprotein (standardized estimate, 0.07; P = .003), and low-density lipoprotein (standardized estimate, 0.04; P = .037) cholesterol levels were associated with larger posterior cingulate volume, and higher triglyceride levels (standardized estimate, 0.06; P = .004) were associated with larger precuneus volume. Total MoCA score was associated with posterior cingulate volume (standardized estimate, 0.13; P = .001) in younger individuals and with hippocampal (standardized estimate, 0.06; P.05) and precuneus (standardized estimate, 0.08; P.023) volumes in older adults.Smaller volumes in specific brain regions considered to be early markers of dementia risk were associated with specific cardiovascular disease risk factors and cognitive deficits in a predominantly midlife multiethnic population-based sample. Additionally, the risk factors most associated with these brain volumes differed in participants younger and older than 50 years, as did the association between brain volume and MoCA score.

Previous studies have demonstrated a relationship between subclinical cardiac dysfunction and cognitive impairment in older adults. However, association between hemodynamic variables and cognitive function has not been determined in an ethnically diverse middle-aged population. Furthermore, previous

Background and purpose Vascular risk factors have been associated with decreased cerebral blood flow (CBF) but this is etiologically nonspecific and may result from vascular insufficiency or a response to decreased brain metabolic activity. We apply new MRI techniques to measure oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen consumption (CMRO2), hypothesizing that decreased CBF related to these vascular risk factors will be associated with increased OEF, confirming a primary vascular insufficiency. Methods 3T MRI was obtained on 70 community-based participants in this IRB-approved study with informed consent, with previous assessment of systolic blood pressure, hypertension medication, elevated serum triglycerides, low serum HDL, and diabetes mellitus. CBF was measured using phase contrast adjusted for brain volume (ml/100 g/min), OEF (%) was obtained from T2-Relaxation-Under-Spin-Tagging (TRUST), and CMRO2 (μmol/100 g/min) was derived using the Fick principle. Stepwise linear regression identified optimal predictors of CBF with age, sex, and hematocrit included for adjustment. This predictive model was then evaluated against OEF and CMRO2. Results Hypertriglyceridemia was associated with low CBF and high OEF. High systolic blood pressure was associated with high CBF and low OEF, which was primarily attributable to those with pressures above 160 mmHg. Neither risk factor was associated with significant differences in cerebral metabolic rate. Conclusion Low CBF related to hypertriglyceridemia was accompanied by high OEF with no significant difference in CMRO2, confirming subclinical vascular insufficiency. High CBF related to high systolic blood pressure likely reflected limitations of autoregulation at higher blood pressures.

Objective The aim of this study was to determine if differences in coronary endothelial function are observed between asymptomatic women with type 2 diabetes mellitus (DM) and control subjects using coronary phase contrast flow velocity magnetic resonance imaging in response to cold pressor stress, an established endothelium-dependent vasodilatory stress. Methods Phase contrast flow velocity imaging of the right coronary artery was performed in 7 asymptomatic premenopausal women with DM and 8 healthy female participants in response to the cold pressor test at 3 T. Results There was no significant difference in percent increase in coronary flow velocity from rest to peak flow velocity between DM and control subjects (32% ± 22% vs 46% ± 17%; P = 0.11). However, percent increase in coronary flow velocity was lower in DM than in control subjects (−3% ± 14% vs 31% ± 30%; P = 0.01) during the second minute of cold pressor stress, when endothelial-mediated vasodilation should occur. Conclusions Asymptomatic women with DM demonstrate reduced coronary flow velocity during the second minute of cold pressor stress, indicating coronary endothelial dysfunction.

ObjectivesThis study was performed to determine whether a 4-tiered classification of left ventricular hypertrophy (LVH) defines subgroups in the general population that are at variable risks of adverse cardiovascular (CV) outcomes.BackgroundWe recently proposed a 4-tiered classification of LVH where eccentric LVH is subdivided into “indeterminate hypertrophy” and “dilated hypertrophy” and concentric LVH into “thick hypertrophy” and “both thick and dilated hypertrophy,” based on the presence of increased left ventricular (LV) end-diastolic volume.MethodsParticipants from the Dallas Heart study who underwent cardiac magnetic resonance and did not have LV dysfunction or a history of heart failure (HF) (n = 2,458) were followed for a median of 9 years for the primary outcome of HF or CV death. Multivariable Cox proportional hazards models were used to adjust for age, sex, African-American race, hypertension, diabetes, and history of CV disease.ResultsIn the cohort, 70% had no LVH, 404 (16%) had indeterminate hypertrophy, 30 (1%) had dilated hypertrophy, 289 (12%) had thick hypertrophy, and 7 (0.2%) had both thick and dilated hypertrophy. The cumulative incidence of HF or CV death was 2% with no LVH, 1.7% with indeterminate, 16.7% with dilated, 11.1% with thick, and 42.9% with both thick and dilated hypertrophy (log-rank p < 0.0001). Compared with participants without LVH, those with dilated (hazard ratio [HR]: 7.3; 95% confidence interval [CI]: 2.8 to 18.8), thick (HR: 2.4; 95% CI: 1.4 to 4.0), and both thick and dilated (HR: 5.8; 95% CI: 1.7 to 19.5) hypertrophy remained at increased risk for HF or CV death after multivariable adjustment, whereas the group with indeterminate hypertrophy was not (HR: 0.9; 95% CI: 0.4 to 2.2).ConclusionsIn the general population, the 4-tiered classification system for LVH stratified LVH into subgroups with differential risk of adverse CV outcomes.

To demonstrate the initial feasibility of non-contrast quantitative pulmonary perfusion imaging at 3T using flow alternating inversion recovery (FAIR), and to evaluate the intra-session and inter-session reliability of FAIR measurements at 3T.Nine healthy volunteers were imaged using our own implementation of FAIR pulse sequence at 3T. Quantitative FAIR perfusion, both with and without larger pulmonary vessels, was correlated with global phase contrast (PC) measured blood flow in the right pulmonary artery (RPA). The same volunteers were also imaged with SPECT perfusion using technetium-99m-macroaggregated albumin and relative dispersion (RD) was assessed between FAIR and SPECT perfusion. Four additional healthy volunteers were evaluated for FAIR repeatability, using intra-class correlation coefficient (ICC) and Bland-Altman analysis. p0.05 was considered statistically significant.FAIR perfusion across all subjects was 858±605mL/100g/min (with vessels) and 629±294mL/100g/min (without vessels) and correlated significantly with the PC measured blood flow in the RPA (r=0.62, p0.01 with vessels; r=0.73, p0.001 without vessels). The median RD of FAIR perfusion across all subjects was 0.73 (with vessels) and 0.49 (without vessels), compared against 0.23 with SPECT perfusion. The intra/inter-session ICC of FAIR perfusion with vessels was 0.95/0.59 and improved to 0.96/0.72, when vessels were removed.Non-contrast quantitative pulmonary perfusion imaging using FAIR is feasible at 3T. This may serve as a reliable method to assess regional lung perfusion at 3T to characterize and monitor treatment response in chronic lung disease without the concerns of repeated exposure to ionizing radiation or the accumulation of exogenous contrast agent.

Background Obesity may increase heart failure risk through cardiac remodeling. Cross‐sectional associations between adiposity and cardiac structure and function have been elucidated, but the impact of longitudinal changes in adiposity on cardiac remodeling is less well understood. Methods and Results Participants in the Dallas Heart Study without cardiovascular disease or left ventricular dysfunction underwent assessment of body weight, anthropometrics, and cardiac magnetic resonance imaging at baseline and 7 years later. Associations between changes in indices of generalized and central adiposity with changes in left ventricular mass, volume, mass/volume ratio (concentricity), wall thickness, and ejection fraction were assessed using multivariable linear regression. The study cohort (n=1262) mean age was 44 years with 57% women, 44% black, and 36% obese participants. At follow‐up, 41% had ≥5% weight gain, and 15% had ≥5% weight loss. Greater weight gain was associated with younger age, lower risk factor burden, and lower body mass index at baseline. In multivariable models adjusting for age, sex, race, comorbid conditions at baseline and follow‐up, baseline adiposity, and cardiac measurement, increasing weight was associated with increases in left ventricular mass (β=0.10, P P P =0.002), with modest effects on end‐diastolic volume (β=0.04, P =0.044) and ejection fraction (β=0.05, P =0.046). Similar results were seen with other adiposity indices. Conclusions Concentric left ventricular remodeling is the predominant phenotype linked to increasing adiposity in middle age. Our findings support the importance of weight management to prevent secular changes in adiposity, concentric remodeling, and eventual heart failure over time.

Background In the conventional paradigm of the progression of left ventricular hypertrophy, a thick-walled left ventricle (LV) ultimately transitions to a dilated cardiomyopathy. There are scant data in humans demonstrating whether this transition occurs commonly without an interval myocardial infarction. Methods and Results Participants (n=1282) from the Dallas Heart Study underwent serial cardiac magnetic resonance ≈7 years apart. Those with interval cardiovascular events and a dilated LV (increased LV end-diastolic volume [EDV] indexed to body surface area) at baseline were excluded. Multivariable linear regression models tested the association of concentric hypertrophy (increased LV mass and LV mass/volume 0.67 ) with change in LVEDV. The study cohort had a median age of 44 years, 57% women, 43% black, and 11% (n=142) baseline concentric hypertrophy. The change in LVEDV in those with versus without concentric hypertrophy was 1 mL (−9 to 12) versus −2 mL (−11 to 7), respectively, P P ≤0.01). The progression to a dilated LV was uncommon (2%, n=25). Conclusions In the absence of interval myocardial infarction, concentric hypertrophy was associated with a small, but significantly greater, increase in LVEDV after 7-year follow-up. However, the degree of LV enlargement was minimal, and few participants developed a dilated LV. These data suggest that if concentric hypertrophy does progress to a dilated cardiomyopathy, such a transition would occur over a much longer timeframe (eg, decades) and may be less common than previously thought. Clinical Trial Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT00344903.

Elevated urinary albumin to creatinine ratio (ACR) and white matter hyperintensity (WMH) volume seen on brain MRI are measures of microvascular disease which may have shared susceptibility to metabolic and vascular insults. We hypothesized that elevated ACR may be useful as inexpensive biomarker to predict presence of cerebral microvascular disease. We assessed the association between ACR at study entry and subsequent WMH volume. We evaluated pulse pressure, mean arterial pressure, hypertension duration, waist circumference, fasting glucose, glomerular filtration rate (GFR) and C-reactive protein (CRP) as potential mediators and diabetes as a moderator of the association between ACR and WMH. Data were collected at study entry and at follow-up approximately 7 years later in a multiethnic population sample of 1281 participants (mean age = 51, SD = 9.5) from Dallas County. Overall, ACR differences were only marginally (p = 0.05) associated with subsequent WMH. In mediator analysis, however, ACR differences related specifically to arterial pulsatility(β = 0.010, bootstrap 95% Confidence Interval (CI): 0.002 to 0.021) and waist circumference (β = -0.004, bootstrap 95% CI: -0.011 to -0.001) were significantly associated with WMH. ACR differences related to serum glucose and CRP were not associated with WMH. ACR evaluated at the same time as WMH had a higher level of significance (p0.001) indicating greater utility in predicting current cerebrovascular insults.

IMPORTANCE: Compared with white individuals, black individuals have increased electrocardiographic voltage and an increased prevalence of concentric left ventricular (LV) hypertrophy. Whether environmental or genetic factors lead to these racial differences is unknown. OBJECTIVE: To determine whether proportion of genetically determined African ancestry among self-reported black individuals is associated with increased electrocardiographic voltage and concentric LV hypertrophy (LVH). DESIGN, SETTING, AND PARTICIPANTS: The Dallas Heart Study is a probability-based cohort study of English- or Spanish-speaking Dallas County, Texas, residents, with deliberate oversampling of black individuals. Participants underwent extensive phenotyping, which included electrocardiography (ECG), cardiac magnetic resonance imaging (CMR), and dual-energy radiography absorptiometry (DEXA) at a single center. Participants aged 18 to 65 years who enrolled in the Dallas Heart Study between July 2000 and December 2002, self-identified as black (n = 1251) or white (n = 826), and had ECG, CMR, and DEXA data were included in this analysis. Data were analyzed from June 2017 to September 2018. EXPOSURES: Proportion of African ancestry. MAIN OUTCOMES AND MEASURES: Electrocardiographic voltage (12-lead and 9-lead) and markers of concentric LVH as assessed by CMR (LV concentricity(0.67) [LV mass/end-diastolic volume(0.67)], LV wall thickness [LVWT], and prevalent LVH [defined by LV mass/height(2.7)]). RESULTS: Of the 2077 participants included in the study, 1138 (54.8%) were women, and the mean (SD) age was 45.2 (9.9) years. Black race and African ancestry were individually associated with increased ECG voltage, LV concentricity(0.67), LVWT, and prevalent LVH in multivariable analyses adjusting for age, sex, systolic blood pressure, antihypertensive medication use, and body composition. When African ancestry and black race were entered together into multivariable models, African ancestry but not black race remained associated with ECG voltage, LVWT, LV concentricity(0.67), and prevalent LVH. Among black participants, African ancestry remained associated with these 4 phenotypes (12-lead voltage: β, 0.05; P = .04; LVWT: β, 0.05; P = .02; LV concentricty(0.67): β, 0.05; P = .045; prevalent LVH: odds ratio, 1.2; 95% CI, 1.03-1.4; P = .02). CONCLUSIONS AND RELEVANCE: Genetically determined African ancestry was associated with electrocardiographic voltage, measures of concentric LV remodeling, and prevalent LVH. These data support a genetic basis related to African ancestry for the increased prevalence of these cardiovascular traits in black individuals.

Hippocampal atrophy is reported in major depressive disorder (MDD). However, sample sizes were generally modest, and participant characteristics, including age, differed between studies. This study used a community sample to examine relationships between current depressive symptom severity and hippocampal volume across the adult lifespan. A total of 1936 adults with magnetic resonance images of the brain and Quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR) scores were included. Brain volumes were quantified using the FSL program. Multiple linear regressions were performed using left, right, and total hippocampal volume as criterion variables, and predictor variables of QIDS-SR total, total brain volume, age, gender, education, psychotropic medications, alcohol use, and race/ethnicity. Post hoc analyses were conducted in participants with QIDS-SR scores ⩾11 (moderate or greater depressive symptom severity) and

To determine the value of two abdominal aortic atherosclerosis measurements at magnetic resonance (MR) imaging for predicting future cardiovascular events.This study was approved by the institutional review board and complied with HIPAA regulations. The study consisted of 2122 participants from the multiethnic, population-based Dallas Heart Study who underwent abdominal aortic MR imaging at 1.5 T. Aortic atherosclerosis was measured by quantifying mean aortic wall thickness (MAWT) and aortic plaque burden. Participants were monitored for cardiovascular death, nonfatal cardiac events, and nonfatal extracardiac vascular events over a mean period of 7.8 years ± 1.5 (standard deviation [SD]). Cox proportional hazards regression was used to assess independent associations of aortic atherosclerosis and cardiovascular events.Increasing MAWT was positively associated with male sex (odds ratio, 3.66; P.0001), current smoking (odds ratio, 2.53; P.0001), 10-year increase in age (odds ratio, 2.24; P.0001), and hypertension (odds ratio, 1.66; P = .0001). A total of 143 participants (6.7%) experienced a cardiovascular event. MAWT conferred an increased risk for composite events (hazard ratio, 1.28 per 1 SD; P = .001). Aortic plaque was not associated with increased risk for composite events. Increasing MAWT and aortic plaque burden both conferred an increased risk for nonfatal extracardiac events (hazard ratio of 1.52 per 1 SD [P.001] and hazard ratio of 1.46 per 1 SD [P = .03], respectively).MR imaging measures of aortic atherosclerosis are predictive of future adverse cardiovascular events.

Purpose To assess if fully automated localization of the aorta can be achieved using phase contrast (PC) MR images. Materials and Methods PC cardiac-gated MR images were obtained as part of a large population-based study. A fully automated process using the Hough transform was developed to localize the ascending aorta (AAo) and descending aorta (DAo). The study was designed to validate this technique by determining: (i) its performance in localizing the AAo and DAo; (ii) its accuracy in generating AAo flow volume and DAo flow volume; and (iii) its robustness on studies with pathological abnormalities or imaging artifacts. Results The algorithm was applied successfully on 1884 participants. In the randomly selected 50-study validation set, linear regression shows an excellent correlation between the automated (A) and manual (M) methods for AAo flow (r = 0.99) and DAo flow (r = 0.99). Bland-Altman difference analysis demonstrates strong agreement with minimal bias for: AAo flow (mean difference [A-M] = 0.47 ± 2.53 mL), and DAo flow (mean difference [A-M] = 1.74 ± 2.47 mL). Conclusion A robust fully automated tool to localize the aorta and provide flow volume measurements on phase contrast MRI was validated on a large population-based study. J. Magn. Reson. Imaging 2014;40:221–228. © 2013 Wiley Periodicals, Inc.

To evaluate the relationship between pulse wave velocity (PWV) from the aortic arch and subsequent cerebral microvascular disease independent of other baseline cardiovascular risk factors among the participants in the multiethnic Dallas Heart Study.Each subject gave written consent to participate in this HIPAA-compliant, institutional review board-approved prospective study. Aortic arch PWV was measured with phase-contrast magnetic resonance (MR) imaging in a population sample (n = 1270) drawn from the probability-based Dallas Heart Study. Seven years later, the volume of white matter hyperintensities (WMHs) was determined from brain MR images. Linear regression was conducted with aortic arch PWV, 15 other cardiovascular risk factors, and age, sex, and ethnicity included as predictors of WMH. The authors implemented a smoothly clipped absolute deviation-penalized variable selection method to evaluate an optimal predictive risk factor model.Aortic arch PWV helped predict WMH volume independent of the other demographic and cardiovascular risk factors (regression coefficient: 0.29; standard error: 0.06; 95% confidence interval: 0.17, 0.42; P.0001). The optimal predictor variables of subsequent WMH volume adjusted for sex and ethnicity included aortic arch PWV, age, systolic blood pressure, hypertension treatment, and congestive heart failure. The authors estimated that a 1% increase in aortic arch PWV (in meters per second) is related to a 0.3% increase in subsequent WMH volume (in milliliters) when all other variables in the model are held constant.Aortic arch PWV measured with phase-contrast MR imaging is a highly significant independent predictor of subsequent WMH volume, with a higher standardized effect than any other cardiovascular risk factor assessed except for age. In an optimal predictive model of subsequent WMH burden, aortic arch PWV provides a distinct contribution along with systolic blood pressure, hypertension treatment, congestive heart failure, and age.

BACKGROUND AND PURPOSE: Asymmetry of the hippocampus is regarded as an important clinical finding, but limited data on hippocampal asymmetry are available for the general population. Here we present hippocampal asymmetry data from the Dallas Heart Study determined by automated methods and its relationship to age, sex, and ethnicity. MATERIALS AND METHODS: 3D magnetization-prepared rapid acquisition of gradient echo MR imaging was performed in 2082 DHS-2 participants. The MR images were analyzed by using 2 standard automated brain-segmentation programs, FSL-FIRST and FreeSurfer. Individuals with imaging errors, self-reported stroke, or major structural abnormalities were excluded. Statistical analyses were performed to determine the significance of the findings across age, sex, and ethnicity. RESULTS: At the 90th percentile, FSL-FIRST demonstrated hippocampal asymmetry of 9.8% (95% CI, 9.3%–10.5%). The 90th percentile of hippocampal asymmetry, measured by the difference in right and left hippocampi volume and the larger hippocampus, was 17.9% (95% CI, 17.0%–19.1%). Hippocampal asymmetry increases with age (P = .0216), men have greater asymmetry than women as shown by FSL-FIRST (P = .0036), but ethnicity is not significantly correlated with asymmetry. To confirm these findings, we used FreeSurfer. FreeSurfer showed asymmetry of 4.4% (95% CI, 4.3%–4.7%) normalized to total volume and 8.5% (95% CI, 8.3%–9.0%) normalized by difference/larger hippocampus. FreeSurfer also showed that hippocampal asymmetry increases with age (P = .0024) and that men had greater asymmetry than women (P = .03). CONCLUSIONS: There is a significant degree of hippocampal asymmetry in the population. The data provided will aid in the research, diagnosis, and treatment of temporal lobe epilepsy and other neurologic disease.

Asthma is associated with an increased risk of mild cognitive impairment and dementia. Depression and oral corticosteroid use are associated with atrophy of the hippocampus and are common in asthma. However, minimal neuroimaging data are available in asthma patients.We conducted a retrospective analysis of 1,287 adult participants from the Dallas Heart Study, an epidemiological sample of Dallas County residents. Study outcome variables were hippocampal volumes measured by FreeSurfer. ANOVA was used to examine a gender difference in hippocampal volumes. General Linear Models (GLM) were conducted to examine asthma diagnosis association with hippocampal volumes.The prevalence rate of asthma among our study sample was 10.8% with 9.6% in males and 11.7% in females. After controlling for demographic characteristics, participants with asthma had significantly smaller total, right, and left hippocampal volumes than those without asthma. The association of asthma with smaller hippocampal volume was significant among males but not among females.Hippocampal volume in a large and diverse sample of adults was significantly smaller in people with asthma as compared to those without asthma. These findings suggest that asthma may be associated with structural brain differences. Thus, medical illnesses without obvious direct neurodegenerative or even vascular involvement can be associated with brain changes. Because the hippocampus is a brain region involved in memory formation, these findings may have implications for treatment adherence that could have important implications for asthma treatment. Study limitations are the reliance on a self-reported asthma diagnosis and lack of additional asthma clinical information.

BACKGROUND AND PURPOSE: Age-related white matter hyperintensities have prognostic implications, but no accepted clinical standard exists for their assessment. We propose a simple objective visual rating system by using 3T brain MR imaging. MATERIALS AND METHODS: MR imaging from 559 participants was processed by using an automated method to determine WMH volumes and evaluated with a new visual rating scale based on the single largest WMH lesion diameter regardless of location. The reproducibility of the visual system was assessed. The association of WMH visual scores and automated volumes was then compared with cognitive scores from the Montreal Cognitive Assessment, which was available for 510 participants. RESULTS: Inter-reader reproducibility was good for subsamples with both high (n = 52) and low (n = 40) prevalence of large automated WMH volumes (agreement of 67% and 87.5%, κ = 0.71 and 0.76, respectively). Correlation between increased WMH and cognitive deficit measurements was equal for our visual ratings and automated volumes (Spearman ρ = 0.118 and 0.109; P values = 0.008 and 0.014, respectively). The visual scale retained a significant association with MoCA score after adjusting for age, sex, and education (standardized β = −0.087, P = .042). CONCLUSIONS: We propose a simple visual WMH scoring system suitable for use as a baseline evaluation in clinical practice.

Objectives Electron beam computed tomography (EBCT) for coronary artery calcification can potentially evaluate liver fat, another marker of cardiovascular risk. We compared quantitative estimates of hepatic steatosis measured by EBCT with those obtained by a well-validated, accurate-measure, magnetic resonance spectroscopy (1H MRS). Methods EBCT and 1H MRS were performed in 2159 subjects from the Dallas Heart Study. Forty subjects were randomly selected from each of 5 subgroups of liver fat percent by 1H MRS (n = 200). EBCT average liver attenuation (HU) was determined in a 1- to 2-cm circular region of interest over the liver lobes. Pearson correlation coefficients were calculated. Using a previously defined 1H MRS hepatic steatosis cut point (>5.5%), an optimized EBCT liver attenuation cut point was determined by receiver operating characteristic analysis. Results 1H MRS liver fat content and EBCT average right lobe liver attenuation were moderately negatively correlated ( r = −0.64, P < 0.0001) in all subjects and in those with 1H MRS hepatic steatosis ( r = −0.71, P < 0.0001). This correlation did not improve with attenuation correction of the EBCT data using a standard calcium phantom or statistical transformation. Using an optimized receiver operating characteristic EBCT cut point (64.5 HU), sensitivity was 78% and specificity was 72% for detecting 1H MRS hepatic steatosis, with a high false negative rate. Risk factors for hepatic steatosis (obesity, diabetes mellitus, insulin resistance, metabolic syndrome) were more strongly correlated with 1H MRS than EBCT liver fat measures. Conclusions Liver attenuation on EBCT acquired for coronary artery calcification screening correlates modestly with 1H MRS measures of liver fat content, with a high false negative rate.

Each year, approximately 6 million U.S. citizens are evaluated for acute chest pain syndromes (ACPSs) and billions of dollars of resources are utilized.1,2 While a large part of this cost is attributable to the expense of hospitalization at the time of index evaluation, 60% of those hospitalized are determined not to have coronary artery disease (CAD) as the underlying factor.3–5 Patients are generally hospitalized for continued evaluation and monitored observation because providers may not feel comfortable in excluding CAD or a myocardial infarction (MI) with the current technologies available to them. As such, the inability to rapidly diagnose MI or underlying CAD as the cause of ACPSs has serious public health and economic consequences. Moreover, considering a reported rate of 2% to 8% for unrecognized acute MI, the risk of malpractice litigation further augments the rate of hospitalization and its associated resource utilization.6 The current emergency department (ED) standard care (SC) for risk stratification of ACPS patients in many institutions includes clinical data, serial electrocardiograms (ECGs), and cardiac biomarkers1,7–9 (Figure 1). The addition of exercise stress testing and echocardiograms to this regimen has been studied, but due to the suboptimal sensitivity of exercise stress testing,10–13 and the significant cost of adding nuclear perfusion studies, neither of these technologies have been adopted routinely in many institutions.11,12 Consequently, the current process for excluding CAD has remained time-consuming and relatively expensive.6,7,14–23 Figure 1 SC risk stratification algorithm for patients presenting with acute chest pain to the emergency department. *Additional testing includes exercise stress test, nuclear perfusion testing, stress echocardiography, transesophageal echocardiography, and/or ... In 2009, researchers demonstrated that coronary computerized tomography angiogram (CCTA) technology (Figure 2) is safe and also quite feasible to perform in the ED chest pain population.12,24,25 Furthermore, computer simulation models including CCTA in chest pain patient evaluation demonstrated a marginal association with improved quality-adjusted longevity, raised cost-effectiveness ratios, and illustrated the need for controlled trials to be executed to guide policy.26,27 Figure 2 Axial image obtained using the 64-slice Toshiba CT scanner for this SC + CCTA versus SC-only resource utilization trial at the level of the aortic root showing the origins of the right and left coronary arteries. CCTA = coronary computerized tomography ... To date, there have been no published randomized controlled clinical trials addressing the primary aim of quantifying the resource utilization of adding CCTA to the current SC in the ED evaluation of ACPS patients. We posited that adding a CCTA to the SC (SC + CCTA) in patients with low- to intermediate-risk ACPS would be associated with lower total resource utilization in the 90-day follow-up period after the index ED visit. Accordingly we performed a prospective randomized controlled trial examining the resource utilization with and without the addition of CCTA to the risk stratification of ACPS patients presenting to the ED.

Background and Purpose— The natural history of white matter hyperintensity (WMH) progression resulting from normal aging versus comorbid vascular insults remains unclear. Therefore we investigated age-related differences in WMH volumes among a group with comorbid hypertension, abnormal body mass index, and diabetes mellitus to a normal aging group drawn from the same population lacking any of these comorbidities. Methods— WMH volumes were acquired using 3T MRI for 2011 Dallas Heart Study participants. The slope of the WMH versus age regression was compared between normal and comorbidity groups Results— Aging was linearly associated with greater log WMH volume for both normal ( P =0.02) and comorbidity ( P P P =0.173). The between-group difference in slope of expected WMH for age was significantly greater in the comorbidity groups ≥50 years of age ( P =0.0008) but not P =0.752). Conclusions— After 50 years of age, but not before, comorbid hypertension, obesity, and diabetes mellitus were associated with significantly larger WMH volumes for age compared with a normal aging group lacking these conditions. These results support the assertion that age-related differences in WMH volumes are significantly increased in the presence of comorbidities, but the effect is only detectable after 50 years of age.