The Functional Connectome and Long-Term Symptom Presentation Associated With Mild Traumatic Brain Injury and Blast Exposure in Combat Veterans.

Mild traumatic brain injury (TBI) sustained in a deployment environment (deployment TBI) can be associated with increased severity of long-term symptom presentation, despite the general expectation of full recovery from a single mild TBI. The heterogeneity in the effects of deployment TBI on the brain can be difficult for a case-control design to capture. The functional connectome of the brain is an approach robust to heterogeneity that allows global measurement of effects using a common set of outcomes.

Quantifying Cardiothoracic Variation with Posture and Respiration to Inform Cardiac Device Design.

Purpose: With extravascular implantable cardioverter defibrillator leads placed beneath the sternum, it is important to quantify heart motion relative to the rib cage with postural changes and respiration.

Methods: MRI scans from five males and five females were collected in upright and supine postures at end inspiration [n = 10 each]. Left and right decubitus [n = 8 each] and prone [n = 5] MRIs at end inspiration and supine MRIs at end expiration [n = 5] were collected on a subset.

Effect of Intensive Blood Pressure Control on Aortic Stiffness in the SPRINT-HEART.

[Figure: see text].

Semiautomatic morphometric analysis of skeletal muscle obtained by needle biopsy in older adults.

Analysis of skeletal muscle mass and composition is essential for studying the biology of age-related sarcopenia, loss of muscle mass, and function. Muscle immunohistochemistry (IHC) allows for simultaneous visualization of morphological characteristics and determination of fiber type composition. The information gleaned from myosin heavy chain (MHC) isoform, and morphological measurements offer a more complete assessment of muscle health and properties than classical techniques such as SDS-PAGE and ATPase immunostaining; however, IHC quantification is a time-consuming and tedious method.

Effect of Intensive Blood Pressure Reduction on Left Ventricular Mass, Structure, Function, and Fibrosis in the SPRINT-HEART.

In observational studies, left ventricular mass (LVM) and structure are strong predictors of mortality and cardiovascular events. However, the effect of hypertension treatment on LVM reduction and its relation to subsequent outcomes is unclear, particularly at lower blood pressure (BP) targets. In an ancillary study of SPRINT (Systolic Blood Pressure Intervention Trial), where participants were randomly assigned to intensive BP control (target systolic BP target <120 mm Hg) versus standard BP control (<140 mm Hg), cardiac magnetic resonance imaging was performed at baseline and 18-month follow-up to measure: LVM, volumes, ejection fraction, and native T1 mapping for myocardial fibrosis.

Beta-Blocker Use Is Associated with Higher Renal Tissue Oxygenation in Hypertensive Patients Suspected of Renal Artery Stenosis.

Background: Chronic renal hypoxia influences the progression of chronic kidney disease (CKD). Blood oxygen level-dependent (BOLD) magnetic resonance (MR) is a noninvasive tool for the assessment of renal oxygenation. The impact of beta-blockers on renal hemodynamics and oxygenation is not completely understood.

Anthracycline-Associated T1 Mapping Characteristics Are Elevated Independent of the Presence of Cardiovascular Comorbidities in Cancer Survivors.

Background: Cardiovascular magnetic resonance T1 mapping characteristics are elevated in adult cancer survivors; however, it remains unknown whether these elevations are related to age or presence of coincident cardiovascular comorbidities.

Methods And Results: We performed blinded cardiovascular magnetic resonance analyses of left ventricular T1 and extracellular volume (ECV) fraction in 327 individuals (65% women, aged 64±12 years). Thirty-seven individuals had breast cancer or a hematologic malignancy but had not yet initiated their treatment, and 54 cancer survivors who received either anthracycline-based (n=37) or nonanthracycline-based (n=17) chemotherapy 2.

Adiposity Is Associated with Gender-Specific Reductions in Left Ventricular Myocardial Perfusion during Dobutamine Stress.

Background: Obesity and visceral adiposity are increasingly recognized risk factors for cardiovascular disease. Visceral fat may reduce myocardial perfusion by impairing vascular endothelial function. Women experience more anginal symptoms compared to men despite less severe coronary artery stenosis, as assessed by angiography.

Prognostic utility of cardiovascular magnetic resonance upright maximal treadmill exercise testing.

Background: Left ventricular wall motion abnormalities (LVWMA) observed during cardiovascular magnetic resonance (CMR) pharmacologic stress testing can be used to determine cardiac prognosis, but currently, information regarding the prognostic utility of upright maximal treadmill induced LVWMA is unknown. Our objective was to determine the prognostic utility of upright maximal treadmill exercise stress CMR.

Methods: One hundred and fifteen (115) men and women with known or suspected coronary arteriosclerosis and an appropriate indication for cardiovascular (CV) imaging to supplement ST segment stress testing underwent an upright treadmill exercise CMR stress test in which LVWMA were identified before and immediately after exercise.

A Method to Quantify Supine to Prone Thoracoabdominal Deformation and Organ Migration in a Set of Healthy Young Adults.

Medical image data used for the development of computational human body models are often retrospectively acquired, and researchers are unlikely to encounter scans of healthy individuals in specific postures. We prospectively acquired scans in both prone and supine postures from 22 healthy young adults; M:F 1:1, with age, height, and weight of 28.8±7.

Chronic statin administration may attenuate early anthracycline-associated declines in left ventricular ejection function.

Background: Recent studies have shown an association between statin therapy and a reduced risk of heart failure among breast cancer survivors. Our goal was to evaluate whether statin therapy for prevention of cardiovascular (CV) disease would ameliorate declines in the left ventricular ejection fraction (LVEF) that is often observed during anthracycline-based chemotherapy (Anth-bC).

Methods: There were 51 participants (33 women and 18 men, aged 48 ± 2 years).

Longitudinal assessment of concurrent changes in left ventricular ejection fraction and left ventricular myocardial tissue characteristics after administration of cardiotoxic chemotherapies using T1-weighted and T2-weighted cardiovascular magnetic resonance.

Background: In a murine anthracycline-related cardiotoxicity model, increases in cardiovascular magnetic resonance myocardial contrast-enhanced T1-weighted signal intensity are associated with myocellular injury and decreases with left ventricular ejection fraction. We sought to determine whether T1- and T2-weighted measures of signal intensity associate with decreases in left ventricular ejection fraction in human subjects receiving potentially cardiotoxic chemotherapy.

Methods And Results: In 65 individuals with breast cancer (n=51) or a hematologic malignancy (n=14), we measured left ventricular volumes, ejection fraction, and contrast-enhanced T1-weighted and T2-weighted signal intensity before and 3 months after initiating potentially cardiotoxic chemotherapy using blinded, unpaired analysis of cardiovascular magnetic resonance images.

Increased cardiovascular stiffness and impaired age-related functional status.

Our objective was to determine if increased cardiovascular (CV) stiffness is associated with disability in middle-aged and older adults at risk for congestive heart failure. CV stiffness (brachial pulse pressure/left ventricular stroke volume indexed to body surface area) and total disability (the summed assessment of activities of daily living, mobility, and instrumental activities of daily living) were measured in 445 individuals. A subset of 109 randomly selected individuals also underwent physical function testing.

Chronic diuretic therapy attenuates renal BOLD magnetic resonance response to an acute furosemide stimulus.

Background: Blood Oxygen Level Dependent (BOLD) magnetic resonance (MR) is a novel imaging tool that detects changes in tissue oxygenation. Increases in renal oxygenation in response to a standard 20 mg intravenous furosemide stimulus have been evaluated to assess kidney viability in patients with renal artery stenosis (RAS). The effect of prior exposure to furosemide on the ability of BOLD MR techniques to evaluate renal function is unknown.

Stress CMR reduces revascularization, hospital readmission, and recurrent cardiac testing in intermediate-risk patients with acute chest pain.

Objectives: The aim of this study was to determine the effect of stress cardiac magnetic resonance (CMR) imaging in an observation unit (OU) on revascularization, hospital readmission, and recurrent cardiac testing in intermediate-risk patients with possible acute coronary syndromes (ACS).

Background: Intermediate-risk patients commonly undergo hospital admission with high rates of coronary revascularization. It is unknown whether OU-based care with CMR is a more efficient alternative.

Aging reduces left atrial performance during adrenergic stress in middle aged and older patients.

Background: During adrenergic stress, the influence of age on left atrial (LA) function is unknown. We hypothesized that aging decreases LA total emptying fraction (LAEF) during maximal adrenergic stress. The aim of the study was to determine the influence of aging on LA function during adrenergic stress in middle aged and older patients.

Provider-directed imaging stress testing reduces health care expenditures in lower-risk chest pain patients presenting to the emergency department.

Background: Among intermediate- to high-risk patients with chest pain, we have shown that a cardiac magnetic resonance (CMR) stress test strategy implemented in an observation unit (OU) reduces 1-year health care costs compared with inpatient care. In this study, we compare 2 OU strategies to determine among lower-risk patients if a mandatory CMR stress test strategy was more effective than a physicians' ability to select a stress test modality.

Methods And Results: On emergency department arrival and referral to the OU for management of low- to intermediate-risk chest pain, 120 individuals were randomly assigned to receive (1) a CMR stress imaging test (n=60) or (2) a provider-selected stress test (n=60: stress echo [62%], CMR [32%], cardiac catheterization [3%], nuclear [2%], and coronary CT [2%]).

Simultaneous measurement of left and right ventricular volumes and ejection fraction during dobutamine stress cardiovascular magnetic resonance.

Objective: During cardiovascular stress, if right ventricular (RV) stroke volume exceeds left ventricular (LV) stroke volume, then a large volume of blood is displaced into the pulmonary circulation that may precipitate pulmonary edema. We sought to determine the metrics by which cardiovascular magnetic resonance (CMR) could measure simultaneous displacement of RV and LV stroke volumes during dobutamine stress.

Methods: Thirteen healthy subjects (5 women) aged 53 ± 10 years without medical conditions and taking no medications underwent 2 CMR examinations at 1.

Stress CMR imaging observation unit in the emergency department reduces 1-year medical care costs in patients with acute chest pain: a randomized study for comparison with inpatient care.

Objectives: This study sought to compare the direct cost of medical care and clinical events during the first year after patients with intermediate risk acute chest pain were randomized to stress cardiac magnetic resonance (CMR) observation unit (OU) testing versus inpatient care.

Background: In a recent study, randomization to OU-CMR reduced median index hospitalization cost compared with the cost of inpatient care in patients presenting to the emergency department with intermediate risk acute chest pain.

Methods: Emergency department patients with intermediate risk chest pain were randomized to OU-CMR (OU care, cardiac markers, stress CMR) or inpatient care (admission, care per admitting provider).

Intraperitoneal fat is associated with thickening of the thoracic aorta in individuals at high risk for cardiovascular events.

Increased intraperitoneal (IP) fat is associated with increased cardiovascular (CV) risk, but mechanisms for this increase in risk are not completely established. We performed this study to assess whether IP fat is associated with ascending aortic wall thickness (AOWT), a risk factor for CV events. Four hundred and forty-one consecutive participants, aged 55-85 years, with risk factors for CV events underwent magnetic resonance measures of AOWT and abdominal fat (subcutaneous (SC) fat + IP fat).

Impaired left ventricular stroke volume reserve during clinical dobutamine stress predicts future episodes of pulmonary edema.

Objectives: The purpose of this study was to determine whether dobutamine-induced abnormal stress changes in left ventricular stroke volume (LVSV) and aortic stiffness predict future pulmonary edema.

Background: Increased aortic stiffness that decreases LVSV during adrenergic stress may serve as a marker for future pulmonary edema (PE).

Methods: We measured LVSV, ventriculovascular stiffness (pulse pressure/LVSV(index)), and aortic distensibility at rest and during intravenous dobutamine administration using cardiovascular magnetic resonance.

3D GRASE PROPELLER: improved image acquisition technique for arterial spin labeling perfusion imaging.

Arterial spin labeling is a noninvasive technique that can quantitatively measure cerebral blood flow. While traditionally arterial spin labeling employs 2D echo planar imaging or spiral acquisition trajectories, single-shot 3D gradient echo and spin echo (GRASE) is gaining popularity in arterial spin labeling due to inherent signal-to-noise ratio advantage and spatial coverage. However, a major limitation of 3D GRASE is through-plane blurring caused by T(2) decay.

Assessment of left ventricular diastolic function using 4-dimensional phase-contrast cardiac magnetic resonance.

Objectives: Phase-contrast magnetic resonance imaging can potentially assess the dynamics of left ventricular (LV) early diastolic filling.

Methods: Fifteen participants underwent phase-contrast magnetic resonance imaging on a 1.5-T whole-body Avanto scanner (Siemens Healthcare, Erlangen, Germany).