Preliminary Promising Findings for Manganese Chloride as a Novel Radiation Countermeasure Against Acute Radiation Syndrome.

Introduction: Military members and first responders may, at moment's notice, be asked to assist in incidents that may result in radiation exposure such as Operation Tomadachi in which the U.S. Navy provided significant relief for the Fukushima Daiichi Nuclear Reactor accident in Japan after an earthquake and tsunami in 2011.

Military-related mild traumatic brain injury: clinical characteristics, advanced neuroimaging, and molecular mechanisms.

Mild traumatic brain injury (mTBI) is a significant health burden among military service members. Although mTBI was once considered relatively benign compared to more severe TBIs, a growing body of evidence has demonstrated the devastating neurological consequences of mTBI, including chronic post-concussion symptoms and deficits in cognition, memory, sleep, vision, and hearing. The discovery of reliable biomarkers for mTBI has been challenging due to under-reporting and heterogeneity of military-related mTBI, unpredictability of pathological changes, and delay of post-injury clinical evaluations.

Recommendations for Imaging Patients With Cardiac Implantable Electronic Devices (CIEDs).

Historically, the presence of cardiac implantable electronic devices (CIEDs), including pacemakers and implantable cardioverter defibrillators (ICDs), was widely considered an absolute contraindication to magnetic resonance imaging (MRI). The recent development of CIEDs with MR Conditional labeling, as well as encouraging results from retrospective studies and a prospective trial on the safety of MRI performed in patients with CIEDs without MR Conditional labeling, have led to a reevaluation of this practice. The purpose of this report is to provide a concise summary of recent developments, including practical guidelines that an institution could adopt for radiologists who choose to image patients with CIEDs that do not have MR Conditional labeling.

Highly efficient head-only magnetic field insert gradient coil for achieving simultaneous high gradient amplitude and slew rate at 3.0T (MAGNUS) for brain microstructure imaging.

Purpose: To develop a highly efficient magnetic field gradient coil for head imaging that achieves 200 mT/m and 500 T/m/s on each axis using a standard 1 MVA gradient driver in clinical whole-body 3.0T MR magnet.

Methods: A 42-cm inner diameter head-gradient used the available 89- to 91-cm warm bore space in a whole-body 3.

Hemodynamic Effects of Late Sodium Current Inhibitors in a Swine Model of Heart Failure.

Objectives: To evaluate possible treatment-related hemodynamic changes, we administered ranolazine or mexiletine to swine with heart failure (HF) and to controls.

Background: Ranolazine and mexiletine potently inhibit depolarizing late Na current (I) and Na entry into cardiomyocytes Blocking Na entry may increase forward-mode Na/Ca exchange and reduce cellular Ca load, further compromising systolic contraction during HF.

Methods And Results: Anesthetized tachypaced HF swine received ranolazine (n = 9) or mexiletine (n = 7) as boluses, then as infusions; the same experiments were performed in 10 nonpaced controls.

Cardiac Imaging Modalities and Appropriate Use.

Cardiovascular imaging with calcium scoring computed tomography (CT), coronary CT angiography (CCTA), and cardiac MRI (CMR) have advanced rapidly over recent years. These imaging modalities have increased in availability, accessibility, and clinical practicality due to technological advances allowing for significant radiation dose reduction for high-quality CCTA and for rapid and reliable imaging techniques in CMR. Hardware and software developments are continually increasing efficiency and accuracy of postprocessing.

Multiacquisition T1-mapping MRI during tidal respiration for quantification of myocardial T1 in swine with heart failure.

Objective: The purpose of this article is to evaluate a free-breathing pulse sequence to quantify myocardial T1 changes in a swine model of tachycardia-induced heart failure.

Materials And Methods: Yorkshire swine were implanted with pacemakers and were ventricularly paced at 200 beats/min to induce heart failure. Animals were scanned twice with a 1.

Flexible cardiac T1 mapping using a modified Look-Locker acquisition with saturation recovery.

A modified Look-Locker acquisition using saturation recovery (MLLSR) for breath-held myocardial T(1) mapping is presented. Despite its reduced dynamic range, saturation recovery enables substantially higher imaging efficiency than conventional inversion recovery T(1) mapping because it does not require time for magnetization to relax to equilibrium. Therefore, MLLSR enables segmented readouts, shorter data acquisition windows, and shorter breath holds compared with inversion recovery.

A review of cohort study design for cardiovascular nursing research.

Nursing research encompasses a wide array of study areas that often times follow specific groups of patients or patient types. The cohort study design is a useful method to study any group, especially to track outcomes or to evaluate exposure or risk factors. Several different cohort study designs can be applied to the general population or to specific subpopulations or groups, such as those with cardiovascular disease.

Simultaneous myocardial and fat suppression in magnetic resonance myocardial delayed enhancement imaging.

Purpose: To develop a method for fat suppression in myocardial delayed enhancement (MDE) studies that achieves effective signal intensity reduction in fat but does not perturb myocardial signal suppression.

Materials And Methods: A new approach to fat suppression that uses a spectrally-selective inversion-recovery (SPEC-IR) tip-up radio frequency (RF) pulse following the conventional nonselective IR RF pulse together with a second SPEC-IR RF pulse is proposed. The tip-up pulse restores the fat longitudinal magnetization after the nonselective IR pulse and allows the fat magnetization to recover more fully toward its equilibrium value, providing for better fat suppression by the second SPEC-IR RF pulse.

Computerized information management for institutional review boards.

The use of human subjects for medical research in most industrialized nations requires the scientific and ethical scrutiny of research proposals by a governing institutional review board (IRB) or its equivalent. As part of their primary charge to protect human subjects, IRBs are responsible for the regulatory oversight of not only the research protocol itself but also the research conduct of the investigators and, if applicable, the funding sponsor. This article will discuss the regulatory requirements for an accurate account of IRB protocols and investigators and present an overview of the general flow of information for an IRB protocol.

Major vascular anomalies in Turner syndrome: prevalence and magnetic resonance angiographic features.

Background: Turner syndrome (TS) is associated with aortic coarctation and dissection; hence, echocardiographic evaluation of all patients is currently recommended. X-ray angiography in clinically symptomatic patients has suggested a range of other vascular anomalies, but the true prevalence of such lesions in TS is unknown. To better understand the prevalence and pathogenesis of cardiovascular defects in TS, we prospectively evaluated a group of asymptomatic adult volunteers with TS using magnetic resonance (MR) angiography.

MRA of the thoracic vessels.

Magnetic resonance imaging (MRI) is well suited for the noninvasive evaluation of the thoracic vasculature, and with improvements in scanner technology, the ability of MR to illustrate the thoracic vessels has significantly improved. Dedicated vascular software and pulse sequences have become commercially available, and fast imaging, in particular, has facilitated the time-efficient and comprehensive MR evaluation of most thoracic vascular lesions. Over the years, a host of black and bright blood MRI methods have evolved into practical tools for illustration of the thoracic vessels.

High-resolution gadolinium-enhanced 3D MRA of the infrapopliteal arteries. Lessons for improving bolus-chase peripheral MRA.

Peripheral magnetic resonance angiography (MRA) is growing in use. However, methods of performing peripheral MRA vary widely and continue to be optimized, especially for improvement in illustration of infrapopliteal arteries. The main purpose of this project was to identify imaging factors that can improve arterial visualization in the lower leg using bolus chase peripheral MRA.

MR angiography using steady-state free precession.

Contrast-enhanced MR angiography (CE-MRA) using steady-state free precession (SSFP) pulse sequences is described. Using SSFP, vascular structures can be visualized with high signal-to-noise ratio (SNR) at a substantial (delay) time after the initial arterial pass of contrast media. The peak blood SSFP signal was diminished by <20% 30 min after the initial administration of 0.

Renal masses: quantitative assessment of enhancement with dynamic MR imaging.

Purpose: To establish a quantitative magnetic resonance (MR) imaging contrast enhancement criterion for distinguishing cysts from solid renal lesions.

Materials And Methods: Regions of interest were measured in 74 patients with renal lesions evaluated by means of dynamic contrast material-enhanced MR imaging with serial breath-hold spoiled gradient-echo acquisitions. Sensitivity for renal tumors and specificity for renal cysts were established by using percentage of enhancement thresholds that varied between 5% and 35%.

Three-dimensional phase-contrast magnetic resonance angiography: a useful clinical adjunct to gadolinium-enhanced three-dimensional renal magnetic resonance angiography?

Objective: To assess the value of three-dimensional (3D) phase-contrast (PC) magnetic resonance angiography (MRA) after gadolinium (Gd)-enhanced 3D MRA for renal artery imaging.

Methods: Twenty-one patients with suspected renal artery hypertension were reviewed. All studies included Gd-enhanced 3D MRA and 3D PC MRA.