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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. This report was written on behalf of and approved by the International Society for Magnetic Resonance in Medicine (ISMRM) Safety Committee. LEVEL OF EVIDENCE: 3. TECHNICAL EFFICACY STAGE: 1.

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 (INa,late) and Na+ entry into cardiomyocytes. Blocking Na+ entry may increase forward-mode Na/Ca exchange and reduce cellular Ca+2 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. The swine with HF had characteristic elevated left ventricular end-diastolic pressure (LVEDP) and reduced maximal left ventricular pressure rise (+dP/dtmax) and left ventricular peak systolic pressure (LVSP). No significant change occurred after ranolazine dosing for any parameter: LVEDP, +dP/dtmax, LVSP, heart rate, maximal LV pressure fall rate (–dP/dtmax), or time constant for isovolumic relaxation. Similar results seen in additional swine with HF: 7 were given mexiletine, and 7 others were given ranolazine after a 27% rate decrement to maximize INa,late. Patch-clamped HF cardiomyocytes confirmed drug-induced INa,late blockade. Conclusions Ranolazine or mexiletine blocking INa,late neither worsened nor improved hemodynamics during advanced HF. Although results must be clinically confirmed, they suggest inhibition of INa,late by ranolazine or mexiletine may not exacerbate HF in patients.

Introduction: Although frequently used in heart failure (HF), long-term furosemide exacerbates HF in a swine model. This paradoxical phenomenon may reflect furosemide-induced alterations in signaling proteins of the extracellular matrix (ECM) to increase fibrosis. Examination of the ECM may clarify how treatments like furosemide enhance the progression of HF. Hypothesis: The administration of furosemide increased inflammation and fibrosis of the heart, leading to accelerated HF deterioration in a swine model. Methods: After Institutional Animal Care and Use Committee (IACUC) approval, Yorkshire swine (N=10, 5 = furosemide, 5 = saline) were paced 3 to 5 weeks at 200 beats per minute to induce HF (left ventricular fractional shortening Results: The overall increase in ECM fibrosis in HF was clearly demonstrated on Masson’s trichrome histology associated with significant, uniform increase in signaling pathways leading to fibrosis associated with furosemide use. SMAD 2-HF Furosemide to Control (p Conclusions: Histologic and biochemical analysis showed worsening HF in furosemide-treated paced swine was associated with consistent increases in fibrosis and indices of adverse ECM remodeling. The diuretic intended to reduce water retention during HF appeared to enhance myocardial fibrosis, paradoxically accelerating pathological processes responsible for HF.

Introduction: Traumatic brain injury (TBI) and stress are significant health concerns that have atherosclerotic cardiovascular disease (ASCVD) effects. Stress and injury can elevate neurochemicals and hormones in the brain that lead to dysfunction of the hypothalamic-pituitary-adrenal axis and the autonomic nervous system increasing inflammation, which plays a role in the development of ASCVD. Animal models can provide a method of separating mild TBI (mTBI) from models of chronic stress. Hypothesis: We hypothesize that mild blast TBI (mbTBI) and chronic variable stress (CVS) will result in elevated ASCVD biomarkers in mice. Methods: Frozen hearts from C57BL/6J mice (8 weeks, N=16, 8 male/8 randomly cycling female) were obtained through an IACUC approved study. The C57BL/6J mice were part of a mild blast TBI (mbTBI) study utilizing a blast chamber to receive a short duration shock wave ( Results: ERK1: mbTBI and CVS (pp ), compared to mbTBI (0.017). ERK2: mbTBI sham = 0.009, CVS only = 0.008, mbTBI only = 0.008 and CVS + mbTBI = 0.012. Galectin-3 (Gal-3): CVS only = 0.144, CVS+mbTBI = 0.168, mbTBI (0.114) to sham (0.111) ( p ). NT-Pro-BNP: CVS+mbTBI = 0.168, sham 0.076. mbTBI alone (0.077) and CVS alone (0.078). NRG1: mbTBI (0.195) and mbTBI with CVS (0.178). CVS only group (0.157). ET-1: mbTBI sham = 0.068, CVS only = 0.080 mbTBI only = 0.084 and CVS+mbTBI = 0.134. BDNF: CVS only = 0.053, CVS+mbTBI = 0.069. Sham group (0.047), mbTBI (0.038). Conclusion: Our results on proteins related to a broad spectrum of vascular growth, innervation, function, inflammation and markers of atherosclerotic plaque development suggest that mbTBI and/or chronic stress may increase risk for developing early ASCVD.

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. In the context of these rapidly developing imaging modalities, it is critical for ordering physicians and providers to be aware of the fundamentals of each modality, imaging challenges and appropriate use criteria.

This chapter will focus on describing the main safety issues of MRI, including pertinent background physics related to safety. This chapter will cover practical tips for keeping patients and staff safe in the MR environment. An overview of implanted medical devices including MR Conditional active devices, off-label (MR unsafe) active devices, and passive implanted devices will be presented. The unique challenges of monitoring patients in MRI as well as contrast agent used for MR will be presented.

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 3.0T magnet by increasing the radial separation between the primary and the shield coil windings to 18.6 cm. This required the removal of the standard whole-body gradient and radiofrequency coils. To achieve a coil efficiency ~4× that of whole-body gradients, a double-layer primary coil design with asymmetric x-y axes, and symmetric z-axis was used. The use of all-hollow conductor with direct fluid cooling of the gradient coil enabled ≥50 kW of total heat dissipation. Results This design achieved a coil efficiency of 0.32 mT/m/A, allowing 200 mT/m and 500 T/m/s for a 620 A/1500 V driver. The gradient coil yielded substantially reduced echo spacing, and minimum repetition time and echo time. In high b = 10,000 s/mm2 diffusion, echo time (TE) 50% reduction compared with whole-body gradients). The gradient coil passed the American College of Radiology tests for gradient linearity and distortion, and met acoustic requirements for nonsignificant risk operation. Conclusions Ultra-high gradient coil performance was achieved for head imaging without substantial increases in gradient driver power in a whole-body 3.0T magnet after removing the standard gradient coil. As such, any clinical whole-body 3.0T MR system could be upgraded with 3-4× improvement in gradient performance for brain imaging.

Gadolinium-based contrast agents (GBCAs) used in MRI have come under fire due to concerns about nephrogenic systemic fibrosis (NSF) and gadolinium retention. These concerns have prompted a search for alternatives to GBCAs. One attractive candidate is superparamagnetic iron oxide (SPIO). Over the past 20 years, several SPIO agents have been developed and approved for niche clinical applications in MRI. One interesting SPIO agent is ferumoxytol (Feraheme®), an FDA-approved intravenous medication used to treat iron-deficiency anemia in patients with chronic kidney disease. In preliminary studies examining its off-label use as an intravenous contrast agent, ferumoxytol appeared promising for MRI and MR angiography. However, experience with this agent remains limited. One key benefit of ferumoxytol is that it carries no risk of NSF in patients with impaired renal function. On the other hand, ferumoxytol has been reported to cause severe adverse events, including hypotension, hypersensitivity reactions, anaphylaxis, and death. Moreover, the rate of such events has been substantially greater than those observed with GBCAs or nonionic iodinated contrast media. In response to these data, the FDA issued a black box warning for ferumoxytol in 2015. To ensure patient safety, hospitals and imaging facilities must develop a plan to train MRI personnel to recognize and manage adverse reactions to ferumoxytol. Another challenge of using ferumoxytol concerns its pharmacokinetics and biodistribution, which differ from those of GBCAs. These differences can lead to unexpected patterns or persistence of tissue enhancement on MRI. In particular, ferumoxytol can remain in the body for days, weeks, or months after intravenous administration, potentially causing an unsuspecting radiologist to misinterpret an MRI. The decision to use ferumoxytol for a specific patient and clinical indication requires the radiologists to carefully weigh risk-benefit tradeoffs and consider alternative diagnostic tests.

We report a case of a 35-year-old active duty male with a rare quadricuspid aortic valve identified via transthoracic echocardiography following the detection of an incidental grade I/VI diastolic murmur. Further characterization of the anatomical findings and aortic valve flow dynamics were evaluated with cardiac magnetic resonance imaging. Accurate assessment of the various valve morphologies is essential, as it guides surgical treatment options to correct the defect. Our case highlights the complimentary role of cardiac magnetic resonance imaging in defining the anatomy and functional consequences of a quadricuspid aortic valve.

A modified Look–Locker acquisition using saturation recovery (MLLSR) for breath-held myocardial T1 mapping is presented. Despite its reduced dynamic range, saturation recovery enables substantially higher imaging efficiency than conventional inversion recovery T1 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. T1 measurements in phantoms using MLLSR showed a high correlation with conventional single-point inversion recovery spin echo. In vivo T1 measurements from normal and infarcted myocardium in 41 volunteers and patients were consistent with previously reported values. Twenty subjects were also scanned with MLLSR using an accelerated sampling scheme that required half the scan time (eight vs. 16 heartbeats) but yielded equivalent results. The flexibility afforded by the improved imaging efficiency of MLLSR allows the acquisition to be tailored to particular clinical needs and to individual patient's breath-holding abilities. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.

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. This new approach was validated in phantom studies and in five patients. Results Effective fat suppression was achieved using the proposed technique with minimal impact on normal myocardial signal suppression. Mean fat suppression achieved using this approach was 67% ± 8%, as measured in the chest wall immediately opposite the heart. Conclusion The results indicate this modular-type approach optimizes fat suppression in myocardial delayed enhancement studies but does not perturb the basic IR pulse sequence or change basic acquisition parameters. J. Magn. Reson. Imaging 2007;26:927–933. © 2007 Wiley-Liss, Inc.

Picture Archive and Communication Systems (PACS) are comprehensive management systems for diagnostic imaging studies that are increasingly used in hospitals and health care systems. It is essential for PACS to be an integrated part of the total hospital electronic information system in order to be maximally effective. The main objective of any new information system in health care is to improve the effectiveness and efficiency of health care. Although the initial implementation of PACS is costly, the ability for care providers to have faster access to diagnostic imaging information allows care to be delivered more expediently, which improves the overall quality of care patients receive. Nurses will have the ability to see images, rather than just reports about imaging studies. An electronic system for diagnostic imaging procedures and management provides nurses with unique opportunities to improve their involvement in clinical discussions, their ability to provide quality patient care, and potential to further nursing research.

The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or reflecting the views of the Uniformed Services University of the Health Sciences or the Department of Defense. This article is being reprinted from Seminars in Ultrasound, CT, and MRI 2003;24:192–216. * Corresponding author. Department of Radiology and Radiological Sciences, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814. E-mail address: vho@usuhs.mil or vho@nih.gov (Vincent B. Ho). With improvements in scanner technology, the ability of MR to illustrate the thoracic vessels has significantly improved beyond gross anatomic depiction using T1-weighted spin echo images. Dedicated software and pulse sequences for vascular imaging have become commercially available and offer not only user-friendly interfaces but also improved reliability of vascular signal, resulting in enhanced diagnostic accuracy and confidence. Fast imaging, in particular, has improved all aspects of vascular imaging, and has enabled the comprehensive evaluation of most nonurgent thoracic vascular conditions within a single 45minute examination period. As with other MRI applications, successful vascular depiction relies significantly on the proper selection and prescription of imaging pulse sequences. Vascular MR exams are in many ways more challenging to prescribe because of the complex signal characteristics inherent to flowing blood and the complex geometry of many vascular

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. As with other MR applications, successful vascular depiction relies significantly on the proper selection and prescription of imaging pulse sequences. In this article, these methods with their specific technical and practical pitfalls for thoracic magnetic resonance angiography (MRA) will be discussed. Current clinical indications for thoracic MRA will also be illustrated.

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. Eighteen healthy adults were imaged on a 1.5T MR scanner. The calf was imaged using conventional three-station bolus chase three-dimensional (3D) MRA, two dimensional (2D) time-of-flight (TOF) MRA and single-station Gadolinium (Gd)-enhanced 3D MRA. Observer comparisons of vessel visualization, signal to noise ratios (SNR), contrast to noise ratios (CNR) and spatial resolution comparisons were performed. Arterial SNR and CNR were similar for all three techniques. However, arterial visualization was dramatically improved on dedicated, arterial-phase Gd-enhanced 3D MRA compared with the multi-station bolus chase MRA and 2D TOF MRA. This improvement was related to optimization of Gd-enhanced 3D MRA parameters (fast injection rate of 2 mL/sec, high spatial resolution imaging, the use of dedicated phased array coils, elliptical centric k-space sampling and accurate arterial phase timing for image acquisition). The visualization of the infrapopliteal arteries can be substantially improved in bolus chase peripheral MRA if voxel size, contrast delivery, and central k-space data acquisition for arterial enhancement are optimized. Improvements in peripheral MRA should be directed at these parameters.

To establish a quantitative magnetic resonance (MR) imaging contrast enhancement criterion for distinguishing cysts from solid renal lesions.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%.The mean percentage of enhancement at MR imaging for the 50 renal cysts was less than 5%; for the 50 renal tumors, it was 97% or higher. With use of a threshold percentage of enhancement of 15% and results obtained between 2 and 4 minutes after administration of contrast material, all malignancies (sensitivity for tumor, 100%) were diagnosed, and there were 6% or fewer false-positive tumor diagnoses. Lower thresholds resulted in unacceptably high false-positive rates (ie, cysts that appeared to enhance-pseudoenhancement), whereas higher threshold values (20%) resulted in an unacceptably lower sensitivity for tumors.The optimal percentage of enhancement threshold for distinguishing cysts from malignancies with the imaging technique prescribed was 15%, and the optimal timing for measurement was 2-4 minutes after administration of contrast material.

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. Blinded interpretation of the images was performed for each technique independently and in combination. Conventional X-ray angiography was used for diagnostic correlation when available. Results: Renal artery stenosis was present in 7 (16.3%) of 43 renal arteries, confirmed by X-ray angiography. MRA images demonstrated 100% sensitivity and 74% specificity for Gd-enhanced 3D MRA and 100% sensitivity and 94% specificity for 3D PC MRA. All vessels were diagnosed correctly when both image sets were viewed. Conclusion: 3D PC MRA can improve the specificity of renal MRA by decreasing the number of false-positive Gd-enhanced 3D MRA interpretations.

Purpose: To investigate the feasibility of preferential arterial imaging using gadolinium-enhanced thick-slice phase-contrast imaging. Methods: Six healthy volunteers were studied using a peripheral-gated segmented k-space CINE phase-contrast pulse sequence using four views per RR interval with flow encoding in the superior-inferior direction. Images at the level of the popiteal trifurcation were acquired postcontrast with different section thicknesses (4–8 cm) and VENC values (20–150 cm/sec), and phase-difference processing. Results: The post-gadolinium contrast-enhanced thick-slice phase-contrast acquisitions demonstrated the ability to visualize the tibio-peroneal (trifurcation) arteries, especially in systole. With MR contrast agents, the signal from blood is raised significantly above that of stationary tissue from T1 shortening such that the partial volume artifact is reduced in thick-slice acquisitions. Furthermore, by selecting the VENC value as a function of the cardiac cycle, the noise floor can be raised to selectively suppress flow values less than that of the noise threshold, allowing better accentuation of arterial structures at systole. Conclusions: Thick-slice phase-contrast acquisition with phase-difference processing has been observed to reduce partial volume artifacts when an MR contrast agent substantially increases signal in the vasculature over that of normal background tissue. Preferential arterial images can be obtained by either increasing the VENC value to selectively suppress signal from slow flow in the veins or by subtracting the diastolic phase image from the peak systolic phase image. J. Magn. Reson. Imaging 2001;13:714–721. © 2001 Wiley-Liss, Inc.

In this pilot study, using a standard 40 mL gadolinium (Gd) chelate contrast dose, dual-rate (first 20 mL at 0.5 mL/sec; remaining 20 mL at 1.5 mL/sec) and fixed-rate (entire 40 mL dose at either 0.7 mL/sec or 2.0 mL/sec) injection schemes for multistation, bolus-chase magnetic resonance angiography (MRA) were compared in normal volunteers. Signal-to-noise ratio, contrast-to-noise ratio, and physician preference were determined for nine arterial segments. At the terminal station (calf), the dual-rate contrast injection improved arterial signal and contrast compared with both fixed-rate injection schemes and improved subjective vessel appearance compared with the 2.0 mL/sec, but not the 0.7 mL/sec, fixed-rate scheme.

Bolus chase 3-dimensional MR angiography (3D MRA) is a recent development that extends the effective field of view for arterial imaging from the typical single 40-50 cm to over 100 cm. This technique is well suited for imaging long vascular territories such as the lower extremity. Bolus chase peripheral 3D MRA is achieved with overlapping 3D gradient-echo scans during the arterial transit of a single intravenous injection of gadolinium-chelate contrast media. This technique can depict the arteries from the infrarenal aorta to the ankles in less than 2 minutes. The initial experiences with bolus chase peripheral MRA using an automated algorithm that controls both table translation and 3D data acquisition are described. Suggestions for future refinements to the technique are also discussed.

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.Yorkshire swine were implanted with pacemakers and were ventricularly paced at 200 beats/min to induce heart failure. Animals were scanned twice with a 1.5-T MRI scanner, once at baseline and once at heart failure. A T1-mapping sequence was performed during tidal respiration before and 5 minutes after the administration of a gadolinium-chelate contrast agent. T1-mapping values were compared between the baseline and heart failure scans. The percentage of fibrosis of heart failure myocardial tissue was compared with similar left ventricular tissue from control animals using trichrome blue histologic analysis.In the study cohort, differences were found between the baseline and heart failure T1-mapping values before the administration of contrast agent (960 ± 96 and 726 ± 94 ms, respectively; p = 0.02) and after contrast agent administration (546 ± 180 and 300 ± 171 ms, respectively; p = 0.005). The animals with heart failure also had a difference histologically in the percentage of myocardial collagen compared with tissue from healthy control animals (control, 5.4% ± 1.0%; heart failure, 9.4% ± 1.6%; p0.001).The proposed T1-mapping technique can quantify diffuse myocardial changes associated with heart failure without the use of a contrast agent and without breath-holding. These T1 changes appear to be associated with increases in the percentage of myocardial collagen that in this study were not detected by traditional myocardial delayed enhancement imaging. T1 mapping may be a useful technique for detecting early but clinically significant myocardial fibrosis.

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. T(1) measurements in phantoms using MLLSR showed a high correlation with conventional single-point inversion recovery spin echo. In vivo T(1) measurements from normal and infarcted myocardium in 41 volunteers and patients were consistent with previously reported values. Twenty subjects were also scanned with MLLSR using an accelerated sampling scheme that required half the scan time (eight vs. 16 heartbeats) but yielded equivalent results. The flexibility afforded by the improved imaging efficiency of MLLSR allows the acquisition to be tailored to particular clinical needs and to individual patient's breath-holding abilities.

Unlike every other form of heart disease, the prevalence and incidence of heart failure is still rising, and heart failure has become the leading causes of morbidity and mortality in the United States (US) (1). Furthermore, heart failure is commonly associated with sudden death at any stage of the condition (2-22). Heart failure is a burden on the health care system with an incidence of 10 per 1,000 persons over the age of 65 in the US (23, 24). The US is also in a nursing shortage. It is estimated that by the year 2025, there will be a short fall of nearly 260,000 nurses (25). Nurses are the primary care givers in the US. The nursing shortage poses a threat to the quality of life for the heart failure patient. More research is needed to better understand heart failure so that care plans, mediations and/or devices can be refined to help streamline patient care.

Methods The method entails the tracking of the left ventricular center point of the left ventricle on 2D SSFP images over time. A polar coordinate map indicating amplitude and angle parameters provides a quantitative way to describe systolic (red) and diastolic (blue) wall motion. Transthoracic echocardiography using 2D strain maps were used to validate the findings from CMR and CPT analysis. Three patients with myocardial infarction (3 Male, 67 ± 4 y/o, EF 54% ± 14%) and one healthy volunteer (1 Female, 51 y/ o, EF 63%) were enrolled in this IRB approved study. On the echocardiography peak systolic strain map, the smaller the magnitude absolute value, the less the echocardiographic strain measurement. Results CPT analysis demonstrates significant movement of the center in the first column Figures 1, 2, 3 (a). The second column (b) represents the corresponding short axis T2 weighted or delayed enhancement positive images. The third column (c) represents the long axis echocardiographic strain maps. Figures 1 and 2 are patients with myocardial infarction of the anteroseptal wall of the left ventricle. The CPT plot provides amplitude and angle of center point progression, which reflects the degree of abnormal wall motion during both systolic contraction, and diastolic filling of the left ventricle. In these two cases, the center point trajectory points toward the hypokinetic anteroseptal wall [arrow on the T2 weighted and myocardial delayed enhancement images (1b and 2b) and echocardiographic strain maps (1c and 2c)]. Figure 3 shows a patient with myocardial infarction of the anterior and anterior lateral wall (3b, arrow) with corresponding hypokinesis and an abnormal strain map clearly visualized on echocardiography. Figure 4 shows a normal volunteer without significant center point movement on CPT and corresponding normal echocardiographic strain maps. Strain analysis from echocardiography confirms the hypothesis of the center point trajectory model from cardiac MR. from 13th Annual SCMR Scientific Sessions Phoenix, AZ, USA. 21-24 January 2010

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. Cohort designs provide a temporal view of groups and exposures that can uncover outcomes and exposures that may be difficult to separate out in smaller, traditional experiments. There are several types of cohort designs, each with their unique advantages. Cohort designs may be prospective or retrospective. Although most cohort designs are longitudinal, there are also cross-sectional types of studies that are useful. As with any type of research design, selection of the study participants and control groups must be made carefully. It is important for the variables to be clearly defined and measurable. The investigator must also be aware of potential biases and weaknesses associated with different cohort study designs and account for these problems when they arise. Reports from cohort studies should be presented clearly, addressing the potential confounding problems. This article explores the many types of cohort designs, with examples from cardiovascular disease research to demonstrate how nurses can use this design in their research.

A novel cardiac chamber volume model is proposed for the assessment of left ventricular mechanical dyssynchrony. The tool is potentially useful for assessment of regional cardiac function and identification of mechanical dyssynchrony on MRI. Dyssynchrony results typically from a contraction delay between one or more individual left ventricular segments, which in turn leads to inefficient ventricular function and ultimately heart failure. Cardiac resynchronization therapy has emerged as an electrical treatment of choice for heart failure patients with dyssynchrony. Prior MRI techniques have relied on assessments of actual cardiac wall changes either using standard cine MR images or specialized pulse sequences. In this abstract, we detail a semi-automated method that evaluates dyssynchrony based on segmental volumetric analysis of the left ventricular (LV) chamber as illustrated on standard cine MR images. Twelve sectors each were chosen for the basal and mid-ventricular slices and 8 sectors were chosen for apical slices for a total of 32 sectors. For each slice (i.e. basal, mid and apical), a systolic dyssynchrony index (SDI) was measured. SDI, a parameter used for 3D echocardiographic analysis of dyssynchrony, was defined as the corrected standard deviation of the time at which minimal volume is reached in each sector. The SDI measurement of a healthy volunteer was 3.54%. In a patient with acute myocardial infarction, the SDI measurements 10.98%, 16.57% and 1.41% for basal, mid-ventricular and apical LV slices, respectively. Based on published 3D echocardiogram reference threshold values, the patient's SDI corresponds to moderate basal dysfunction, severe mid-ventricular dysfunction, and normal apical LV function, which were confirmed on echocardiography. The LV chamber segmental volume analysis model and SDI is feasible using standard cine MR data and may provide more reliable assessment of patients with dyssynchrony especially if the LV myocardium is thin or if the MR images have spatial resolution insufficient for proper resolution of wall thickness-features problematic for dyssynchrony assessment using existing MR techniques.

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. The current and potential uses of information management systems by IRBs will also be reviewed and accompanied by a discussion of the potential advantages and disadvantages of various computerized information systems for management of clinical research.

In 1985, Wedeen et al [1,2] described the ability of MR imaging to illustrate blood vessels by using flow-dependent techniques, methods now well known as time-of-flight MR angiography. It was not until the 1990s, however, with numerous innovations for the more reliable and robust method of contrast-enhanced (CE) MR angiography, that the use of MR imaging has become routine clinically for vascular diagnosis. Today a variety of gadolinium (Gd)-chelate contrast agents are commercially available in the United States for neurologic and body imaging applications, although none is approved yet by the Food and Drug Administration specifically for MR angiography. Although off-label, the use of contrast media for MR angiography [3,4] has been shown to be reliable, safe, and accurate in clinical practice [5–11] and in many centers has replaced more invasive x-ray catheter angiography as a primary standard for vascular diagnosis [12]. In its current implementation, CE MR angiography typically is performed using one of the commercially available extracellular Gd-chelate contrast agents with a three-dimensional (3D) fast spoiled gradient echo pulse sequence timed for contrast bolus filling of the target vasculature (Fig. 1). Vascular illustration on CE MR angiography is provided by the T1 shortening effects of Gd on blood. The preferential timing of 3D MR

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. Methods and Results— A total of 85 adults with TS and 27 normal female adult volunteers underwent gadolinium-enhanced 3D MR angiography. A high prevalence of aortic anomalies was seen in women with TS, including elongation of the transverse arch (49%), aortic coarctation (12%), and aberrant right subclavian artery (8%). Venous anomalies were also prominent, including persistent left superior vena cava (13%) and partial anomalous pulmonary venous return (13%). None of these anomalies were found in healthy female controls. The constellation of elongation of the transverse arch, aortic coarctation, and persistent left superior vena cava was significantly associated with women with TS. Neck webbing and increased thoracic anterior-to-posterior dimension diameters were strong predictors for arterial and venous anomalies. Conclusions— Thoracic vascular anomalies are common in TS, occurring in ≈50% of a group not preselected for cardiovascular disease. The highly significant association between neck webbing, increased chest diameter, and these vascular anomalies suggests that in utero, centrally localized lymphatic obstruction may contribute to these cardiovascular deformities in TS. Improved recognition of these often-undetected vascular lesions may be important for identification of patients in need of closer cardiovascular monitoring.

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

A new method was investigated for improving the efficiency of ECG-gated coronary magnetic resonance angiography (CMRA) by accurate, automated tracking of the vessel motion over the cardiac cycle. Vessel tracking was implemented on a spiral gradient-echo pulse sequence with sub-millimeter in-plane spatial resolution as well as high image signal to noise ratio. Breath hold 2D CMRA was performed in 18 healthy adult subjects (mean age 46 ± 14 years). Imaging efficiency, defined as the percentage of the slices where more than 30 mm of the vessel is visualized, was computed in multi-slice spiral scans with and without vessel tracking. There was a significant improvement in the efficiency of the vessel tracking sequence compared to the multi-slice sequence (56% vs. 32%, P < 0.001). The imaging efficiency increased further when the true motion of the coronary arteries (determined using a cross correlation algorithm) was used for vessel tracking as opposed to a linear model for motion (71% vs. 57%, P < 0.05). The motion of the coronary arteries was generally found to be linear during the systolic phase and nonlinear during the diastolic phase. The use of subject-tailored, automated tracking of vessel positions resulted in improved efficiency of coronary artery illustration on breath held 2D CMRA. J. Magn. Reson. Imaging 2001;14:368–373. Published 2001 Wiley-Liss, Inc.

A method of three-station three-dimensional magnetic resonance (MR) angiography of the lower extremities with segmented volume acquisition is presented. Three-dimensional MR angiographic data were acquired in two passes, with the central k-space views acquired during the arterial phase for the more proximal stations. This allowed a faster bolus injection rate and potentially improved visualization of the tibioperoneal arteries.

To follow the motion of the coronary artery in magnetic resonance angiography, the authors evaluated vessel tracking, a method for prospective adjustment of the section location as a function of the delay from the cardiac trigger. In 10 volunteers and four patients, this method allowed the vessel to be maintained in the plane of acquisition throughout the cardiac cycle. With a single-phase multisection sequence, vessel-tracking acquisitions had an efficiency of 0.68 +/- 0.04 for both the right and left coronary arteries compared with 0.19 +/- 0.03 for a non-vessel-tracking acquisition (P.001).

The chemical shift phenomenon refers to the signal intensity alterations seen in magnetic resonance (MR) imaging that result from the inherent differences in the resonant frequencies of precessing protons. Chemical shift was first recognized as a misregistration artifact of image data. More recently, however, chemical shift has been recognized as a useful diagnostic tool. By exploiting inherent differences in resonant frequencies of lipid and water, fatty elements within tissue can be confirmed with dedicated chemical shift MR pulse sequences. Alternatively, the recognition of chemical shift on images obtained with standard MR pulse sequences may corroborate the diagnosis of lesions with substantial fatty elements. Chemical shift can aid in the diagnosis of lipid-containing lesions of the brain (lipoma, dermoid, and teratoma) or the body (adrenal adenoma, focal fat within the liver, and angiomyolipoma). In addition, chemical shift can be implemented to accentuate visceral margins (e.g., kidney and liver).