Echocardiography curriculum development for physician assistants using entrustable professional activities

BACKGROUND: With the projected increase of cardiovascular disease in the aging population, a higher demand for echocardiography use is predicted. However, there is a shortage in the supply of cardiologists, to the point that a 2009 American College of Cardiology survey report called it a "cardiology workforce crisis". The report also recommends a more aggressive use of PAs and NPs as one of the solutions to fill the shortage. Currently, echocardiography is not routinely included in the scope of practice for PAs in cardiology. While PAs attain strong basic science knowledge and clinical training experience in PA school, they typically do not receive additional formal postgraduate training. PAs have limited training opportunities to train in echocardiography and receive certification of recognition, but a formally standardized training program and certifying examination geared specifically for PAs are yet to be developed. This study seeks to develop a pilot curriculum in training echocardiography which can be standardized for utilization across various regions and medical subspecialties. The curriculum draws on the concept of Entrustable Professional Activities (EPA), which is being actively used in graduate medical education. HYPOTHESIS: After participating in the proposed pilot curriculum which involves online didactic learning and supervised hands-on clinical training, trained PAs will be able to reach proficiency in echocardiography operation and interpretation at level 4 supervision according to the EPA guidelines. METHODS: This study proposes a pilot curriculum with framework based on the EPA titled “performing and interpreting echocardiography” by PAs. The curriculum involves didactic and clinical training in echocardiography, with the goal to achieve mastery of level 4 supervision (minimal supervision). 2 subjects will be recruited from a teaching medical institution in the Greater Boston area with an IAC accredited echocardiography laboratory. After the 12-month training, participants will take ASCeXAM/ReASCE Online Practice Exam Simulation offered by the ASE. Upon 1) achievement of individualized EPAs as assessed by supervisor, and 2) simulation exam score of >80%, participants will earn a STAR in echocardiography. CONCLUSION: The study is the first step to establishing an effective training curriculum that will eventually be a basis for creating a certifying exam in echocardiography, designed specifically for PAs. As this study merely suggests a new curriculum, future studies should focus on identifying strengths and weaknesses of the curriculum after implementation and expansion to multiple sites, and gather data to use for continual improvement of the training curriculum

Speckle Reduction and Contrast Enhancement of Echocardiograms via Multiscale Nonlinear Processing

This paper presents an algorithm for speckle reduction and contrast enhancement of echocardiographic images. Within a framework of multiscale wavelet analysis, the authors apply wavelet shrinkage techniques to eliminate noise while preserving the sharpness of salient features. In addition, nonlinear processing of feature energy is carried out to enhance contrast within local structures and along object boundaries. The authors show that the algorithm is capable of not only reducing speckle, but also enhancing features of diagnostic importance, such as myocardial walls in two-dimensional echocardiograms obtained from the parasternal short-axis view. Shrinkage of wavelet coefficients via soft thresholding within finer levels of scale is carried out on coefficients of logarithmically transformed echocardiograms. Enhancement of echocardiographic features is accomplished via nonlinear stretching followed by hard thresholding of wavelet coefficients within selected (midrange) spatial-frequency levels of analysis. The authors formulate the denoising and enhancement problem, introduce a class of dyadic wavelets, and describe their implementation of a dyadic wavelet transform. Their approach for speckle reduction and contrast enhancement was shown to be less affected by pseudo-Gibbs phenomena. The authors show experimentally that this technique produced superior results both qualitatively and quantitatively when compared to results obtained from existing denoising methods alone. A study using a database of clinical echocardiographic images suggests that such denoising and enhancement may improve the overall consistency of expert observers to manually defined borders

Semi-automated quantification of left ventricular volumes and ejection fraction by real-time three-dimensional echocardiography

<p>Abstract</p> <p>Background</p> <p>Recent studies have shown that real-time three-dimensional (3D) echocardiography (RT3DE) gives more accurate and reproducible left ventricular (LV) volume and ejection fraction (EF) measurements than traditional two-dimensional methods. A new semi-automated tool (4DLVQ) for volume measurements in RT3DE has been developed. We sought to evaluate the accuracy and repeatability of this method compared to a 3D echo standard.</p> <p>Methods</p> <p>LV end-diastolic volumes (EDV), end-systolic volumes (ESV), and EF measured using 4DLVQ were compared with a commercially available semi-automated analysis tool (TomTec 4D LV-Analysis ver. 2.2) in 35 patients. Repeated measurements were performed to investigate inter- and intra-observer variability.</p> <p>Results</p> <p>Average analysis time of the new tool was 141s, significantly shorter than 261s using TomTec (<it>p </it>< 0.001). Bland Altman analysis revealed high agreement of measured EDV, ESV, and EF compared to TomTec (<it>p </it>= <it>NS</it>), with bias and 95% limits of agreement of 2.1 ± 21 ml, -0.88 ± 17 ml, and 1.6 ± 11% for EDV, ESV, and EF respectively. Intra-observer variability of 4DLVQ vs. TomTec was 7.5 ± 6.2 ml vs. 7.7 ± 7.3 ml for EDV, 5.5 ± 5.6 ml vs. 5.0 ± 5.9 ml for ESV, and 3.0 ± 2.7% vs. 2.1 ± 2.0% for EF (<it>p </it>= <it>NS</it>). The inter-observer variability of 4DLVQ vs. TomTec was 9.0 ± 5.9 ml vs. 17 ± 6.3 ml for EDV (<it>p </it>< 0.05), 5.0 ± 3.6 ml vs. 12 ± 7.7 ml for ESV (<it>p </it>< 0.05), and 2.7 ± 2.8% vs. 3.0 ± 2.1% for EF (<it>p </it>= <it>NS</it>).</p> <p>Conclusion</p> <p>In conclusion, the new analysis tool gives rapid and reproducible measurements of LV volumes and EF, with good agreement compared to another RT3DE volume quantification tool.</p

Low Dose Sarin Leads to Murine Cardiac Dysfunction

It has been reported that low dose sarin is associated with long-term pathology in the brain and heart; however, the effects of sarin on the heart have yet to be determined. In addition, sarin has been implicated as an etiological agent in Gulf War Illness. Thus, the role of sarin in producing illness has important military consequences. This study used echocardiography, electrocardiography, and histology to determine sarin’s effect on the murine cardiovascular system. C57BL/6J mice were injected with sarin at 0.4 LD50, 0.5 LD50, or saline on two consecutive days and studied for 10 weeks post exposure. The sarin animals had marked increases in heart weight to body weight ratios (p = 0.026), and the left ventricular lumen size was significantly decreased (p = 0.0014). In addition, cardiomyocytes were significantly larger in the sarin mice (p = 0.025) and atrial/brain natriuretic peptide levels were increased (p = 0.028 and 0.010, respectively). Results of the electrocardiograms show significant ST/T-wave changes in the sarin groups (p = 0.0015 and 0.032, respectively). Similarly, echocardiograms showed significantly decreased performance of the left ventricle in the sarin animals. This study indicates that sarin plays a role in cardiac remodeling and reducing cardiac performance

FAME - A Flexible Appearance Modelling Environment

Combined modelling of pixel intensities and shape has proven to be a very robust and widely applicable approach to interpret images. As such the Active Appearance Model (AAM) framework has been applied to a wide variety of problems within medical image analysis. This paper summarises AAM applications within medicine and describes a public domain implementation, namely the Flexible Appearance Modelling Environment (FAME). We give guidelines for the use of this research platform, and show that the optimisation techniques used renders it applicable to interactive medical applications. To increase performance and make models generalise better, we apply parallel analysis to obtain automatic and objective model truncation. Further, two different AAM training methods are compared along with a reference case study carried out on cross-sectional short-axis cardiac magnetic resonance images and face images. Source code and annotated data sets needed to reproduce the results are put in the public domain for further investigation

Assessment of visual quality and spatial accuracy of fast anisotropic diffusion and scan conversion algorithms for real-time three-dimensional spherical ultrasound

Three-dimensional ultrasound machines based on matrix phased-array transducers are gaining predominance for real-time dynamic screening in cardiac and obstetric practice. These transducers array acquire three-dimensional data in spherical coordinates along lines tiled in azimuth and elevation angles at incremental depth. This study aims at evaluating fast filtering and scan conversion algorithms applied in the spherical domain prior to visualization into Cartesian coordinates for visual quality and spatial measurement accuracy. Fast 3d scan conversion algorithms were implemented and with different order interpolation kernels. Downsizing and smoothing of sampling artifacts were integrated in the scan conversion process. In addition, a denoising scheme for spherical coordinate data with 3d anisotropic diffusion was implemented and applied prior to scan conversion to improve image quality. Reconstruction results under different parameter settings, such as different interpolation kernels, scaling factor, smoothing options, and denoising, are reported. Image quality was evaluated on several data sets via visual inspections and measurements of cylinder objects dimensions. Error measurements of the cylinder's radius, reported in this paper, show that the proposed fast scan conversion algorithm can correctly reconstruct three-dimensional ultrasound in Cartesian coordinates under tuned parameter settings. Denoising via three-dimensional anisotropic diffusion was able to greatly improve the quality of resampled data without affecting the accuracy of spatial information after the modification of the introduction of a variable gradient threshold parameter