David Prater

Echocardiographic Quantification of Regional Left Ventricular Wall Motion With Color Kinesis

BACKGROUND Color kinesis is a new technology for the echocardiographic assessment of left ventricular wall motion based on acoustic quantification. This technique automatically detects endocardial motion in real time by using integrated backscatter data to identify pixel transitions from blood to tissue during systole on a frame-by-frame basis. In this study, we evaluated the feasibility and accuracy of quantitative segmental analysis of color kinesis images to provide objective evaluation of regional systolic endocardial motion. METHODS AND RESULTS Two-dimensional echocardiograms were obtained in the short-axis and apical four-chamber views in 20 normal subjects and 40 patients with regional wall motion abnormalities. End-systolic color overlays superimposed on the gray scale images were obtained with color kinesis to color encode left ventricular endocardial motion throughout systole on a frame-by-frame basis. These color-encoded images were divided into segments by use of custom software. In each segment, pixels of different colors were counted and displayed as stacked histograms reflecting the magnitude and timing of regional endocardial excursion. In normal subjects, histograms were found to be highly consistent and reproducible. The patterns of contraction obtained in normal subjects were used as a reference for the objective automated interpretation of regional wall motion abnormalities, defined as deviations from this pattern. The variability in the echocardiographic interpretation of wall motion between two experienced readers was similar to the diagnostic variability between the consensus of the two readers and the automated interpretation. CONCLUSIONS Color kinesis is a promising new tool that may be used clinically to improve the qualitative and quantitative evaluation of spatial and temporal aspects of global and regional wall motion. In this initial study, segmental analysis of color kinesis images provided accurate, automated, and quantitative diagnosis of regional wall motion abnormalities.

A Suggested Roadmap for Cardiovascular Ultrasound Research for the Future

Sanjiv Kaul, MD, FASE,* James G. Miller, PhD,* Paul A. Grayburn, MD, Shinichi Hashimoto,Mark Hibberd, MD, PhD, Mark R. Holland, PhD, FASE, Helene C. Houle, BA, RDMS, RDCS, RVT, FASE,Allan L. Klein, MD, FASE, Peg Knoll, RDCS, FASE, Roberto M. Lang, MD, FASE,Jonathan R. Lindner, MD, FASE, Marti L. McCulloch, RDCS, FASE, Stephen Metz, PhD,Victor Mor-Avi, PhD, FASE, Alan S. Pearlman, MD, FASE, Patricia A. Pellikka, MD, FASE, Nancy DeMarsPlambeck,BS,RDMS,RDCS,RVT,DavidPrater,MS, ThomasR.Porter,MD,FASE,DavidJ.Sahn,MD,FASE,James D. Thomas, MD, FASE, Kai E. Thomenius, PhD, and Neil J. Weissman, MD, FASEINTRODUCTIONThe leadership at the American Society of Echocardiography (ASE)decided on a proactive role in defining selected areas of researchnecessary in this decade that will meet our future clinical needs.Consequently, ASE sponsored a Technology and ResearchSummit in the fall of 2010 in conjunction with the AmericanHeart Association Scientific Sessions in Chicago. In addition to theASE executive committee, in attendance were the editor, deputyeditor, and one of the associate editors of the Journal of theAmerican Society of Echocardiography. Also invited were physician-scientists active in the field of cardiovascular ultrasound, respectedultrasound physicists, and senior engineers from the various ultra-sound companies.The agenda for the full-day meeting covered a selected range ofsubjects including the assessment of global and regional left ventricu-lar function, regional myocardialperfusion, molecular imaging, thera-peutic ultrasound, and peripheral vascular imaging. Also addressedwere research necessary to determine the broad clinical utility ofhand held ultrasound devices and the impact of future technologicaldevelopments on the field of cardiovascular imaging.Because of time constraints, other important and worthy areas ofresearch were not discussed. There was an hour devoted to the dis-cussion of each subject that was initiated by the chairs and panelistsassigned to each of the topics. The discussion was robust, and at theend, the chairs and panelists for each topic were requested to sub-mit in writing a short synopsis of the discussion. These have beencompiled into a document that we believe will serve as a roadmapfor cardiovascular ultrasound research for this decade. At the endof each section a short list of references for selected reading isprovided.Although we have defined the areas that are ripe for future re-search, we also strongly believe that we havetotrain the future scien-tists who will implement this research agenda. ASE has historicallyawarded one or two fellowship training grants a year and also anaward for researchtraining of a sonographer. At some institutions fel-lowshavealsoreceivedtraininggrantsfromthelocalAmericanHeartAssociation, and very occasionally a training grant (F32) from theNational Institutes of Health. However, this is not enough. We needmore institutional training grants from the National Institutes ofHealth in order to train an adequate number of MD and PhD scien-tists in cardiovascular imaging. To our knowledge there are currentlyonlyahandfulofsuchtraininggrantsinthecountry,whichiswoefullyinadequate. We believe that we need at least 20–25 such traininggrants devoted to the general field of cardiovascular imaging so thatwithin a decade there will be enough physicians trained in scientificmethods and clinical research to address the subjects that havebeen discussed in this report.The field of cardiovascular ultrasound is very broad, ranging fromclinical validation of new technology to studies requiring knowledgeof physics, mathematics, organic chemistry, physiology, pharmacol-ogy, molecular and vascular biology, genetics, clinical trials, and out-come research. Cross-training of individuals in one or more of thesefields is essential for cardiovascular ultrasound to thrive and succeed.Ourhopeisthatthisreportwillencourageyoungpeopletorealizethescope of cardiac ultrasound research and make a career in this dy-namic field.Selected Reading

Two-dimensional speckle tracking echocardiography: Standardization efforts based on synthetic ultrasound data

AIMS Speckle tracking echocardiography has already demonstrated its clinical potential. However, its use in routine practice is jeopardized by recent reports on high inter-vendor variability of the measurements. As such, the European Association of CardioVascular Imaging (EACVI) and the American Society of Echocardiography (ASE) set up a standardization task force, which was joined by all manufacturers of echocardiographic equipment as well as by companies offering software solutions only, with the ambition to tackle this problem by standardization and quality assurance (QA). METHODS AND RESULTS In this study, a first step towards QA of all commercially available tracking solutions based on computer-generated ultrasound images is presented. The accuracy of the products was acceptable with relative errors below 10% and intra-vendor reproducibility within 5%. CONCLUSION Whether these results can be extrapolated to the clinical setting is the topic of an ongoing study of the EACVI/ASE/Industry Task Force to standardize deformation imaging. This study was an important first step in the development of generally accepted tools for QA of speckle tracking echocardiography.

American society of echocardiography cardiovascular technology and research summit: A roadmap for 2020

From the Divis (P.A.P., M.E.S Medicine, Dur Washington U Baltimore, M Germany (R. Maryland (D. Tennessee (B Hackensack U Healthcare, H Mountain View Oregon Healt Clinic, Clevel Chicago, Illino Ontario, Can Bioengineerin Menlo Park, DeBakey Hea (M.L.M., S.F University o Institute/Lava General Hosp M.S.-C.); the Philips Healt Irvine, Califor (G.S.S.); Yale Imaging, Nor San Francis Pennsylvania Center, Wash

Detection and display of acoustic window for guiding and training cardiac ultrasound users

Successful ultrasound data collection strongly relies on the skills of the operator. Among different scans, echocardiography is especially challenging as the heart is surrounded by ribs and lung tissue. Less experienced users might acquire compromised images because of suboptimal hand-eye coordination and less awareness of artifacts. Clearly, there is a need for a tool that can guide and train less experienced users to position the probe optimally. We propose to help users with hand-eye coordination by displaying lines overlaid on B-mode images. The lines indicate the edges of blockages (e.g., ribs) and are updated in real time according to movement of the probe relative to the blockages. They provide information about how probe positioning can be improved. To distinguish between blockage and acoustic window, we use coherence, an indicator of channel data similarity after applying focusing delays. Specialized beamforming was developed to estimate coherence. Image processing is applied to coherence maps to detect unblocked beams and the angle of the lines for display. We built a demonstrator based on a Philips iE33 scanner, from which beamsummed RF data and video output are transferred to a workstation for processing. The detected lines are overlaid on B-mode images and fed back to the scanner display to provide users real-time guidance. Using such information in addition to B-mode images, users will be able to quickly find a suitable acoustic window for optimal image quality, and improve their skill.

Machine learning based automated dynamic quantification of left heart chamber volumes

AIMS Studies have demonstrated the ability of a new automated algorithm for volumetric analysis of 3D echocardiographic (3DE) datasets to provide accurate and reproducible measurements of left ventricular and left atrial (LV, LA) volumes at end-systole and end-diastole. Recently, this methodology was expanded using a machine learning (ML) approach to automatically measure chamber volumes throughout the cardiac cycle, resulting in LV and LA volume-time curves. We aimed to validate ejection and filling parameters obtained from these curves by comparing them to independent well-validated reference techniques. METHODS AND RESULTS We studied 20 patients referred for cardiac magnetic resonance (CMR) examinations, who underwent 3DE imaging the same day. Volume-time curves were obtained for both LV and LA chambers using the ML algorithm (Philips HeartModel), and independently conventional 3DE volumetric analysis (TomTec), and CMR images (slice-by-slice, frame-by-frame manual tracing). Automatically derived LV and LA volumes and ejection/filling parameters were compared against both reference techniques. Minor manual correction of the automatically detected LV and LA borders was needed in 4/20 and 5/20 cases, respectively. Time required to generate volume-time curves was 35 ± 17 s using ML algorithm, 3.6 ± 0.9 min using conventional 3DE analysis, and 96 ± 14 min using CMR. Volume-time curves obtained by all three techniques were similar in shape and magnitude. In both comparisons, ejection/filling parameters showed no significant inter-technique differences. Bland-Altman analysis confirmed small biases, despite wide limits of agreement. CONCLUSION The automated ML algorithm can quickly measure dynamic LV and LA volumes and accurately analyse ejection/filling parameters. Incorporation of this algorithm into the clinical workflow may increase the utilization of 3DE imaging.