Motion-Based Technical Skills Assessment in Transoesophageal Echocardiography

This paper presents a novel approach for evaluating technical skills in Transoesophageal Echocardiography (TEE). Our core assumption is that operational competency can be objectively expressed by specific motion-based measures. TEE experiments were carried out with an augmented reality simulation platform involving both novice trainees and expert radiologists. Probe motion data were collected and used to formulate various kinematic parameters. Subsequent analysis showed that statistically significant differences exist among the two groups for the majority of the metrics investigated. Experts exhibited lower completion times and higher average velocity and acceleration, attributed to their refined ability for efficient and economical probe manipulation. In addition, their navigation pattern is characterised by increased smoothness and fluidity, evaluated through the measures of dimensionless jerk and spectral arc length. Utilised as inputs to well-known clustering algorithms, the derived metrics are capable of discriminating experience levels with high accuracy (>84 %)

Automated Performance Assessment in Transoesophageal Echocardiography with Convolutional Neural Networks

Transoesophageal echocardiography (TEE) is a valuable diagnostic and monitoring imaging modality. Proper image acquisition is essential for diagnosis, yet current assessment techniques are solely based on manual expert review. This paper presents a supervised deep learning framework for automatically evaluating and grading the quality of TEE images. To obtain the necessary dataset, 38 participants of varied experience performed TEE exams with a high-fidelity virtual reality (VR) platform. Two Convolutional Neural Network (CNN) architectures, AlexNet and VGG, structured to perform regression, were finetuned and validated on manually graded images from three evaluators. Two different scoring strategies, a criteria-based percentage and an overall general impression, were used. The developed CNN models estimate the average score with a root mean square accuracy ranging between 84% − 93%, indicating the ability to replicate expert valuation. Proposed strategies for automated TEE assessment can have a significant impact on the training process of new TEE operators, providing direct feedback and facilitating the development of the necessary dexterous skills

Perioperative and acute care transesophageal echocardiography (TOE)

In Pakistan perioperative transoesophageal echocardiography (TOE) during cardiac surgery is available in a few centers with reliance on cardiologists and cardiac technicians and its use in noncardiac surgery and intensive care units is very limited. In view of the increasing popularity of TOE based on obvious benefits this review is presented with an aim to evaluate the current indications and potential benefits of using TOE during anesthesia for cardiac and non-cardiac surgery and the intensive care units and compare TOE with pulmonary artery catheter (PAC) and transthoracic echocardiography (TTE) as an hemodynamic monitor in the acute care setting

Validation of a Focused Basic Transthoracic Echocardiography Training Programme for Irish Critical Care Doctors

Transthoracic Echocardiography (TTE) is a technique for scanning the human heart using ultrasound. It enables us to acquire vital information about the size, structure and function of the heart. This test is a crucial cardiac diagnostic test. Historically TTE was used only in cardiology departments, undertaken by trained personnel called cardiac physiologists or cardiology doctors. More recently, TTE has been recognized to be very useful in the management of critically ill patients in the intensive care and high dependency units of our hospitals. Currently bedside TTE on these patients is performed by cardiac physiologists who are generally only available during the hours of 8am to 5pm Monday to Friday or by the cardiology registrar who may be only available on a limited basis. In 2012 a pilot training programme in TTE for intensivists was undertaken at the Mater Misericordiae University Hospital (MMUH) Critical Care Complex. The aim of the programme was to teach basic echocardiography skills to intensive care fellows over a six month period. This overall study expands on that pilot study and evaluates a training course for critical care fellows in practical and cognitive aspects of basic echocardiography. Purpose of study Achieving competency in TTE by intensive care fellows has become officially endorsed by ICU training bodies. During 2013 the Joint Faculty of Intensive Care Medicine Ireland, formally recognized TTE as an important and desirable skill for the ICU fellow in training. Since 2014 the Australian College of Intensive Care Medicine requires all ICU fellows in training to complete an approved basic TTE training course. Therefore,it is clear that the future of intensive care medicine programmes in Ireland must include formal echocardiography training. Methodology In January 2014 we introduced data collection sheets on our bi annual hands-on training course in the MMUH Intensive Care Department. At the end of the 20 week training programme the fellows were given a written exam, video cases and a practical exam and the results were collated in data sheets. The study was a comparison between expert and fellow – with expert being the gold standard/reference – in acquiring the echo views and assessing the specific clinical domains required for a critical care fellow. Results The results showed that after 20 weeks (40 hours) of training the fellows showed competency in acquiring the standard echo views, and also showed a favourable comparison with expert in terms of assessing the clinical domains required for a critical care fellow. Conclusion It is recommended that basic echocardiography should be part of the curriculum for Irish critical care fellows. This study demonstrates that a suitably structured 20 week training programme in TTE for intensive care fellows can achieve competency in performing a TTE in the intensive care setting

What is new in pediatric cardiac imaging?

Cardiac imaging has had significant influence on the science and practice of pediatric cardiology. Especially the development and improvements made in noninasive imaging techniques, like echocardiography and cardiac magnetic resonance imaging (MRI), have been extremely important. Technical advancements in the field of medical imaging are quickly being made. This review will focus on some of the important evolutions in pediatric cardiac imaging. Techniques such as intracardiac echocardiography, 3D echocardiography, and tissue Doppler imaging are relatively new echocardiographic techniques, which further optimize the anatomical and functional aspects of congenital heart disease. Also, the current standing of cardiac MRI and cardiac computerized tomography will be discussed. Finally, the recent European efforts to organize training and accreditation in pediatric echocardiography are highlighted

Measurement of left ventricular function in anaesthetised horses using transoesophageal doppler echocardiography

Studies were undertaken using transesophageal Doppler echocardiography to monitor left ventricular systolic function in anaesthetised horses. A 3.5 MHz transoesophageal probe was specifically developed in collaboration with Vingmed Sound for equine use. The indices of systolic function investigated were maximum acceleration of aortic blood flow (dv/dt^J, maximum blood flow velocity, (V^J, cardiac output (CO), left ventricular pre-ejection period (PEP) and left ventricular ejection time (ET).The feasibility of the technique was demonstrated in a group of 8 healthy Thoroughbred horses anaesthetised using a standard protocol. It was established that two dimensional transoesophageal echocardiography provided a reference view of the left ventricular outflow tract and aorta that consistently allowed high quality Doppler echocardiographic measurement of aortic blood flow velocity. The flow envelopes obtained were suitable for measurement of indices of left ventricular systolic function. The repeatability of the measured indices was similar to that of the maximum rate of rise of left ventricular pressure (LVdp/dtmax), obtained simultaneously by cardiac catheterisation.Cardiac output estimations made using transoesophageal Doppler echocardiography were compared with those obtained by thermodilution in the same group of horses under general anaesthesia. Cardiac output was altered by infusions of the sympathomimetic amine, dobutamine. Aortic velocity spectra obtained both by high pulse repetition frequency and continuous wave insonation modes were used to obtain the velocity time integral for calculation of cardiac output. The measurements derived from transoesophageal echocardiography agreed well with those obtained by thermodilution. Both correlation coefficients and limits of agreement between the two techniques were better than those obtained from similar studies in standing horses using transthoracic echocardiography.The sensitivity of the Doppler derived indices of left ventricular function to inotropic intervention was assessed in the final sequence of studies. As these indices are derived during the ejection period they are load dependent, so their response to changes in ventricular loading was also assessed and compared with the most commonly used index of myocardial contractility in horses, LVdp/dtmax. Three drugs were administered to the anaesthetised horses in a randomised sequence during three separate anaesthetic episodes. The drugs, dobutamine, dopamine and dopexamine were selected because of their relatively different effects on afterload, preload and contractility. Maximum acceleration of aortic blood flow was as sensitive to the changes in ventricular performance as LVdp/dtmax. Maximum aortic blood velocity showed the same qualitative response to infusion of the drugs but the changes were quantitatively less than in dv/dtmax and LVdp/dtmax. The systolic time intervals, PEP and ET, were also responsive to drug infusion; pre-ejection period shortened with each drug, whilst ET increased after dopamine and dopexamine, but was reduced by dobutamine.These studies have shown that dv/dtmax is as sensitive as the invasive index LVdp/dtmax for detecting changes in left ventricular performance. In addition dv/dtmax and Vmax appear to be no more affected by changes in ventricular loading conditions than the isovolumic index LVdp/dtmax. It is concluded that transoesophageal Doppler echocardiography provides a minimally invasive technique for assessment of left ventricular systolic function in anaesthetised horses

Evaluation of the quality of transesophageal echocardiography images and verification of proficiency

Various metrics have been used in curriculum-based transesophageal echocardiography (TEE) training programs to evaluate acquisition of proficiency. However, the quality of task completion, that is the final image quality, was subjectively evaluated in these studies. Ideally, the endpoint metric should be an objective comparison of the trainee-acquired image with a reference ideal image. Therefore, we developed a simulator-based methodology of preclinical verification of proficiency (VOP) in trainees by tracking objective evaluation of the final acquired images. We utilized geometric data from the simulator probes to compare image acquisition of anesthesia residents who participated in our structured longitudinal simulator-based TEE educational program vs ideal image planes determined from a panel of experts. Thirty-three participants completed the study (15 experts, 7 postgraduate year (PGY)-1 and 11 PGY-4). The results of our study demonstrated a significant difference in image capture success rates between learners and experts (χ2 = 14.716, df = 2, P < 0.001) with the difference between learners (PGY-1 and PGY-4) not being statistically significant (χ2 = 0, df = 1, P = 1.000). Therefore, our results suggest that novices (i.e. PGY-1 residents) are capable of attaining a level of proficiency comparable to those with modest training (i.e. PGY-4 residents) after completion of a simulation-based training curriculum. However, professionals with years of clinical training (i.e. attending physicians) exhibit a superior mastery of such skills. It is hence feasible to develop a simulator-based VOP program in performance of TEE for junior anesthesia residents