Real-time transmission of full-motion echocardiography over a high-speed data network: impact of data rate and network quality of service

Use of Real-Time Remote Tele-mentored Ultrasound Echocardiography for Cardiovascular Disease Diagnosis in Adults: A Systematic Review

Cardiovascular diseases remain a major health challenge, leading to high rates of death and hospitalization globally. In the battle against these ailments, echocardiography stands as the frontline tool for diagnosis. Pioneering the charge in innovation, real-time remote tele-mentored ultrasound echocardiography (RTMUS echo) has emerged. This cutting-edge technique facilitates the instant transmission of cardiac imaging from the patient's side to experts in far-off locations, enabling prompt diagnosis and expert consultation. To bridge this gap, a systematic review was conducted to understand RTMUS echo's current applications in diagnosing heart diseases. Searches across six databases, guided by strict inclusion and exclusion criteria, yielded nine relevant articles. These studies assessed the feasibility of RTMUS echo and the technology behind it, confirming its potential for high-quality cardiac imaging. The findings reveal that RTMUS echo could notably improve care for cardiac patients, especially those in resource-constrained settings or in isolation because of infection risks. This technology enables quick access to diagnostic expertise, which is otherwise unavailable in such areas. Future research should aim to optimize the cost-effectiveness and application of RTMUS echo to enhance its benefits for global healthcare.

Open access integrated therapeutic and diagnostic platforms for personalized cardiovascular medicine

It is undeniable that the increasing costs in healthcare are a concern. Although technological advancements have been made in healthcare systems, the return on investment made by governments and payers has been poor. The current model of care is unsustainable and is due for an upgrade. In developed nations, a law of diminishing returns has been noted in population health standards, whilst in the developing world, westernized chronic illnesses, such as diabetes and cardiovascular disease have become emerging problems. The reasons for these trends are complex, multifactorial and not easily reversed. Personalized medicine has the potential to have a significant impact on these issues, but for it to be truly successful, interdisciplinary mass collaboration is required. We propose here a vision for open-access advanced analytics for personalized cardiac diagnostics using imaging, electrocardiography and genomics.

Near real-time echocardiography teleconsultation using low bandwidth and MPEG-4 compression: feasibility, image adequacy and clinical implications

We assessed the feasibility, image adequacy and clinical utility of a tele-echocardiography service which combined video compression with low-bandwidth store-and-forward transmission. Echocardiograms were acquired by a hospital geriatrician, compressed and transmitted using both near real-time (urgent) and delayed (pre-programmed) protocols via an Internet connection to the notebook PC of a remote cardiologist. Clinical utility was evaluated as a change in therapeutic management. During a one-year period, 101 tele-echocardiography consultations were successfully performed (feasibility = 100%) on 95 patients (age 22-95 years), admitted with cardiovascular or neurological diagnoses (24% of the consultations were urgent). In total, 4617 files (1.4 GByte of data) were transmitted, 2669 of which were short video clips. On average, 46 files (13.8 MByte) were transmitted (mean duration 10 min) at each examination. Consultations (both urgent and pre-programmed) were clinically useful in 83% of examinations. Logistic regression analysis showed that both a low left ventricular systolic function and the examination indication were determinants of clinical utility. The transmitted images were considered adequate for diagnosis in 100% of the pre-programmed teleconsultations. Tele-echocardiography using MPEG-4 video compression is a feasible, adequate and clinically useful tool for telemedicine.

Tele-ultrasound and paramedics: real-time remote physician guidance of the Focused Assessment With Sonography for Trauma examination

OBJECTIVES

The aim of this study was to examine the capability of ultrasound-naïve paramedics to obtain interpretable Focused Assessment With Sonography for Trauma (FAST) images under the remote direction of emergency physicians (EPs).

METHODS

Paramedics without experience using ultrasound participated in a 20-minute lecture covering orientation to the ultrasound machine and the FAST examination. The paramedics subsequently performed FAST examinations on a model patient, whereas the EP remained in another room, out of visual contact. The EP communicated with the paramedic via radio, viewing video from the ultrasound machine on a monitor and directing the probe movements to obtain the views of the FAST examination. We examined the success rate, time to complete the examinations, and adequacy of images from the paramedics' first FAST examination.

RESULTS

Fifty-one paramedics performed their first FAST examinations and were able to successfully complete 100% of the views of the FAST. The median time from probe placement to examination completion was 262 seconds (interquartile range, 206-343 seconds). The median time to complete right upper quadrant (RUQ) versus left upper quadrant (LUQ) views was 39 and 50 seconds, respectively. The time to complete the LUQ scan took significantly longer than the RUQ (P < .01). Paramedics completed cardiac and pelvic view in a median time of 42 and 25 seconds, respectively.

CONCLUSIONS

The study demonstrated that paramedics with no prior ultrasound experience could obtain FAST images under remote guidance from experienced EPs in less than 5 minutes. Given rapidly evolving data transmission technology, this has applicability in battlefield, remote, and rural prehospital settings.

Pilot study to determine the feasibility of training Army National Guard medics to perform focused cardiac ultrasonography

OBJECTIVE

To assess the ability of Army National Guard combat medics to perform a limited bedside echocardiography (BE) to determine cardiac activity after a brief training module.

METHODS

Twelve Army National Guard health care specialists trained to the level of emergency medical technician-basic (EMT-B) underwent an educational session consisting of a 5-minute lecture on BE followed by hands-on practical training. After the training session, each medic performed BEs, in either the subxiphoid (SX) or parasternal (PS) location at his or her discretion, on four healthy volunteers. The time required to complete the BE and the anatomic location of the examination (SX vs. PS) was documented. A 3-second video clip representing the best image was recorded for each BE. These clips were subsequently reviewed independently by two of the investigators with experience performing and interpreting BE; each BE was graded on a six-point scale designed for the study, the Cardiac Ultrasound Structural Assessment Scale (CUSAS). A score of 3 or greater was considered to be adequate to assess for the presence of cardiac activity. Where there was disagreement on the CUSAS score, the reviewers viewed the clip together and agreed on a consensus CUSAS score. We calculated the median time to completion and interquartile range (IQR) for each BE, the median CUSAS scores and IQR for examinations performed in the SX and PS locations, and kappa for agreement between the two reviewers on the CUSAS.

RESULTS

A total of 48 BEs were recorded and reviewed. Thirty-seven of 48 (77%) were obtained in the SX location, and 11 of 48 (23%) were obtained in the PS location. Forty-four of 48 (92%) were scored as a 3 or higher on the CUSAS. Median time to completion of a BE was 5.5 seconds (IQR: 3.7-10.9 seconds). The median CUSAS score in the SX location was 4 (IQR: 4-5), and the median CUSAS score in the PS location was 4 (IQR: 4-4). Weighted kappa for the CUSAS was 0.6.

CONCLUSION

With minimal training, the vast majority of the medics in our study were able to rapidly perform a focused BE on live models that was adequate to assess for the presence of cardiac activity.

Validation of an automatic tool for the assessment of image quality in digital tele-echocardiography

We investigated a novel tool for assessing image degradation in tele-echocardiography. Different video recordings from an echocardiographic examination were transmitted using commercial videoconferencing equipment via a local area network. Different compression schemes were selected, ranging from MPEG 1 to MPEG 4, with transmission at different bit rates ranging from 1.0 to 4.5 Mbit/s. Three methods were used to compare the transmitted and received video sequences: the peak signal to noise ratio, the Double Stimulus Impairment Scale (DSIS) and the National Telecommunication and Information Administration Virtual Quality Metric (VQM). The results showed that the most useful grading procedure was the subjective DSIS. There was a high correlation between the DSIS results and the VQM. The VQM could be thus an effective tool for evaluating tele-echocardiography transmission systems, avoiding the costs and times associated with conducting subjective tests in repeatable conditions.

High-grade video compression of echocardiographic studies: a multicenter validation study of selected motion pictures expert groups (MPEG)-4 algorithms

BACKGROUND

Large files produced by standard compression algorithms slow down spread of digital and tele-echocardiography. We validated echocardiographic video high-grade compression with the new Motion Pictures Expert Groups (MPEG)-4 algorithms with a multicenter study.

METHODS

Seven expert cardiologists blindly scored (5-point scale) 165 uncompressed and compressed 2-dimensional and color Doppler video clips, based on combined diagnostic content and image quality (uncompressed files as references). One digital video and 3 MPEG-4 algorithms (WM9, MV2, and DivX) were used, the latter at 3 compression levels (0%, 35%, and 60%).

RESULTS

Compressed file sizes decreased from 12 to 83 MB to 0.03 to 2.3 MB (1:1051-1:26 reduction ratios). Mean SD of differences was 0.81 for intraobserver variability (uncompressed and digital video files). Compared with uncompressed files, only the DivX mean score at 35% (P = .04) and 60% (P = .001) compression was significantly reduced. At subcategory analysis, these differences were still significant for gray-scale and fundamental imaging but not for color or second harmonic tissue imaging. Original image quality, session sequence, compression grade, and bitrate were all independent determinants of mean score.

CONCLUSIONS

Our study supports use of MPEG-4 algorithms to greatly reduce echocardiographic file sizes, thus facilitating archiving and transmission. Quality evaluation studies should account for the many independent variables that affect image quality grading.

The architecture of a mobile outreach echocardiography service

We describe the outreach echocardiography program at our tertiary care referral center in southeast Minnesota. Cardiac sonographers from our institution transport ultrasonographic imaging equipment to regional hospitals and clinics where they perform complete transthoracic echocardiographic examinations. Digital images from standard 2-dimensional, color flow, and Doppler echocardiography are transferred to our clinic for interpretation by a cardiologist. The outreach program enables physicians without access to echocardiography to use this powerful diagnostic tool in the local evaluation of patients with suggested or known heart disease. We detail the organization of our outreach echocardiography program and emphasize the team approach that facilitates optimal image acquisition, prompt interpretation, and timely reporting of results.

A low-cost digital filing system for echocardiography data with MPEG4 compression and its application to remote diagnosis

The high cost of digital echocardiographs and the large size of data files hinder the adoption of remote diagnosis of digitized echocardiography data. We have developed a low-cost digital filing system for echocardiography data. In this system, data from a conventional analog echocardiograph are captured using a personal computer (PC) equipped with an analog-to-digital converter board. Motion picture data are promptly compressed using a moving pictures expert group (MPEG) 4 codec. The digitized data with preliminary reports obtained in a rural hospital are then sent to cardiologists at distant urban general hospitals via the internet. The cardiologists can evaluate the data using widely available movie-viewing software (Windows Media Player). The diagnostic accuracy of this double-check system was confirmed by comparison with ordinary super-VHS videotapes. We have demonstrated that digitization of echocardiography data from a conventional analog echocardiograph and MPEG 4 compression can be performed using an ordinary PC-based system, and that this system enables highly efficient digital storage and remote diagnosis at low cost.

A Perioperative Echocardiographic Reporting and Recording System

Advances in video capture, compression, and streaming technology, coupled with improvements in central processing unit design and the inclusion of a database engine in the Windows operating system, have simplified the task of implementing a digital echocardiographic recording system. I describe an application that uses these technologies and runs on a notebook computer.

Digital video for the documentation of colonoscopy

BACKGROUND

The aim of this study was to determine whether digital video is suitable for the documentation of colonoscopy. Standards are required for the visual documentation of endoscopic findings and to optimize image quality while limiting file size and bandwidth requirements.

METHODS

Video recordings of colonoscopy procedures were encoded using a common video compression method at selected data rates and resolutions. Twelve reviewers were selected, each of whom was assigned 8 video review sessions, each consisting of 5 colonoscopy procedures. The reviewers rated the following: level of confidence that the cecum was demonstrated, subjective quality of the video compared with actual videocolonoscopy, and whether the video was of "diagnostic quality."

RESULTS

Reviewers were confident that the cecum was demonstrated in all cases except at the lowest data rate. The 1.0 Mbps standard interchange format video provided an optimal balance between quality and file size.

CONCLUSIONS

For the documentation of colonoscopy, 1.0 Mbps is acceptable and results in a file size of 7.5 Mbytes/min, which is manageable for most modern hospital and telehealth networks.

Telemedicine of the heart: real-time telescreening of echocardiography using satellite telecommunication

The early detection of disease is important to keep people healthy, but it is not easy for elderly residents living in rural areas at a distance from well-equipped medical institutes to be examined. Therefore, the present study evaluated the usefulness of real-time telescreening of echocardiography using satellite communications. The participants in this study were 57 residents of a rural community in Japan. The resolution of the real-time ultrasound images sent by communications satellite was almost identical to that of the original images taken in the hospital. Although some problems remain to be solved, telescreening of echocardiography will be a practical method for public health in the near future.

Feasibility of real-time echocardiographic evaluation during patient transport

Echocardiography is a key diagnostic tool in evaluating patients with cardiac emergencies and chest trauma. The lack of qualified real-time interpretation limits its use by emergency first responders. Early diagnosis of cardiac emergencies has the potential to facilitate triage and medical intervention to improve outcomes. We investigated the feasibility of remote, real-time interpretation of echocardiograms during patient transport. Echocardiograms using a hand-carried ultrasound device were transmitted from an ambulance in transit to a tertiary care facility using a distributed mobile local area network. Transmitted studies were reviewed by a cardiologist for ability to interpret predefined features. Transmission quality and reliability were assessed. Echocardiographic images were successfully transmitted greater than 88% of transport time. The evaluation of left-ventricular size and function, and presence of pericardial effusion were greater than 90% concordant, but only 66% of all echocardiographic features were concordant. Most transmission losses were brief (<or=10 seconds) with little impact on interpretability. Wireless infrastructures in metropolitan areas provide the ability for real-time transmission of echocardiograms during patient transport of adequate quality for accurate interpretation.

Real-time transmission of pediatric echocardiograms using a single ISDN line

We tested the adequacy of a videoconferencing system using a single integrated systems digital network (ISDN) line (128 kilobits per second) for the remote diagnosis of children with suspected congenital heart disease (CHD). Real-time echocardiogram interpretation was compared to subsequent videotape review in 401 studies with concordance in 383 (95.5%) studies. A new diagnosis of CHD was made in 98 studies. Immediate patient transfer was arranged based upon a real-time diagnosis in five studies. In 300 studies, a normal diagnosis obviated further evaluation. A single ISDN line is adequate for transmission of pediatric echocardiograms and it allows for remote management of patients with CHD.

Digital echocardiography 2002: now is the time

The ability to acquire echocardiographic images digitally, store and transfer these data using the DICOM standard, and routinely analyze examinations exists today and allows the implementation of a digital echocardiography laboratory. The purpose of this review article is to outline the critical components of a digital echocardiography laboratory, discuss general strategies for implementation, and put forth some of the pitfalls that we have encountered in our own implementation. The major components of the digital laboratory include (1) digital echocardiography machines with network output, (2) a switched high-speed network, (3) a high throughput server with abundant local storage, (4) a reliable low-cost archive, (5) software to manage information, and (6) support mechanisms for software and hardware. Implementation strategies can vary from a complete vendor solution providing all components (hardware, software, support), to a strategy similar to our own where standard computer and networking hardware are used with specialized software for management of image and measurement information.

Telecardiology: potential impact on acute care

Echocardiography is often used to diagnose and exclude important cardiac diagnoses in adults and children. Evolving telemedicine technology has the potential to improve access to echocardiography diagnoses in the intensive care unit, emergency room, and newborn nursery. The two primary modes of telemedicine practice are "store and forward" and "real-time" videoconferencing. A digital echocardiogram (often several one cardiac cycle loops) can be stored at one site and forwarded across a telemedicine network to a receiving station for review at a later time. Pediatric cardiologists often favor "real-time" telemedicine because of the ability to guide sonographers with limited experience in congenital heart disease. A complete telemedicine system requires a modified computer, a low- or high-speed connection, and telemedicine inputs. Several adult and pediatric clinical studies have shown telemedicine to be accurate and cost-effective, improve patient care, enhance echocardiogram quality and sonographer proficiency, and promote practice expansion. Obstacles to widespread implementation of telemedicine include lack of standardization of telemedicine components, confusing legal issues and licensure requirements, and poor reimbursement.

Telecardiology and the intensive care unit

Technology continues to advance at a pace that produces a new innovation daily. To move forward, clinicians must assess these potential technological solutions adequately for their clinical, financial, and customer satisfaction efficacies. Whether the payers, the patients, or health care will find these systems acceptable has yet to be established completely. The preliminary data in the literature seem to point to physicians' trepidations as the limiting factor. More work is needed on the legal and ethical issues surrounding telemedicine. Telemedicine is progressing quickly from a strange rare subtype of medicine into something that is part and parcel of the practice of medicine in general. Cardiology and intensivist practices have been impacted directly by this technology. As it matures it will be intertwined with daily practice.