Methods of measurement of image quality in teleultrasound

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.

Accuracy and reliability of tele-ultrasonography in detecting gastrointestinal obstruction in dogs and cats

OBJECTIVES

To assess the accuracy and interobserver agreement of tele-ultrasonography for the diagnosis of gastrointestinal obstruction in small animals by radiologists with different levels of experience.

MATERIALS AND METHODS

A retrospective cross-sectional study including dogs and cats admitted with gastrointestinal signs, between 2017 and 2019, that had abdominal ultrasonographic (US) examination performed and images saved for review. Patients were classified into two categories based on final diagnosis: animals with or without complete or partial gastrointestinal obstruction. Observers with four experience levels interpreted the archived ultrasound examinations, simulating a tele-ultrasonography consultation. Analyses of accuracy, sensitivity, specificity, positive and negative predictive values were obtained for each observer for detection of gastrointestinal obstruction. Agreement between observers for the gastrointestinal obstruction diagnosis was assessed using Fleiss's Kappa statistics.

RESULTS

Ninety patients with gastrointestinal signs were included. Of these, 23 of 90 had partial or complete gastrointestinal obstruction. Interpretation of the images by observers via tele-ultrasonography showed intervals of accuracy, sensitivity, specificity, positive and negative predictive values, respectively, of 78.9% to 87.8%, 73.9% to 100%, 77.6% to 89.6%, 55.9% to 70.8% and 90.9% to 100% for diagnosis of gastrointestinal obstruction. Agreement for the gastrointestinal obstruction diagnosis across all reviewers was moderate (Kappa 0.6).

CLINICAL SIGNIFICANCE

Tele-ultrasonography had good accuracy for detection of gastrointestinal obstruction, however had a rather low positive predictive value and only moderate interobserver agreement. Therefore, this technique should be used with caution in this clinical context, given the potential surgical decision at hand.

Society for Maternal-Fetal Medicine Special Statement: Telemedicine in obstetrics-quality and safety considerations

The frequency of telemedicine encounters has increased dramatically in recent years. This review summarizes the literature regarding the safety and quality of telemedicine for pregnancy-related services, including prenatal care, postpartum care, diabetes mellitus management, medication abortion, lactation support, hypertension management, genetic counseling, ultrasound examination, contraception, and mental health services. For many of these, telemedicine has several potential or proven benefits, including expanded patient access, improved patient satisfaction, decreased disparities in care delivery, and health outcomes at least comparable to those of traditional in-person encounters. Considering these benefits, it is suggested that payers should reimburse providers at least as much for telemedicine as for in-person services. Areas for future research are considered.

Dermatologic Ultrasound in Primary Care: A New Modality of Teledermatology: A Prospective Multicenter Validation Study

OBJECTIVES

This study aimed to validate dermatologic ultrasound as a complementary teledermatologic imaging modality in primary and tertiary care centers.

METHODS

Six primary care centers and 1 tertiary care dermatology department collaborated in the program. Images were sent through the institutional teledermatologic platform to the tertiary care dermatology department. At the reference hospital, ultrasound images and clinical data were received and registered by a physician trained in dermatologic ultrasound. An in-person consultation was scheduled to confirm the teleultrasound diagnosis. The time of response by the tertiary center, quality and size of the teledermatologic image, and concordance with the in-person diagnosis were assessed for each dermatologic lesion.

RESULTS

A total of 147 teleultrasound consultations with 143 patients (93 women and 50 men; mean age ± SD, 47 ± 23 years) were evaluated between June 2018 and January 2019. Nine teleultrasound consultations (6.1%) were not valid. Discordance between teleultrasound and the in-person diagnosis was evident in 6 of 138 cases (4.3%). Most cases corresponded to benign skin tumors (66.7%), followed by inflammatory skin lesions (15.9%), nonmelanoma skin lesions (13%), and other skin lesions (4.3%). All malignant tumors were detected (sensitivity, 100%), although 2 cases of benign lesions were telediagnosed as malignant (specificity, 97.8%). The positive and negative predictive values of a teleultrasound diagnosis of cutaneous malignancy were 90% and 100%, respectively.

CONCLUSIONS

Asynchronous primary care teleultrasound combined with dermatologic ultrasound training at tertiary centers is an effective teledermatologic modality.

Trans-Pacific tele-ultrasound image transmission of fetal central nervous system structures

OBJECTIVE

To assess the quality of images and video clips of fetal central nervous (CNS) structures obtained by ultrasound and transmitted via tele-ultrasound from Brazil to Australia.

METHODS

In this cross-sectional study, 15 normal singleton pregnant women between 20 and 26 weeks were selected. Fetal CNS structures were obtained by images and video clips. The exams were transmitted in real-time using a broadband internet and an inexpensive video streaming device. Four blinded examiners evaluated the quality of the exams using the Likert scale. We calculated the mean, standard deviation, mean difference, and p values were obtained from paired t tests.

RESULTS

The quality of the original video clips was slightly better than that observed by the transmitted video clips; mean difference considering all observers = 0.23 points. In 47/60 comparisons (78.3%; 95% CI = 66.4-86.9%) the quality of the video clips were judged to be the same. In 182/240 still images (75.8%; 95% CI = 70.0-80.8%) the scores of transmitted image were considered the same as the original.

CONCLUSION

We demonstrated that long distance tele-ultrasound transmission of fetal CNS structures using an inexpensive video streaming device provided images of subjective good quality.

Image quality in real-time teleultrasound of infant hip exam over low-bandwidth internet links: a transatlantic feasibility study

Evolution of communication systems, especially internet-based technologies, has probably affected Radiology more than any other medical specialty. Tremendous increase in internet bandwidth has enabled a true revolution in image transmission and easy remote viewing of the static images and real-time video stream. Previous reports of real-time telesonography, such as the ones developed for emergency situations and humanitarian work, rely on high compressions of images utilized by remote sonologist to guide and supervise the unexperienced examiner. We believe that remote sonology could be also utilized in teleultrasound exam of infant hip. We tested feasibility of a low-cost teleultrasound system for infant hip and performed data analysis on the transmitted and original images. Transmission of data was accomplished with Remote Ultrasound (RU), a software package specifically designed for teleultrasound transmission through limited internet bandwidth. While image analysis of image pairs revealed statistically significant loss of information, panel evaluation failed to recognize any clinical difference between the original saved and transmitted still images.

Tele-obstetric ultrasound: analysis of first-trimester ultrasound images transmitted in realtime

We evaluated the diagnostic quality of first-trimester ultrasound images transmitted in realtime using low-cost telecommunications. A prospective sample of fetal ultrasound images from 11 weeks to 13 weeks and six days of pregnancy was obtained from pregnant women over 18 years old. The examinations were transmitted in realtime to three independent examiners who carried out a qualitative assessment based on parameters established by the Fetal Medicine Foundation. All fetal structures could be viewed and the quality of images received by the examiners was considered normal. There were significant differences for crown-rump length and nuchal translucency in the transmitted images but the loss in definition was acceptable. Thus the quality of images transmitted via the Internet through the use of low-cost software appeared suitable for screening for chromosomal abnormalities in the first trimester of pregnancy.

Telesonography: foundations and future directions

The practice of telesonography has yielded promising results in several domestic and international projects aimed at providing basic sonography services. Common themes that recur within telesonography-based research include the quality of transmitted images, clinical applications, and technical and nontechnical barriers to implementation. The research base continues to grow in concert with expanding telecommunications capabilities and refinement of small portable sonographic devices. Persistent barriers to the deployment of telesonography systems include a lack of telecommunications access, a lack of standard training and operational protocols, and a paucity of research regarding the long-term health impact of telesonography within target communities. Telesonography may be used directly to improve the standard of care within a given community; however, limited resources and interest may prevent sustained operations. Future projects may use telesonography to supplement the training of health care providers in remote locations in an effort to establish permanent sonography services for their respective communities.

A comparison of telesonography with standard ultrasound care in a rural Dominican clinic

We compared telesonography to usual patient care in a rural clinic in the Dominican Republic. A total of 108 low-income Dominican and Haitian patients volunteered to participate. The patients were randomly assigned to either telesonography or control groups. Patients in the telesonography group were scanned and sonographic images and Request for Interpretation (RFI) forms were sent by email to six volunteer radiologists in the USA. Completed RFI forms were transmitted back to the clinic at the radiologists' earliest convenience. Patients in the control group received an ordinary ultrasound referral, which required travel to a tertiary medical centre where their scans were completed by a local sonographer. Sonographic reports from the control group were hand delivered to the referring physician at patient follow-up. The telesonography system provided a four-fold increase in the proportion of patient follow-ups and a six-fold increase in the proportion of returned radiological reports. In the telemedicine group, the median total elapsed time from referral to report return was 17.8 h (interquartile range, IQR 12.2-27.1) and the median time to patient follow-up was 67.1 h (IQR 45.9-113.7). The latter was similar in the control group, where the median total elapsed time was 76.7 h (IQR 65.8-144.7). The pilot study demonstrated that store-and-forward telesonography reduced time to diagnosis and increased the continuity of care compared to the usual ultrasound referral system in the region of the Dominican Republic which was studied.

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.

A blurring index for medical images

This study was undertaken to investigate a useful image blurring index. This work is based on our previously developed method, the Moran peak ratio. Medical images are often deteriorated by noise or blurring. Image processing techniques are used to eliminate these two factors. The denoising process may improve image visibility with a trade-off of edge blurring and may introduce undesirable effects in an image. These effects also exist in images reconstructed using the lossy image compression technique. Blurring and degradation in image quality increases with an increase in the lossy image compression ratio. Objective image quality metrics [e.g., normalized mean square error (NMSE)] currently do not provide spatial information about image blurring. In this article, the Moran peak ratio is proposed for quantitative measurement of blurring in medical images. We show that the quantity of image blurring is dependent upon the ratio between the processed peak of Moran's Z histogram and the original image. The peak ratio of Moran's Z histogram can be used to quantify the degree of image blurring. This method produces better results than the standard gray level distribution deviation. The proposed method can also be used to discern blurriness in an image using different image compression algorithms.

Defining obtrusiveness in home telehealth technologies: a conceptual framework

The literature of home telehealth technology recommends that systems be designed to minimize their obtrusiveness to end users. However, this term is neither explicitly defined nor consistently used. This paper presents a definition of the concept of obtrusiveness. Within this definition, twenty-two categories of what may be perceived as obtrusive in home telehealth technology are proposed based on a review of the literature. These categories are grouped into eight dimensions. This effort represents an initial step toward developing measures of obtrusiveness associated with home telehealth technology. A validated and reliable instrument would allow for evaluation of individual applications as well as theory-building across applications.

To Telemedically Err Is Human

BACKGROUND

As telemedicine alters the process of health care and introduces new technology, the extent to which it introduces new errors or allows for the occurrence of familiar errors needs to be examined. TELEMEDICINE'S IMPACT ON PATIENT SAFETY FEATURES OF TRADITIONAL CARE: The accuracy of diagnostic decisions reached via telemedicine can be directly affected by the technology's limitations and the care providers' lack of training. Telemedicine could increase the risk of familiar types of patient-provider communication failure and introduce the possibility of cumulative errors. TELEMEDICINE'S IMPACT ON NEW CARE FEATURES AND CONCEPTS: Telemedical applications that use the Internet to enhance disease management and detection and monitoring of symptoms may place the privacy and confidentiality of individual health information at risk, which imposes a possible barrier to communication. In addition, home care patients' functional limitations need to be addressed by human factors engineering.

RECOMMENDATIONS

Patient safety should be integrated in organizational readiness and budget planning for telemedical interventions in hospitals, academic settings, nursing homes, home care agencies, and other health care settings. Specific recommendations are proposed for the development and diffusion of standards in telemedical care, risk management and reduction, and continuous quality improvement.

SUMMARY AND CONCLUSIONS

To address patient safety and provide high-quality care, a framework for addressing and examining telemedical errors needs to be established.

A statistical method for evaluation quality of medical images: a case study in bit discarding and image compression

Many studies have been performed on quality evaluation for subtle differences in medical images. However, only limited success has been achieved. In this paper, medical images were prior manipulated by denoising, lossy compression and filtering. The Moran statistics is then applied to extract spatial information of images and using Kolmogorov-Smirnov (KS) test to determine whether the manipulated and original images differ significantly. Results show that on average discarding 1-2 bits in T1 and CR images or 2-3 bits in T2 and body CT images are indistinguishable. This method is also applied to a reconstructed MR, body CT image and an electronic SMPTE (Society of Motion Picture and Television Engineer) phantom from lossy image compression software. Compression ratios of 16:1 for a MR image, 8-9:1 for a cropped body CT image, 7:1 and 5:1 for high- and low-resolution regions in electronic phantom is proved undifferentiated from original. The proposed method is useful for complementing the human visual system, to optimize the performance of image compression technique.

Quality degradation in lossy wavelet image compression

The objective of this study was to develop a method for measuring quality degradation in lossy wavelet image compression. Quality degradation is due to denoising and edge blurring effects that cause smoothness in the compressed image. The peak Moran z histogram ratio between the reconstructed and original images is used as an index for degradation after image compression. The Moran test is applied to images randomly selected from each medical modality, computerized tomography, magnetic resonance imaging, and computed radiography and compressed using the wavelet compression at various levels. The relationship between the quality degradation and compression ratio for each image modality agrees with previous reports that showed a preference for mildly compressed images. Preliminary results show that the peak Moran z histogram ratio can be used to quantify the quality degradation in lossy image compression. The potential for this method is applications for determining the optimal compression ratio (the maximized compression without seriously degrading image quality) of an image for teleradiology.

A novel image quality index using Moran I statistics

Measurement of image quality is very important for various applications such as image compression, restoration and enhancement. Conventional methods (e.g., mean squared error; MSE) use error summation to measure quality change pixel by pixel and do not correlate well with subjective quality measurement. This is due to the fact that human eyes extract structural information from the viewing field. In this study a new quality index using a Moran I statistics is proposed. The Moran statistic that measures the sharpness from a local area is a good index of quality as most image processing techniques alter the smoothness of the image. Preliminary results show that the new quality index outperforms the MSE significantly under various types of image distortions.