Utility of hand-held echocardiography in outpatient pediatric cardiology management

Handheld Ultrasound Video High-Quality Reconstruction Using a Low-Rank Representation Multipathway Generative Adversarial Network

Recently, the use of portable equipment has attracted much attention in the medical ultrasound field. Handheld ultrasound devices have great potential for improving the convenience of diagnosis, but noise-induced artifacts and low resolution limit their application. To enhance the video quality of handheld ultrasound devices, we propose a low-rank representation multipathway generative adversarial network (LRR MPGAN) with a cascade training strategy. This method can directly generate sequential, high-quality ultrasound video with clear tissue structures and details. In the cascade training process, the network is first trained with plane wave (PW) single-/multiangle video pairs to capture dynamic information and then fine-tuned with handheld/high-end image pairs to extract high-quality single-frame information. In the proposed GAN structure, a multipathway generator is applied to implement the cascade training strategy, which can simultaneously extract dynamic information and synthesize multiframe features. The LRR decomposition channel approach guarantees the fine reconstruction of both global features and local details. In addition, a novel ultrasound loss is added to the conventional mean square error (MSE) loss to acquire ultrasound-specific perceptual features. A comprehensive evaluation is conducted in the experiments, and the results confirm that the proposed method can effectively reconstruct high-quality ultrasound videos for handheld devices. With the aid of the proposed method, handheld ultrasound devices can be used to obtain convincing and convenient diagnoses.

Pocket-sized echocardiography for screening structural heart disease: diagnostic accuracy and cost-effectiveness for population-based studies

BACKGROUND

The standard transthoracic echocardiography has some limitations in emergent and community-based situations. The emergence of pocket-sized ultrasound has led to influential advancements.

METHODS

In this prospective study, in the hospital-based phase, children with suspected structural heart diseases were enrolled. In the school-based phase, healthy children were randomly selected from six schools. All individuals were examined by experienced operators using both the standard and the pocket-sized echocardiography.

RESULTS

A total of 73 individuals with a mean age of 9.9 ± 3.2 years in the hospital-based cohort and 143 individuals with a mean age of 12.8 ± 2.9 years in the school-based cohort were examined. The agreements between the standard and the pocket-sized echocardiography were good or excellent for major CHDs in both cohorts (κ statistics > 0.61). Among valvular pathologies, agreements for tricuspid and pulmonary valves' regurgitation were moderate among school-based cohorts (0.56 [95% confidence interval 0.12-1] and 0.6 [95% confidence interval 0.28-0.91], respectively). The agreements for tricuspid and pulmonary valves' regurgitation were excellent (>0.9) among hospital-based population. Other values for valvular findings were good or excellent. The overall sensitivity and specificity were 87.5% (95% confidence interval 47.3-99.7) and 93.8% (95% confidence interval 85-98.3) among the hospital-based individuals, respectively, and those were 88% (95% confidence interval 77.8-94.7) and 68.4% (95% confidence interval 56.7-78.6) among the school-based individuals, respectively. The cost of examination was reduced by approximately 70% for an individual using the pocket-sized device.

CONCLUSIONS

When interpreted by experienced operators, the pocket-sized echocardiography can be used as screening tool among school-aged population.

Smartphone interfaced handheld echocardiography for focused assessment of ventricular function and structure in children: A pilot study

INTRODUCTION

Miniaturized echocardiographic machines improve availability and portability and can be particularly useful for underserved and resource-limited settings. The goal of this study was to compare left ventricular fractional shortening (FS) and left ventricular ejection fraction (LVEF) obtained by a newer handheld echo (HHE) machine to standard transthoracic echocardiogram (TTE) in children.

METHODS

Pediatric outpatients (Birth-18 years) undergoing TTE were prospectively enrolled. HHE protocol included 2D and M-mode images from the parasternal long, short, and apical-4 chamber views. HHE and TTE measurements were reviewed for agreement. Kappa statistic was used to analyze qualitative indices while FS and LVEF were analyzed with Lin's concordance correlation coefficient (CCC) and Bland-Altman limits of agreement (loa).

RESULTS

Sixty children were enrolled; 55 were included in the quantitative analysis. Mean age was 7.5 ± 5.5 years; 67% males; median HHE image acquisition duration was 2.3(1-5) minutes. Fractional shortening and EF by HHE showed good agreement with TTE [CCC = 0.82, 95%CI (0.73,0.90), mean bias -3.18%, loa (-7.00,6.44%) vs CCC = 0.81 (0.72,0.90), mean bias -0.87%, loa (-6.94,5.17%], respectively. In children ≤5 years, HHE FS (n = 20) and EF (n = 21) agreed with TTE measurement [0.59 (0.31, 0.88), mean bias 0.30%, loa (-8.5, 9.1%); 0.79 (0.63, 0.96), mean bias 0.10%, loa (-5.99, 6.14)]. Kappa values for RV size, function, and LV function were 1.00 (P < .05); 0.75 for LV size (P < .05) and 0.66 for pericardial effusion (P < .05).

CONCLUSION

Handheld echo demonstrates good correlation with standard TTE for focused assessment of ventricular chamber sizes and function in children.

Utility of expert focused cardiac ultrasound in paediatric cardiology outreach clinics

OBJECTIVE

This prospective observational study evaluates the utility of expert focused cardiac ultrasound (eFCU) with spectral Doppler to inform decision making in established patients with specific, selected congenital cardiac defects in outreach clinics. Secondary objectives include determining if the addition of eFCU expands capacity in paediatric cardiology outreach clinics and if it improves the patient experience.

METHODS

Patients aged 2 months to 19 years old with a diagnosis of ventricular septal defect, atrial septal defect, atrioventricular septal defect, patent ductus arteriosus, aortic valve stenosis, or pulmonary valve stenosis with the need for follow-up echocardiography in an outreach clinic from August 2017 to June 2018 were studied. A novel assessment tool was used to determine the success of eFCU.

RESULTS

Forty-two patients from 11 clinics underwent eFCU with one unsuccessful exam making the failure rate 2.3% (95% CI 0.0006-0.1256). Addition of eFCU led to a significant increase in volume of patients able to be seen 19 versus 15.5 (p < 0.01). A majority of parents/patients reported a positive experience with eFCU.

CONCLUSION

Expert focused cardiac ultrasound with spectral Doppler can be used successfully for follow-up in patients with select CHD and the addition of eFCU permits increased patient capacity in outreach clinics and has the potential to improve the patient experience.

Image Quality Improvement of Hand-Held Ultrasound Devices With a Two-Stage Generative Adversarial Network

As a widely used imaging modality in the medical field, ultrasound has been applied in community medicine, rural medicine, and even telemedicine in recent years. Therefore, the development of portable ultrasound devices has become a popular research topic. However, the limited size of portable ultrasound devices usually degrades the imaging quality, which reduces the diagnostic reliability. To overcome hardware limitations and improve the image quality of portable ultrasound devices, we propose a novel generative adversarial network (GAN) model to achieve mapping between low-quality ultrasound images and corresponding high-quality images. In contrast to the traditional GAN method, our two-stage GAN that cascades a U-Net network prior to the generator as a front end is built to reconstruct the tissue structure, details, and speckle of the reconstructed image. In the training process, an ultrasound plane-wave imaging (PWI) data-based transfer learning method is introduced to facilitate convergence and to eliminate the influence of deformation caused by respiratory activities during data pair acquisition. A gradual tuning strategy is adopted to obtain better results by the PWI transfer learning process. In addition, a comprehensive loss function is presented to combine texture, structure, and perceptual features. Experiments are conducted using simulated, phantom, and clinical data. Our proposed method is compared to four other algorithms, including traditional gray-level-based methods and learning-based methods. The results confirm that the proposed approach obtains the optimum solution for improving quality and offering useful diagnostic information for portable ultrasound images. This technology is of great significance for providing universal medical care.

Hand-held echocardiography in children with hypoplastic left heart syndrome

BACKGROUND

When performed by cardiologists, hand-held echocardiography (HHE) can assess ventricular systolic function and valve disease in adults, but its accuracy and utility in congenital heart disease is unknown. In hypoplastic left heart syndrome (HLHS), the echocardiographic detection of depressed right ventricular (RV) systolic function and higher grade tricuspid regurgitation (TR) can identify patients who are at increased risk of morbidity and mortality and who may benefit from additional imaging or medical therapies.

METHODS

Children with HLHS after Stage I or II surgical palliation (Norwood or Glenn procedures) were prospectively enrolled. Subjects underwent HHE by a pediatric cardiologist on the same day as standard echocardiography (SE). Using 4-point scales, bedside HHE assessment of RV systolic function and TR were compared with blinded assessment of offline SE images. Concordance correlation coefficient (CCC) was used to evaluate agreement.

RESULTS

Thirty-two HHEs were performed on 15 subjects (Stage I: n = 17 and Stage II: n = 15). Median subject age was 3.4 months (14 days-4.2 years). Median weight was 5.9 kg (2.6-15.4 kg). Bedside HHE assessment of RV systolic function and TR severity had substantial agreement with SE (CCC = 0.80, CCC = 0.74, respectively; P < .001). HHE sensitivity and specificity for any grade of depressed RV systolic function were 100% and 92%, respectively, and were 94% and 88% for moderate or greater TR, respectively. Average HHE scan time was 238 seconds.

CONCLUSIONS

HHE offers a rapid, bedside tool for pediatric cardiologists to detect RV systolic dysfunction and hemodynamically significant TR in HLHS.

Recurrent Cardiology Evaluation for Innocent Heart Murmur: Echocardiogram Utilization

We conducted a retrospective study to identify electrocardiogram (ECG) and echocardiogram utilization among patients presenting for a follow-up cardiology evaluation with innocent heart murmur between 2012 and 2014. The 2014 echocardiogram Appropriate Use Criteria was applied. We observed high rates of ordering ECGs and echocardiograms on follow-up visits (79% and 36%); only 1 patient had an appropriate indication for echocardiogram while the rest had rarely appropriate indication. Having had an ECG done did not affect echocardiogram ordering behavior. Older patient age was the only factor associated with a higher likelihood for ordering echocardiograms on follow-up visit (odds ratio = 1.016, P = .021). In this small sample study, we noticed high rates of test utilization and low-probability utilization of echocardiogram in the recurrent evaluation of children with innocent heart murmur. A larger, multicenter prospective study to investigate patterns and drivers of test utilization in children with innocent heart murmur presenting for a follow-up cardiology visit is needed.

Validation of the accuracy of handheld echocardiography for diagnosis of congenital heart disease

Background:

Handheld echocardiography (HHE) has been increasingly used for rheumatic heart disease screening and in adult emergency room settings.

Aims:

This study aimed to validate the accuracy of HHE in the diagnosis of congenital heart disease (CHD).

Settings and Design Methodology:

This is a prospective study carried out at three pediatric cardiology outpatient clinics in Khartoum, Sudan.

All patients with suspected CHD were evaluated by clinical examination followed by HHE, performed using a modified segmental approach. Then, a complete study was performed using a standard echocardiography machine. The results were then compared using appropriate statistical tools.

Results:

A total of eighty cases were included with the following diagnoses either in isolation or combination: ventricular septal defect (n = 23), atrial septal defect (n = 10), pulmonary stenosis (n = 7), tetralogy of Fallot (n = 7), patent ductus arteriosus (n = 6), atrioventricular septal defect (n = 6), transposition of the great arteries (n = 6), and other diagnoses (n = 15). Agreement between HHE and SE was excellent both for visualizing heart segments (κ =77%–100% with a mean of 92.9%) and for diagnosis of CHD (κ =66%–100% with a mean of 91.7%). The sensitivity of HHE was 69.2%–100% (mean = 90.2%) and specificity was 98.5%–100% (mean = 99.3%).

Conclusion:

This study supports extending the utility of HHE in children for screening of CHD in addition to its current role in rheumatic heart disease screening.

The 200th anniversary of the stethoscope: Can this low-tech device survive in the high-tech 21st century?

In 1816, Laennec discovered that auscultation of the heart and lungs could effectively be performed by placing a hollow cylinder (initially made of a roll of paper) between the chest of the patient and the ear of the examiner. This was the first step in the development of the stethoscope, which was a breakthrough in the diagnosis and management of cardiac and pulmonary patients. Technical improvements of the stethoscope followed and in cardiac patients auscultation soon became a major diagnostic tool. In the second half of the 20th century, new powerful non-invasive diagnostic modalities were developed and the interest in auscultation declined. As a result, the auscultatory skills of students and physicians at all levels of training decreased to a disappointingly low level. We now must decide whether we should stimulate the use of and proficiency in auscultation or if we should accept the further decline and eventual abolishment of this component of the physical examination. Reviewing the literature and taking into consideration the setting in which the patients are presented, including the availability of advanced diagnostic facilities, we conclude that the time-honoured stethoscope, in spite of its limitations, still has potential as a patient-friendly, effective, and economical instrument in medical practice. However, new initiatives are required to train students, physicians and allied health professionals in cardiac auscultation to avoid misinterpretations that may harm the patients and generate extra costs. To be successful such programs will require wide support from the medical community.

Rheumatic heart disease echocardiographic screening: approaching practical and affordable solutions

Rheumatic heart disease (RHD) affects at least 32.9 million people worldwide and ranks as a leading cause of death and disability in low-income and middle-income countries (LMICs). Echocardiographic screening has been demonstrated to be a powerful tool for early RHD detection, and holds potential for global RHD control. However, national screening programmes have not emerged. Major barriers to implementation include the lack of human and financial resources in LMICs. Here, we focus on recent research advances that could make echocardiographic screening more practical and affordable, including handheld echocardiography devices, simplified screening protocols and task shifting of echocardiographic screening to non-experts. Additionally, we highlight some important remaining questions before echocardiographic screening can be widely recommended, including demonstration of cost-effectiveness, assessment of the impact of screening on children and communities, and determining the importance of latent RHD. While a single strategy for echocardiographic screening in all high-prevalence areas is unlikely, we believe recent advancements are bringing the public health community closer to developing sustainable programmes for echocardiographic screening.