Evaluation of the accuracy of aorta scan BVI 9600 in screening for abdominal aortic aneurysm

Performance of an automated ultrasound device in identifying and tracing the heart in porcine cardiac arrest

BACKGROUND

While intra-arrest echocardiography can be used to guide and monitor chest compression quality, it is not currently feasible on the scene of out-of-hospital cardiac arrests. Rapid and automated sonographic localization of the heart may provide first-responders guidance to an optimal area of compression without requiring them to interpret ultrasound images. In this proof-of-concept porcine study, we sought to describe the performance of an automated ultrasound device in correctly identifying and tracing the borders of the heart in three distinct states: pre-arrest, arrest, and late arrest.

METHODS

An automated ultrasound device (bladder scanner) was placed on the chests of 7 swine, along the left sternal border (4th-8th intercostal spaces). Scanner-generated images were recorded for each space during pre-arrest, arrest, and finally late arrest. 828 images of the LV and LV outflow tract were randomized and 150 (50/state) selected for analysis. Scanner tracings of the heart were then digitally obscured to facilitate tracing by expert reviewers who were blinded to the physiologic state. Reviewer tracings were compared to bladder scanner tracings; with concordance between these images determined via Sørensen-Dice index (SDI).

RESULTS

When compared to human reviewers, the bladder scanner was able to identify and trace the borders during cardiac arrest. The bladder scanner performed best at the time of arrest (SDI 0.900 ± 0.059). As resuscitation efforts continued and time from initial arrest increased, the scanner's performance decreased dramatically (SDI 0.597 ± 0.241 in late arrest).

CONCLUSION

An automated ultrasound device (bladder scanner) reliably traced porcine hearts during cardiac arrest. It is possible a device could be developed to indicate where compressions should be performed without requiring the operator to interpret ultrasound images. Further investigation into rapid, automated, sonographic localization of the heart to identify the area of compression in out-of-hospital cardiac arrest is warranted.

Screening for aneurysms of the abdominal aorta using a simple screening device

Introduction

Several countries advocate screening for aneurysms of the abdominal aorta (AAA) in selected patients. In the Netherlands, routine screening is currently under review by the National Health Council. In any screening programme, cost-efficiency and accuracy are key. In this study, we evaluate the Aorta Scan (Verathon, Amsterdam, Netherlands), a cost-effective and easy-to-use screening device based on bladder scan technology, which enables untrained personnel to screen for AAA.

Methods

We subjected 117 patients to an Aorta Scan and compared the results to the gold standard (abdominal ultrasound). We used statistical analysis to determine sensitivity and specificity of the Aorta Scan, as well as the positive and negative predictive values, accuracy, and inter-test agreement (Kappa).

Results

Sensitivity and specificity were 0.86 and 0.98, respectively. Positive predictive value was 0.98 and negative predictive value was 0.88. Accuracy was determined at 0.92 and the Kappa value was 0.85. When waist–hip circumferences (WHC) of > 115 cm were excluded, sensitivity raised to 0.96, specificity stayed 0.98, positive and negative predictive value were 0.98 and 0.96, respectively, accuracy to 0.97, and Kappa to 0.94.

Conclusion

Herein, we show that the Aorta Scan is a cost-effective and very accurate screening tool, especially in patients with WHC below 115 cm, which makes it a suitable candidate for implementation into clinical practice, specifically in the setting of screening selected populations for the presence of AAA.

Cardiovascular Ultrasound Combined With Non-invasive Screening for the Detection of Undiagnosed Cardiovascular Disease: A Literature Review

Non-invasive screenings have been widely utilized in the United States and worldwide to provide early identification of cardiovascular disease, allowing for earlier diagnosis and treatment. Screening sonography detects valve disease, cardiac dysfunction, and carotid disease in 5% to 20% of the population. This review discusses the current data regarding cardiovascular screening, the methodologies, and the resources required for performance of screenings. Cardiac and carotid sonography is highly accurate and discovers cardiovascular diseases that impact quality of life and risk of future events. Screenings are performed in a variety of settings and accuracy depends on the quality of personnel performing the non-invasive testing, the equipment utilized, and the personnel interpreting the studies. Despite the potential benefit for disease detection, population screening to detect cardiovascular disease is not widely supported by national organizations due to the theoretical cost of further testing and lack of cost versus benefit data. Additional studies are necessary to compare costs and benefits of non-invasive cardiovascular screening in the community setting.