New Ultrasound Telediagnostic System for Low-Resource Areas: Pilot Results From Peru.

Billions of people around the world lack access to diagnostic imaging. To address this issue, we piloted a comprehensive ultrasound telediagnostic system, which uses ultrasound volume sweep imaging (VSI) acquisitions capable of being performed by operators without prior traditional ultrasound training and new telemedicine software capable of sending imaging acquisitions asynchronously over low Internet bandwidth for remote interpretation. The telediagnostic system was tested with obstetric, right upper quadrant abdominal, and thyroid volume sweep imaging protocols in Peru. Scans obtained by operators without prior ultrasound experience were sent for remote interpretation by specialists using the telemedicine platform. Scans obtained allowed visualization of the target region in 96% of cases with diagnostic imaging quality. This telediagnostic system shows promise in improving health care disparities in the developing world.

Changes in Internal Carotid Artery Doppler Velocity Measurements With Different Angles of Insonation: A Pilot Study.

OBJECTIVES: Doppler velocity measurements are fundamental diagnostic criteria for vascular ultrasound examinations. Insonation angles are kept to 60° or less to minimize error. The purpose of this study was to assess variance of Doppler-detected peak systolic velocity (PSV) measurements in the internal carotid arteries at different angles (45°, 50°, 55°, and 60°) with different beam steering. METHODS: The PSV was recorded from the right and left internal carotid arteries in 22 asymptomatic volunteers with straight vessels (total of 44 vessels). A standardized approach was used for recording velocities with the Doppler cursor center steered and steered 15° from right to left. An analysis of variance was performed. RESULTS: The PSV varied significantly with the 4 different angles of insonation (P < .01). The maximum variation between 45° and 60° angles within a single vessel was 29 cm/s. The average variation over the 4 angles was 14 ± 6 cm/s. Relative to the calculated mean velocity for all patients, the standard deviation for the PSV at 60° was nearly twice that recorded at 50° (7.9 versus 3.9). The best correlation of the calculated mean velocity for all patients existed between the angles of 45° and 50° [r(36) = 0.92; P < .001 for center-steered data; and r(40) = 0.96; P < .001 for right-steered data]. CONCLUSIONS: These results indicate a statistically significant difference in the PSV measurements taken at varying Doppler angles. The greatest mean, variance, and lowest correlations all result when using 60°. The findings support the need for consistent ultrasound techniques and suggest that further study is warranted regarding the optimal Doppler angle for velocity measurements.

Left ventricular summit arrhythmias with an abrupt V3 transition: Anatomy of the aortic interleaflet triangle vantage point.

BACKGROUND: While early precordial electrocardiographic (ECG) characteristics are useful to differentiate left-sided from the right-sided outflow tract ventricular arrhythmia (OTVA), few patterns predict an origin from the septal margin of the left ventricular (LV) summit. OBJECTIVE: The purpose of this study was to report mapping and ablation characteristics of a new ECG pattern with left bundle branch morphology and an abrupt R-wave transition in lead V3 (ATV3). METHODS: Over a 3-year period, 78 consecutive patients (mean age 57±15 years; 35% female) with OTVA were referred for mapping and ablation. Twenty patients (26%) exhibited an ATV3 pattern, of whom 65% failed prior ablation. RESULTS: Ninety-two percent of patients with ATV3 that underwent simultaneous epicardial and endocardial mapping demonstrated an intramural or epicardial site of origin. Eighty percent of OTVA with ATV3 was eliminated by ablation from the vantage point of the interleaflet triangle below the right-left coronary junction. The ATV3 pattern showed higher sensitivity, specificity, predictive value, and accuracy than validated ECG criteria (notch or "w" pattern in lead V1, qrS pattern in leads V1 through V3, and pattern break V2) for predicting successful ablation in the region of the anterior LV ostium. At 12±11 months, freedom from ventricular arrhythmia recurrence was 89% and 82% in the ATV3 and control groups, respectively. CONCLUSION: ATV3 is a simple and distinct ECG pattern indicative of a site of origin from the septal margin of the LV summit. The right-left aortic interleaflet triangle vantage point was effective to eliminate OTVA with ATV3 that overwhelmingly exhibited the earliest activation from the epicardium or mid-myocardium. Test characteristics for ATV3 were superior to ECG patterns validated for the anterior LV ostium.

New tele-diagnostic model using volume sweep imaging for rural areas.

Advances in information and communications technologies provide a new opportunity to improve the access to healthcare in remote rural areas (RA) where there is a lack of infrastructure and medical experts. This paper implements a new model for tele-ultrasound (US) based on volumetric sweep imaging protocols specially designed for the acquisition of US. Non-physician health personnel from the RA are trained on the use of these protocols in a few days. The operator utilizes the medical box (MB), a specially designed telecommunication system, to guide, compress, encrypt and transmit the US sweeps through the cloud to the radiologist who performs the diagnosis remotely. The report is automatically sent back to the MB. The system was able to send US volumetric images with poor connectivity conditions in 6 minutes on average. These results of implementing this tele-ultrasound model in RAs are encouraging and support future validations.