Non-Invasive Detection of Pulmonary Right-to-Left Shunts Using the SONAS Ultrasound Device (SONAS)

Novel Approach For The Non-Invasive Detection of Pulmonary Right-to-Left Shunts

The goal of this clinical trial is to learn how well the SONAS ultrasound device can detect right-to-left shunts of adults with hereditary hemorrhagic telangiectasia (HHT) who are already scheduled for a contrast bubble echocardiogram (TTCE). The main questions it aims to answer are:

1. How accurately does SONAS detect right-to-left shunts compared to the standard TTCE test?
2. Can SONAS results help tell the difference between shunts in the heart and shunts in the lungs?

Participants will wear a headband with the SONAS device on the head while they undergo their routine TTCE bubble test. They will receive the usual contrast (agitated saline) through a vein, and both SONAS and TTCE signals will be recorded at the same time. There will be one examination in rest, and one during a breathing exercise (the Valsalva manoeuvre).

Study Overview

• Status: Recruiting
• Conditions: PFO - Patent Foramen Ovale; Pulmonary Arteriovenous Malformation; Hereditary Haemorrhagic Telangiectasia
• Intervention / Treatment: Device: Transcranial Ultrasound Device

Detailed Description

This study is being done to find out whether a new ultrasound device called SONAS can safely and reliably detect "right-to-left shunts" in people with hereditary hemorrhagic telangiectasia (HHT). Right-to-left shunts are abnormal connections between blood vessels that allow blood to bypass the lungs and go directly from the right side of the heart to the left side. This can increase the risk of problems such as stroke or brain abscess. Today, these shunts are usually found with a "bubble heart ultrasound" (TTCE), which needs experienced staff and can be time-consuming. SONAS is a small, portable device that detects blood flow signals in the brain after a bubble injection and may offer a simpler way to detect these shunts.

In this study, all participants are are already scheduled to have a bubble heart ultrasound as part of their regular care. The study adds the SONAS device on top of this routine test. During the procedure, a soft headband with small ultrasound sensors is placed in frond of the ears on both sides of the head. At the same time, the standard bubble test is done: normal saline mixed with a small amount of the participant's blood and some air is injected into a vein, and the heart is imaged with ultrasound. Participants will be asked to perform a straining manoeuvre (called a Valsalva) to see if this makes a shunt more visible. While this is happening, SONAS continuously records signals from the brain that show when the bubbles pass through.

There will be a comparison between what SONAS shows with what the standard heart ultrasound shows. By comparing these results, the researchers want to see how closely the SONAS score matches the standard test and whether certain SONAS outcomes indicate a clinically important shunt. They will also look at the timing and pattern of the bubble signals to explore whether SONAS can help tell the difference between shunts that come from the heart and those that come from the lungs. The study does not change any decisions about diagnosis or treatment: all medical decisions remain based on the usual heart ultrasound and other standard tests.

Throughout the procedure, the safety and comfort of participants are closely monitored. SONAS does not deliver any contrast or radiation. All problems or unusual events that occur during or shortly after the combined test are recorded. The information collected in this study will help determine whether SONAS is a practical, safe, and useful tool to support or simplify screening for right-to-left shunts.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Pier HJ van Veen, Medical Doctor; Phone Number: 0883205336; Email: ja.van.veen@antoniusziekenhuis.nl

Study Locations

• Netherlands
  • Utrecht
    • Nieuwegein, Utrecht, Netherlands, 3435CM
      • Recruiting
      • St. Antonius Hospital
      • Contact: Pier H.J. van Veen, Medical Doctor; Phone Number: 0883205336; Email: ja.van.veen@antoniusziekenhuis.nl

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18 years or older.
• Suspected or confirmed hereditary hemorrhagic telangiectasia (HHT).
• Incidentally: Patients who have experienced cryptogenic stroke

Exclusion Criteria:

• Pregnancy or breastfeeding.
• Known or suspected fracture(s) of the temporal / parietal skull bones, or with open skin injuries in the anatomical area of the temporal / parietal lobes.
• Patients with known metal skull implants in the anatomical area of the temporal / parietal bones, or with anatomical formation of the head or ear tha may interfere with proper headset placement.
• Patients with known allergies or reactions to parabens, which are present in the gel pad material of the applied part.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: SONAS Ultrasound During Contrast Echocardiography; This study has a single arm in which all participants undergo SONAS monitoring during a standard contrast echocardiogram (transthoracic contrast echocardiography). In this arm, adults with (possible) hereditary hemorrhagic telangiectasia or PFO who are already scheduled for a clinically indicated bubble echocardiogram have a headband with the SONAS ultrasound device examination. Agitated saline is injected into a vein as part of usual care, and the heart is imaged with echocardiography while SONAS simultaneously records ultrasound signals from the brain.

Device: Transcranial Ultrasound Device; The intervention is the SONAS ultrasound device used during a routine bubble echocardiogram. A battery-powered unit connects to a headset with two ultrasound sensors placed in front of the ears. The device does not deliver contrast or drugs; it records ultrasound signals in the brain while standard agitated saline is injected and the heart is imaged. SONAS analyzes bubble-related signals and calculates a numeric score to evaluate right-to-left shunts without changing the usual echocardiography protocol.; Other Names: SONAS; Foqus

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Capability of detecting Right-to-Left Shunts	Device capability of detecting High Intensity Transient Signals (HITS) using SONAS in presence of RLS, as confirmed by reference method TTCE. SONAS output is expressed as maximum HITS Density Score (0-100%). TTCE outcome is assessed by RLS grade (0-3), maximum microbubble count in left ventricle, and corrected change in echo density.	Periprocedurally
Diagnostic accuracy	Diagnostic accuracy (sensitivity and specificity) of SONAS for detection of clinically significant RLS (≥grade 2 on TTCE) at different HITS Density Score thresholds.	Periprocedurally

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Distinguishing intracardiac from pulmonary Right-to-Left Shunts	SONAS capability to distinguish intracardiac from pulmonary RLS based on time delay between contrast administration and first HITS occurrence, and difference in HITS Density Score between rest and Valsalva maneuver.	Periprocedurally
Test-retest reliability of SONAS for HITS assessment	Test-retest reliability of SONAS for HITS assessment using Intraclass Correlation Coefficient.	Periprocedurally

Collaborators and Investigators

• Sponsor: St. Antonius Hospital
• Collaborators: Burl Concepts, Inc.
• Investigators: Principal Investigator: Martijn C. Post, Professor, St. Antonius Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 7, 2026
• Primary Completion (Estimated): April 1, 2026
• Study Completion (Estimated): April 1, 2026

Study Registration Dates

• First Submitted: February 3, 2026
• First Submitted That Met QC Criteria: February 10, 2026
• First Posted (Actual): February 17, 2026

Study Record Updates

• Last Update Posted (Actual): February 17, 2026
• Last Update Submitted That Met QC Criteria: February 10, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Patent Foramen Ovale; Cryptogenic Stroke; Microbubbles; Pulmonary Arteriovenous Malformation; Right-to-Left Shunt; Transcranial Ultrasound; Hereditary Hemorrhagic Telangiectasisa; Contrast Echocardiography
• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Heart Diseases; Hematologic Diseases; Congenital Abnormalities; Cardiovascular Abnormalities; Heart Defects, Congenital; Hemostatic Disorders; Hemorrhagic Disorders; Stroke; Heart Septal Defects, Atrial; Heart Septal Defects; Vascular Malformations; Telangiectasis; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Hemic and Lymphatic Diseases; Ischemic Stroke; Foramen Ovale, Patent; Telangiectasia, Hereditary Hemorrhagic; Pulmonary Arteriovenous Fistulas
• Other Study ID Numbers: R25.111

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All anonymized Individual Patient Data that underlie results in the publication.
• IPD Sharing Time Frame: Beginning 3 months and ending 2 years after the publication of results.
• IPD Sharing Access Criteria: Fellow researchers interested in doing a meta-analysis of data will be able to access the IPD and supporting information. There will be access to the Study Protocol and anonymized individual patient data. Access is possible by contacting the Central Contact Person or Principal Investigator of the study.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No