4DMedical has achieved a significant regulatory milestone with FDA 510(k) clearance for its CT:VQ software, positioning the technology to transform respiratory diagnostics across the United States. The clearance marks the first time a non-contrast CT-based ventilation-perfusion tool has been approved to replace traditional nuclear medicine scans for assessing airflow and blood flow in the lungs.
The breakthrough opens access to a potential addressable market of more than US$1.1 billion annually in the US alone, where over one million ventilation-perfusion scans are performed each year. The US Centers for Medicare & Medicaid Services has confirmed reimbursement for CT:VQ under Category III CPT codes, providing payment in addition to existing reimbursement for the underlying chest CT.
Addressing Critical Barriers in Lung Imaging
Traditional ventilation-perfusion scans present significant challenges for both patients and healthcare systems. The current standard requires patients to undergo two separate procedures involving radioactive tracers, a process that can take more than an hour and places substantial pressure on hospital nuclear medicine resources.
CT:VQ fundamentally changes this paradigm by leveraging existing CT infrastructure to generate detailed ventilation and perfusion maps without additional equipment, tracers, or contrast agents. The software-as-a-service solution integrates directly with routine radiology workflows through DICOM-based PACS reporting, transforming standard non-contrast chest CTs into quantitative, lobar ventilation and perfusion maps.
"CT:VQ gives clinicians all the contrast—and none of the injections," said Andreas Fouras, PhD, founder and CEO of 4DMedical. "With FDA clearance and Medicare payment in place, any hospital with a CT scanner can turn a routine chest CT into a high-resolution ventilation-perfusion study in minutes, without new hardware or workflow complexity."
Expanding Access and Clinical Applications
The technology's ability to operate on the approximately 14,500 CT scanners already installed across the US significantly broadens its potential reach. Smaller and regional hospitals that lack nuclear medicine departments can now offer patients functional lung imaging, democratizing access to what has previously been a resource-intensive procedure.
CT:VQ enables clinicians to diagnose multiple conditions including pulmonary embolism, asthma, and chronic obstructive pulmonary disease while reducing patient risk. The combination of speed, resolution, and accessibility provides new tools for PE workups, CTEPH assessment, COPD phenotyping, BLVR planning, and ongoing monitoring.
Patients benefit from a streamlined process that eliminates injections and completes the entire imaging study in a single CT appointment. Radiologists receive high-resolution, quantitative V/Q maps directly in PACS, enabling more efficient workflow integration.
Clinical Validation and Early Adoption
FDA clearance followed extensive clinical testing that benchmarked CT:VQ against single photon emission computed tomography (SPECT), the established standard in nuclear ventilation-perfusion imaging. Side-by-side comparisons demonstrated strong agreement between the two methods, while physicians noted that CT:VQ delivered clearer images and avoided common artifacts caused by tracer clumping or leakage.
Early US clinical partners have included Stanford University and Brooke Army Medical Center, with the latter presenting initial findings at the recent 2025 American Thoracic Society meeting. These deployments have provided real-world validation across multiple lung conditions and supported the technology's clinical utility.
Market Potential and Commercial Strategy
The regulatory breakthrough positions 4DMedical to capture significant market share in the established ventilation-perfusion imaging market. With reimbursement rates established and workflow integration straightforward, management believes CT:VQ can quickly gain adoption and eventually displace nuclear scans altogether.
Beyond replacing existing procedures, the technology could expand the overall market by removing barriers to ordering functional lung imaging. Clinicians may be more likely to request scans when they can perform them rapidly on existing CT equipment, potentially opening new applications in chronic disease management and routine screening.
Fouras characterized the regulatory clearance as "a complete redefinition of the standard of care in pulmonary imaging" because it enables doctors to order perfusion scans without exposing patients to radioactive tracers. The company plans to work closely with healthcare providers and academic partners to accelerate adoption across the US.
Strong Financial Performance
The FDA clearance comes following strong financial results for 4DMedical. Operating revenue climbed 56% to A$5.9 million in the 12 months to June 30, 2025, driven by rising adoption of its Software-as-a-Service model. The company delivered nearly 195,000 scans during the year, with quarterly volumes more than doubling from 2024, highlighting momentum in both domestic and international markets.
The group also reduced costs by A$6.5 million on an annualized basis through a restructuring program, improving its path toward operating leverage as it prepares for commercial rollout in the US market.
