--- title: "4DMedical's CT:VQ Receives FDA Clearance: Non-Contrast Lung Imaging from Standard Chest CTs" slug: 4dmedical-ctvq-fda-clearance-non-contrast-lung-imaging category: health category_label: "Health" author: "BrainWavePost Staff" date: 2026-06-29 tags: ["medical imaging", "FDA", "lung health", "CT scan", "respiratory", "diagnostics", "health tech"] read_time_minutes: 7 canonical_url: https://brainwavepost.com/article/4dmedical-ctvq-fda-clearance-non-contrast-lung-imaging source: BrainWavePost --- # 4DMedical's CT:VQ Receives FDA Clearance: Non-Contrast Lung Imaging from Standard Chest CTs *Health · 2026-06-29 · BrainWavePost Staff · 7 min read* > 4DMedical's CT:VQ software has gained FDA 510(k) clearance to generate ventilation-perfusion maps from routine, non-contrast chest CT scans — removing the need for injected radiotracers and expanding access to functional lung assessment. > **Not medical advice** _(note)_ > > This article reports on a regulatory clearance and published research. It is not a substitute for professional medical advice, diagnosis, or treatment. Patients and clinicians should consult qualified healthcare providers for individual care decisions. On 28 August 2025, the U.S. Food and Drug Administration granted 510(k) clearance to 4DMedical's CT:VQ software (K251484), classifying it as a Class II Software as a Medical Device under 21 CFR 892.1750. [1] The clearance makes CT:VQ the first FDA-authorized technology that can derive quantitative ventilation (V) and perfusion (Q) maps directly from standard, non-contrast chest CT scans — without injected radiotracers, radioisotopes, or specialized nuclear-medicine infrastructure. [1][2] ## What CT:VQ does and why it matters Ventilation-perfusion (V/Q) imaging is a cornerstone of pulmonary diagnostics. It helps clinicians assess how well air and blood are moving through the lungs, which is critical for evaluating conditions such as chronic obstructive pulmonary disease (COPD), pulmonary embolism, and lung-cancer surgical planning. [2][3] Traditionally, this assessment requires either a nuclear-medicine V/Q scan using inhaled and injected radiotracers, or a contrast-enhanced CT pulmonary angiogram. Both approaches involve additional procedures, specialist facilities, and — in the case of nuclear medicine — radioactive agents. [3] CT:VQ takes a different approach. The software applies proprietary post-processing algorithms to routine chest CT datasets that have already been acquired without contrast. It then generates color-coded, lobar-level ventilation and perfusion maps that quantify regional lung function. [2] Because the technology is delivered as software-as-a-service, results can be returned to the ordering clinician without requiring new hardware or scanner upgrades at the imaging site. [2] - **FDA 510(k)** — Cleared 28 August 2025 (K251484) [1] - **Non-contrast** — No injected radiotracers or radioisotopes needed [2] - **SaaS delivery** — Cloud-based post-processing from standard CT data [2] ## Clinical validation and published evidence Independent research has begun validating the accuracy of non-contrast CT-based ventilation imaging against established reference standards. A study published in PMC and supported by the National Institutes of Health compared CT-derived ventilation maps with PET-ventilation imaging — a highly sensitive but far less accessible functional measure — and found strong association and agreement between the two modalities. [4] The authors concluded that non-contrast CT-ventilation offers a viable, more accessible alternative for functional lung assessment in settings where PET is unavailable. [4] Separately, 4DMedical announced in May 2026 that a study evaluating CT:VQ for lung-surgery planning had been accepted for publication in the American Journal of Respiratory and Critical Care Medicine, a peer-reviewed journal of the American Thoracic Society. [5] While the full manuscript was not yet public at the time of this article, the acceptance signals that independent peer review is underway for surgical-planning applications. [5] ## Reimbursement and real-world access Regulatory clearance is only one step toward clinical adoption; reimbursement determines whether hospitals and imaging centers can actually offer a test. In its September 2025 announcement, 4DMedical noted that Medicare had confirmed a Category III CPT reimbursement code for CT:VQ when performed alongside a standard chest CT. [2] Category III codes, established by the American Medical Association, describe emerging technologies and services; while they typically carry interim payment rates, their existence allows providers to bill for the procedure and gather the claims data needed for permanent Category I status. [2][3] The combination of FDA clearance plus a billing pathway is significant for smaller community hospitals and outpatient imaging centers that lack nuclear-medicine departments. Diagnostic Imaging, a trade publication serving radiology professionals, reported that the technology 'allows for additional Category III CPT reimbursement beyond the chest CT,' potentially making functional lung assessment financially viable in settings where it was previously unavailable. [3] ## Limitations and open questions As with any new diagnostic technology, there are caveats. The FDA 510(k) clearance indicates that CT:VQ is substantially equivalent to legally marketed predicate devices, not that it has undergone large-scale prospective outcome trials. [1] The software's accuracy depends on the quality of the input CT dataset; low-dose or motion-degraded scans may yield less reliable functional maps. [2] Clinicians will also need training to interpret the color-coded V/Q maps in the context of each patient's clinical picture. [3] Long-term questions remain about whether CT:VQ-based management decisions improve patient outcomes compared with traditional V/Q scanning or clinical assessment alone. Outcome studies — the kind that compare groups managed with and without the technology — will be needed to answer that question definitively. [3] ## The bottom line 4DMedical's CT:VQ represents a genuine technical advance in respiratory diagnostics: it transforms routine, non-contrast chest CTs into quantitative functional lung maps, eliminating the need for radiotracers and nuclear-medicine infrastructure. [1][2] FDA clearance, Medicare reimbursement, and early independent validation suggest the technology is moving from concept to clinical reality. [1][2][3][4] For patients in community hospitals and for health systems looking to expand pulmonary assessment without building new departments, that accessibility could meaningfully change how lung function is evaluated. [3] ## Sources (clickable) - [1] U.S. Food and Drug Administration — 510(k) Premarket Notification K251484 for CT:VQ (decision date 28 August 2025): https://www.accessdata.fda.gov/cdrh_docs/pdf25/K251484.pdf - [2] 4DMedical — '4DMedical's CT:VQ Receives FDA 510(k) Clearance; First-and-Only Non-Contrast VQ Imaging' (4 September 2025): https://4dmedical.com/4dmedicals-ctvq-receives-fda-510k-clearance-first-and-only-non-contrast-vq-imaging/ - [3] Diagnostic Imaging — 'FDA Clears Non-Contrast CT-Based Ventilation Perfusion Imaging' (4 September 2025): https://www.diagnosticimaging.com/view/fda-clears-non-contrast-ct-based-ventilation-perfusion-imaging - [4] PMC/NIH — 'More accessible functional lung imaging: non-contrast CT-ventilation demonstrates strong association and agreement with PET-ventilation': https://pmc.ncbi.nlm.nih.gov/articles/PMC12034206/ - [5] 4DMedical — ASX Announcement: 'Major publication validates CT:VQ for lung surgery' (19 May 2026): https://asx.api.markitdigital.com/asx-research/1.0/file/2924-03091442-3A693553 - [6] 4DMedical — CT:VQ Product Overview: https://4dmedical.com/products/software/ctvq/ --- _Canonical article: [https://brainwavepost.com/article/4dmedical-ctvq-fda-clearance-non-contrast-lung-imaging](https://brainwavepost.com/article/4dmedical-ctvq-fda-clearance-non-contrast-lung-imaging) — © BrainWavePost. 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