Pinned straw:
I attended the $4DX webinar flagged yesterday by @Jimmy. What follows is my BA's summary of the transcript I captured, and I conclude with some of my own thoughts at the end.
1. Summary of the Transcript
Here’s a structured summary of the Bell Potter interview with Dr. Kyle Hogarth (University of Chicago) on the implications and potential of 4DMedical’s software products, particularly CT:VQ.
Overall Takeaway
Dr. Hogarth sees 4DMedical’s software as transformative, with CT:VQ poised to replace nuclear perfusion scans and become embedded in standard valve and surgical workflows. The combination of clinical efficiency, improved patient outcomes, and compelling hospital economics creates strong tailwinds for adoption. Beyond emphysema and valves, 4D’s platform has the potential to influence cancer surgery, transplant workups, and broader cardiopulmonary care.
Background & Clinical Practice
- Dr. Hogarth is a senior interventional pulmonologist at the University of Chicago, running a large bronchoscopy and lung cancer screening program (~1,800 bronchoscopies/year).
- His team performs lung cancer diagnosis/staging, robotic bronchoscopy, lung volume reduction (LVR) procedures, and valve placements.
- LVR is highly profitable in the US system, but patient workups are historically cumbersome, involving multiple tests (CT, perfusion scans, PFTs, echo), long delays, and patient drop-off.
4DMedical’s Value Proposition
Select/EnBio Product (Olympus Partnership):
- Automatically quantifies emphysema from existing CT scans.
- Provides a ready-made, embedded report in PACS without disrupting radiology workflow.
- Identifies optimal valve targets and screens out non-candidates, reducing wasted effort.
- Has increased referral flow and efficiency: “half the workup is done with little/no extra effort.”
- Benefits extend beyond pulmonology: smoking cessation counselling, ILD, transplant assessment, and coronary calcium scoring.
Workflow Transformation:
- Eliminates outdated manual processes (burning CDs, uploading to third-party portals).
- Automates case finding by flagging patients with incidental emphysema.
- Enables faster throughput → fewer drop-outs and higher procedure volumes.
CT:VQ – A Game Changer
- FDA-approved CT:VQ adds perfusion mapping to CT (inspiratory/expiratory protocol).
- Replaces nuclear perfusion scans (planar/SPECT) that are outdated, poorly available, and hard to interpret.
- Offers clear, anatomically correlated perfusion + emphysema images side by side.
Clinical advantages:
- Improves valve targeting (choosing between multiple lobes, avoiding worsening gas exchange).
- Shortens patient journey (one CT vs. multiple tests).
- Expands surgical candidacy by quantifying regional emphysema/perfusion in borderline lung cancer patients.
- Surgeons are particularly enthusiastic, as it will reshape pre-operative planning.
Adoption Drivers & Economics
- Hospitals: Economics are compelling. Adding just ~8 extra valve cases/year covers software costs.
- Physicians: Workflow is dramatically simplified, cognitive burden reduced.
- Patients: Faster, less testing, lower cost, better outcomes.
- Payers: Reduced redundant tests and lower overall morbidity.
- Thoracic surgeons’ buy-in is expected to accelerate uptake (“they usually get what they want”).
- Pushback is minimal since radiology workflow is unaffected.
Broader Implications & Future Potential
- CT is expected to remain the core modality for lung imaging; MRI unlikely to compete.
- 4D’s platform could expand into:
- Interstitial lung disease quantification.
- Cardiac analysis (e.g., amyloidosis, RV strain).
- Dynamic airway changes, predicting collapse or stent needs.
- Sequential/bilateral valve planning by comparing perfusion redistribution.
- Positioning: Hospitals can market “more from your CT scan” as a competitive advantage.
- Growing data presentations (ATS, AABIP conferences) are expected to accelerate standard-of-care adoption.
CEO Andreas Fouras’ Brief Remarks
- Confirmed Dr. Hogarth’s perspectives reflect broader feedback across specialties (transplant, post-PE clinics, etc.).
- Emphasised low resistance to adoption and excitement across multiple clinical domains.
- Reinforced that early adopters like Hogarth will drive visibility and credibility for 4DMedical.
2. My Observations and Reflections
2.1 Deal or No Deal?
Dr. Hogarth is a leader in his field and has had an extensive association with $4DX’s products, including, by the sounds of it, prior to its acquisition by $4DX.
My sense was that much of the interview focused on the value Hogarth sees from CT:VQ in providing a convenient perfusion map to help decide how to proceed with patients who are candidates for Lung Volume Reduction (LVR) surgery. This is a procedure sometimes applied in patients with severe emphysema. Essentially, as I understand it, it prevents diseased parts of the lung from unproductively using available airflow, so that the healthier parts of the lung receive proportionately more of the flow.
So, CT:VQ is a game changer for Hogarth because it allows him to include perfusion assessment as part of the same CT visit patients already attend for their diagnostic work-up, avoiding the need for V/Q scintigraphy (or “planar lung scan”). He believes CT:VQ helps him make better decisions and sees the incremental cost of a few hundred dollars as irrelevant when the “back-end” surgery costs around US$40,000. That sounds very exciting, doesn’t it?
However, it is very important to recognise that LVR surgeries are low-volume procedures, and that Hogarth is clearly a national specialist. His unit is likely a centre of excellence for pulmonary surgery. According to my BA, the combined total volume of LVR surgery is roughly ~600–700/year (all payers) and BLVR/EBV ~300–500/year (all payers), leading to a total of about ~900–1,200 LVR procedures per year.
So the potential gross revenue due to this source for CT:VQ is about US$0.6m, meaning likely only US$0.2–0.3m net to $4DX. Basically, it’s peanuts.
So, I am not running away from the webinar with my hair on fire shouting “buy, buy, buy,” and I hope you can see why.
2.2 What about NUC:VQ?
Hogarth once again confirmed the wise warning of our own Dr @Chagsy that V/Q scintigraphy ("planar scans") is in decline.
He referred to ageing infrastructure that is hard to access and breaks down, in contrast with the proliferation of CT units, upgrades, and advanced processing power (like $4DX) appearing ubiquitously.
His remarks give me confidence that the analysis I posted last week on the ongoing decline of NUC:VQ (based on CMS procedure counts) is correct.
And so it creates even further doubt in my mind that there is a NUC:VQ market of US$1.1bn in the US waiting to be captured by CT:VQ.
2.3 However, I am not being Eeyore (honest)
I’m not trying to pour cold water on $4DX. I want to invest in this business, but only at the right price, and I am trying to get a handle on what that might be.
It is clear from several remarks by Hogarth that, whether in the screening of lung cancer, emphysema/COPD, other bronchial conditions, or PE, CT is a widespread and common part of the diagnostic work-up. He clearly advocates widespread adoption of the CT:VQ (inhale/exhale) step in the standard CT procedure, because at "little incremental cost", it will give the clinician another rich diagnostic view across a whole range of conditions.
So, the question is, does that become the rallying cry of the US clinical workforce in pulmonary medicine? And if so, can they make the case for general hospitals to buy the software on a “$600-per-scan, thank-you-very-much-from-Dr-Andreas-and-Crew” basis?
Clearly, for preparation for LVR surgery, Hogarth believes the economics are a no-brainer, and he gave some indications of that. But LVR is a very specialised, low-volume application. (And quietly, I wonder how many of the 300 or so investors at todays webinar are aware of that!)
In practice, more studies will be needed to demonstrate the utility of CT:VQ and its health economics in use case by use case. Hogarth said as much himself during the interview—albeit he is confident that podiums at conferences will soon be full of presenters showing the benefits of CT:VQ as part of the standard CT workflow.
That process is going to take time—by which I mean years. Maybe only one or two, but even that would be lightning fast in the healthcare space.
My Key Takeaways
I am very much in learning mode, being new to pulmonary medicine and not a healthcare professional. Today advanced my learning a few more steps. However, it did not materially contribute to my view as to whether $4DX will become a multi-billion-dollar business, which is what I need to form an investment thesis.
My current view is that it will take time for the clinical evidence and economic support for widespread adoption of CT:VQ to build. I will continue to monitor that, but importantly I am becoming increasingly convinced that the best way to track the progress of $4DX as a business is to follow the customers, i.e., the announcements of contracts signed, hopefully with increased transparency by Andreas as to contract KPIs.
The learning continues. So does the waiting.
Great write up @mikebrisy
I have been off on a climbing trip to the Bluies for the last few weeks so not keeping tabs on much really. Need to see the FLX meeting for one. Am currently on the road home at Sydney airport:
I would like to spend a bit of time on 4DX to understand what the fuss is about. I just can’t understand the use case: from what you and others have posted.
VQ for PE is dead, I can’t believe the predicted volume is as large as it is - in your previous posts. There must be some curious incentives at play.
LVR is last gasp (ho ho) stuff for end of the road emphysema and as you note, very small volume. This won’t change.
Screening for lung cancer. Maybe but even plain CT can do that though the health economics are dubious (and I reckon CT will be margins cheaper)
Then there is something about valves that I don’t understand, but Echo (ultrasound) is cheap, no radiation exposure and a well established gold standard for pulmonary pressures and valve function.
Happy to stand corrected on any points!
C
@Stevie_B I’ve tried to sketch the bigger picture of the US lung imaging and screening market across disease states and technologies. I used my BA (ChatGPT5) to build the framework, sense-checked sources, and added a confidence layer. Many ranges are wide due to lack of reporting, so results should be viewed cautiously, but “High Confidence” ranges are anchored in solid references.
NUC:VQ
- NUC:VQ still has meaningful volume, mainly for PE and CTEPH.
- For PE, CTPA has taken over, with V/Q declining ~10% p.a. recently. V/Q is now largely reserved for CTPA contraindications (~10% of PE patients) or in centers with strong nuclear expertise.
- Claims of “1 million V/Q scans per year” in the US look outdated — I may even ask $4DX IR for a source.
- With CT:VQ now FDA-cleared, contraindicated PE patients (~0.3–0.4M/year) could shift from V/Q to CT:VQ — a ~$200M gross market, ~$50–100M net to 4DX.
- Open questions: Will CT:VQ also be run alongside CTPA, even where not contraindicated? If so, what’s the incremental value, and how will pricing adapt? Current economics remain unclear.
Broader Chest CT / LDCT (low dose CT) Market
- A much larger prize lies in integrating $4DX software into the broader chest CT and LDCT workflows for cancer, COPD, etc. (~10M scans annually vs ~0.3–0.4M for V/Q substitution).
- 4DX has not disclosed its revenue model — is adoption being subsidized or trialled?
- This market is ~20x larger in volume, but clinical studies will be needed to prove cost-benefit. Early evidence suggests value in two niches: replacing V/Q in CTPA contraindications, and lung volume reduction surgery workups.
- Future uptake depends on ongoing research — as Dr Hogarth noted in last week's webinar, FDA approval should trigger studies to show broader value.
Conclusion
- The clear, immediate case is CT:VQ replacing V/Q for CTPA contraindications.
- The broader 4DX suite has big potential but needs clinical validation before widespread adoption.
- For now, contract announcements and published studies are the key indicators to watch.
- Until more evidence emerges, valuing $4DX remains speculative. I can model the base substitution opportunity, but the wider market potential is not yet tangible enough for me to invest.
