Pulmonary vascular abnormalities in Long COVID: a radiological perspective

🚨Your CT is ‘normal,’ yet you’re still breathless months after COVID. New review shows hidden microvascular damage (perfusion defects, vessel pruning, gas-transfer defects) that standard scans miss, mptoms that routine imaging miss!

➡️Interesting new narrative review from India shifts the focus of LongC0VID from parenchymal lung damage to a distinct pulmonary vascular phenotype! REMEMBER SARSCOV2 is basically a VASCULAR VIRUS!

➡️Core mechanisms:
- SARSCoV2 enters endothelial cells via ACE2 receptors, triggering endotheliitis that creates a pro-coagulant environment and promotes the formation of in-situ microthrombi,
- This is amplified by immunothrombosis (driven by neutrophil extracellular traps) and the generation of amyloid-like fibrin microclots that resist normal breakdown,
- Over time, the vasculature undergoes maladaptive remodelling, including intussusceptive angiogenesis and progressive “pruning” of small vessels, which reduces the available surface area for gas exchange,

➡️Conventional CT pulmonary/angiography frequently appears normal or near-normal and misses microvascular disease,

➡️Advanced imaging uncovers the pathology:
1. Dual-energy CT (DECT) detects persistent wedge-shaped perfusion defects in otherwise normal lung tissue, seen in 36–60% of symptomatic patients and still present in 36.3% at roughly 3 months,
2. Quantitative CT shows reduced small-vessel volume (PBV5), which correlates with lower DLCO and poorer exercise tolerance,
3. Hyperpolarized xenon-129 MRI reveals a hallmark gas-transfer defect, impaired alveolar-to-RBC gas exchange, even when standard CT and pulmonary function tests appear normal,
4. V/Q SPECT and PREFUL MRI demonstrate mottled perfusion patterns consistent with diffuse small-vessel disease,

➡️Findings correlate with ongoing dyspnoea, fatigue, and reduced exercise capacity,

➡️Higher (admission) D-dimer/CRP often predict later defects,

➡️2025 RSNA/STR/ESTI consensus guidelines recommend imaging at 3 months with paired inspiratory/expiratory protocols and the term “Post-COVID-19 Residual Lung Abnormality.”

‼️So, AGAIN, routine CT scans can look reassuring while the pulmonary microvasculature remains structurally and functionally damaged, directly accounting for persistent breathlessness and fatigue in a substantial subset of LongC0VID patients.

‼️The proposed framework matters clinically every day: many patients with ongoing dyspnoea or exercise intolerance after COVID have occult vascular injury that conventional imaging and basic Pulmonary Function Tests(PFTs) fail to detect. Recognizing the vascular phenotype guides use of functional/quantitative techniques (DECT, xenon MRI, etc.), supports standardized 3-month imaging protocols, and should shift management toward vascular rather than purely parenchymal explanations. It also helps differentiate vascular from airway-related causes of symptoms and UNDERSCORES the public-health scale of residual impairment in survivors!

REMINDER AGAIN, COVID-19(SARSCOV2) is basically a VASCULAR INFECTION!
#AvoidSars2 #AvoidReinfections #Mitigation
link.springer.com/article/10.118…

Clean air plea
my.uplift.ie/petitions/prot…

Fabulous resource and fantastic to see clean air in schools brought into focus with 10 easy steps on how teachers and school leaders can improve health and learning by implementing these 10 simple strategies. Well done @twinklresources

💙So happy to share a BRAND NEW #CleanIndoorAir educational resource! 💙
@twinklresources just published this fabulous resource which highlights how crucial clean air in classrooms is.
Please share! 🙏
@erbrooker @_CatintheHat @Lessnessprimary #EduTwitter
twinkl.co.uk/resource/leadi…

We do too!
Every classroom should have one!
ventilation +air purifiers = healthy air

Incredible speech delivered by Baroness Linforth in the House of Lords today calling for clean indoor air in schools.

“It would cost less than a tenner per child per year to provide pupils and staff with clean air - about the same cost as a coffee and a cake.”

☕️🧁

Well done Róise

We got a message this week from Róise, a student who completed her project on air quality in primary school classrooms at Scoil Naomh Bríd in Muff, Donegal and found Smart Air along the way.

She said she wishes her own school had air purifiers... 💙

x.com/SmartairUk/sta…

GO AQS (Global Open Air Quality Standards) is proud to announce the introduction of GO IAQS for Schools, a strategic plan designed to transform educational environments from passive shelters into active, health-protective zones.
🔗 goaqs.org/go-iaqs-for-sc…
#IAQ

Damn, that’s wild—Harvard stuck 24 office workers in the same room for 6 days, secretly tweaking the air quality (ventilation, CO2, and VOCs from typical office stuff), and their cognitive scores doubled in the cleaner “green+” conditions vs. standard stale setups. Better gy, crisis response—all crushed by poor indoor air we breathe 90% of the time.
Open windows, crank ventilation, cut the junk emitters. Your brain’s paying the price right now. Fix the air, sharpen the mind.

RT @UNISONinSchools: Coming up next week!

Join #LongCOVIDAwareness discussions at Defense Series III, Mar 4, 2026, 4:30pm-9pm EST in honor of patients and allies tirelessly advocating for health justice in this historic struggle, 6 Q&A sessions will feature an extraordinary panel of speakers. masktogetheramerica.org/blog/long-covi…

On the cover of The Lancet:
Editorial — “Robert F Kennedy Jr: 1 year of failure”

Read the latest issue: spkl.io/6011Aa3Et

Further to our open letter we welcome this update

1/2

@hazardscampaign @cv_cev @LongCovidAdvoc
@CleanAirIE @SFotonium @hazardscampaign @jneill @ThisHouseFresh @SalWitcher @AirborneAllergy

If filtration is good enough for schools in London, why not everywhere? Clean indoor air should not depend on postcode. It is a basic public health measure for every child. go.corsirosenthalfoundation.org.uk/iL8DHhW #CleanAir #CleanAirInSchools #AirQuality #HealthEquity

"Children whose mothers had COVID-19 during pregnancy show an altered brain structure and different behavior.

COVID-19 will sustainably change our society because both adults and children feel less empathy and are less able to anticipate."

1. Outstanding article from Tess Finch Lees:

'Meanwhile, when asked why she’s masking during chemo, Meg now says, “I’m training for the Olympics” '.

Please click on the paywalled link first, archived link in next tweet. Also consider sharing.

m.independent.ie/opinion/commen…

Long COVID hasn’t disappeared.

People continue to develop it after new infections—yet the myth that it’s “over” still persists.

Bára’s story shows the reality: after her 3rd COVID‑19 infection in 2025, she became house‑bound with severe fatigue and heart issues.

A groundbreaking study has pinpointed a microscopic culprit behind the debilitating fatigue, brain fog, and other persistent symptoms of long COVID: abnormal, sticky microclots embedded with neutrophil extracellular traps (NETs) in patients' blood.

These microclots—tiny proteins—are small enough to obstruct the body's tiniest blood vessels (capillaries), restricting oxygen delivery to tissues and organs without triggering obvious large-scale clotting events. In long COVID patients, researchers observed a dramatic ~20-fold increase (median 19.7 times higher) in the number of these microclots compared to healthy controls, with the clots also tending to be larger.

What sets this finding apart is the discovery that these microclots are structurally intertwined with NETs—web-like structures of DNA, enzymes (such as myeloperoxidase and neutrophil elastase), and proteins released by neutrophils (a type of white blood cell) to ensnare pathogens. Normally, NETs form temporarily and then dissolve, but in long COVID, they persist and become physically embedded within the microclots, creating highly resistant, "gummy" structures that evade the body's natural clot-breaking processes (fibrinolysis). This creates a chronic thromboinflammatory state, where blocked microcirculation and ongoing low-grade inflammation may sustain symptoms like exhaustion and cognitive impairment.

The differences were so pronounced that machine learning models analyzing anonymized blood samples (via fluorescence microscopy for markers like ThT for amyloid-like structures, DNA stains, and MPO for NETs) could distinguish long COVID patients from healthy individuals with 91% accuracy—offering a potential objective biomarker for a condition that has long evaded reliable diagnosis through standard tests (e.g., normal D-dimer, PT/INR, or aPTT levels despite significant microclot burden).

This work, led by teams including Prof. Etheresia Pretorius (Stellenbosch University) and Dr. Alain Thierry (Montpellier University), reframes long COVID as a tangible, blood-based disorder driven by dysregulated coagulation and innate immunity rather than vague "post-viral malaise." Targeting NETs or microclots—perhaps with therapies to degrade NETs or prevent their stabilization—could open doors to treating root causes instead of merely alleviating symptoms.

[Thierry, A. R., Usher, T., Sanchez, C., Turner, S., Venter, C., Pastor, B., Waters, M., Thompson, A., Mirandola, A., Pisareva, E., Prevostel, C., Laubscher, G. J., Kell, D. B., & Pretorius, E. (2025). Circulating Microclots Are Structurally Associated With Neutrophil Extracellular Traps and Their Amounts Are Elevated in Long COVID Patients. Journal of Medical Virology, 97(10), e70613.
DOI: 10.1002/jmv.70613]

Attendance is critical for students to do well in school. A cheap way to increase attendance: clean the air!!

Check out the success story below.

We have solutions. We need to use them.

@erbrooker @CleanAir4KidsUK