HHT lung and brain screening

HHT lung and brain screening refers to specific tests used to look for arteriovenous malformations (abnormal blood vessel connections) in the lungs and brain in people diagnosed with, or at risk of, hereditary haemorrhagic telangiectasia (HHT). These malformations can be present without symptoms but carry a risk of serious complications if not identified and, where appropriate, treated. Screening is a key part of managing HHT, given how significant these particular complications can be if missed.

Arteriovenous malformations in the lungs or brain can remain completely silent, causing no symptoms, until they cause a serious complication such as a stroke (from lung malformations allowing blood clots or bacteria to bypass the lung’s normal filtering function) or bleeding within the brain. Because these silent malformations carry real but preventable risk, proactive screening rather than waiting for symptoms is the recommended approach in HHT. Finding and treating significant malformations before they cause a complication is the main goal of screening.

Lung screening typically involves a specific type of contrast echocardiogram (a "bubble study") to detect abnormal blood vessel connections in the lungs, sometimes followed by a CT scan if abnormalities are found, to characterise the malformation further. This is generally a straightforward, non-invasive process. Screening is usually repeated periodically, since new malformations can develop over time.

Brain screening typically uses MRI to look for arteriovenous malformations within the brain, since these can be present without any symptoms. This is a non-invasive scan, though it may not be suitable for everyone (such as those with certain implanted metal devices), which your specialist team will check beforehand. The frequency of repeat screening depends on individual factors and initial findings, guided by your specialist HHT team.

Yes, skipping recommended screening means potentially missing a silent arteriovenous malformation that could later cause a serious complication, such as a stroke or brain bleed, that might have been prevented with earlier identification and treatment. This is why screening is specifically recommended as part of standard HHT management, even for people who feel entirely well. If you have been recommended screening as part of an HHT diagnosis, it is worth prioritising rather than deferring.

If a significant lung or brain arteriovenous malformation is found, further specific assessment determines whether treatment is needed, which for lung malformations often involves a minimally invasive procedure called embolisation to block off the abnormal vessel, reducing the associated risks. Brain malformations are assessed individually by a specialist neurosurgical or neurology team to determine the most appropriate management, which may range from monitoring to specific treatment depending on the malformation’s characteristics. Not every malformation found necessarily needs treatment; the decision is individualised based on size, location, and risk.

Screening schedules vary based on individual risk factors and previous findings, but are typically repeated periodically, for example every few years for lung screening in adults, since new malformations can develop over time even if initial screening was clear. Your specialist HHT centre will advise on the specific screening schedule appropriate for your individual situation. Consistent, structured follow-up is generally more valuable than intensive one-off testing given the ongoing nature of the underlying condition.

If you have a confirmed or strongly suspected diagnosis of HHT, screening should be arranged as part of standard specialist care, ideally through a dedicated HHT centre experienced with this rare condition. Ask your GP or specialist about referral to such a centre if this has not already been arranged. Family members of someone with confirmed HHT should also discuss testing and, where relevant, their own screening needs with a specialist team.