There are several tests available for known or suspected cases of HHT. Since lung and brain AVMs can cause serious damage without warning, and they can be successfully treated, testing is strongly suggested for these AVMs.

Testing for brain and lung AVMs is often referred to as ‘preventative screening’, meaning the AVM is looked for prior to it causing a problem.

To screen for brain AVMs, an MRI is recommended. Current practice in Canada is to perform on brain MRI early in life, and then every 5 years until the adult age. Most brain AVMs are thought to be congenital (present at birth), but there may be some that develop in late childhood or adolescence.

Screening for lung AVMs is dependent on the age of the individual, and to a lesser degree their symptoms. During childhood, oxygen saturation should be checked every one to two years by finger oximetry done in both lying and sitting positions. Any subnormal result should be followed up with appropriate diagnostic testing. At 10-12 years of age, more sensitive screening should be done to rule out lung AVM(s). Curr