Brain MRA (blood vessel MRI, without contrast)

What it is

An ordinary brain MRI shows tissue. An MRA shows plumbing. The distinction is worth holding onto, because the two are often done in the same session and people assume they are one test. The images here are reconstructed into a three-dimensional map of the arteries at the base of the brain and their branches, which a radiologist can rotate and inspect for a bulge, a narrowing, or an abrupt stop. What makes the unenhanced version possible is a trick of physics: blood flowing into the slice being imaged has not been exposed to the same radio pulses as the stationary tissue around it, so it stands out brightly without any dye at all. That is why a contrast injection is not always necessary for brain vessels, and why this code exists as a common, injection-free study.

Why it is done

• To look for an aneurysm, a weak bulging area in an artery wall, or to follow one already known about
• To find a narrowing or blockage in the arteries feeding the brain, usually after a stroke or a transient ischemic attack
• To look for a tear in an artery wall, which can follow a neck injury and can cause stroke in younger people
• To investigate an abnormal tangle of vessels
• To check arteries in someone with a family history of aneurysm

What to expect

No fasting, no IV and no injection for this version. Screening for metal implants, pacemakers, aneurysm clips and metal fragments happens first and is thorough — the magnet is permanently on. Inside the scanner the requirement is stillness, because the vessel map is assembled from many thin slices and movement smears them together. It is loud, and hearing protection is provided. An MRA of the head alone takes roughly fifteen to thirty minutes, though most appointments run longer because a brain MRI is booked in the same slot. Nothing about the exam limits what you do afterward.

Questions worth asking

• If a brain MRI is being done in the same appointment, that is a second code and a second charge even though you never leave the scanner. Ask for both on the estimate.
• An MRA of the neck vessels is a third code again. Confirm whether the order covers the head only or the head and neck.
• Ask whether a with-contrast MRA was ordered instead of this one, and if so what it adds — the unenhanced study is standard for many brain vessel questions.
• If an aneurysm is being monitored with a scan every year or two, ask the facility for its cash or self-pay price and compare it against your deductible before scheduling each round.
• Ask whether the reading radiologist bills separately from the imaging centre.