Diagnosing a Brain Aneurysm

A brain aneurysm is an emergency medical situation. The sudden onset of brain aneurysm symptoms may indicate that the aneurysm has ruptured and is bleeding into the brain, and urgent neurologic evaluation and testing is essential to survival.

The neurosurgeons at UI Health are experts at diagnosing and treating brain aneurysms.


Brain aneurysms can be diagnosed by several imaging tests, though an unruptured brain aneurysm also may be found while undergoing brain imaging — such as MRI or CT scan — or a medical evaluation for another reason, such as an evaluation for headaches or other neurological symptoms. At UI Health, our brain aneurysm doctors will use one of the following imaging tests to detect and diagnose an aneurysm.

Computerized Tomography (CT scan)/Computerized Tomography Angiography (CTA scan)

A CT scan uses X-rays to take a series of images of the structures of the brain. These may be one of the first tests used to discover if you have an aneurysm.

A variation of this test called a CTA scan is a noninvasive radiographic test of the blood vessels in the brain using CT technology. A series of thin-cut X-rays are taken after a dye is inserted through an IV in your arm. The X-rays show a 3D image of the blood vessels and surrounding tissue of the brain. The test is easily tolerated by patients and takes only a few minutes.

Cerebral Angiography

A cerebral angiogram is a diagnostic procedure that evaluates the blood vessels of the brain to look for blockages or abnormalities, such as aneurysms. The test involves the insertion of a catheter in a large blood vessel of the leg, which is threaded up toward the brain. A dye is then injected and X-ray pictures are taken of the blood vessels as the blood moves through the brain arteries and veins. If an aneurysm is found, this test determines the best treatment plan.

Lumbar Puncture

A lumbar puncture, or spinal tap, is a procedure to remove a sample of cerebrospinal fluid from your spine with a needle to look for blood in the spinal fluid. If imaging tests show that you have bleeding in the brain, blood is likely to be present in the cerebrospinal fluid surrounding your brain and spine. This test may be ordered if you have symptoms of a ruptured aneurysm, but the CT scan does not show evidence of bleeding.

Magnetic Resonance Angiography (MRA) scan

An MRA is a type of MRI  that uses a magnetic field to evaluate the blood flow through the network of brain blood vessels. MRA does not use X-rays, but a dye may be used during MRA to show blood vessels more clearly.


NOVA (Noninvasive Optimal Vessel Analysis) MRA is a new technology that goes beyond traditional MRA in imaging the brain blood vessels. This technology was first developed by Dr. Fady T. Charbel in order to better understand complex cerebrovascular problems and more effectively develop treatment strategies.

NOVA MRA is the first type of scan that noninvasively measures blood flow in cerebral blood vessels. It incorporates interactive 3D images with a 360-edgree view that allows precise identification of each blood vessel for volumetric blood flow measurement. NOVA provides physicians with the flexibility to evaluate and pinpoint specific areas within a vessel that may be of concern. This type of scan is helpful in diagnosing patients who have had a stroke, cerebral aneurysms, and those who suffer from neurovascular disease related to chronic conditions like high blood pressure and diabetes.