Cerebral Aneurysm

Diagnosis

Diagnosis of Ruptured Cerebral Aneurysm

A ruptured cerebral aneurysm leads to bleeding within the brain, causing sudden onset of extremely severe headaches, loss of consciousness, stiff neck or seizures. In the emergency room, a ruptured cerebral aneurysm is diagnosed with two main tools:

• Computed tomography (CT) An X-ray technique that produces detailed images of the brain in cross-sectional slices. CT scans are very sensitive in detecting blood in the subarachnoid space from a ruptured aneurysm. The scan reveals the distribution of blood in the brain, providing important clues regarding the aneurysm's location.
• A cerebrospinal fluid (CSF) examination In cases where a subarachnoid hemorrhage is suspected, but the hemorrhage doesn't appear on a CT scan, examination of CSF for the presence of blood can help confirm a ruptured aneurysm. A needle is inserted into the lower back to withdraw a small amount of spinal fluid.

Cerebral angiogram of a basilar tip aneurysm

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Diagnosis of Unruptured Aneurysm

If a cerebral aneurysm is suspected, a CT scan or MRI is usually the first step toward diagnosing the cause of the problem.

If an unruptured aneurysm is seen on a CT or MRI scan, or a subarachnoid hemorrhage is found, the physician may perform a diagnostic test known as a cerebral arteriogram (also called cerebral angiogram) to pinpoint the aneurysm's location and clarify potential treatment options. A catheter (thin tube) is inserted into an artery in the leg and guided through the bloodstream to the arteries in the neck that lead to the brain. Dye is injected into the arteries as X-rays are taken. These images provide a map of the arteries. MRI and CT scans that use dye to help highlight blood circulation (MRA and CTA) also can be used to find a brain aneurysm. A cerebral angiogram, however, often provides more definitive information.

Screening for People at High Risk

Screening for cerebral aneurysms using MRI, MRA or CTA is recommended for people at high risk, including those with a significant family history of cerebral aneurysms and those with a disease called autosomal dominant polycystic kidney disease.

Imaging is performed by radiologists who specialize in imaging the brain, ensuring that brain examinations are performed and interpreted to the highest standard of quality. Mayo has an international reputation for high quality imaging and rapid results. In Mayo's efficient system, exams are interpreted almost immediately afterwards, and results available in Mayo's electronic record system.