How is a brain aneurysm diagnosed?
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The majority of brain aneurysms never cause health problems; because of that, many go undiagnosed. Brain aneurysms typically are discovered only after a rupture, when the unruptured aneurysm is causing head pain, or when someone is undergoing tests for another condition. There are four main tests that can detect a brain aneurysm.
- Angiography (also referred to as a cerebral angiogram) is a test in which dye is injected in the body. As the dye travels through veins and arteries, x-rays are taken and analyzed to determine the site of the aneurysm.
- A computed tomography (CT) scan provides a detailed x-ray of the head that shows images of the brain and skull layer by layer.
- A Magnetic resonance imaging (MRI) is another way to capture an image of the brain in detail.
- Cerebrospinal fluid analysis is a test in which fluid is extracted from the space between the spinal cord and surrounding membrane and is tested for signs of bleeding or hemorrhage.
The majority of brain aneurysms never cause health problems; because of that, many go undiagnosed. Brain aneurysms typically are discovered only after a rupture, when the unruptured aneurysm is causing head pain, or when someone is undergoing tests... More -
Dr. Joshua Bederson of The Mount Sinai Medical Center answered:Patients with ruptured aneurysms producing Subarachnoid Hemorrhage (SAH) are usually diagnosed by CT scan. However, no test is 100 percent sensitive, and CT scans may not always detect SAH, particularly when it is mild, or if it occurred more than 24 hours before the scan. Therefore, whenever a diagnosis of SAH is being entertained, if the CT scan is negative, a lumbar puncture (spinal tap) must be performed, analyzing the spinal fluid for blood or its byproducts ("xanthochromia").
All patients with a diagnosis of SAH, or in whom an aneurysm is suspected require 4-vessel cerebral angiography. Cerebral angiography is currently the only test sensitive enough to definitively confirm the presence of an aneurysm, and also provides critical information regarding the size, shape, and location of the aneurysm, as well as the presence of vasospasm.
For patients without recent SAH, the initial diagnostic test is usually an MRI (Magnetic Resonance Image), an MRA (Magnetic Resonance Angiogram), or a CTA (Computed Tomographic Angiogram. These noninvasive tests have become increasingly sensitive in detecting intracranial aneurysms, and are generally sufficient to decide if 4 vessel angiography is warranted. In certain situation noninvasive imaging can be used to make treatment decisions as well.
Patients with ruptured aneurysms producing Subarachnoid Hemorrhage (SAH) are usually diagnosed by CT scan. However, no test is 100 percent sensitive, and CT scans may not always detect SAH, particularly when it is mild, or if it occurred more... More -
Dr. Rafael Alexander Ortiz answered:Brain aneurysms can present and manifest in different ways. The most dangerous way an aneurysm presents is with rupture and bleeding in the head (subarachnoid hemorrhage). Patients with bleeding in the head will need a CT scan of the head to diagnose the hemorrhage and follow up studies that will find the aneurysm. Other aneurysms are diagnosed in studies performed as part of the work up for headaches, or other symptoms that might be unrelated to the aneurysm. Radiographical studies commonly performed in the work up to diagnose a brain aneurysm include:
- CT scan and CTA of the head: This is a non-invasive way to look for an aneurysm in the head with injection of contrast through an IV line.
- MRI and MRA of the head: This is a non-invasive way to look for an aneurym in the head. There is no need to inject contrast in the vein and more information about the brain will be obtained when compared to the CTA, but small aneurysms measuring less than 2 mm might not be seen.
- Femoral Cerebral Angiogram: Is an invasive diagnostic procedure in which a catheter is introduced into the femoral artery (artery that takes blood to the leg) and navigated into the arteries of the neck to inject contrast (iodine) and create a map of the arteries of the brain under X-Ray (fluoroscopy). It is the most specific and sensitive test to look for a brain aneurysm, its size, shape, and any other associated features of the aneurysm. The femoral cerebral angiogram is important in the work up of aneurysms to determine the need and feasibility of treatment.
Brain aneurysms can present and manifest in different ways. The most dangerous way an aneurysm presents is with rupture and bleeding in the head (subarachnoid hemorrhage). Patients with bleeding in the head will need a CT scan of the head to... More -
Dr. David Newell of Swedish answered:Aneurysm experts use a variety of imaging tests to diagnose a brain aneurysm. You may have one or more of the following imaging exams:
- CT scan
- MRI angiography (MRA)
- Cerebral angiogram
- Lumbar puncture
MRI or MRI angiography (MRA): An MRI or MRA are additional methods of determining the location, size and condition of an aneurysm, and whether the aneurysm is bleeding into the skull. MRI and MRA use magnets, radio-wave energy and computers to create images. The images can be either 3-D or 2-D. MRI and MRA are very similar, except an MRA uses a small amount of dye to help highlight the aneurysm.
Cerebral angiogram: The neurosurgeon will use a cerebral (brain) angiogram to see how the blood is flowing through the arteries and veins in your brain. During this x-ray test, a small amount of dye is injected through a tiny tube (catheter) into the blood vessel in the brain to make it easier to see the blood flow. The angiogram can identify defects in a blood vessel, such as a blockage or a weak area that may develop into an aneurysm. It is often used to detect very small aneurysms.
Lumbar puncture: Your doctor may request a lumbar puncture if he or she suspects your aneurysm is bleeding into your brain. A needle is inserted into the lower-back portion of the spine to withdraw a small amount of spinal fluid. The fluid is examined to determine if there is blood present.Aneurysm experts use a variety of imaging tests to diagnose a brain aneurysm. You may have one or more of the following imaging exams: CT scan MRI angiography (MRA) Cerebral angiogram Lumbar puncture CT scan and CT angiography (CTA): A CT... More
