​Brain imaging and cerebrospinal fluid analysis are commonly used to diagnose brain aneurysms.

Computed Tomography (CT)
CT scan is a fast and painless test to detect blood in the brain (SAH). This is often the first test to detect a rupture. 

Computed Tomography Angiography (CTA)
CTA is a non-invasive test where a contrast dye is injected into the vein while a CT scan is carried out to produce detailed images of blood flow in the brain arteries.

Magnetic Resonance Imaging (MRI) and Magnetic Resonance Angiography (MRA)
MRI uses strong magnetic field instead of x-rays to obtain detailed images of the brain and soft tissues. This investigation is sometimes used to supplement a CT scan. Similar to CTA, a good quality MRA can also be used for aneurysm detection and assessment.

Cerebral Angiography
Cerebral angiography is a minimally invasive test that allows detailed assessment of the blood vessels in the head and neck. Cerebral angiography could provide information on the location, the size and the exact configuration of an aneurysm to guide subsequent treatment strategy. 

Cerebrospinal Fluid Analysis
Brain fluid is retrieved from the spine using a needle. The fluid is tested for presence of blood. This may be ordered if a ruptured brain aneurysm is suspected despite a normal CT scan.