Screening for asymptomatic cerebral aneurysms is warranted, as rupture is associated with a very poor prognosis and treatment of unruptured aneurysms is associated with a low morbidity and mortality.[8]Schievink WI. Intracranial aneurysms. N Engl J Med. 1997 Jan 2;336(1):28-40.
http://www.ncbi.nlm.nih.gov/pubmed/8970938?tool=bestpractice.com
Magnetic resonance angiography (MRA) is considered the appropriate first test in cerebral aneurysm screening, as it is noninvasive and safe. The primary limitation is the inability to reliably detect aneurysms <3 mm in diameter.[36]Maeder PP, Meuli RA, de Tribolet N. Three-dimensional volume rendering for magnetic resonance angiography in the screening and preoperative workup of intracranial aneurysms. J Neurosurg. 1996 Dec;85(6):1050-5.
http://www.ncbi.nlm.nih.gov/pubmed/8929494?tool=bestpractice.com
CT angiography (CTA) adds the small risk associated with giving a bolus of nonionic contrast, but it is particularly helpful in visualizing cerebral vasculature with clips in place.
The joint American Heart Association and American Stroke Association guidelines recommend screening for cerebral aneurysms by CT angiography or magnetic resonance angiography in people with two or more family members affected by cerebral aneurysm or subarachnoid hemorrhage.[18]Thompson BG, Brown RD Jr, Amin-Hanjani S, et al. Guidelines for the management of patients with unruptured intracranial aneurysms: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2015 Aug;46(8):2368-400.
http://stroke.ahajournals.org/content/46/8/2368.long
http://www.ncbi.nlm.nih.gov/pubmed/26089327?tool=bestpractice.com
A subsequent systematic review found strong arguments in favor of screening people with one or more first-degree relatives affected.[37]Van Hoe W, van Loon J, Demeestere J, et al. Screening for intracranial aneurysms in individuals with a positive first-degree family history: a systematic review. World Neurosurg. 2021 Jul;151:235-48.e5.
http://www.ncbi.nlm.nih.gov/pubmed/33684573?tool=bestpractice.com
For these people, a history of hypertension, smoking, and female sex are risk factors associated with aneurysm occurrence.[18]Thompson BG, Brown RD Jr, Amin-Hanjani S, et al. Guidelines for the management of patients with unruptured intracranial aneurysms: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2015 Aug;46(8):2368-400.
http://stroke.ahajournals.org/content/46/8/2368.long
http://www.ncbi.nlm.nih.gov/pubmed/26089327?tool=bestpractice.com
Screening is also indicated for people with certain genetic syndromes, such as Ehlers-Danlos syndrome type IV, Marfan syndrome, neurofibromatosis type 1, and autosomal dominant polycystic kidney disease, particularly if they have a family history of cerebral aneurysm.[18]Thompson BG, Brown RD Jr, Amin-Hanjani S, et al. Guidelines for the management of patients with unruptured intracranial aneurysms: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2015 Aug;46(8):2368-400.
http://stroke.ahajournals.org/content/46/8/2368.long
http://www.ncbi.nlm.nih.gov/pubmed/26089327?tool=bestpractice.com
It is also judicious to offer CTA or MRA to patients with coarctation of the aorta, and patients with microcephalic osteodysplastic primordial dwarfism.[18]Thompson BG, Brown RD Jr, Amin-Hanjani S, et al. Guidelines for the management of patients with unruptured intracranial aneurysms: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2015 Aug;46(8):2368-400.
http://stroke.ahajournals.org/content/46/8/2368.long
http://www.ncbi.nlm.nih.gov/pubmed/26089327?tool=bestpractice.com
Patients with a prior history of cerebral aneurysms also have a higher rate of future de novo aneurysm formation and should be screened at 5-year intervals.[38]Rinne JK, Hernesniemi JA. De novo aneurysms: special multiple intracranial aneurysms. Neurosurgery. 1993 Dec;33(6):981-5.
http://www.ncbi.nlm.nih.gov/pubmed/8134011?tool=bestpractice.com