This website calculates the UIATS and PHASES score for inputs provided through a form. It also computes the estimated 5-year rupture rate according to the ISUIA study as well as the estimated annual rupture rate based on the UCAS study.

For patients with multiple aneurysms, it is possible to test each aneurysm separately, which will result in separate recommendations for each aneurysm. For ISUIA, UCAS and the PHASES score, only the most relevant aneurysm should be taken into account.

The team has made every effort to ensure that the information provided is correct. However, it is strongly recommended to review the results carefully. It remains the responsibility of the user to adhere to the latest medical best practice. Neither the team nor any other party involved in setting up this service can be held responsible for any errors or consequences that may arise from the information provided.

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ISUIA (International Study on Unruptured Intracranial Aneurysms): "Unruptured intracranial aneurysms: natural history, clinical outcome, and risks of surgical and endovascular treatment”; The Lancet 2003; doi: 10.1016/s0140-6736(03)13860-3

UCAS (Unruptured Cerebral Aneurysm Study in a Japanese Cohort): "The Natural Course of Unruptured Cerebral Aneurysms in a Japanese Cohort”; New England Journal of Medicine 2012; doi: 10.1056/NEJMoa1113260

PHASES: "Development of the PHASES score for prediction of risk of rupture of intracranial aneurysms: a pooled analysis of six prospective cohort studies”; The Lancet Neurology 2014; doi: 10.1016/S1474-4422(13)70263-1

UIATS: "The unruptured intracranial aneurysm treatment score”; Neurology 2015; doi: 10.1212/WNL.0000000000001891