Towards Accurate Measurement of Abdominal Aortic Aneurysm Wall Thickness from CT and MRI

Abdominal Aortic Aneurysm (AAA) is the focal dilation or widening of the infrarenal artery. It is a vascular disease commonly found in older adults with prevalence increasing steadily with age. The disease is often discovered by unrelated medical examinations and screenings due to its asymptomatic nature. People unaware of their condition may only find out after the catastrophic event of a ruptured AAA, where most patients will not survive if left untreated. The current clinical rupture risk indicator for AAA repair is a AAA diameter exceeding 5.5 cm. There are many limitations with the clinical rupture risk indicator due to its derivation coming from population statistics and not patient-specific circumstances. Computation of AAA wall stress using three-dimensional (3D) reconstructions of patient CT scans have often been used by researchers as a potential patient-specific rupture risk indicator. A property that has a great influence on the stress distribution and magnitude is the aortic wall thickness. Unfortunately, there are no validated, non-invasive methods for measuring aortic wall thickness of patients with AAA. Researchers have utilised either CT or MRI as input into their custom wall detection algorithms, however, there has not yet been a study which utilises both. Therefore, this study aims to develop a non-invasive, and patient-specific method of detecting aortic wall thickness utilising both CT and MRI scans.