1 CHAPTER 4 COMPUTER-AIDED DIAGNOSIS OF ABDOMINAL AORTIC ANEURYSMS Dr. Barry J. Doyle and Prof. Timothy M. McGloughlin Centre for Applied Biomedical Engineering Research (CABER), Department of Mechanical and Aeronautical Engineering, and the Materials and Surface Science Institute, University of Limerick, Ireland. Address: MSG-013-022, MSSI Building, University of Limerick, Ireland. Email: Barry.Doyle@ul.ie ABSTRACT Computer-aided diagnosis (CAD) systems have been used in several areas of medicine for the last number of years. A typical CAD system interprets medical images and provides guidance for the clinician. The concept of CAD in the assessment of abdominal aortic aneurysm (AAA) has essentially been examined since the first reports of computationally analyzing AAAs, however, the technique is gaining momentum as of late. Computer modeling of AAAs is becoming prevalent with several novel approaches of CAD reported over the past number of years. CAD is possible through computer-aided detection (CADe) and computer-aided quantification (CADq) techniques that work together to return usable quantities aimed at helping identify AAAs that may be at risk of rupture. This chapter examines some recent developments within the area of CAD for AAAs, in particular, the commonly used and somewhat clinically accepted peak wall stress, and also asymmetry and the finite element analysis rupture index (FEARI). All three tools provide additional data to the clinician through the CAD system and help compliment the use of maximum diameter in identifying high-risk AAAs.