Examining a CT scan of an abdominal aortic aneurysm. Part 1: Measuring the thrombus to aneurysm ratio using MatLab.

Abdominal Aortic Aneurysms are a relatively common medical condition that occurs when the wall of the aorta expands to an above average diameter somewhere in the abdominal region of the body. Since an abdominal aortic aneurysm has a good chance of rupturing, which usually results in death, it must be detected and treated before rupture occurs. The current method of determining whether surgery is necessary depends on factors such as size and expansion rate of the aneurysm as well as the age and health of the patient. A proposed hypothesis is that the ratio of thrombus area to overall aneurysm area may also aid in determining whether surgery is necessary because it correlates to whether the aneurysm is stable or expanding. Currently the sizes of the aneurysm, thrombus and lumen are determined by manually measuring the diameter of the overall aneurysm and the diameter of the lumen, then employing these in the area formula for a circle to determine their respective sizes. The thrombus area is calculated by subtracting the area of the lumen from the area of the overall aneurysm. Since the aorta may not be perfectly circular in shape and this method is time consuming and error prone, an improved method for finding these areas is needed. This paper discusses a preliminary study of using MatLab as a tool to implement an algorithm that better approximates the area of the thrombus and overall aneurysm.