Hi Mark; I don’t know about CT scans being able to accurately determine the size of a hernia, but I just got an ultrasound for my (bilateral reducible direct inguinal) hernia and the ultrasound report gave me lots of very detailed and helpful information about my hernias — including the exact size of each one (measured to the nearest tenth of a cm — for the length, width, and depth of each). So if it is important for you to know the size of your hernia, you may want to get an ultrasound. PS–I paid cash for my hernia ultrasound and it only cost $78 (I live in northern California), which I thought was quite reasonable and well worth it.