Is it easy to miss an aneurysm on abdominal ultrasound?

NO. Duplex ultrasound is an excellent screening tool for abdominal aortic aneurysm detection. Limitations such as a very large abdomen, overlying bowel gas, or an inexperienced technician can lead to "missing" an aneurysm, but if the aorta can be seen, the test is very accurate.
NO. Abdominal ultrasound is very good , for diagnosis of aortic aneurysm , safe, relatively inexpensive, gives no radiation .