I'm glad you got your results.
Stenosis is a medical term for narrowing.
The report would indicate that you have a narrowing of your celiac artery.
Atherosclerosis is hardening and plaque formation of an artery. You have hardening and possible plaque formation (fatty deposits) in your abdominal aorta. Over time it can cause the artery to weaken or become narrow.
Atherosclerosis is the major cause of diseases of arteries including the cardiovascular, cerebrovascular, and peripheral arteries.
Atherosclerosis can be prevented by controlling things such as high blood pressure, diabetes mellitus, smoking, obesity, high cholesterol.
Many people have family history of atherosclerosis and that can not be prevented. It starts in childhood usually (very small amounts) and can grow rapidly.
This is not to be confused with an aneurysm or dissection. However, it can cause such problems should it not be monitored carefully.
Make sure you talk to your doctor about these results and find out what he recommends for a treatment option. It could be something as simple as monitoring with a CT scan every year or 2. It would be worth monitoring as it can turn into something more life-threatening should it not be monitored appropriately.
Hope this helps and keep us posted!