Lower left back pain that moves ct scan shows kidney stones but md says not relevant father and aunt died from renal cell ca help?

MRI: If your medical doctor does not feel it's coming from the kidney, can consider getting an mri. It will better show soft tissue pathology than the ct scan will and may reveal a disc or other problem in the lumbar spine. This is indicated if you have had the pain for a while and have not responded to conservative treatment.

CT scan answers this: A ct scan with intravenous contrast will see a renal mass if present. A small mass can be missed "without contrast". A ct looking for stones is done without contrast. Discuss with your doctor regarding an abdomen ct with contrast.

Appropriate imaging: Although kidney stones can cause back pain, this is uncommonly felt in the lower back alone and migratory. Most stones that cause pain (but not all!) do so through blocking your kidney and/or ureter. This is something that can be seen on ct scan. I agree with others that you will need either a contrast ct or an us to exclude a small kidney cancer although this is very unlikely given symptoms.