I have had a liver lesion since 2007 that was never followed up on until now and a ct scan with barium was ordered...why? is it to look for cancer?

To follow up on it: The ct cannot absolutely tell you what it is, so its behavior (rate of growth, etc.) is assessed to help decide on any subsequent step. If it is stable after 6 years, it is probably something you were born with. If it is enlarging, then how much change will help guide you to gi/hepatologist, surgeon, oncologist, etc.

Probably not.: In a young woman, most common liver tumors are benign hemangioma, but hepatoma is possible, with increased likelihood if you are on birth control pills. Enlarging liver masses sometimes need surgery to keep them from causing bleeding, even if they aren't cancerous. You are young: if this is liver, think about asking for ultrasound or an MRI with Eovist instead, to avoid the small radiation risk.