What are the chances of cancer showing up on a MRI but not on the 3 CT scans I recently had?

I have been sick for months and lost a lot of weight. I have itching and yellowing in the corner of my eyes. I was told by my GP that Jaundice starts around the iris not in the corner. Also I have had numerous blood tests and none of them revealed anything out of the ordinary, such as elevated bilirubin, liver enzymes etc. I am worried please help. I have had 3 CT scans and 3 xrays and yesterday my digestive specialist had me do an MRI and I won't get the results for a few more days.