MRI scanning reports indicate no lipoma even when there are several very visible lipomas all my body.

I have been having several lumps appear all over my body, especially on my arms and thighs. They are of varying size and hardness. I showed by physician who ordered a series of MRI scans. However, the radiologist reports indicated 'no lipomas'. I was totally confused, along with my physician, because the lumps are visible even to naked eye. I wonder if there are any circumstances under which these lipomas may not detected in MRI scans or if there has been some clerical issue with my reports?