So I Recently Have Had A MRI Done And My

So I recently have had a MRI done and my neurologist found an incidental non-enhancing hyperdense lesion on my right kidney. It's only 10mm. Is this something that might not be a big deal since it's so small? I don't know what non-enhancing means but I would think it means it's not active? I had an ultrasound on it yesterday but was wondering if it's something that could be serious or not?