Hi, Thanks for writing in. The findings suggest a small area in the left cerebellar white matter which looks more of a fluid area by imaging characteristics. It may be an area of degeneration or old trauma, if you have a history of head injury. Remotely it can be due to infection but this is often accompanied by edema, which is not mentioned in your report. A 4 mm lesion may be followed up after 6 months or a year to look for any change in appearance or new findings. At present you may consult a neurologist and take treatment for any symptoms which you might be having.