A diagnosis of Chiari I malformation is generally made using a conventional MRI scan and is often an incidental finding during an evaluation of other abnormalities, making an interpretation of the significance of the imaging findings difficult. Patients that have symptoms which potentially indicate abnormally positioned tonsils can have normal imaging findings, tonsilar ectopia or mild Chiari I malformation. In the case that the cerebellar tonsils are not clearly abnormal, according to our conventional imaging diagnostic criteria, it can be difficult to determine the cause of the symptoms. They may be caused by the low tonsils, in which case a surgical decompression would be performed, or they may simply be incidental findings.