MR artifact mimicking a temporal lobe lesion in an epilepsy patient

A ten-year-old healthy child presented with a right upper extremity focal seizure which secondarily generalized. Magnetic resonance imaging (MR) revealed a 1-cm area of abnormal signal intensity in the left posterior temporal lobe at the gray-white junction. This did not appear on all imaging sequences, raising the suspicion of an artifact. Repeat MR revealed no intracranial or extracranial pathology. This case illustrates MR 'wrap around' artifact that mimicked a temporal lobe abnormality in an epilepsy patient. The physics of MR are reviewed as they pertain to this artifact.