Coronary artery bypass graft (CABG) surgery is one of the most frequently done surgical procedures in the US, accounting for around 100,000 cases per year. Most of these are done by placing the patient on cardiopulmonary bypass pump (heart-lung machine) and stopping the heart while sewing in the fragile new bypass blood vessels. Neurologists are familiar with post-CABG strokes, which are thought to occur in about 3-4% of all cases. However, this has been based on patients with neurological deficits severe enough to come to the attention of their surgeons, as few of them would receive pre- and post-operative neurological examinations by neurologists otherwise. The new study by Nah and colleagues shows that if patients are given MRI scans with diffusion weighted imaging (DWI) pre- and post-operatively, that almost 28% of them can be demonstrated to have a new cerebral infarct after CABG surgery and half of these have multiple lesions. The presence of severe aortic atherosclerosis and the use of cardiopulmonary bypass were strong predictors of later infarction. While most of these strokes were in the cerebral cortex, many were in “silent” areas and no neurological deficit was detected on post-operative examinations by a neurologist in almost 90% of cases. Thus the rate of clinically apparent stroke, about 3%, would be equivalent to other series, suggesting that the technique used and the skill of the surgeons in this Korean series was similar to large US series. Considering the high odds ratio of stroke after surgery for patients with aortic atherosclerosis, patients undergoing CABG surgery might want to have an imaging study quantifying their aortic plaque burden to adequately assess their risk for procedure related infarcts.