BackgroundPostmortem imaging (PMI) refers to the imaging of cadavers by computed tomography (CT) and/or magnetic resonance imaging (MRI). Three cases of cerebral infarctions that were not found during life but were newly recognized on PMI and were associated with severe systemic infections are presented.Case presentationsAn 81-year-old woman with a pacemaker and slightly impaired liver function presented with fever. Imaging suggested interstitial pneumonia and an iliopsoas abscess, and blood tests showed liver dysfunction and disseminated intravascular coagulation (DIC). Despite three-agent combined therapy for tuberculosis, she died 32聽days after hospitalization. PMI showed multiple fresh cerebral and cerebellar infarctions and diffuse ground-glass shadows in bilateral lungs. On autopsy, the diagnosis of miliary tuberculosis was made, and non-bacterial thrombotic endocarditis that involved the aortic valve may have caused the cerebral infarctions.A 74-year-old man on steroid therapy for systemic lupus erythematosus presented with severe anemia, melena with no obvious source, and DIC. Imaging suggested intestinal perforation. The patient was treated with antibiotics and drainage of ascites. However, he developed adult respiratory distress syndrome, worsening DIC, and renal dysfunction and died 2聽months after admission. PMI showed infiltrative lung shadow, ascites, an abdominal aortic aneurysm, a wide infarction in the right parietal lobe, and multiple new cerebral infarctions. Autopsy examination showed purulent ascites, diffuse peritonitis, invasive bronchopulmonary aspergillosis, and non-bacterial thrombotic endocarditis that likely caused the cerebral infarctions.A 65-year-old man with an old pontine infarction presented with a fever and neutropenia. Despite appropriate treatment, his fever persisted. CT showed bilateral upper lobe pneumonia, pain appeared in both femoral regions, and intramuscular abscesses of both shoulders developed. His pneumonia worsened, his level of consciousness decreased, right hemiplegia developed, and he died. PMI showed a newly diagnosed cerebral infarction in the left parietal lobe. The autopsy revealed bilateral bronchopneumonia, right-sided pleuritis with effusion, an intramuscular abscess in the right thigh, and fresh multiple organ infarctions. Systemic fibrin thrombosis and DIC were also found. Postmortem cultures showed E. coli and Burkholderia cepacia.ConclusionCerebral infarction that is newly recognized on PMI might suggest the presence of severe systemic infection.Electronic supplementary materialThe online version of this article (doi:10.1186/s12880-016-0174-4) contains supplementary material, which is available to authorized users.