**1. Introduction**

Due to the increase of aged patients with atherosclerosis, more attention should be paid to the endothelial damage of great vessels. The damaged endothelium is more susceptible to bacterial infections. The reports or papers of infected aneurysms (mycotic aneurysms) are increasing in Pubmed search (Figure 1), which is consistent with personal experience in dai‐ ly practice. The reasons for the increase were due to several causes: 1) the increase of aged patients with more risk of atherosclerosis than before, 2) an improvement of CT imaging and MR imaging, 3) more awareness of the disease. We focused the diagnosis and manage‐ ments of infected aneurysms, and the diseases needed to differentiate from infected aneur‐ ysms, such as collagen vascular diseases and periaortitis.
