A 93-year-old man presented with low back and right leg pain, malaise and low-grade fever of 4 month duration; he had an abdominal aortic aneurysm treated with vascular graft 18 years before. Axial T1-weighted MR image of the lumbar spine shows pathological signal intensity of the L3 vertebral body, and continuous abnormal soft tissue of similar signal intensity extending from the posterior aneurysmal sac to L3 vertebral body (arrows). The aortic lumen is irregular, with flame-shaped areas of pointing contrast suggesting inflammatory infiltration into the aortic wall. With the presumptive diagnosis of infection, he was treated by his local physicians with antibiotics (ciprofloxacin and rifampicin) and analgesics, in addition to lumbar spine immobilization with a brace. CT-guided biopsy was done at his admission; cultures were negative, probably because of antibiotics administration. Because of deteriorated general health status, a joint decision was obtained for conservative treatment with long term suppression with antibiotics. Four months later, the patient is afebrile with improved but constant low back pain.