Vertebral osteomyelitis secondary to infective endocarditis detected by repeated magnetic resonance imaging: a case report

Background: Patients with infective endocarditis (IE) experience various symptoms, a major one being back pain, which is occasionally caused by concomitant vertebral osteomyelitis (VO). Magnetic resonance imaging (MRI) is generally used to detect VO; however, the sensitivity of detection using MRI is very low in the early stages of VO.

Case summary: A 60-year-old man visited our hospital with complaints of fever and persistent back pain over the past 7 days. A holosystolic heart murmur was auscultated, and an echocardiography revealed a vegetation on the posterior mitral leaflet. Blood cultures were positive for Streptococcus sanguinis. He was diagnosed with IE and treated with antimicrobials. A lumbar spine MRI on Day 1 showed no clear signs of vertebral infection, but the back pain continued and gradually worsened. Magnetic resonance imaging retest on Day 8 showed high signal intensity within the lumbar vertebral bodies and the disk on T₂-weighted sequences, indicating VO. Intravenous antimicrobial therapy was extended, followed by oral antimicrobials, and a corset was put on to protect the lumbar spine to prevent bone degradation.

Discussion: For persistent back pain in IE patients, repeat MRIs at regular intervals of time can detect possible vertebral infection even if signs of vertebral infection were absent on the initial MRI.