Vertebral Hemangiomas : Prevalence, New Classification and Natural History. Magnetic Resonance Imaging-Based Retrospective Longitudinal Study

Background and purpose: To determine the prevalence of vertebral hemangiomas (VHs), establish a new classification of VHs based on their MRI-signal pattern, and study their natural history. Methods: MRI of 1000 consecutive patients who underwent at least two MRI with an interval of at least 3 years. Growth rate and change of MRI-signal pattern during the follow-up period were the parameters included in studying the natural history of VHs. Results: The prevalence of VHs was 41%. VHs were classified as type I–IV with fat-rich VHs (type I), constituted 79% of all VHs. VHs were more common among females 43% versus males 39%, p =.22. The most affected vertebra was L1. Occurrence rates for cervical (1%), thoracic (7%), and lumbar spine (10%) differed significantly (p <.001). The prevalence of VHs increased with age regardless of gender or spinal part involved (p <.001). Only 26% of VHs changed their size and 4% changed their signal during the average follow-up of 7 years. All VHs were slowly growing lesions (average expected growth of