Utility of fat suppressed sequences in differentiation of aggressive vs typical asymptomatic hemangioma of the spine.

Objective: While haemangiomas are common benign vascular lesions involving the spine, some behave in an aggressive fashion. We investigated the utility of fatsuppressed sequences to differentiate between benign and aggressive vertebral haemangiomas. Methods: Patients with the diagnosis of aggressive vertebral haemangioma and available short tau inversion-recovery or T-2 fat saturation sequence were included in the study. 11 patients with typical asymptomatic vertebral body haemangiomas were selected as the control group. Region of interest signal intensity (SI) analysis of the entire haemangioma as well as the portion of each haemangioma with highest signal on fatsaturation sequences was performed and normalized to a reference normal vertebral body. Results: A total of 8 patients with aggressive vertebral haemangioma and 11 patients with asymptomatic typical vertebral haemangioma were included. There was a significant difference between total normalized mean SI ratio (3.14 vs 1.48, p=0.0002), total normalized maximum SI ratio (5.72 vs 2.55, p=0.0003), brightest normalized mean SI ratio (4.28 vs 1.72, p<0.0001) and brightest normalized maximum SI ratio (5.25 vs 2.45, p=0.0003). Multiple measures were able to discriminate between groups with high sensitivity (>88%) and specificity (>82%). Conclusion: In addition to the conventional imaging features such as vertebral expansion and presence of extravertebral component, quantitative evaluation of fatsuppression sequences is also another imaging feature that can differentiate aggressive haemangioma and typical asymptomatic haemangioma. Advances in knowledge: The use of quantitative fatsuppressed MRI in vertebral haemangiomas is demonstrated. Quantitative fat-suppressed MRI can have a role in confirming the diagnosis of aggressive haemangiomas. In addition, this application can be further investigated in future studies to predict aggressiveness of vertebral haemangiomas in early stages.