Hemangiomas (proliferating endothelial tumors) are the most common benign tumors of infancy. Most often hemangiomas are self-regressing lesions without any treatment. Approximately 10% of hemangiomas cause complications such as major ulceration/destruction, distortion of involved tissues, and obstruction of a vital structure. When the situation becomes complicated, there are different treatment alternatives, ranging from systemic or local corticosteroid use to surgery. Sclerotherapy using intralesional polidocanol (Aethoxysklerol) injection may be used before surgery to decrease blood loss or when a vital structure of the face is in danger because of sudden increase in size of a surrounding hemangioma. Before any kind of treatment for both hemangiomas and vascular malformations, pre-operative diagnosis and anatomic position of the lesion must be documented thoroughly. With the help of magnetic resonance imaging, tridimensional vascular pattern of such lesions can be shown successfully. We used three-dimensional contrast-enhanced time-resolved magnetic resonance angiography to detect the changes of lesions for 2 children who have large hemangiomas on their faces, before and after sclerotherapy with polidocanol injection. The findings of three-dimensional magnetic resonance imaging studies help to better assess the success rate of treatment not only for us as the physicians but also for the parents of these children who cannot understand anything with standard two-dimensional radiologic imaging.