A 1-year old girl with presents with scalp hemangioma since birth. 3D CT demonstrates a midline hemangioma with hypertrophied feeding arteries and draining veins. Infantile hemangioma is a benign neoplasm of endothelial cells. They commonly develop in neonates within first few months of life. These birthmarks are more common in whites. Girls are affected 3-5 times more often than boys. Most infantile hemangiomas undergo rapid initial proliferation, with a subsequent plateau phase at age 9-10 months, before finally involuting. The involution phase extends from 1 year until 5 to 7 years of age. About 50% of lesions are completely resolved in 5 years. Differential diagnosis includes other neonatal and infantile soft tissue sarcomas e.g. fibrosarcoma or rhabdomyosarcoma. In general, hemangiomas are characterized by discrete margins, relatively homogenous signal intensity, and homogenous contrast enhancement, whereas sarcomas tend to be heterogeneous. Cases that do not exhibit the typical appearance and growth patterns for hemangioma are often biopsied to exclude malignancy.
Here is a sagittal CT.

References: 1. Infantile Hemangioma: Diagnosis and Treatment Strategies.
2. Donnelly etal; Vascular Malformations and Hemangiomas. A Practical Approach in a Multidisciplinary Clinic. AJR 2000; 174:597-608.

Credit: Dr Ahmed Haroun http://www.radpod.org