Advanced Neuroimaging of Pediatric Brain Tumors: MR Diffusion, MR Perfusion, and MR Spectroscopy

After leukemia, brain tumors are the second most common malignancy among children [1]. Brain tumors are the most common form of solid tumor in children and the leading cause of death from solid tumors in children. Approximately 9% of the brain tumors reported to the Central Brain Tumor Registry of the United States (CBTRUS) between 1997 and 2001 occurred in persons less than 20 years of age [2]. The prevalence rate for all pediatric (ages 0–19 years) primary brain and central nervous system (CNS) tumors was estimated at 9.5 per 100,000, with more than 26,000 children estimated to be living with this diagnosis in the United States in 2000 [2]. Most brain tumors in children are primary CNS lesions [3]. In adults, most tumors (90%) are found in and around the cerebral hemispheres, whereas in children older than 1 year of age, 50% of brain tumors are found infratentorially [4]. MR imaging is the imaging modality of choice for diagnosis and evaluation of the child with an intracranial neoplasm. It is the idealmodality for initial preoperative diagnosis, including tumor extent, treatment planning, and image-guided therapies (surgery, radiotherapy [RT], and chemotherapy) because of its multiplanar capability, anatomic detail, and superior resolution [5]. The ability to characterize tissue allows for improved assessment of fatty, hemor-