are younger than year of age at the time of diagnosis and in whom the tumor is still localized to the point of origin In such favorable cases, the tumor can be totally excised When widespread dissemination occurs, complete resection is unwarranted because of the risk to other vital structures CT with contrast enhancement demonstrates precise anatomy, as well as renal function and organ vascularity The CT characteristics of neuroblastoma include irregular shape, irregular margins, lack of well-defined capsules, and mixed lowdensity center Neuroblastoma often displaces surrounding organs and encases vessels Prevertebral midline extension is common There are calcifications in at least 75% ( Fig 116.23 ) Ultrasonography has limitations in accurately determining tumor margins or local extension