This chapter provides an overview of the radiological representation—X-ray, MRI, and CT—of foreign material iatrogenically introduced into the skull cap and intracranially. First, the anatomy is depicted with the skull cap, brain structures, vascular system. Which landmarks to visit is shown as well as foreign material iatrogenically introduced into the cerebrospinal fluid spaces and the vascular system. The radiological representation of accesses for trepanations, craniectomies, and skull roof plastics is shown as well as catheters and probes, especially intracranial pressure probes and other foreign bodies. Intracranial vascular clips, stents, and coils in imaging form another focus. Cerebrospinal fluid drainage disorders lead to various CT and MR morphologically detectable changes. The acute diagnosis is usually made by CT. The therapy often consists of a temporary or permanent drainage with e.g. shunt systems.