Role of radiology in central nervous system stimulation.

Central nervous system (CNS) stimulation is becoming increasingly prevalent. Deep brain stimulation (DBS) has been proven to be an invaluable treatment for movement disorders and is also useful in many other neurological conditions refractory to medical treatment, such as chronic pain and epilepsy. Neuroimaging plays an important role in operative planning, target localization and post-operative follow-up. The use of imaging in determining the underlying mechanisms of DBS is increasing, and the dependence on imaging is likely to expand as deep brain targeting becomes more refined. This article will address the expanding role of radiology and highlight issues, including MRI safety concerns, that radiologists may encounter when confronted with a patient with CNS stimulation equipment in situ.

Acute mastoiditis--the role of radiology.

Acute mastoiditis is a commonly occurring condition in children and adults, and one that most radiologists will come across at some point during their on-call duties. Acute mastoiditis is usually clinically apparent. However, the complications, especially the intracranial ones, can be more insidious and may have fatal consequences. Therefore, it is imperative that the radiologist is well versed in identifying these. Local spread of infection from the mastoids and middle ear cleft may occur via four routes: bone erosion, thrombophlebitis, periphlebitis, and via the anatomical pathways. The role of radiology is largely to demonstrate the complications of mastoiditis, which can be clinically occult and are often serious; this article will highlight these complications.