CT Findings in the Brain of Adult Patients with HIV/AIDS

Abstract

The availability of modern imaging techniques of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) scans have enabled us to investigate and study brain conditions of HIV CNS involvement commonly seen in Sub-Saharan Africa. Computed Tomography scan of the head displays a two dimensional anatomy of the brain in the form of cross-sectional images enabling one to see structures enclosed within the skull bones. The structural changes due to intracranial pathologies can be easily detected and administration of intravenous iodinated contrast medium further characterizes these lesions to aid in diagnosis. The earlier radiological methods of investigating intracranial pathology, like pneumo-encephalography, conventional angiography or even skull x-rays were invasive or provided limited information. Ultrasound is only applicable in young children before closure of the fontanelle or if adults in the presence of a bone defect, like a burr hole. This chapter will review degenerative brain changes in HIV/AIDS patients due to HIV-related infections, viremia, malignancy, neuronal death, demyelination or those involving the meninges, ventricles, arachnoid matter and also lesions due to bleeds from a variety of causes. However, normal Contrasted CTs were also a common finding despite documented HIV CNS involvement. This calls for more stringent guidelines for ordering this, expensive but otherwise new and modern useful neuro-imaging investigation.