Dynamic computed tomography: intracranial applications

Rapid sequential computed tomography of the brain after the bolus injection of contrast material provides invaluable information as to the characteristic blood flow of intracranial lesions in a noninvasive manner. Plotted dynamic curves permit accurate diagnosis of particularly difficult cases of infarcts and neoplasms. Dynamic computed tomographic (CT) scanning has become a part of the CT work-up for infarcts, which has allowed their earlier demonstration, detected as areas of hypoperfusion not clearly evident on an initial conventional CT study. Quantitative assessment of vasogenic edema and hypoperfusion are helpful in establishing the diagnosis of infarction and neoplasia. Orbital and parasellar neoplasms can be distinguished accurately from vascular lesions. Dynamic CT studies complemented conventional film screen arteriography in the evaluation of three cases of intracavernous internal carotid artery aneurysm, defining thrombus formation and wall thickness and thus influencing the therapeutic approach. In addition, this modality is useful in differentiating jugular fossa neoplasm from vascular malformation. This review elaborates on the technique involved in dynamic CT scanning and the subsequent results.