Conclusions on the Use of Diagnostic Procedures

Abstract

The neuroradiologist today has many diagnostic facilities for studying patients with occlusive disease of the cerebral vessels. These give much information on the parenchyma (CT; RBS) and on the vessels (radionuclide dynamic study, doppler sonography, intravenous angiography). Nevertheless, only angiography gives the selective spatial solution in the demonstration of cerebral vessels, which is often essential for a precise diagnosis. Angiography, an invasive investigation, is today a relatively safe procedure and complications are very rare. These are nevertheless not completely excluded and this should be always kept in mind, particularly in the study of patients where severe atherosclerotic changes of the vessels are frequently present. Using new less hyperosmolar contrast media in small amounts perhaps with the aid of digital subtraction techniques will further reduce risks also in this group of patients. Although, as we have already stated (Sect. 2.3.4), we think that the contrast medium is not the most important risk factor. Taking into account these considerations we outline the following guide:

• 1) In patients with TIAs catheter angiography remains the most important and necessary diagnostic step. CT will give information about the overall aspect and trophicity of the brain. Moreover it allows elimination of a different pathology. Radionuclide dynamic study, Doppler, and, above all, intravenous angiography may help in detecting stenosis or occlusion of cerebral arteries particularly if extracranially located. But if the patient should be operated on, angiography remains mandatory.

• 2) In patients with completed stroke, CT generally show directly the brain lesion. Radionuclide dynamic study, Doppler, or possibly intravenous angiography may give the required information on the extracranial portion of the cerebral vessels. In most of these patients an overall diagnosis of cerebrovascular occlusive disease is arrived at without angiography. Nevertheless, angiography should be performed later in all cases where a precise diagnosis is needed, as in young patients or in patients who are to be operated on.