Angiographic Diagnosis of Expanding Intracranial Lesions by Vascular Displacement

Abstract

Through their combined efforts, neurosurgeons and roentgenologists have accomplished much to place the diagnosis of expanding intracranial lesions upon an exact basis. Pneumoencephalography, and particularly ventriculography, have been highly successful in the analysis of obscure situations. The more recently developed procedure of intracranial angiography is another standard method of neurosurgical diagnosis. To a certain extent angiography and ventriculography are interchangeable; more importantly, they supplement each other, each having its advantages and limitations. In cases of brain tumor, angiography has the following advantages: 1. It is a safe procedure, even in the presence of high intracranial pressure, as it avoids traumatizing punctures of the diseased brain and does not materially interfere with intracranial hydrodynamics; the patients, therefore, face major surgical intervention in better condition following angiography than after ventriculography. This is especially true of comatose subjects in whom, as a rule, roentgenographic contrast methods are indispensable for an accurate diagnosis. In such cases ventriculography is notoriously dangerous and may jeopardize the patient's dwindling chances of survival, whereas angiography may provide as much or even more information at a far lesser risk. A total of 194 angiographies, among which were 136 cases of expanding intracranial lesion, were performed in the University Hospital without a single death attributable to the procedure. Serious immediate complications, such as cerebral thrombosis or late radioactive damage due to the use of thorotrast, were not observed. 2. Angiography may give information both as to the location and the anatomic type of the suspected lesion. The site of the lesion is revealed by localized displacement of cerebral blood vessels. The angiographic picture is most striking if the tumor encroaches on large vessels, i.e., if it is located not far from the surface of the brain. Conversely, tumors buried deeply in the cerebral substance or within the ventricular cavities are less clearly demonstrated. The anatomic type of the lesion can be frequently recognized by a characteristic manner of vascular deformation and by a specific pathologic vascular pattern within the lesion itself. Moreover, in cases with doubtful diagnosis, angiography not only rules out tumor (as does ventriculography), but may contribute positive evidence for a vascular lesion. From the above considerations the following indications for angiography have been evolved: 1. In certain expanding lesions of the base of the brain and skull. 2. In space-occupying lesions of the cerebral hemisphere which have been grossly localized, or at least lateralized, by other diagnostic methods. 3. In the differential diagnosis of neoplasm versus vascular lesion (especially aneurysm or vascular malformation).