Stereotaxic Angiography in Cerebral Tumors

Stereotaxic angiography offers many advantages over conventional tech­ niques for the diagnosis of cerebral tumours : three dimensional ana­ lysis of the vascular pedicles supplying thetumours; precise identifi­ cation of the structures with which certain cortical vascular loops are connected; early detection of small pathologic displacements; pre~ planning of a precise surgical procedure, and finally a radiographic con­ trol of each intervention under the same circumstances. Stereotaxic angiography is part of a method of exploring the central nervous system morphologically and functionally which TALAIRACH et al. (1,2,3) have been developing for over twenty years, and which will be­ come progressively more important in the future for the examination of cerebral tumours. Stereotaxic exploration is a means of getting vascular, ventricular, and cisternal information radiographically with neither magnification nor distortion. All data thus obtained during one or several examina­ tions are perfectly superimposable, even when the examination is repeated at a much later date under exactly the same circumstances. Once this information has been obtained, one can investigate a large number of facts with great precision: puncture of cystic tumours with cystography: superimposed stereotactic biopsies allowing an histologic diagnosis of the examined tumour, implantation of electrodes for stereo-encephalo­ graphy (3) and introduction of radioactive material for interstitial irradiation (4). These precise anatomic techniques determine the extent of the tumour and the therapy and/or surgical intervention necessary. We base our experience on more than 100 cases of cerebral tumours in various loca­ tions, all examined with this method. We have contributed a series of technical improvements in the field of radiology. We use a "NEUROCENTRIX" with an isocentric seat (Fig. l), two film changers and an image intensifier. One is mobile and can be moved on a cart for the frontal view, the other is attached to the middle of the ring. Frontal and lateral tubes are fixed at 5 meters; thus both magnification and distortion are insignificant.The various free angular and linear movements allow us to achieve strictly identical centering, whatever the position of the head within the space: one thus obtains orthogonal exposures in frontal and lateral projections. The chair of the stand can recline for transfemoral angiography and the frontal image intensifier is used to monitor the catheterization of different carotid and vertebral pedicles. For immobilization of the head we use the frame of TALAIRACH, either with non-surgical points (allowing us to leave the patient's head unshaven) or with surgical points inser­ ted as far as the dura mater.