Angiographic semiotics of tumors of the brain and its membranes.
Radiation semiotics of tumors of the brain and its membranes is presented on the basis of X-ray and invasive radiopaque angiography of cerebral vessels in 48 patients (men 32, women 16) aged 20 to 50 years. The most common brain tumors were observed at the age of 30-40 years (67%). Of the total number of detected brain tumors, 64% were arachnoidendotelioma (meningioma) and 36% intracerebral (Kamalov I. , 1993). The most frequent localization of meningiomas was the posterolateral, parietal and parasagittal areas. Intracerebral tumors were more often observed in the frontal, parieto-occipital and temporal lobes.
Patients under the indications were subjected to cerebral angiography (CAG) using the Seldinger catheterization technique. In 100% of cases, the access site was the right or left common femoral artery. For the convenience of manipulating the diagnostic catheter and in order to reduce the likelihood of the appearance of a hematoma in the artery, an introducer. The tip of the diagnostic catheter was placed in the proximal segment of the artery of interest, under the fluoroscopy regime, a trial dose (3-5 ml) of the X-ray contrast medium (PCB).
It was statistically proved that in 21% of patients without primary reactions to the antigen the probability of occurrence of severe anaphylactic reactions is high. According to Katayama H. , severe anaphylactic reactions with RAC are observed in 0,04-0,22%, especially the risk of complications associated with the introduction of RVC, increases with the application of ionic RKV. From 20% to 40% of patients has a high risk of developing small anaphylactic reactions associated with the introduction of RKV. Reduction of the body's reactions to the introduction of RVB, according to Ansell G. , Tweedie, Cohan R. , depends on timely medication preparation and use of low molecular weight non-ionic RKV.
Preference in the selection of radiopaque substances was given by a nonionic RCB-ultravist 300 or omnipak 300, since they are low osmolar (616 and 690 mOsm / kg H2O, respectively), have high hydrophilicity (-2.42 and -2.51 Ig KH), sufficiently low viscosity parameters (4.5 and 5.7 mPa / s) and have very low toxicity, good tolerability, no response to the atherosclerotic altered endothelium, even with repeated administration.
The most frequent localization of tumors was the frontal lobe of the brain, where the tumors located on the convectional surface of the brain, as well as para- sagittal, polar, basal.
Convexial tumors of the frontal lobe were located close to the cortex of the brain. In the arterial phase of the CAG, the frontal type of anterior cerebral artery dislocation (PMA) was determined, the front-polar artery was displaced to a lesser degree and its distal segments returned to the median line. On the radiographs, the convective frontal lobe tumors moved down the upper boundary of the Sylvian triangle in its anterior two-thirds.
At TsAG for frontal lobe tumors the frontopolar branch was shifted to the same degree of severity as PMA, and in 5 (10.4%) cases it exceeded its. Segment A3 PMA was pushed back and flattened with increasing its vertical dimension. The terminal-venous angle remained intact.
Basal tumors of the frontal lobe are predominantly extrinsic in the vast majority; intracerebral are extremely rare. Radiographically, they were defined in the projection of a large olfactory fovea, the tubercle of a Turkish saddle, small wings of the base bone. Since the basal tumors of the frontal lobe almost never had their own vascular network of blood vessels, the main indicator of basal tumors on the CAG was the condition of the proximal segment of the PMA (A1), which either remained intact or changed dramatically (bending downward with intracerebral or arched upward upwards with extramarginal tumors). Extra-cerebral tumors raised the proximal segment A1 PMA from both sides. In these cases, we had to conduct differential diagnosis with atherosclerotic lesions of the PMA, in which segment A1 can also be arched and clinically manifested by the same symptoms as the basal tumor of the frontal lobe. Atherosclerosis, asymmetric, one-sided elevation of the proximal segment of the PMA in the middle sagittal plane with an unchanged vessel diameter is determined, in contrast to the basal frontal lobe tumors, when there is a two-sided elevation of segment A1.
In tumors, the proximal segment of the PMA is raised, its lumen tapers, the diameter of the vessel decreases. In addition, basal frontal lobe tumors change the internal carotid siphon due to pressure on it from the top down, as a result of which the siphon is deformed (closed siphon). The segment A2 of the PMA is pushed back and forth, as a result of which the transition of segment A2 to A3 becomes sharp, the vertical dimension of A3 decreases, and A2 increases. The terminal-venous angle can be shifted upward and posteriorly.
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