14.1. METHODS OF DIAGNOSTIC RADIOLOGY
The main diagnostic radiology methods in neurology and neurosurgery are CT and MRI, as they are the most informative in the diagnosis of a number of injuries and diseases. In several cases, the radiological method has preserved its significance. The cerebral angiography is applied in peripheral vascular diseases and cerebral tumors. CT and MRI are applied in diagnostically complicated cases. The radionuclide method is used in functional studies (such as SPECT and PET).
14.1.1. Radiological method X-ray imaging of the skull (craniography)
The X-ray examination begins with two images of the skull in two mutually perpendicular views - frontal and lateral. In cases of the severe craniocerebral injury, the craniograms are performed in four views, such as posteroanterior, posterior half-axial and two lateral views (Fig. 14.1).
Due to the complexity of the configuration of the skull, the X-ray image in two views does not display all anatomical structures. In this regard, a number of special views are proposed to study both the skull as a whole and its separate structures.
The X-ray image in frontal view provides information about the state of the calvarial bones, their inner patterns and cranial sutures. When studying the cardiograms in the lateral view, the particular attention should be paid to the thickness and structure of the calvarial bones. In normal condition, the thickness of the calvarial bones should be irregular. In the frontal lobe, it is significantly thinner than in the parietal and occipital. The thickness of the bones reaches its peak in the external occipital protuberance zone. The image clearly shows the external and internal bone plates and diploe. The thickness of the internal plate equals the thickness of the external and sometimes even surpasses it. In the thickness of the diploic substance, there are numerous channels in which the diploic veins are enclosed. There are sulci of the meningeal arteria and venous sinuses visible on the internal surface of the calvaria. The sulci of the meningeal arteries have a dichotomous division like a tree branch with a gradual thinning to the periphery. The sulci of the venous sinuses, unlike the sulci of the meningeal arteries, do not change the width of their lumen. The so-called convolutional markings - prints of the cerebral convolutions - are poorly visible in the frontal and temporal bones. In other parts of the arch, they are not visible in normal condition in adults.