tailieunhanh - Applied Radiological Anatomy for Medical Students Applied - part 6

Ngành thiết bị đầu cuối của động mạch đáy là động mạch não sau, cung cấp các chẩm (hình ảnh) vỏ não (Figs. (g), 7,23 (b)). Nhiều chi nhánh nhỏ hơn phát sinh từ các động mạch đáy, mà là quá nhỏ để được hiển thị ở mạch máu. Những động mạch "đục lỗ | The skull and brain PAUL butler a b Fig. . The vascular territories. The terminal branches of the basilar artery are the posterior cerebral arteries which supply the occipital visual cortex Figs. g b . Many smaller branches arise from the basilar arteries which are too small to be shown at angiography. These perforating arteries pass posteriorly to the brainstem. It is also the case that similar very small arteries arise from all of the major intracerebral arteries including the communicators. Vascular territories Knowledge of the cerebral arterial territories can be of assistance in the identification of a lesion as an infarct. These are illustrated in Fig. . Cerebral venous drainage A complex venous system drains blood from the brain into the internal jugular veins in the neck Fig. . The superficial veins over the cerebral surface drain into the dural venous sinuses venous spaces within the dura Fig. . There is also a deep system draining into the paired internal cerebral veins Figs. i g . The internal ceebral veins lead into the single great vein of Galen thence into the straight sinus. This venous confluence is situated in the quadrigeminal plate cistern. Another confluence this time of the dural venous sinuses occurs at the internal occipital protuberance or torcula where the superior sagittal transverse and straight sinuses converge. 79 The skull and brain PAUL butler a b Superior sagittal sinus c Inferior sagittal sinus a b Lateral sinus Superior sagittal sinus Internal jugular vein Fig. . The cerebral venous system a T1 weighted sagittal MRI after intravenous gadolinium DTPA b carotid angiogram venous phase lateral view c carotid angiogram venous phase frontal view. Note that the lateral sinuses are not seen on the MRI because it is a midline slice. The angiograms represent a 3-D arrangement displayed in 2-D. Transverse sinus Internal cerebral vein Great vein of Galen Straight sinus I Internal jugular vein ị