Ventricular compression and displacement refers to CT examination or cerebral angiography found that the ventricles of the brain are displaced, ventricular compression, most often found in traumatic brain injury or brain tumors. The lesion is located in the head and can be seen in the hospital’s surgery or neurology department. Differential diagnosis is based on different ventricles, displacement in different directions, displacement of midline structures, and different compression. Then, what tests are needed for ventricular compression and displacement? The following is the examination items that need to be done for ventricular compression and displacement: I. Tumor of lower frontal lobe 1. Anteroposterior image: the lateral ventricle of the same side is smaller in anteroposterior image, and it is often obviously shifted to the opposite side. The septum pellucidum and the third ventricle are often shifted to the opposite side in an arc shape. Lateral image: the anterior horn of the lateral ventricle and the anterior part of the body are consistently displaced downward on the lateral image; the bottom of the anterior horn and the top of the tip of the inferior horn may be flattened by compression. If the growth is posterior, the inferior horn becomes narrower and is displaced posteriorly and inferiorly. The anterior and inferior portions of the third ventricle may be flattened and displaced posteriorly and inferiorly. The midbrain aqueduct and the fourth ventricle are unchanged. Anteroposterior image: the lateral ventricle can be seen to be displaced to the healthy side, and the displacement is not significant; the lateral ventricle is not clearly differentiated, and the base of the anterior horn is pressed up. Lateral image: the anterior horn is displaced to the posterior or superior side; it narrows and flattens at the base with arcuate indentation or mass; the anterior end of the lateral ventricle is flattened or has an arcuate indentation. The third ventricle is well filled and is seen to flatten and shift posteriorly and inferiorly. There was no abnormality in the midbrain aqueduct and the fourth ventricle. Parasagittal frontal sinus tumor 1. Anteroposterior view: Anteroposterior view showed that the roof of the ipsilateral lateral ventricle was obviously shifted downward and flattened by compression, and the superior angle of the outer part of the ventricle was blunted and also shifted downward; the pellucid septum and the third ventricle were also shifted to the contralateral side in an oblique shape, with the upper part being more and the lower part being less. The ipsilateral corpus callosum sulcus and cingulate sulcus were also flattened and shifted downward, and then shifted to the contralateral side. Lateral image: the anterior horn and the anterior part of the body can be seen to be shifted downward in the lateral image, and the top of the body is pressed and flattened, with curved indentation or lumpy shadow protruding into it; it is narrowed or closed. The inferior anterior portion of the third ventricle is flattened and displaced downward and posteriorly. The midbrain aqueduct and the fourth ventricle are unchanged. Frontal pole tumor: anteroposterior image: anteroposterior image, the lateral ventricles are not clearly differentiated, which is due to the closure or narrowing of the anterior horn caused by the tumor; the lateral ventricles are displaced to the healthy side; the septum pellucidum and the third ventricle are shifted to the opposite side in a straight line; and the tumor encroaches on the two sides, which is lightly displaced or has no anisotropic position. Lateral image: on the lateral image, the anterior horn is closed, the anterior end of the lateral ventricle has an arcuate compression or filling defect, and is displaced to the posterior and inferior part, the pressure mark is heavier in the upper part and lighter in the lower part, and the anterior horn is shortened, narrowed and displaced to the posterior part. The anterior and inferior portions of the third ventricle are often flattened and displaced posteriorly and inferiorly. There is no abnormality in the midbrain duct and the fourth ventricle. E. Epidural hematoma: CT shows a biconvex mirror-shaped or bow-shaped high-density shadow between the inner plate of the skull and the dura mater, and it can be seen that the ventricles are compressed or the midline is shifted. In subdural hematoma, CT shows crescent-shaped high-density, mixed density or isodense shadow on the surface of the brain, mostly accompanied by cerebral contusion and cerebral compression. Displacement of midline structures in fatal craniocerebral injury: caused by intracerebral hematoma and hematoma inside or outside the hard curtain, the third ventricle is compressed and displaced to the opposite side, and it is generally believed that displacement of midline structures more than 5mm can lead to cerebral herniation. Cerebral angiography of the fourth ventricular tumor; hydrocephalus is produced due to obstruction of cerebrospinal fluid circulation, and the ventricles are consistently enlarged. Carotid arteriography shows signs of hydrocephalus, showing upward displacement of the anterior cerebral artery and outward displacement of the lateral fissure artery; lateral image shows upward straightening of the pericallosal artery and disappearance of the knee, and upward elevation of the lateral fissure portion of the middle artery. Because fourth ventricle tumors often herniate into the foramen magnum, the vertebral artery shows displacement of the posterior inferior cerebellar artery, which may move into or under the foramen magnum.