0 1 First of all, we should make clear the structure of the skull, which is the same as looking at the chest and abdomen. Only by knowing the specific anatomical position and the positional relationship of various organs can we know if there is any problem.

In addition, we can also observe whether the two sides are symmetrical in the film. If the two sides are asymmetrical, there is probably a problem.

Generally speaking, besides bleeding and calcification, there are infarction, inflammation, tumor and so on. Most of them showed low density, and some lesions also showed equal density. Specific problems need more detailed observation and analysis.

In fact, the head ct film is more complicated, and watching the film is also a very professional imaging knowledge, which is not as simple as imagined. If in doubt, you'd better consult a doctor instead of guessing for yourself.

2 0 1 cerebral hemorrhage

? A perforating branch of cortical artery-cerebral lobe hemorrhage

? Lentiform artery-putamen hemorrhage.

? Thalamic c perforating artery-thalamic hemorrhage

? Pontine branch of basilar artery-pontine hemorrhage

? Superior cerebellar artery or anterior inferior cerebellar artery-cerebellar hemorrhage

Epidural hemorrhage

It is divided into acute phase, subacute phase and chronic phase. It can be seen that there are high-density fusiform or biconvex shapes under the skull inner plate. According to the number of hematoma, there are different occupying effects, such as disappearance of sulcus, compression and deformation of ventricle, displacement of midline structure and so on. With the extension of time, its density can change from high to equal density and low density.

03 subdural hematoma

Acute subdural hematoma: crescent-shaped high-density shadow under the skull inner plate, often accompanied by brain contusion, with obvious occupying effect.

Subacute subdural hematoma: crescent-shaped or half-moon-shaped, with high or equal density of hematoma.

Chronic subdural hematoma: high and low mixed density, and finally become low density until it disappears.

04 cerebral infarction

According to the anatomical site can be divided into:

① Large-area cerebral infarction: large-area infarction-more than one leaf, more than 5cm; Moderate infarction-one lobe is less than 3-5 cm; Small infarction1.6-3 cm; Lacunar infarction-below 65438+0.5 cm; Multiple infarcts-multiple small, medium and lacunar infarcts.

② Cerebellar infarction

③ Brain stem infarction

05 skull base level, canthus line level

① Bottom of anterior cranial fossa: orbit, eyeball, ethmoid sinus, sphenoid sinus, anterior clinoid process, etc.

② Middle cranial fossa: anterior margin-sphenoid bone; Posterior boundary-petrous part of temporal bone (petrous bone); Inner margin-cavernous sinus and pituitary fossa; Outer edge-temporal bone, temporal lobe in fossa, medial hippocampus.

③ Posterior cranial fossa: anterior margin-petrous bone; Posterior edge-occipital bone; Behind the saddle, the anterior pontine cistern extends to both sides to form the cerebellopontine angle cistern.

④ The fourth ventricle: located in the midline of the posterior cranial fossa, with cerebellar vermis in the back and cerebellar tonsils on both sides.

⑤ Medulla oblongata and pons: located in front of the fourth ventricle.

06 suprasellar cistern level

① Anterior cranial fossa: temporal lobe.

② Suprasellar cistern: above the pituitary fossa, between the bilateral middle cranial fossa, bounded by the front edge of temporal gyrus and the lateral side of temporal lobe hippocampus, in a pentagonal or hexagonal shape. Its front corner is connected with the longitudinal fissure pool, two outer corners are connected with the outer fissure pool, two rear outer corners continue to the ring pool, and the sixth corner is located in the middle of the trailing edge, which is the inter-corner pool. The edge of suprasellar cistern is cerebral artery ring, which is more common in the front of cistern. v？ Font visual intersection.

③ Posterior cranial fossa: fourth ventricle or fourth ventricle cistern.

07 lower part of the third ventricle

① showing the lower part of the anterior horn of the lateral ventricle: anterior-frontal lobe; Lateral head of caudate nucleus; In the posterior midline-the third ventricle, its two sides are connected with the thalamus.

② Posterior cranial fossa:? y？ Glyph or? v？ Zigzag tentorium cerebelli, with infratentorial structure on the inside (vermis on cerebellum) and supratentorial structure on the outside (occipital lobe).

③ Four cisterns: located in front of vermis of cerebellum.

Upper part of third ventricle.

① Basal nucleus and thalamus.

② Forefoot (forelimb) of internal capsule; Between the caudate nucleus and the lenticular nucleus.

③ Knee and hind foot of internal capsule: located between lentiform nucleus (composed of lateral putamen and medial globus pallidus) and thalamus.

④ The outer side of the putamen: outer capsule, cribriform nucleus, outermost capsule and insular lobe.

⑤ The cistern of the fourth ventricle: between the occipital lobes on both sides, there is a pineal body in the cistern, which is connected with the third ventricle forward.

Lateral ventricular body level

It consists of frontal lobe, temporal lobe and occipital lobe. There is a septum pellucidum between the lateral ventricles, and the caudate nucleus and body are on the outside. The posterior horn (occipital horn) of lateral ventricle can be asymmetrical, and choroid plexus calcification can be seen indoors. Longitudinal fissure cistern and cerebral falx can be seen in the midline.

10 lateral supraventricular level

The lateral ventricle of the medial wall is separated by the corpus callosum, and the parietal lobe is outside the lateral ventricle. The parietal occipital sulcus and the central sulcus divide the brain into frontal lobe, parietal lobe and occipital lobe.

1 1 subcortical layer (semi-elliptical central layer)

Above the corpus callosum and lateral ventricle, the cerebral falx runs through the midline from front to back. The white matter is a semi-oval center, the frontal lobe area decreases, the proportion of the parietal lobe increases, and the occipital lobe basically disappears.

Semioval center: myelinated fibers formed by the medulla of the left and right hemispheres above the corpus callosum, symmetrically located on both sides of the cerebral falx.

12 upper layer of cerebral cortex (upper layer of semi-oval area)

Near the cranial top, the cerebral falx is clearly visible, and the gray matter and sulcus next to it are very clear. The parietal lobe is smaller and the frontal lobe is smaller.

Radiation crown: it is a radial fibrous white matter from the internal capsule to the cerebral cortex.