Types of hernia and their imaging characteristics

Brain hernia, a condition in which brain tissue shifts from its normal position to a nearby space, is a fatal condition

Depending on its location, herniation syndrome is usually divided into intracranial hernia and extracranial hernia

In order to make an accurate diagnosis, the author recommends the implementation of the "6 points of concern" approach:

(1) Comprehensive analysis of the patient's detailed medical history and clinical examination results;

(2) knowledge of anatomical signs;

(3) direct placeholder effect;

(4) Understand the structure of the shift;

(5) detection of indirect imaging manifestations;

(6) Possible complications

CT and MRI are imaging methods

Schematic of different types of cerebral hernias: Extracranial hernia (extracranial hernia), Subfalcine hernia (subsickle hernia), Central DTH (central descending cerebellar chaeal hernia), Lateral DTH (lateral descending cerebellar hiatal hernia), Tonsillar hernia (cerebellar tonsillar hernia), ATH (ascending cerebellar curtain hiatus

The "6 Concerns" method for diagnosing hernia syndrome:

● Clinical information (green circle): neurological syndrome, patient history

● Anatomical signs (grass green circles): brain sickle, transparent septum, cerebellar curtain, occipital foramen

● Direction of the mass effect (warm yellow circle): Analyze the location of the lesion and the force vector it generates

● Shifting structure (red circle): on the screen? Under the curtain? Specific anatomical areas (buckle-back grate, hook-back, etc.

● Indirect signs (other affected structures) (purple circles): cerebrocy, brainstem

● Complications associated with ventricular herniation (blue circles): stroke (anterior cerebral artery, posterior cerebral artery, inferior cerebellar artery), cranial nerve syndrome (oculomotor nerve), hydrocephalus

Schematic of major dural reflexes: Falx cerebri (brain sickle), Incisura (incision), Tentorium cerebelli (cerebelli)

Anatomical sites associated with cerebral hernia

(a) The cerebral sickle (white long arrow), cerebellar curtain (white short arrow), cerebellar curtain incision (structure circled by a dotted oval), corpus callosum (CC), cingulate gyrus (CG), hippocampus (H), pericallosum sulcus and pericallous artery (black short arrow)

(b figure) occipital large pool (CM), interfoot pool (IPC), medullary pool oblongata (MC), pontine pool (PC), quadruple pool (QC), supracerebellar pool (SCC), corpus callosum (CC), cingulate gyrus, slope (*), brainstem composition: midbrain (Mb), pontons, medulla oblongata (M).

(c-panel) midbrain aqueduct (white short arrow), posterior cerebral artery (white long arrow), cerebral foot pool (CrC), hippocampal gyrus (HG), cerebral interfoot pool (IPC), pericenaal pool (PMC), quadruplex pool (QC), hookback (U).

Subsickle hernia of the

33-year-old male, brain metastasis, subsickle hernia of the

Split subdural hematoma and subsickle hernia

Due to the subsickle hernia of the brain, the pericallous artery (long white arrow) is squeezed into the brain sickle

Descending cerebellar mutual hiatal hernia

26-year-old male, subdural hematoma after hemodialysis with end-stage renal disease, right pupil dilated, and light reflex disappears

Schematic of laterally descending cerebellar curtain hiatus hernia with compression of the posterior cerebral artery (white short arrow), compression of the oculomotor nerve (black short arrow), attention to ipsilateral pupil dilation (black long arrow), contralateral ventricular temporal angle dilation (*).

Descending cerebellar mutual hiatal hernia

(a) Ascending cerebellar curtain hiatal hernia
.
26-year-old male, after
removal of medulloblastoma.
Occlusion
of the quadruple pool, the upper cerebellar pool, the inter-cerebral pool.
The lower mound (short white arrow) is folded below the upper mound, and both the upper and lower mounds are shifted upwards
.
The brainstem shifts forward, resulting in narrowing of the spaces between the pontine and medulla luff (white curved arrows), note the upward shift of the top of the third ventricle (long white arrow), and the papilloma and gray nodules shift forward and are closely connected to the midbrain (white circle).

(b) Ascending cerebellar hiatal hernia, 33-year-old male, suspected of having intracranial lesions
.
Cerebellar tissue (white*) is herniated upward through the right cerebellar curtain incision (short white arrow), resulting in occlusion of the right midbrain pericerebral pool and the left cerebral foot pool, narrowing of the quadruplex pool space, expansion of the lateral ventricular temporal angle (black*), edema of the apical cap and right cerebral foot (long white arrow).

In contrast to the McRae line (white dotted line), the cerebellar tonsils are shifted downward (more than 5 mm), note the occlusion of the occipital pool, the forward shift of the medulla oblonga (white long arrows), and hydrocephalus (white*)

Chiari malformation type
I.
Decreased cerebellar tonsils (white curved arrow in b-panel), with forward displacement of the brainstem (a figure white long arrow), and occlusion of cerebrospinal fluid in the macrofora of the occipital bone (white short arrow in a-figure).

Schematic of cerebellar tonsillar hernia
.
(a) Cerebellar tonsils extending below the foramen of the occipital bone (white curved arrow), brainstem squeeze slope (white long arrow), occlusion of the medulla oblonga pool (black long arrow), obstructive hydrocephalus (black*).

(b) Axial map at the level of the oak macroaperum, displaced cerebellar tonsils (black*) leading to occlusion of peripheral cerebrospinal fluid, medulla oblongata shifting forward (white curved arrow), squeezing of spinal arteries (black short arrows) and vertebral arteries (white short arrows).

Extracranial hernia
.
(A panel) Acute infarction of the left frontal lobe, note the small foci-like lesions on the right (white short arrows).

A few days later, the patient developed angiogenic cerebral edema and underwent decompression of the bone flap
.
(b) After decompression of the bone flap, the cerebral parenchyma is herniated from the location of the left frontotemporal defect (long white arrow).

Lateral fissures of the brain are enlarged, and the frontal and occipital corners of the left ventricle retract
.