Key points of imaging diagnosis - central nervous system and ears, nose, throat

Key points of imaging diagnosis - central nervous system and ears, nose, throat

Classification of skull fractures:

☆ depending on the location: vault fracture, skull base fracture

☆ Open by opening: closed fracture, open fracture

☆ According to the form: linear fracture, cranial suture split, pitted fracture, comminuted fracture, permeable fracture, green branch fracture

Key points in the diagnosis of skull base fractures:

☆ Cerebrospinal fluid nasal leakage, ear hemorrhage

☆ Intracranial gas accumulation

☆ Effusion in the sinus cavity and mastoid air chamber

☆ bone structure interruption

Key points in the diagnosis of acute epidural hematoma:

☆ CT is the preferred test

☆ Fusiform high-density area (CT) under the inner plate of the skull

☆ Spindle abnormal signal (MRI) under the intracranial plate

☆ May be accompanied by cerebral parenchymal edema and mass effect

☆ Can be placed skull fracture

CT manifestations of subdural hematoma:

☆ Acute subdural hematoma appears as a crescent-shaped high-density shadow under the inner plate of the skull

☆ Subacute subdural hematoma is manifested as a crescent-shaped or half-moon mixed density or isodensity shadow under the intracranial plate

☆ Chronic subdural hematoma is manifested as a half-moon shaped low density or a layered density shadow with low and low upper and lower levels under the intracranial plate

Diagnostic points for diffuse axonal injury:

☆ Severe symptoms and mild imaging findings

☆ The cerebral cortex medullary junction area, corpus callosum, basal nerve and upper part of the brainstem are frequent

☆ CT can see small patchy low-density areas with scattered small bleeding foci

☆ MRIT2WI is a patchy high-signal foci, and the long axis of the lesion is consistent with the nerve fibers

☆ No edema or slight edema

CT manifestations of a hematoma in the brain:

☆ Acute phase (within 3 days) uniform high density, clear boundaries, regular or irregular; May break into the ventricles or subarachnoid space

☆ During the absorption period (3 days to 2 months), the edges are blurred, the density is gradually reduced, the edema is severe during the dry period, and it disappears in the later stage

☆ Cystic metastasis (after 2 months) liquefaction, cystic change, water-like density, can form a permeable malformation cyst

Evolution of MRI signals for hematomas in the brain:

☆ Approximately gray matter signal on T1WI during the hyperacute phase (minutes to hours) and high signal on T2WI

☆ Slightly lower or equal signal on T1WI in the acute phase (hours to days), and significantly lower signal on T2WI

☆ Subacute phase (days to months) T1WI high signal, T2WI early low signal, late elevation

☆ Chronic phase (months later) T2WI peripheral enveloping a pronounced low signal ring

Types of cerebral infarction: infarction in the blood supply area of the branch of the cerebral artery is mainly seen in the blood supply area of the middle cerebral artery and the anterior cerebral artery, and a relatively small number are located in the brain and cerebellum

☆ Marginal band infarction is mainly seen in the junction of the parietal occipital lobe and the convex surface of the brain

☆ Lacunar infarction is mainly found in the basal ganglion, thalamus and center of the semi-ovate

TC diagnostic points for cerebral infarction:

☆ 24 hours is a relatively blind zone, but CT perfusion imaging can make a diagnosis in about 2 hours

☆ 1 week after onset of disease, uneven low-density areas, triangles or wedges (curved infarction)

☆ In the 2nd to 4th weeks after the onset of the disease, it is uniform and low-density, the boundary is clear, consistent with the blood supply range, and there is edema and mass effect

☆ One month after the onset of the disease, the density continues to decrease, and by 2 months, the density of the water sample, edema and mass effect disappear

☆ Later legacy changes are cerebral laxative foci and permeable malformation cysts

MRI manifestations of cerebral infarction:

☆ Conventional MRI 8 hours can display T2WI high signal

☆ MR diffusion imaging and perfusion imaging can make a diagnosis up to 2 hours after illness

☆ The curved infarct area is T1WIW low signal with clear edges

☆ Can show "ischemic semi-dark band", guide thrombolytic therapy and follow-up

Arteriovenous malformations and broken points:

☆ DSA, CTA, MRA can be seen abnormal vascular masses and thickened sui arteries and drainage veins developed early

☆ CT and MRI can show concomitant bleeding, CT can also show calcification, intravascular thrombosis and hemosideraxanosis

Key points of imaging diagnosis of cerebral aneurysms:

☆ DSA is preferred, but CTA and MRA can also be applied

☆ The purpose of imaging examination (1) to identify aneurysms; (2) Confirm the onco-bearing artery; (3) Identify the opening of the aneurysm; (4) Identify secondary conditions: vasospasm, secondary infarction, hematoma; (5) Interventional therapy-oriented

Imaging diagnostic points for purulent encephalitis:

☆ Low-density shadow with blurred borders on CT

☆ MRI T1W1 low signal, T2W1 high signal shadow

☆ edema and mass effect

☆ irregular diffuse reinforcement

Key points of imaging diagnosis of brain abscess:

☆ round or quasi-round, single or multi-haired, tension

☆ Peripheral edema and mass effect

☆ Annular reinforcement of the abscess wall (CR, MRI)

☆ Abscesses are characterized by watery density (CT) or signal (MRI), which can also vary slightly depending on the composition of the contents

Key points in the diagnosis of tuberculous meningitis:

☆ Better than the bottom of the brain

☆ CT and MRI enhancement scans can show significant local meningeal strengthening

☆ Tuberculous vasculitis can be secondary to cerebral infarction, but scattered

☆ Meningeal adhesive edges can be secondary to hydrocephalus

☆ CT can sometimes be seen to cause calcification around the basal pool

Key points in the diagnosis of tuberculous brain abscess:

☆ Adults tend to occur on the curtain, children are more common under the curtain

☆ Abscess is irregular, prone to multiple occurrences, uneven wall thickness, no tension

☆ Purulent cavity is watery density (CT) or signal (MRI)

☆ The abscess wall is significantly strengthened

☆ edema is visible all around

Staging and imaging diagnostic points of neurocysticercosis:

☆ Vesicle stage: for live cystists, thin envelope, clear and transparent liquid, no inflammatory reaction, no edema, no strengthening

☆ Gelatinous vesicle stage: cysticer death, cyst fluid opacity, cyst wall atrophy and thickening, inflammatory reaction, peripheral edema, wall ring strengthening

☆ Granuloma nodule periodicity: the surrounding granuloma formation, cephalic calcification, edema remains, nodular or small and thick ring strengthening

☆ Nodule calcification stage: complete calcification, no edema and strengthening

☆ MRI is the preferred examination method, followed by CT

Localization and qualitative basis of intracranial tumors

☆ changes in the skull

☆ Relationship with dura mater

☆ Changes adjacent to the subarachnoid space

☆ Changes in cerebral parenchymal compression

☆ Tumor boundary

☆ edema and mass effect around the tumor

☆ Strengthen behavior

Grading and imaging diagnostic points of astrocytoma:

☆ Class I Benign Boundary is not clear, no mass effect, CT low density, MRIT1WI low or equal signal, T2WI high signal, no reinforcement

☆ Grade II Low malignancystity is common, the walls are thin but uneven, there are wall nodules, no only slight mass effect, no edema, and the cyst walls and nodules can be strengthened

☆ Class III.

Diagnostic points of imaging oligodendroglioma:

☆ The frontal lobe is most common, followed by the parietal and temporal lobes

☆ Characteristic change to band calcification within the tumor (50% to 80%)

☆ There is no edema or only slight edema around the tumor, no reinforcement or only slight strengthening

☆ A small number of malignant high patients are not easy to distinguish from malignant astrocytoma

Key points of imaging diagnosis of ependymoma:

☆ It is more common in children, mostly located in the quadruple ventricles, followed by the lateral ventricular triangle and the three ventricles

☆ Leafy soft tissue masses in the ventricle or across the ventricles and cerebral parynum

☆ The inside can be accompanied by local cystic degeneration or calcification, uniform or uneven strengthening

☆ There may be room room membrane transfer, CT, MRI shows local endodontic thickening, strengthening

☆ It can block the cerebrospinal fluid circulation channel and form hydrocephalus

Key points of imaging diagnosis of brain metastases:

☆ It is more likely to occur in middle age and above, and some primary tumors are unknown

☆ More common in the cortical and subcortical areas of the blood supply area of the middle cerebral artery

☆ Characterized by small lesions, large edema and multiple occurrences

☆ It is easy to have necrosis, cystic degeneration and bleeding in the tumor, and the strengthening is obvious

☆ Known primary tumor or confirmation of metastatic lesions elsewhere is helpful in diagnosis

Diagnostic points of imaging for meningioma:

☆ More common in middle-aged women, slow growth, long course of disease

☆ Round, dumbbell or lobed lumps with clear borders and relatively mild oedema

☆ Broad base and skull or dural mater border, there may be skull reactive hyperplasia and (or) compression

☆ After enhancement, it shows obvious uniform strengthening, and some dural caudal signs are visible

☆ Located in a good area can indicate diagnosis

Key points for the diagnosis of pituitary adenoma:

☆ According to the secretory function, it can be divided into non-functional adenomas and functional adenomas

☆ According to the size, it can be divided into microadenoma (less than 1cm) and large adenoma

☆ Benign, round or lobulated mass shadow in the pituitary fossa, with an envelope

☆ Can be extended to the saddle, next to the saddle, under the saddle, and behind the saddle

☆ Enhancement scans show obvious uniform reinforcement except for cystic degeneration and bleeding

Key points in the diagnosis of craniopharyngioma:

☆ The most common supraslachial area tumor in childhood or adolescence

☆ Cystic, solid or cystic solid lumps with envelope

☆ Common calcification

☆ Enhancement check the sac wall and solid part can be strengthened

☆ The cystic part of CT is negative, and the MRI is different signals due to different contents

Key points for the diagnosis of acoustic neuroma:

☆ Onset is unilateral tinnitus, hearing loss, or deafness

☆ When smaller, the tumor is located in the inner ear canal; In larger cases, it is a round or irregular mass in the corner area of the ponbuterol

☆ The contact surface with rock bone is at an acute angle, and the center is located in the plane of the inner ear canal, and the inner ear canal is enlarged

☆ Significantly enhanced after enhancement

☆ Bilateral protoneuroma is a type I manifestation of neurofibromatosis

Key points of imaging diagnosis of spinal ependymoma:

☆ better than spinal cord cone and horsetail

☆ The tumor is cystic and solid, showing the localization and diagnosis characteristics of intramedullary tumors

☆ Secondary spinal cavity, fan-shaped compressive changes of the pyramid and enlarged neural foramen

☆ Plant metastases in the spinal canal can occur

Diagnostic points for spinal astrocytoma:

☆ It is easy to occur in the neck and chest

☆ 75% is I.

☆ It can occur in multiple segments, local spinal cord thickening, common cystic changes, and irregular strengthening can be seen

☆ The upper and lower ends of the tumor can be secondary to the spinal cavity

Imaging diagnostic points for schwannomas and nerve fibers:

☆ Pedicle root compression, enlarged intervertebral foramen

☆ The tumor is round, round-like or dumbbell-shaped, with clear and smooth edges, which can be significantly strengthened

☆ Widening of the subarachnoid space on the ipsilateral side of the upper and lower margins of the tumor

☆ Neurofibromas can occur more often (neurofibromatosis)

Diagnostic points for chronic middle ear mastoiditis:

☆ Purulent discharge from the external auditory canal on the affected side

☆ Pathology can be divided into simple type, necrotic type and cholilipoma type

☆ Plain x-ray can show increased mastoid air chamber density, upper tympanic chamber, drum sinus destruction, enlargement and bone erosion

☆ High-resolution CT can show the soft tissue density in the mastoid air chamber of the middle ear, which can show the change of the auditory bone chain and the corresponding bone destruction

Key points of imaging diagnosis of nasopharyngeal cancer:

☆ First CT enhancement examination

☆ The pharyngeal crypt becomes shallow or disappears, the pharyngeal cavity on both sides is asymmetrical, and the parapharyngeal space shifts outward

☆ MRI is easy to detect early small lesions and better shows the range of middle and advanced nasopharyngeal cancer

☆ Late stage can invade the base of the skull, adjacent vertebral bodies and blood metastasis

Key points of imaging diagnosis of laryngeal cancer:

☆ Depending on the scope of the cancer, it is divided into supraglottic area, glottic area and subglottic area

☆ Soft tissue mass of the larynx, asymmetrical laryngeal morphology

☆ The anterior epiglottic space, piriform fossa and laryngeal chamber can become smaller or even disappear

☆ MRI has ribs with early detection of cartilage involvement changes