Easy CT brain
PIYAWAN CHIEWTHANAKUL
Brain window
Bone window
Noncontrast CT
contrast CT
Normal structures on nenhanced CT (section through basal ganglia): 1, Falx cerebri; 2 , margin between cortex and
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subcortical white matter; 2 3 , internal capsule (anterior limb); 4, external capsule; 3 5, calcification of inner pallidum; 4 6, internal capsule (posterior limb); 5 7, straight sinus; 6 8, frontal cortex; 9, frontal subcortical white matter; 10, head of the caudate nucleus; 11, insular cortex; 7 12, putamen; 13, thalamus; 14 trigone 15, occipital cortex.
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Systemic analysis of CT brain Anatomical landmarks
Brain structures, CSF space, calcifications
Symmetry etry
Midli idlin ne str struc uctu ture res s: fal falx, x, 3& 3&4 4 ven venttricl ricle es
Brain tissue Density: gray matter = cortex + BG white matter = subcortical Gray-white Gray-white interface: = cytotoxic edema (ischemia) = vasogenic edema (tumors, abscess) Lesions: intraaxial or extraaxial density density - edema edema (cytotoxic, (cytotoxic, vasogen vasogenic) ic) density – blood, calcification (BG) distortion of brain tissue (mass effect or volume loss) contrast
Enhancing lesions – tumor tumor,, abscess, granulomatous lesion
CSF spaces
Ventricles, cisterns, cortical sulci & fissures Ventricular enlargement – atrophy, hydrocephalus density density - blood, blood, calcification calcification (choroids (choroids plexus) plexus)
Systemic analysis of CT brain Subdural window
Extraaxial blood collection adjacent to skull Crescent shape Not cross dural attachment (falx cerebri)
Epidural window
Lentiform usually combine skull fracture
Bone window
Skull fractures, orbits, sinus, mastoid air sinus
Scalp swelling, sinus, orbits, fractures Skull& soft tissues
SDH & EDH SAH ICH
EDH
Multi-stage SDH
Chronic SDH
Subacute SDH
QUIZ
Isodense subdural
SAH •
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High density fluid collection in sulci, cistern Look for fracture , combine brain injury Aneurysm
CT brain
Hypertensive ICH
Cerebral infarction
CT brain
CT brain
ACA infarction
ICA infarction
CT brain
CT brain
Normal lateral ventricle
Compressed lateral ventricle (mass effect)
CT brain
CT brain
Lacunar infarction
Encephalomalacia
Cerebral venous infarction
right transverse sinus thrombosis
Non-enhanced axial CT increased density within the right transverse sinus (arrow ), ), consistent with thrombus
Empty delta sign
Venous hemorrhage
Venous sinus thrombosis
Infections
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Tuberculous meningitis A postcontrast CT study shows marked enhancement of the basal cisterns with ventricular dilatation indicative of communicating hydrocephalus. areas of low density in the right thalamus, right internal capsule, and left lentiform nuclei (B), representing lacunar infarcts from the vascular compromise in this meningovascular disease process.
Cerebritis
ring-enhancing lesion
a thin, well-defined, ring-enhancing lesion adjacent to the left trigone with w ith surrounding vasogenic edema, producing mass effect and ventricular compression.
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Cysticercosis with Cysticercosis w ith lesions in multiple stages unenhanced CT : multiple, well-defined lesions of very low density, having central high-density foci.= vesicular stage and scolices. Other nodular lesions have high density= nodular stage, and are undergoing mineralization. A few punctuate lesions of very high density = involuted calcific stage. A number of the low-density ring lesions enhance (B), representing the inflammatory reaction to the dying parasites in the colloidal stage, and the enhancement of those in the nodular stage. Note the enhancing lesion in the right occipital soft tissues.
Brain abscess
CNS TUBERCULOMA
CNS TUBERCULOMA
TUBERCULOSIS BRAIN ABSCESS
Brain abscess
Cerebral toxoplasmosis
CNS lymphoma
Encephalomalacia
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Brain metastasis Multiple , at corticomedullary junction Hypo or hyperdense Hypodense : kidney, lung, breast, H&N Hyperdense : GI, choriocarcinoma,melanoma, hematologic malignancy Surrounding vasogenic brain edema
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Meningeal lymphoma bilateral nodular meningeal enhancement in the occipital regions.
Hydrocephalus
Communicating hydrocephalus
Obstructive hydrocephalus
Obstructive hydrocephalus
Brain atrophy
Brain edema
Vasogenic edema
Ischemic edema
Cytotoxic edema
Interstitial edema
QUIZ
Cerebral calcification
Physiological cerebral calcification
Pathological cerebral calcification
QUIZ
Lupus vasculitis
Brain herniation
Subfalcine herniation
Uncal herniation
tonsillar herniation
Reversible posterior leukoencephalopathy
non-contrast CT
contrast CT
