Brain Computed tomography.interpretation of brain ct
- 1. BRAIN CT Presentation by Group 1 Mwaka Habanji Peter Kakwama Dorothy Maambo Deborah Ngwira
- 2. OUTLINE • Introduction • Principles of CT • Types of CT Scans • CT scan of head trauma -epidural haemorrhage -subdural haemorrhage • CT scan of sinus pathology • CT scan of masses -CT Scan in diagnosing brain tumours • CT Scan of cerebrovascular accident (CVA)
- 3. INTRODUCTION Computed tomography (CT) This is a non invasive medical imaging test that uses x rays or the use of ionizing radiation to produce cross sectional images.
- 4. PRINCIPLE • Collimated X rays are passed through the patient and information is obtained with a detector on the other side • The X rays source and the detector are interconnected and rotated around the patient during scanning period. • Digital computers then assemble the data that is obtained and integrate it to provide a cross sectional image(tomogram).
- 5. Types of CT 1. Non contrast - CT no contrast agent is used 2. Contrast enhanced CT – Contrast agent is injected to highlight specific areas 3. Spiral(Helical) CT – There is continuous scanning in spiral motion. 4. High speed CT- fast scanning for cardiac or pulmonary imaging. 5. Low dose CT- reduced radiation dose 2 for screening or pediatric imaging.
- 7. CT Scan in head trauma Imaging modality of choice in head is non contrast CT scan Important CT finding of head trauma: 1. Epidural haemorrhage(EDH) 2. Subdural haemorrhage(SDH)
- 8. EPIDURAL HEAMORRIAGE • Location of epidural is between the inner space of the skull and outer layer of the dura(periosteum) • As a result of EDHs are usually limited in their extent by the cranial sutures. • Features in ct: it is biconvex in shape,hyperdense sharply demarcated • indications;evaluate the epidural hematoma or epidural abcesses and mass effect (i.e midline shift and uncal herniations )may be present. • Reporting outcomes location and size of the epidural lesions. Displacement of adjacent brain structures. midline shift or herniation. associated fractures or trauma.
- 10. SUBDURAL • Location between the dura and the arachnoid mater. • In contrast to EDH, Subdural haemorrhage (SDH) is not limited by sutures but are limited Dural reflections( falx cerebri, tentorium and falx cerebelli • Appearance of SDH depends upon the time since its formation: a. Acute SDH (less than 3 days) crescentic hyperdense b. subacute SDH(3-14 days) nearly isodense for detection often CECT is needed. c. Chronic SDH(greater 14)hypodense with enhancing membrane. Indication: evaluate subdural hematomas SDH or subdural empymas. Reporting outcomes -location and size of subdural lesion -displacement of adjacent brain structures -midline shift or herniation -Associated trauma or bleeding disorders.
- 12. CT SCAN IN SINUS PATHOLOGY • Physicians who are interested in treating patients with sinus disease must be able to read and interpret sinus CT scans. • Indication: Evaluate the paranasal sinus disease, such as acute sinusitis, chronic sinusitis complication( e.g. abscess). • Reporting outcomes: -opacification or air-fluid levels and sinuses. -thickening of the sinus mucosa. -bony changes(e.g erosion or destruction) complications( abscess, orbital cellulitis)
- 14. MASSES • - Indication: Evaluate intra-axial or extra-axial brain masses (e.g., tumors, cysts, abscesses). • - Reporting outcomes: • - Location, size, and shape of the mass • - Enhancement pattern (e.g., solid, cystic, ring-enhancing) • - Edema or mass effect on adjacent brain structures • - Associated bony changes (e.g., erosion or hyperostosis)
- 15. CT SCAN IN DIAGNOSING BRAIN TUMOR (MASSES) • Although the most effective and common tool for diagnosing a brain tumour is the use of an mri scan ,ct scan serve as an effective scanning tool for supratentorial abnormalities
- 16. STROKE Indication: Evaluate acute ischemic stroke, hemorrhagic stroke, or transient ischemic attack (TIA). - Reporting outcomes: - Early signs of ischemia (e.g., hyperdense artery sign, loss of gray- white matter differentiation) • - Infarct location and size • - Hemorrhage location and size • - Vascular occlusion or stenosis
- 20. CT UN CEREBROVASCULAR ACCIDENT (CVA) HEMORRHAGIC STROKE) • There are two types of haemorrhagic strokes : there are those that are caused by intracerebral haemorrhage (ICH) and those that are caused by subarachnoid haemorrhage(SAH). • Common locations: basal ganglia and thalamus, pons and cerebellar hemisphere. • Acute blood is markedly hyperdense compared to brain parechyma, and as such usually poses little difficulty in diagnosis.
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