Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
Upcoming SlideShare
Radiological anatomy of the brain
Next
Download to read offline and view in fullscreen.

79

Share

Download to read offline

Ct brain basics and anatomy

Download to read offline

Related Books

Free with a 30 day trial from Scribd

See all

Ct brain basics and anatomy

  1. 1. CT BRAIN-BASICS AND ANATOMY M3 BRAINSTORMING 23/11/09
  2. 2. HISTORY <ul><li>Sir Godfrey hounsfield-1972 </li></ul><ul><li>Nobel prize in 1979 with cormack </li></ul><ul><li>six generation of scanners </li></ul><ul><li>Latest 128 multidetector ct </li></ul>
  3. 3. PRINCIPLE <ul><li>Internal structure of an object can be reconstructed from multiple projections of the object. </li></ul><ul><li>Uses x rays applied in sequence of slices across the organ </li></ul><ul><li>Images reconstructed from xray absortion data </li></ul><ul><li>Xray beam moves around the patient in a circular path </li></ul>
  4. 4. PARTS <ul><li>1)xray tube-akin to that in a x ray machine. </li></ul><ul><li>2)detectors </li></ul><ul><li>3)gantry- which houses xray apparatus </li></ul><ul><li>4)patient couch </li></ul><ul><li>5)viewing console </li></ul>
  5. 5. HOW A CT SCAN IS DONE <ul><li>A motorized table moves the patient through the CT imaging system </li></ul><ul><li>a source of x-rays rotates within the circular opening, and a set of x-ray detectors rotates in synchrony on the far side of the patient. </li></ul><ul><li>In axial CT, which is commonly used for head scans, the table is stationary  </li></ul>
  6. 6. <ul><li>In helical CT, which is commonly used for body scans, the table moves continuously as the x-ray source and detectors rotate, producing a spiral or helical scan </li></ul><ul><li>Data processed by computer to form image </li></ul>
  7. 7. TYPES <ul><li>Spiral ct- </li></ul><ul><ul><li>uses principle of volumetric acquisiton. </li></ul></ul><ul><ul><li>no respiratory misregistration </li></ul></ul><ul><li>EBCT-coronary calcium measurement </li></ul><ul><li>HRCT </li></ul><ul><li>CT cisternography and myelography </li></ul>
  8. 8. INDICATIONS <ul><li>Acute changes in mental status </li></ul><ul><li>Focal neurologic findings </li></ul><ul><li>Trauma </li></ul><ul><li>Suspected SAH </li></ul><ul><li>Initial evaluation of conductive hearing loss </li></ul>
  9. 9. CT <ul><li>Advantages – </li></ul><ul><ul><li>Easy availabilty </li></ul></ul><ul><ul><li>Fast </li></ul></ul><ul><ul><li>Better for bone and acute blood,lesions of skull base and calvarium </li></ul></ul><ul><ul><li>Calcification </li></ul></ul><ul><ul><li>Less limited by patient factors </li></ul></ul><ul><li>Disadvantages- </li></ul><ul><ul><li>high radiation </li></ul></ul><ul><ul><li>poor visualisation of posterior fossa lesions </li></ul></ul>
  10. 10. CT DENSITY MEASUREMENT <ul><li>Hounsfield units </li></ul><ul><li>Water-0HU </li></ul><ul><li>Air- -1000 HU </li></ul><ul><li>Calcification- +1000HU </li></ul><ul><li>Fat-100HU </li></ul><ul><li>CSF-3HU </li></ul><ul><li>Grey matter-38HU </li></ul><ul><li>White matter-30HU </li></ul><ul><li>Fresh blood-70-80HU </li></ul>
  11. 11. CECT <ul><li>To detect abnormal disrution caused by tumor,abscess ,infarct etc </li></ul><ul><li>Uses ionic or non ionic contrast(6 fold reduction in allergic reactioin 0.04%) </li></ul><ul><li>In normal CNS vessels,pituitary choroid and dura enhance </li></ul>
  12. 12. Indications for non ionic contrast <ul><li>Prior adverse reaction </li></ul><ul><li>BA </li></ul><ul><li>Allergy or atopy hx </li></ul><ul><li><2yr </li></ul><ul><li>RF(Cr>2) </li></ul><ul><li>Cardiac </li></ul><ul><li>DM </li></ul><ul><li>Severe debilitation </li></ul>
  13. 13. Recommedations in renal failure Non ionic, C/I for diabetics 2-2.5 Non ionic ,only to patient receiving dialysis in 24hr >3 Non ionic. If DM 1ml/kg/hr x10hr hydration 1.5-2 Ionic/non ionic 2ml/kg upto 150ml total <1.5 RECOMMENDATION CREATININE
  14. 21. INTERPRETATION OF CT BRAIN <ul><li>1-GENERAL INFORMATION </li></ul><ul><li>2-EXTRACRANIAL TISSUE </li></ul><ul><li>3-CRANIAL BONE </li></ul><ul><li>4-BLOOD </li></ul><ul><li>5-CSF FLOW </li></ul><ul><li>A-VENTRICULAR SYSTEM </li></ul><ul><li>B-CISTERNS </li></ul><ul><li>6-BRAIN TISSUE </li></ul><ul><li>A-MASS LESIONS </li></ul><ul><li>B-SULCI & GYRI </li></ul><ul><li>C-GRY & WHITE DIFFERENTIATION </li></ul>
  15. 22. Blood Air Contrast Fat Calcification Fluid Bone Csf High density Low density
  16. 23. I-EXTRACRANIAL TISSUE II-CRANIAL BONES
  17. 24. III-BLOOD
  18. 25. III-VENTRICULAR SYSTEM
  19. 26. LV V3
  20. 27. IV-BRAIN TISSUE
  21. 28. V3
  22. 30. Physiologic calcifications <ul><li>Chorid plexus-rare before 10yrs </li></ul><ul><li>Basal ganglia-rare before 40ys </li></ul><ul><li>Pineal gland-common after 30 yr rare before 10yr </li></ul><ul><li>Falx </li></ul><ul><li>Dentate nuclei </li></ul>
  • DoctorFoziaHussain

    Jun. 8, 2021
  • abdurrahman721

    Apr. 22, 2020
  • JaiRam29

    Apr. 17, 2020
  • ALhasanHussein

    Mar. 27, 2020
  • AvineshAvi

    Nov. 10, 2019
  • AnjanaRamachandran6

    Sep. 12, 2019
  • Lameesshaat2

    Aug. 2, 2019
  • NguynTrn45

    Jun. 27, 2019
  • xubairxahid

    Apr. 25, 2019
  • RathikaThendralarasu

    Feb. 12, 2019
  • VikasNaik16

    Jan. 10, 2019
  • kishorekumar659

    Dec. 11, 2018
  • MaheshSah8

    Sep. 1, 2018
  • ArunRaja46

    Jul. 12, 2018
  • prasiddh09

    Jun. 23, 2018
  • TapasLaha3

    Jun. 21, 2018
  • TriptiBanerjee

    Jun. 5, 2018
  • NachiketaShringi

    May. 20, 2018
  • SamreenKhan70

    May. 13, 2018
  • mahmoudkareem1

    Apr. 21, 2018

Views

Total views

31,276

On Slideshare

0

From embeds

0

Number of embeds

52

Actions

Downloads

1,333

Shares

0

Comments

0

Likes

79

×