Neuroimaging

Question 1

Pneumoencephalography: Mechanism & Function

Answer 1

• X-ray based
• Mechanism: Air replaces small amount of cerebrospinal fluid
• Allows imaging of ventricles

Question 2

Cerebral Angiography

Answer 2

• X-ray based that images the arterial and venous systems of the brain.
• Arteriovenous malformations and aneurysms

Question 3

Digital Substraction Angiography (DSA)

Answer 3

• X-ray based
• Mechanism: Resulting images are digitized and the static tissues are attenuated by substraction process.
• Blood vessels are black on a grey background
• To diagnose: arterial occlusions, aneurysms and arteriovenous

Question 4

Magnetic Resonance Angiopgraphy

Answer 4

• MRA depicts arteries, permitting doagnosis of aneurysms or stenoses.
• Blood vessels are white on black background.

Question 5

Functional MRI

Answer 5

• Examine the most active areas of Brain

- Most active areas of Brain have a high demand for oxygen

Question 6

Positron Emission Tomography

Answer 6

• Examine metabolically active areas of brain
• In PET F-deoxyglucose is administered.
• Neurons take up but do not metabolize F-deoxyglucose.
• F-deoxyglucose accumulates in more active neurons, which emit higher #s of positrons.

Question 7

Single Photon Emission Topography

Answer 7

• Examine cerebral blood flow
• SPECT (Single Photon Emission Computed Tomography).
• Tissues with higher perfusion accumulate more of the radiotracer, leading to locally higher gamma-ray emission.