Neuroimaging Flashcards
(22 cards)
Give the anatomical planes of neuroimaging.
- Sagittal (y-z plane)
- Transverse (axial x-y plane)
- Coronal (x-z plane)
List the densities of tissue in order from lowest HU to highest HU.
Air
Fat
Water
CSF
White M
Grey M
Blood clot
Bone
What is the unit of measurement for a CT?
Hounsfield Units
Which of the following has a range of 50-70 HU on CT?
A. Bone
B. Blood clot
C. Grey matter
D. White matter
B. Blood clot
Which of the following has a value of 1000 HU on CT?
A. Bone
B. Blood clot
C. Grey matter
D. White matter
A. Bone
Which of the following has a range of 25-30 HU on CT?
A. Bone
B. Blood clot
C. Grey matter
D. White matter
D. White matter
Which of the following has a range of 35-45 HU on CT?
A. Bone
B. Blood clot
C. Grey matter
D. White matter
C. Grey matter
Which of the following has a range of 15 HU on CT?
A. Bone
B. Blood clot
C. CSF
D. White matter
C. CSF
Which of the following has a range of 0 HU on CT?
A. Water
B. Blood clot
C. CSF
D. White matter
A. Water
Which of the following has a range of -50 to -100 HU on CT?
A. Water
B. Fat
C. CSF
D. White matter
B. Fat
Which of the following has a range of 0 HU on CT?
A. Water
B. Fat
C. CSF
D. White matter
A. Water
Which of the following has a range of -50 to -100 HU on CT?
A. Water
B. Fat
C. CSF
D. White matter
B. Fat
Which of the following has a range of -1000 HU on CT?
A. Water
B. Fat
C. CSF
D. Air
D. Air
What view are CT images taken from?
Caudal View (Feet –> Head)
How do you interpret a CT image with regards to the process?
Interpretation: ABCS
• Adequacy/Alignment/Artifact
• Bones/Blood/Brain
- Extra blood: Changes density through consolidation
- Brain parenchyma
Note: EDH and SDH are complete opposites in bleeding shape + intensity/absorption
• Cisterns + Ventricles
- Fluid-filled spaces
- Symmetrical
- Enlarged
• Subcutaneous and surfaces
- Subcutaneous surfaces
Outline the process of MRI
Person enters + magnetic field –> atomic nuclei re-orientate along magnetic field –> radiofrequency pulse flips nuclei from orientated position and synchronises precession of spin axis –> receiver measure time until nuclei return to original orientation (structural scans) or desynchronize (functional scan)
What view are MRI images taken from?
Caudal view (Feet –> Head)
What is a T1 and T2 MRI image used to view predominantly?
• Generated by emission: T1 (CSF black) cf T2 (CSF white)
- -> T1 for structural abnormalities
- -> T2 for inflammation/ischaemia
What process can you use to interpret an MRI scan?
- Adequacy + Alignment
- Bone, Blood + Brain
- Cisterns + Ventricles
- Subcutaneous and surfaces
What is SPECT?
3D nuclear medicine imaging technique combining information from scintigraphy with CT allowing distribution of radionuclide to be displayed in 3D manner
What is PET?
non-invasive imaging technique quantifying radioactivity in vivo using IV injection of positron-emitting radiopharmaceutical then scanning for detection and quantification of patterns of accumulation in the body
Outline the process of PET.
Radiolabeled biological compound (e.g. FDG) injected IV –> Uptake by tissues –> FDG to FDG-6-P (cannot be further metabolized in tumour cells) –> accumulation in tumour cells and detected = quantified