Lecture 17: Imaging of Head and Neck Flashcards
(17 cards)
What are indications for an x-ray?
Trauma
Degenerative Diseases
Post-Operative
What is fluoroscopy?
What can you use as contrast?
Continuous X-ray radiation that creates a moving x-ray
Contrast: Barium, Iodine
What are the three types of flouroscopy discussed?
Barium Swallow
Angiography
Myelography
What is a swallow test?
Use contrast and fluoroscopy to evaluate esophagus while swallowing
Example: Zenker’s Diverticulum
What is angiography used for?
What are its pros and cons?
Evaluate peripheral vasculature in case of aneurysms, vascular malformations, fistulae, stenting, thrombosis, etc
Pros
- Fast
- Diagnostic and Therapeutic
Cons
- Invasive and Radiation
- Contrast
What is myelography
Imaging that involves spinal needle into spinal canal and use of contrast
Indications:
- Anesthesia
- Spinal Stenosis
- Nerve Root Compression
- Spinal Block
What will look white in a CT scan?
What will look black?
White: anything hyperdense
- Bone
- White MAtter
- Muscle
- Gray Matter
- Hemorrhage
Black: anything hypodense
- Fat
- Air
When do you use CT?
Detecting Large Pathology
- Skull and verebrae trauma
- Anything to do with ventricles
- Intracranial masses
- Hemorrhage, Ischemia
- stroke
- Calcification
When is contrast indicated for a CT, and when is it not indicated?
-
Contrast Indicated:
- Neoplasm
- Infection
- Vascular disease
- Inflammatory disease
-
No Contrast
- Trauma
- To rule out hemorrhage
- Hydrocephalus
- Dementia
- Epilepsy
What is CT contrast made of?
What does it tell you?
Iodine (based)
Tells if Blood Brain Barrier is intact since contrast can’t cross it
Why might one prefer a CT angiography over a fluoroscopy angiography?
Why might one prefer fluoroscopy?
CT angiography is not invasive, because — unlike fluoroscopic angiography — you don’t have to inject contrast directly into the artery. In CT angiography the contrast is administered via an IV bolus.
Also in CT angiography, you can evaluate blood vessels from the heart to the point of interest, unlike fluoroscopic angiography - which is more distal.
All that said, fluoroscopy angiography has a higher resolution.
What will look white in a MRI scan?
What will look black?
White: anything hyperintense
Black: anything hypodense
When do you use MRI?
- Further evaluation of CT findings
- Tumors
- INfections
- Joint Imaging
- TMJ
What is bright and dark in T1 MRI?
What is it good for?
CSF is dark, white matter is light.
Good for anatomy.
What is bright and dark in a T2 MRI?
What is it good for?
T2 = CSF is bright, white matter is dark.
(T2 = too bright)
Good for pathology
What is a T2 FLAIR good for?
Visualizing edema.
-Can remove CSF fluid
(FLuid Attenuated Inversion Recovery)
When would an MRI be preferable to a contrast CT?
If blood (and therefore contrast) cannot get to the area - such as in ischemic areas..
