Imaging of the head and the nek Flashcards
What are the indications for an x-ray
Trauma
Degenerative diseases
post-operative
Indications for Fluroscopy/angiography
swallow study
interventional radiology
arthography
cardiac catheterization
what is Angiography and its indications
form of fluoroscopy intended to evaluate peripheral vasculature
indications: aneurysm, vascular malformations, fistulae, stenosis, thrombosis, dissection, stenting, thrombolysis
Angiography pros and cons
pros;
fast
diagnostic and therapeutic
cons;
invasive
contrast
radiation
what is myelography and what is its functions
uses fluoroscopy and intrathecal injection of contrast
indications;
spinal stenosis, nerve root compression, CSF leak
pros and cons of myelography
pros:
defines subarachnoid space
identifies spinal block
cons: invasive CSF leak, headache radiation contrast
how is radiodensity measured
measured in Hounsfield units
water = 0 HU
All densities are compared to water
hyperdense = white
hypodense = black
how are CTs read
cans are read as if looking at the patient from the feet
What is CT used for
skull skull base and vertebrae:
-trauma and bone lesions
ventricles:
-hydrocephalus, masses and mass effect
Intracranial masses, mass effect
-headachers, nausea, vomitting, visual symptoms
hemorrhage, ischemia
-stroke, mental status change, focal neurological defects
calcification
-lesion characterization
pros and cons of CT
Pros:
fast
relatively inexpensive
good at detecting large pathology
cons:
less detail than MRI
Radiation exposure
low sensitivity in posterior fossa
When do you use contrasts
Neoplasm infection Vascular disease Inflammatory disease More than 3 hours after onset of symptoms
When do you not use contrasts
trauma hemorrhage hydrocephalus dementia epilepsy within 3 hours of symptoms
How to tell if the BBB is broken using contrast
If using a IV contrast, it should not be able to get into the BBB
if it does then you know the BBB is broken somwhere
WHat structures get enhanced with IV contrast
cerebral blood vessels memninges-dura, arachnoid mater, and pia mater pineal bland pituitary gland choroid plexus
what is CT angiography and what is its uses
Rapid IV contrast bolus
scanned during arterial phase
digitally reconstructed into 2D and 3D images
Pros and cons of CT angiography
pros:
Non invasive
examine vessels from orgin
cons:
contrast
radiation
lower resolution
what is the radiodensity for MRI
Hyperintense = white hyperintense = black
What are the uses of MRI
furthur evaluation of CT findings, tumors, infection, joint imaging
What are the pros and cons of MRI
pros:
High level of detail
safe to use in pregnancy
vessel imaging can be obtained without the use of contrast
cons: time consuming contraindictions (metal/implantable devices) expensive claustrophobia
what is the details of T1 weighted MRI
CSF is dark
hypointense
white matter is bright
hyperintense
good for imaging normal anatomy
what are the details of T2 weighted MRI
CSF is bright
hyperintense
white matter is dark
hypointense
good for visualizing pathology
WHat is special about a T2 flair
removes CSF from T2
enhances fluid with high protein content
-edema and abscesses
FLAIR
- fluid attenuated inversion recovery
What is and are the uses of ultrasound
noninvasive imaging technique
transducer emits ultrasound waves into the body
transducer then functions as a reciever that records the energy
uses:
evaluation of carotid arteries, placement of central lines
what are the pros and cons of ultrasound
Pros:
non-invasive
cheap
no radiation
cons:
learning curve
