Diagnostic Tools Flashcards
Uses of CT scan
Acute hemorrhage
Infartcs, Tumors
Good for the brain and skull
Advantages of CT Scan
Faster than MRI
Cheaper than MRI
Disadvantages of CT scan
Not good in terms of visualization of the structures of the spinal cord
PET in PET scan stands for
Positron Emission Tomography
PET scan functions are
measures the metabolic activity of the cortex
records O2 uptake by the neurons
may be used to see the activity of tumors
MRI functions
detects small lesions
can view the CNS in many angles
Developed to look at multiple sclerosis (MS)
Advantage of MRI
provides a good resolution of the spinal cord
When is Diffusion Weighted MRI used?
to see the area of the brain that is infarcted
When is Perfusion Weighted MRI used?
to see the area of the brain that is not working
MRI spectroscopy function
looks at the metabolic/biochemical activity of a tissue
to see how aggressive or malignant a tumor is
Lumbar puncture functions
Analysis of CSF for infections of the CNS
Detection of blood in the CSF
Where is the needle introduced in lumbar puncture?
between the L3-L4 vertebrae
4 vessel digital subraction angiography
2 carotid arteries
2 vertebral arteries
Function of angiogram
to see the status of the blood vessel
Diffusion tractography
MRI based
can trace white matter tracts
Magnetic Resonance Angiogram and CT angiogram
Non-invasive
Evoke potentials function
measures speed of transmission in the pathways
abnormality in tract presents with:
a delay in transmission
Visual Evoke Potentials procedure
measures light from the retina to the occipital lobe (area 17)
In what condition is visual evoke potential commonly abnormal
multiple sclerosis
Brainstem Auditory Evoke Potentials procedure
measures speed of transmission from auditory pathways
measures ear to temporal lobe (Area 41)
Segments of brainstem auditory evoke potentials
divided into 5 segments:
first 2 are CN 8
last 3 inside the brain
Somatosensory Evoke Potentials procedure
measures transmission of sensory pathways
measures from spinal cord to areas 3, 1, 2
Electroencephalogram functions
measures the voltage of the cerebral cortex
When is EEG used?
for seizures and background electrical activity of the brain
Function of EMG NCV
EMG - detects muscle and nerve defects
NCV - measures speed of transmission in the peripheral nervous system
Transcranial doppler
ultrasound in nature
provides a real-time flow of arterial blood
what can the transcranial doppler detect?
anterior and posterior circulations
detects micro embolism
can be used to scan pts @ risk for stroke
Transmagnetic Stimulation
using a magnetic field can depolarize or hyperpolarize neurons
Diagnostic use of TMS
measures neural circuits
Therapeutic use of TMS
neuro rehabilitation in retraining neural circuits
