Neuroanatomy and Cases Flashcards
CT uses _____ radiation and can get what two planes of xray?
Iodination
get coronal and sagittal
Use this to get Fast scan, unfortunately its expensive but it is readily available
Computed Tomography
Has strong magnetic waves (cant use with metal) with multiplanar images. Slower results and very pricey
MRI
What contrast is used in MRI?
Gadolinium
Best for brain, bone, soft tissue and lung. Views images in different ‘windows’ and only scan once
Computed Topography
Scan several times and get multiple planes with seen with different pulse sequences but view each image set with only one window
MRI
Best for soft tissue adn marrow with contrast enhancement
MRI
Best for assesing bone and to see acute hemorrhage, trauma and fluid
CT
Bone and hemorrhage are WHITE in______
Fat and Brain is WHITE in _____
Bone and hemorrhage are bright in CT
Fat and brain are bright in MRI
What is dark in MRI T1?
what is dark in CT?
Bone/CSF/Air are dark in MRI
Fat/CSF/ dark in CT
Difference between T1 and T2 MRI
In T1 CSF is Dark, in T2, CSF is bright
In T1 white matter is brighter
In T2, grey matter is brighter
Become familiar with anatomy
Note location of central sulcus
Become familiar with the neuro anatomy
What are the benefits of CTA real time
non invasive and low risk
mainstay for dx of vascular pathology
What do we use MRA to see?
to visualize vasculature
What pathologies occur in the Brain?
Stroke, MS, HTN, Aneurysm, Tumor, Trauma
Common CNS Pathologies in the Spine
Trauma, Degenerative disease, Infection, Metestatic Disease
Common Pathologies in the Head and Neck
When do we perform CT with contrast?
of head and neck soft tissues looking for infection or malignancy
CT angiograms of head and neck
CT venograms of head and neck
When would you use Gadolinium contrast in MR imaging
Infection, Primary tumors or metestatic disease
Demyelinating disease (MS)
Contrast not usually necessary when evaluating stroke, trauma, or degenerative spine disease:
MRA head is done ____ contrast
MRA neck and MRV best when done ______ contrast
without
with
Key resource to select appropriate imaging modality
ACR appropriateness criteria from the American College of Radiology
This is cheaper, uses ionizing radiation, takes minutes but has more tendency for allergic reactions
CT
More expensive, no radiation, takes about a half hour to acquire, is usually well tolerated
MRI
What is the best imaging modality to use to eval for a bleeding source?
CT angiography of the head
***need contrast !!
Acute hemorrhage is _____ while chrnoic hemorrhage is _____ on CT
acute = hyperdense or BRIGHT
chronic = hypodense or DARK
Most common causes of subarachnoid hemorrhage
from trauma or ruptured aneurysm
Pt has acute onset right side weakness and aphasia for one day
Hx of fibrillation, HTN and COPD with previous stroke and residual Left side weakness. Been on antiocags in past but stopped d/t frequent falls
DDX?
Cerebrovascular accident, transient ischemic attack, seizure, encephalopathy.
You suspect a pt is suffering from acute infarct and order a CT. The results come back negative. What is the next step?
Your pt presents with all sypmtoms pointing to acute infarct. The CT comes back negative, what do you order next (be specific and why)
order MRI with DWI (diffusion weighted imaging)
pay attention to functional anatomy
What benefits does a CT vs MRI provide for spinal cord injuries?
CT good for bone and fractures
MRI is better at seeing ligament and disk problems
What is the first screening exam done for spine trauma?
CT is initial screen for trauma pts not cleared with sensitivity increased from 50-75% with plain film to 90-100% in CT
