MRI Brain Imaging
Card Set Information
MRI Brain Imaging
MRI brain head neck
MRI Brain imaging, head and neck imaging
How many lobes of the brain are there? List them.
4...Frontal, parietal, temporal, occipital
What does the Sylvian fissure divide?
The frontal and parietal lobes from the temporal lobe
What artery passes through the Sylvian Fissure?
Middle cerebral artery
Where should the landmark be for routine brain imaging?
What sequence demonstrates a hemorrhagic infarct better in the brain
Gradient echo sequence
Where is the insular cortex found?
Folded deep within the lateral sulcus between the temporal and frontal lobe
What is the insular cortex a portion of?
the cerebral cortex
What function do the insulae perform?
Diverse functions linked to emotion or regulation of bodys homeostasis.
Perception, motor control, self awareness, cognitive function, interpersonal experience
How many cranial nerves are there?
Olfactory Nerve number?
Olfactory nerve location?
Cribiform plate ethmoid bone
Olfactory nerve function
smell from nasal mucosa
Optic nerve number
Optic nerve location
Optic nerve function
Vision from retina
Oculomotor nerve number
Oculomotor nerve location
Midbrain to orbital fissure
Oculomotor nerve function
Motor function to superior, inferior and medial rectus muscles
Trochlear nerve number
Trochlear nerve location
Posterior midbrain to orbital fissure
Trochlear nerve function
Motor function to superior oblique that directs gaze Inf-lat
Trigeminal nerve number
Trigeminal nerve location
Pons to foramen ovale/rotundum
Trigeminal nerve function
Facial sensation, forehead/scalp to mouth/lip/anterior tongue
Abducens nerve number
Abducens nerve location
Pons to superior orbital fissure
Abducens nerve function
Motor to lateral rectus that controls lateral gaze
Facial Nerve number
Facial nerve location
Pons to submandibular ganglion, IAC/Facial canal
Facial nerve function
Motor to muscles controlling facial expression, stapedius of middle ear, taste to anterior tongue
Vestibulocochlear nerve number
Vestibulocochlear nerve location
Vestibular ganglion to IAC
Vestibulocochlear nerve function
vestibular sensation from semicircular ducts, hearing from spiral organ
Glossopharyngeal nerve number
Glossopharyngeal nerve location
Medulla/superior and inferior ganglion to Jugular foramen
Glossopharyngeal nerve function
Swallowing motor, parotid gland parasympathetic, taste from posterior tongue, cutaneous sensation from external ear.
Vagus Nerve number
Vagus nerve location
Medulla/inferior ganglion to jugular foramen
Vagus nerve function
Motor to pharynx, larynx, palate muscles, taste from epiglottis. Para sympathetic innervation to trachea, bronchi, digestive tract, coronaries
Spinal accessory nerve number
Spinal accessory nerve location
Spinal accessory nerve function
Motor to trapezius and sternocleidomastoid
Hypoglassal nerve number
Hypoglossal nerve location
Medulla to hypoglossal canal
Hypoglossal nerve function
Motor to intrinsic and extrinsic muscles of tongue
When is DWI used in brain imaging?
When a CVA is suspected
What are common problems with DWI?
Sensitivity to magnetic susceptibility when using echo planar readout
Bulk patient motion
Where is the hippocampus located?
Medial temporal lobe
What imaging plane best shows the hippocampus?
What is contained within the aqueduct of Sylvius?
What does the aqueduct of Sylvius connect?
3rd and 4th ventricle
What structure is adjacent to the anterior horn of lateral ventricle?
head of the caudate nucleus
What is an acoustic neuroma aka?
What nerve does an acoustic neuroma affect?
vestibulocochlear nerve (CN VIII)
What should the protocol include for an acoustic neuroma?
thin cuts through the IACS or 7th and 8th cranial nerves
Where should the centering be for an IAC exam?
External Auditory Meatus
What is a Chiari Malformation?
Downward displacement of the cerebellar tonsils through the foramen magnum
Which imaging plane best visualizes a Chiari malformation?
In a CSF flow study (CINE), the bright white signal in CSF space indicates what?
Flow during systole
In CINE of CSF the black signal void indicates
Flow during diastole
What protocols are useful in diagnosing micro adenomas and pituitary tumors?
Thin slice sagittals and coronals
Dynamic Contrast enhanced thin coronals
Why is it important to scan rapidly following contrast injection when scanning for a pituitary tumor?
Because tumors appear as low signal intensity compared to the enhanced pituitary gland
What is the pituitary stalk called?
What sits within the sella turcica?
the pituitary gland
Which direction can a pituitary tumor extend? What is a result?
Only upward in the superior direction
compression of the optic chiasm
What sequence is useful in determining amount of CSF superior to pituitary gland?
Small FOV T2 weighted coronal
What sequences are used for attention to optic nerves?
thin cuts through orbits
3mm axial/coronal including FATSat pre and post contrast
What causes Bells palsy?
dysfunction of the cranial nerve VII (facial nerve)
What does multiple sclerosis refer to?
scars or lesions in the white matter of the brain and spinal cord
What should the approach be to scanning MS patients?
Thin slice FLAIR high resolution Axial and Sagittal sequences
Delaying post contrast T1 weighted images to allow accurate contrast visualization
What is utilized to suppress signal from CSF?
FLAIR sequence with long T1
Where do the vertebral arteries branch from?
the subclavian arteries
What do the vertebral arteries merge to form?
the single midline basilar artery
Where do the vertebral arteries join together?
at the base of the medulla oblongata
What is received by the dural venous sinuses
blood from internal and external veins of the brain
receive CSF from subarachnoid space
Where do the dural venous sinuses empty?
the internal jugular vein
Where is the superior sagittal sinus located?
Runs the length of the falx cerebra
What drains into the superior sagittal sinus
blood from lateral aspects of the anterior cerebral hemispheres
Where does the superior sagittal sinus drain into?
confluence of sinuses
What are drained by the transverse sinuses?
from the back of the head
What sinus drains into the transverse sinus
Confluence of sinuses
where does the transeverse sinus drain into?
The sigmoid sinus into the internal jugular vein
Where does the articular disc lie in the TMJs
mandibular condyle and mandibular fossa
What will allow more arterial vessels to visualized in an MRA head and neck
Increasing the Velocity encodings (VENC)
An intracranial MRA exam is defined as an ____
MRA Circle of Willis or head MRA
An extracranial MRA exam is defined as an MRA of _____
Carotid and vertebral arteries
What supplies blood to anterior brain
internal carotid artery
What supplies blood to the face
External carotid artery
What supplies blood to posterior brain
How is the removal of signal from vessels accomplished in a non contrast MRA sequence
By spatial presaturation
Where would a presaturation pulse be applied to acquire arterial blood flow MRA?
superior to the slice group
nulls signal from intracranial venous blood flow
Where would a prostration pulse be applied to acquire MR venogram
inferior to the slice group
nulls signal from arterial blood flow
What is used to best visualize the Circle of Willis
3D time of flight
At what level is the common carotid artery bifurcation
c3-4 disc space