final Flashcards
T/F: coverage for the axial slices of the head includes the foramen magnum to the superior surface of the brain
true
sagittal slices through the head are prescribed from
left to right
setting up the sagittal slices of the head is best and often easiest to be achieved using the ______ series of images in the 3 plane localizer
coronal
which of the following best describes the appearance of acute stroke on an axial DWI
bright
which structures of the brain are M/S plaques NOT common to be seen
basal nuclei
when positioning a patient for a head MRI exam, their _____ should be parallel to the couch/table
IPL
which of the following sequences provides temporal resolution of enhancing lesions and indicates brain activity
perfusion
a patient who has had a stroke will have blood that appears _______ on a T2 weighted image
bright
contrast is used to assess which of the following
- metastases
- active MS plaques
- the age of an infarct
- tumors such as meningiomas or neuromas
the DWI is usually performed with _____ aligned slices
axial
post contrast will enhance ______ seen in the brain
MS plaques
axial slices through the brain are typically aligned with what anatomical structures
parallel to the genu & splenium of the corpus callosum
alignment for the axial images of the brain are usually set up on the ______ series of images
sagittal
axial slices through the head & brain are prescribed from
inferior to superior
which sequence is used to visualize blood flow & detection of tumors
perfusion
for imaging of the brain, the patient is usually laying ____ on the table/couch
supine
which landmark is used for positioning centering / localizing with the red laser light in the brain imaging
glabella/nasion
propellers, blade, multivane, & jet sequences are performed to
reduce motion artifacts
the b value determines the
amount of diffusion weighting on an image
a DWI is most often acquired using a _______ sequence
T2 EPI
a T1 weighted image will have a _______ TR & _______ TE
short & short
metastatic lesions in the spinal cord can be seen after contrast enhancement on T1 weighted images because
lesions enhance while the spinal cord does not
flow from the CSF in the thoracic spine can be minimized by utilizing
saturation pulses
the conus and cauda equina is NOT demonstrated on
sagittal cervical spine
when the X,Y, & Z axis have been set to zero it is said to be at the
isocenter
in T2 imaging , fluid is
bright
what causes cross-talk artifact in the lumbar spine sequences
adjusting angulation where the slices end up overlapping
how many blocks/sets of slices are typically set up when doing the axial slices for the thoracic spine imaging
two
during patient positioning, centering for the thoracic spine should be on vertebral level
T4
on T1 weighted images, the vertebral bodies appear bright because
bone marrow contains fat
where can you place the SAT bands for the lumbar images
anterior to the spine
for optimal imaging of the cervical spine, patient positioning and local coil placement are
supine/around the neck to include from C1 to C7
what may appear bright on T2 images
- synovial fluid
- infection
- CSF
- inflammation
on a T1 weighted image, the CSF will appear
hypointense (dark) to the spinal cord
most spine imaging uses
a surface / local coil
how many cranial nerves are there ?
12
to check for hydrocephalus, a provider may order a _____ study
CSF
if performing an axial sequence in a CSF study, the slice should be prescribed to be
perpendicular to the aqueduct of sylvius
someone with unilateral hearing loss may be sent to have an ______ scan performed
IAC’s
cranial nerve I
olfactory
cranial nerve II
optic
cranial nerve III
oculomotor
cranial nerve IV
trochlear
cranial nerve V
trigeminal
cranial nerve VI
abducens
fMRI uses ______ sequence
BOLD
which nerve is best visualized on the orbits exam
CN II
which study requires peripheral getting to be used
CSF
on the coronal IAC sequence, the posterior slices should begin at which structures edge?
cerebellum
what do you angle your axial slices with (to make parallel with) on the axial orbits sequence
optic nerve
the coronal orbit slices should extend from the front of the orbit globe through the _____
chiasm
3D TOF uses ____ slices, so it has ______ spatial resolution
- thin
- better/greater
the circle of willis is the main structure being imaged in
MRA
what portions of the brain are examined when performing fMRI?
- motor function
- language function
- passive cognitive thinking
exam done for the trigeminal nerve
facial / cranial nerve study
exam done for aneurysm
MRA study
exam done for ringing in the ears
IAC’s study
which portion of the blood flow process is blood pumped into the brain & CSF is pumped into the aqueduct of sylvius
systolic
positioning for an abdominal MRI would include centering the horizontal alignment light on the patients
lower costal margin (L3)
prior to an MRCP examination, patients should be NPO for ___ hours
4
patients fast prior to an MRCP to which of the following
- promote gallbladder distention
- decrease bowel peristalsis
- decrease fluid secretions in the stomach & duodenum
the accumulation of excess fluid in the abdominal cavity
ascites
enlargement of the left lobe of the liver is most likely a sign of which disease
cirrhosis
which organ lies transversely and bit obliquely and across the lumber spine in the abdominal cavity
pancreas
an MRCP utilizes ____ TEs
long
this sequence helps distinguish the difference between fatty tissues and maybe a metastatic lesion
in & out phase
which kidney typically extends further distally / inferiorly
right
what additional device, placed on the patient before the scan begins, helps monitor patient breathing during the abdomen exam
bellows
what are some possible artifacts when performing abdominal imaging
- peristalsis
- breathing motion
- inconsistent breathing
TR range of 400-800
T1 FSE
TR range of 3000-6000
T2 FSE
TR range of 1800-3000
PD SE
TR range of 8000- 10000
T2 FLAIR
arterial flow goes _____ the leg
down
the femur of interest should be
as close to isocenter as possible
increasing your NEX/NSA will _______ your scan time
increase
T/F: due to the foot anatomy, the slice sequences are usually set up with some oblique quality to them
true
what is a good general range for a short TR on a 1.5 magnet ?
400-700 ms
which weighting is best used for anatomy identification
T1
if a patient has a hip prosthesis, the technologist should use ______ to help reduce the magnetic susceptibility of the device
SE or FSE sequences with large bandwidths
STIR images are typically ____ weighted
T1
which is the main magnetic field?
B0
a proton dense image uses _____ TR & _____ TE
long & short
MRI uses which atoms of the body
hydrogen
which slices should be aligned with the superior aspect of the femoral heads when setting them up in a hip image
axial
traditionally, the axial slices of the foot should be
perpendicular to the long axis of the foot
axial slices of the long bone femur image should be planned
superior to inferior
TE controls
T2
T/F: increasing your NEX/NSA will increase your SNR as well
true
TR controls
T1
the most optimal plane to use when evaluating patients for cruciate ligament (posterior or anterior) tears of the knee is the
sagittal
what structure at minimum needs to be included in the lateral aspect of the body in a sagittal hip sequence
greater trochanters
coronal slices of the elbow are set up
aligned/ parallel with the humeral epicondyles
to tighten the tendons of the rotator cuff, positioning for the shoulder may require
slight external rotation
a ______ tear occurs where the biceps tendon anchors to the labrum
SLAP
the coil usually preferred to image the shoulder for the maximization of SNR is the
surface/ local coil
the imaging sequence best used to visualize bruises or contusions within the bone is
STIR
the axial slices in the humerus imaging series should be prescribed
superior to inferior
which type of sequence is best to visualize contrast in the joints
T1 FS
coronal oblique images of the shoulder are angled parallel with which anatomy
supraspinatus muscle
the _____ slices in the elbow are aligned with humeral epicondyles
coronal
the muscles that make up the rotator cuff
- teres minor muscle & tendon
- infraspinatus muscle & tendon
- supraspinatus muscle & tendon
- subscapularis muscle & tendon
adhesive capsulitis is also known as
frozen shoulder
when positioning the patient into the bore, where would you landmark for the humerus images
midshaft of the humerus
what structure superiorly needs to be included in the prostate scanning in axial/ oblique slices
seminal vesicles
the prostate gland is located ______ & ______ to the bladder in the male pelvis
inferior & posterior
when scanning a routine female pelvis exam, axials would be angled in which manner
perpendicular to the uterus
prostate scanning is typically done because
elevated PSA levels in blood work
to best demonstrate the uterine anatomy the ____ plane should be selected
sagittal
_____ slice sequence best demonstrates anatomy that is lateral such as lymph nodes
axial
which slices sequence would best demonstrate the ovaries in the female pelvis scan
axial
positioning for a female pelvis MR exam would include centering the horizontal alignment light to pass
through a point midway between the symphysis pubis & the iliac crest (ASIS)
ways to limit metal artifacts
- use MARS
- small FOV
- run STIRS instead of T2 FS
how can you reduce scan time, to help reduce motion artifacts?
- lower NEX/NSA
- lower TR
for the magic angle artifact
a tendon/ ligament is oriented at 55 degrees to B0
the artifact that is caused by
- pixels not being square
- high tissue contrast interfaces
- on FSE/TSE sequences
- by partial echo acquisitions
Gibb’s also known as ringing & truncation
the main way to eliminate the moire’ effect is
keep the TR short
T/F: if you swap your phase & frequency, the chemical shift artifact is still there but just in a different direction
true
gradient wrap or distortion is seen on images with a
large FOV
one way to eliminate cross talk, where you the tech, tells the scanner to skip every other slice, then fill in the missing ones is called
interleave
chemical shift of the first kind is controlled by
B/W
the time between successive excitations is termed
TR
which image sequence is best for pathology conditions
T2 weighted
tissues with short T1 relaxation times appear _______ as compared to normal structures on T1 weighted images
hyperintense / brighter than
STIR images typically have
low fat signal with high fluid signal
the plane to best evaluate patients with a seizure history would be
coronal
the number of echos acquired following a single initial excitation is termed
ETL
as the TR increases the amount of T1 weighted contrast _____
decreases
a T1 weighted image has an echo time (TE) in the range of
10-30 ms
inversion recovery pulse sequence
180 degree RF followed by 90 degree RF
spin echo pulse sequence
90 degree RF followed by 180 degree RF
fast spin echo pulse sequence
90 RF followed by train of 180 RF pulses
the magnetic field that extends beyond the scanner is called
the fringe field
what can induce neurological signals
transient magnetic field
what is the cryogen used in modern MRI scanner
helium
where does the maximum spatial gradient /magnetic field occur in the typical closed bore MRI magnet
at the opening of the magnet
what material should an oxygen cylinder for use in MRI be made of
aluminum
earplugs are given to reduce the noise & can reduce it by
10-20 dB
metal materials cause what type of artifact
signal void
on an image that is proton dense and fat suppressed, the fracture would/should appear
white
best views for evaluation of the ACL include
sagittal & oblique
increasing NEX will increase
SNR
water containing areas on a T1 image should be
dark
the fat in a fat suppressed image should be
darker / blacker
the 3D GRE is good at identifying
cartilage pathology & intraarticular spaces for loose bodies
the blacker the structures the _____ sensitive the scan you are looking at
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