outcomes 1, 3, 6- head, neck + spine Flashcards
(140 cards)
1
Q
what is the modality of choice when imaging the spine?
A
MRI
2
Q
when is CT superior than MRI for imaging of the spine?
A
- when evaluating spine for bony abnormalities, or if there is metal
3
Q
visualization of _______ _____ is improved by intrathecal administration of CM
A
intradural structures
4
Q
what are the indication for a spine CT
A
-Disc herniation
-Spinal stenosis
-Spinal infection
- Trauma (fracture, dislocation)
-Intraspinal tumors
- Etc..
5
Q
True or false:
no IV contrast is used when evaluating post-op lumbar spine, inflammatory and
neoplastic lesions
A
FASLE, iv contrast is used for : Post-op lumbar spine, inflammatory and
neoplastic lesions+spinal infections
6
Q
when is IV contrast used for the spine
A
IV contrast is only used when specified by the
rad. (Romans says 100ml at 1.5ml/s. scan
when injection is finished)
7
Q
is IV contrast administration used for any other pathology like disc lesions, spinal
trauma, congenital anomalies
A
NO
8
Q
is oral contrast used for the spine?
A
NOOOO
9
Q
patient position for the c-spine
A
-supine
-head first
-leaser at glabella
10
Q
whats the SFOV for the c-spine
A
just above base of skull to mid T1
11
Q
what recons + reformates are used from the C-spine
A
-always include a bone window
-reformates= coronal+sagittal
12
Q
what is the patient position for the T-spine
A
-supine with knees bent
-FF
-arms above head
13
Q
where’s the internal laser light for the T-spine
A
-2 inch above jugular notch- NEED T1
14
Q
patient position for the L=spine
A
-supine, knees bent
-FF
-arms raised above head
15
Q
where is the internal laser light for a CT of the L-spine
A
-xiphoid process=T9/T10
16
Q
where does the scan of the L-spine begin+ stop
A
Scan above L1 to mid Sacrum -all L-spine unless specified
17
Q
what is prefered for detail of the spine, 3D recons or 2D images
A
more detail is displayed in 2D D images due to anatomical
complexities in the spine. (axial, coronal,
sagittal)
18
Q
what is the windowing for soft tissue spine
A
350 ww/ 50wl
19
Q
what is the windowing for bone spine
A
2000ww/500wl
20
Q
True or false:
CT examinations are performed after myelography
to enhance or clarify findings
A
TRUE
21
Q
what is the recommended scan delay for between the intrathecal
injection and scanning is recommended.
A
1-3 hours, allow CM to dilute
-CM that is too dense may mask intradural structures
22
Q
when is intrathecal contrast done
A
in fluoroscopy
23
Q
what does a sagittal reformatted CT myelogram revel?
A
Multisegmental severe disc
degeneration
Disc space height reduction,
Vacuum phenomenon
End-plate sclerosis of the lower
lumbar spine
Thecal sac compressions at the
L3–4 and L4–5 levels (arrows).
b–d | Axial images shows
Circumscribed severe LSS
(lumbar spinal stenosis) of L3–4
Typical hourglass constriction
of the thecal sac (arrow)
adjacent to relatively normal
areas.
24
Q
why do we perform a CT myelogram
A
Some patients can not have an MRI
Demonstrates CSF leaks as well
-widely used for operative planning
25
what is a CT myelogram best suited for
-dynamic stenosis
-postoperative leg pain
-severe scoliosis, spondylolisthesiis
-metalic implants
26
indications for CTA spine(Angio)
-AV fistulas, ATM
-blunt trauma
27
what is the Iv cm for a CTA spine angio
120 mL of cm at 6mL/s
28
whats are the 2 sets of scans for CTA spine angio
◦ 1st scan (Arterial) scan delay=bolus tracking ROI in aorta
just below diaphragm
◦ 2nd delayed scan immediately after 1st arterial scan
28
What is the slice thickness and interval utilized for reconstructing a helical T-spine scan on a 16-Detector CT scanner?
2.50mm/1.25mm
28
true or false
MRI provides higher soft tissue sensitivity than CT
TRUE
29
T or F
For conditions such as spinal stenosis MRI is equivalent to CT
TRUE
29
In a CT myelogram, the suggested delay between injection and scanning is ?
1-3 hours
30
Scouts of the spine include
AP= lateral
31
Before a CT myelogram, it is recommended that a patient
roll over once or twice
32
T or F
On CT spine protocols the gantry is tilted
FALSE
33
T or F
The display FOV is much smaller on CT spine protocols compared to abdomen or chest CT
TRUE
34
T or F
Compared to conventional radiography CT spine has inherently high soft tissue contrast
TRUE
35
are pathologies often "visible" in the neck region
YES
36
Indications for CT soft tissue of the neck
- Bone:
* tumors
* infection
* trauma
*-Soft tissue:
* tumors
* congenital defects
* enlargement of
glands
* infection
* abscess
* vasculature
37
patient prep for CT soft tissue of the neck
It is recommended that patients wear loose,
comfortable clothing for the exam.
* Patients will need to remove
▫ dentures, dental appliances
▫ glasses
▫ hearing aids, earrings
▫ Hairpins, wig
▫ any other object that may be in the area of interest
38
patient position for CT soft tissue of the neck
-supine
-head first
-ask patient to lower shoulders as much as possible
-EXTEND NECK SLIGHTLY= hard palate perpendicular to table or angle gantry parallel
39
neck protocol
DFOV 18 cm
* Helical mode, most often
* Neck Soft tissue window 450ww/75wl
* Bone window 4000ww/400wl
* Reconstruction slice thickness 2.5mm at 1.25mm
intervals
40
is iv contrast enhancement used in the neck
YES ALWAYS
41
what is the goal with CM in the neck
Goal is to allow sufficient time for CM to enhance:
▫ Mucosa
▫ lymph nodes
▫ pathological tissue
While acquiring images with the vasculature opacified
42
is a split bolos used in the neck
YES
43
what is the split bolus that is used for teh neck
* Split bolus is used (total CM injection 125 ml at 2.0 ml/s):
▫ First bolus (50mL) given, 2 mins delay
This allows for structures that are slower to enhance
▫ Second bolus (75mL), scan 25 sec delay (arterial phase).
This allows for all vessels to be fully opacified.
44
what is the first bolus for in the neck split bolus
This allows for structures that are slower to enhance
45
what is the second bolus for in the neck spilt bolus
This allows for all vessels to be fully opacified
46
is oral contrast given for CT of soft tissue of the neck
Usually none, unless in combo with other exams…
* The entire procedure normally takes 5-10 minutes.
* IV contrast studies may take an additional 10-15 min.
* If oral contrast is required, you will also need an
additional 45-50 minutes prior to the test
47
what are the 2 types of breathing techniques used for CT of the neck
* Perform modified Valsalva maneuver “puff
cheeks out” – distends pyriform sinuses
* Pronounce long “e” during scanning– evaluate
aryepiglottic folds, and pyriform sinus
48
what is the possible combination exam for the CT of the neck
Combination exam example (C/A/P/N/H – neck done
@95 secs)
* Start with arms up,
* At the end of the pelvic scan the patient lowers arms
down to their sides (being careful not to move their
head)
* Glabella to SC joints if in combo with chest
* Could be done 3ml/sec to compliment C/A/P scan
injection rate.
49
CTA of the soft tissue of the neck
* Arterial phase
* Evaluate vessel walls, relationship of lesions & surrounding
structures, valuable for surgical planning
* Cerebral catheter angiography (digital subtraction angio) can be
diagnostic & therapeutic (but more time, $$$ & risk of complications)
50
what can be the downside to Cerebral catheter angiography (digital subtraction angio) of the soft tissue of the neck?
-more time
-more money
-greater risk complications
51
what are some advantages of the CTA of the soft tissue of the neck
Non-invasive
* Widely available
* Time saving (especially with stroke)
* Can combine with brain perfusion studies
* Less expensive
52
what can be used to evaluate the Circle of Willis
for completeness in 3D
-CTA- for neck and head
53
what is CTV (CT Venography)
* CT venous phase (a modification of CTA)
* Used to visualize venous anatomy
* Same protocol, however, acquired in venous
enhancement phase (longer scan delay 40-50
seconds for example)
54
Routine neck CT is preformed with the patient in what position?
supine, neck slightly extended
55
Neck studies are most often preformed in which mode
Helical
56
Scanning a CT neck too early could result in what going undetected?
Certain neoplastic and inflammatory diseases
57
CTA techniques of the neck are taken in...
arterial phase
58
CTV techniques of the neck are taken in...
Venous phase
59
CTA of the neck is used to accurately measure...
Carotid stenosis
60
As per the text book, what is the delay between split bolus injections during a CT neck?
2 min.
61
indications for a CT scan of the head
Stroke
TIA
hemorrhage
trauma
Acute neuro changes
tumors
AVM
thrombosis
aneurysm
headache/seizures
mass/lesion /hearing loss
Unknown/Surprises…parasites etc…
62
patient position for CT of the head
Supine, head placed in head holder,
immobilize head.
Rare, if coronal is needed patient can extend
chin & drop head back if possible or patient may be
prone (which requires a special holder).
Typically head first into the gantry.
Patients orbitomeatal line or better still
the supraorbital meatal line should
be parallel with gantry. (tilt gantry or
tuck the chin down)
63
Why does recent practice in CT favour having slices
of the brain/head to be parallel to the supraorbital
meatal line? (Rather than the OML)
To reduce the radiation exposure to the lens of the eye.
64
what type of scan is the routine brain scan
axial scan- Scan just below base of skull to just above vertex
65
what type of scan is the skull base(posterior fossa)
axial-Foramen magnum through petrous ridge
66
what type of scan is the temporal bones ct scan
axial scan
Just below mastoid process to just above petrous ridge
(DFOV10cm, include entire mastoid, IAC & external auditory canal)
67
what is the sella ct scan
– 99% performed in MRI- axial in CT
Below sellar floor through dorsum sellae (DFOV 14cm)
68
what artifact is often see in the images of the posterior fossa
beam-hardening
69
what is the routine slice thickness for the head
1.25mm
70
what type of scanning is used for CTA's
helical scanning
71
why is IV contrast used in the head
IV contrast used for infection,
neoplasm…
72
soft tissue of the brain for slices in post fossa
160ww/40wl
73
soft tissue of the brain for slices in post fossato vertex
100ww/30wl
74
what is the bone and blood ww + wL for the head/brain
bone= 2500/400wl
blood=200ww/60wl
75
T or F
Scans of the head usually start at the base of the skull and continue superiorly to the vertex
TRUE
76
T or F
A head holder may be used for both CT head scans as well as neck scans
True
77
T or F
A head sponge on the scan table may be used in place of a head scoop or holder?
TRUE
78
is Suspended breath is necessary for a CT of the head
NO its not
79
Cross sectional slices of the brain should be parallel to the ...
SOML
80
Why do recent practices favour using the supraorbital meatal line for CT heads?
Protects the lens of the eye
81
Beam Hardening is common through which area
Posterior fossa
82
How may this beam hardening in the posterior fossa be reduced?
decrease slice thickness, and increase KVP
83
ICH will appear hyperdense to normal brain tissue for approximately
3 days
84
What is the DFOV for a routine CT head?
23
85
What is the scan location for a CTV head?
Just below skull base to just above vertex
86
The anatomy demonstrated in CT head images predominately is determined by
Angle of gantry
87
What is the scan range for a T-spine?
Above T1 to below T12
88
A patient requires a CT myelogram. Which department will inject the contrast?
Fluoroscopy
89
Why would a patient require a myelogram?
CSF leak
90
What slice thickness are C-spine images acquired with a helical scan type reconstructed to?
2.5mm
91
What interval thickness are C-spine images acquired with a helical scan type reconstructed with?
1.25mm
92
What is a indication for an enhanced CT Spine?
Spinal infection
93
What IV contrast protocol is used for routine spine CT according to Roman's?
100 ml at 1.5 ml/s, scan when injection is finished
94
When bolus tracking for a CT spine IV injection, the ROI should be placed where?
in the descending aorta, just below diaphragm
95
A CT Sinuses scan is often a roadmap used by surgeons for
endoscopic surgery
96
Sinus screening in CT is not intended as a/an....
high radiation dose method
97
T or F
Clinical indications of recurrent or chronic sinusitis are done with IV contrast
true
98
T or F
Indications of recurrent or chronic sinusitis are scanned in the direct coronal or axial & reformatted to coronal plane
true
99
T or F
Other clinical indications for sinuses CT may require IV contrast
true
100
CT angiography has advantages over traditional angio ...the biggest advantage is
time saving
101
CTA occurs during what phase
arterial phase
102
Carotid and vertebral _________ may be accurately measured in CTA's
stenosis
103
CTA's can evaluate
vascular lesions
dissections
occlusions
104
T or F
Facial bones CT is done in helical scans
true
105
What is the focus of sinus CT anatomically
Frontal, ethmoid, sphenoid, and maxillary sinuses as well as nasal passages, turbinates, and septum
105
Facial bones CT scan axis is parallel to the
IOML
105
What are the benefits of Sinus CT
Screening is inexpensive, low radiation, and accurate
105
What is the more common scan plane for sinuses: Coronal or Axial
Axial supine
106
What is the scan range for sinuses
From above the frontal sinus to below the hard palate including from mid sella through frontal sinus
107
How do you position a patient for sinuses
Supine (sometimes prone), extend the chin and drop head as far back as possible in a special head holder.
Align hard palate perpendicular to the table (OML line) OR angle the gantry if not possible
108
Do you use CM for sinuses
no
109
What are you trying to demonstrate in chronic sinusitis coronal axial image
air-fluid level
110
What is the preferred modality for imaging of the face
CT. It is most sensitive for fracture detection
111
What is a disadvantage of CT imaging for the face
It has potential to miss a subtle tooth fracture along the axial plane
112
What are some indications for a non-enhanced face ct
facial fractures and soft tissue injury
113
What are some indications for an enhanced ct scan of the face
Infection and masses
114
Is face CT axial or helical
Helical: crucial to make accurate reconstructions!
115
If contrast IS used, will it be single or split bolus in the neck
split
116
How will some techs opt to position patient
angle gantry parallel to the IOML
117
What type of scan is routine brain according to romans
Axial (step and shoot)
118
What is included in a scan of the head
Skull base: Foramen magnum through petrous ridges
Temporal bones: just below mastoid process to just above petrous ridges
Sella: below sellar floor through dorsum sellae
119
Why are beam hardening artifacts often seen in images of posterior fossa
Because the skull base is so dense
120
How might artifacts be reduced for skull artifacts?
thinner slices
121
At what rate may someone hand inject CM for a head CT
~1ml/s
122
What must every study include for the spine
AP and lateral scouts
123
What is improved by administering intrathecal CM
Intradural structures
124
How do you position a patient for T-spine
Q
How do you position a patient for T-spine
A
Feet first, supine, sponge under the knees, arms over head
125
What is the start and end location for T-Spine
Just above T1 to just below T12 (UNLESS specific levels specified)
126
What is the most frequently used initial exam( modality) for imaging intracranial hemorrhage stroke (ICH)
CT
127
where does density loss start at
Density loss starts at the periphery of the hematoma; portions
become isodense. Progresses to become completely hypodense
128
what is the timeline for when is ICH hyperdense
4-10 days
129
What is the timeline for when is ICH isodense
11days to 6 months
130
what is the timeline for ICH stroke to be hypodense to normal
Hypodense to normal brain tissue after 6 months
131
when should t-PA be administered to be affective for acute ischemic stroke
To be effective, t-PA must be administered within 3
hours of the first signs of stroke.
This means that the stroke victim must be transported
to the hospital, diagnosed, and administered the t-PA
treatment before the 3-hour window has expired…or
have the stoke ambulance come to them
132
what contraindications t-PA therapy
ICH contraindicates t-PA therapy.
133
what is done to differentiate ischemic stroke from hemorrhagic stroke
A noncontrast CT of the brain is routinely performed to
differentiate ischemic stroke from hemorrhagic stroke.
134
when is CM used for a stroke
CM is used to assess the state of cerebral circulation
and tissue, and secondarily, to assess the underlying
disease.
