Imaging Procedures Flashcards
IGRT stands for what?
Image Guided Radiotherapy
IGRT images the patient ___after/prior___ to treatment
prior
IGRT is a way to confirm what?
patient positioning
MV and kV sources are calibrated to the same __________
isocenter
____ imaging =
-image patient on table prior to treatment
-after imaging, shifts are made prior to beam on
online imaging
______ imaging =
-images are reviewed after trt
-example is when rad onc looks at images after trt
offline imaging
EPID stands for what?
electronic portal imaging devices
EPID took the place of what old technique?
developing/exposing films
what allows us to image and see those images instantly?
EPID
what does OBI stand for?
On Board Imaging
what does ODI stand for?
Optical Distance Indicator - projects our SSD numbers
with ____ we can image bone, soft tissue, fiducial markers and compare them to sim images in order to ensure proper positioning
IGRT
2D images are like ______ or ______ and can be compared to DRRs
– whereas 3D images are like our _______ which are compared to CT
MV ports or kV imaging = 2D
CBCT = 3D
overall, IGRT reduces _______ uncertainties and reduces the chance of a geometrical miss of the tumor
set-up
IGRT allows for a smaller ____. Which leads to fewer trt complications and allows for an increased dose to tumor
PTV
modern LINACs have 2 types of imaging systems being ____ and _____
kV and MV
the following is describing MV or kV ?
-conventional xray tube and flat panel detector
kV
the following is describing MV or kV ?
-uses same trt source (ie. source comes from trt head)
-has panel detector opposite of LINAC trt head
MV
T/F: both the KV arms and MV panel are retractable
TRUE
MV stands for _______
megavoltage
kV stands for __________
kilovoltage
port films/portal imaging is MV or kV?
MV
comparing kV and MV… which has poorer image quality?
MV
why does MV have poorer image quality than kV?
mainly due to Compton Scatter from the MV source (trt head)
___ images are required for 3D plans
MV
MV images are required for 3D plans and are considered _________ documents
legal
what exposure types does MV imaging have? (2)
-single open port
and
-double exposure
the following is describing MV single open port or double?
-takes one port w/ MLCs and whatever other beam shaping devices may be in place, and then ANOTHER open port to view more anatomy
double
the following is describing MV single open port or double?
-takes a port with no MLCs or beam shaping devices
single beam open
MV images (single open port and double) are taken in what view?
BEV (beam’s eye view)
BEV stands for what?
Beam’s Eye View
why does it make sense that an MV image is in BEV?
MV source comes from trt head
a _______ exposure port film is required minimum of how often for both 3D and complex plans?
double exposure port film is required minimum of once a wk for both 3D and complex plans!!!
- considered a legal document
the following is describing MV or kV ?
-acquired in orthogonal pairs
kV
kV imaging is used for _____scopy
fluoroscopy
_________ = real-time imaging to show patient motion; an xray imaging procedure that takes a realtime video showing movement within the body
fluoroscopy
_____ _____ = orthogonal pair of 2D images; 90 degrees apart = orthogonal
kV pair
which has BETTER image quality between an MV and kV image
kV
which is good for bony anatomy?
-CBCT
-kV
-MV
kV
the kV source is located ___ degrees from the MV source and MV panel
90
the kV source is located ___ degrees from it’s detector panel
180
what types of CBCTs are there? (2)
kv-CBCT
MV-CBCT
which is most common CBCT? (kv vs. MV)
kv-CBCT
the following is describing MV or kV CBCT?
-best for soft tissue matching
-higher contrast
-more photoelectric effect
kV-CBCT
what energies does kV-CBCT use typically?
(kVp)
30-140 kVp
what energies does MV-CBCT use typically?
(MV)
1-6 MV
_____ utilizes 3D technique/effect alongside kV or MV source(s)
CBCT
CBCTs are gotten by ________around the patient, unlike a stationary 2D image
rotating
CBCTs are reconstructed in the ____, _____, and ____ planes for imaging
axial
sagittal
coronal
which CBCT (kV or MV) acquires images with LESS artifacts when imaging patients with metal
MV-CBCT; MV
the following is describing MV or kV CBCT?
-lower contrast
-best for imaging high Z # materials
-more Compton scatter
MV-CBCT
**the Compton scatter is what ultimately lowers the image contrast
___-CBCT has higher contrast whereas __-CBCT has lower contrast
MV-CBCT= lower contrast
kV-CBCT = higher contrast
MV or kV -CBCT is often seen with tomo units
MV-CBCT
MV-CBCT Compton scatter basically ____ out any metal artifacts
blurs
describe tomotherapy unit -
basically CT scanner and radiation trt machine in one
label the following as kV or MV images -
A = kV
B = MV
