Diagnostic Imaging Flashcards
x-ray versus radiograph
invisible light bean vs image of an anatomical part
x-ray tube has a ______ and an _______ inside a glass case
cathode
anode
how is a radiograph produced
high volt current passes through a vacuum creating an x-ray and it penetrates through the body onto a film cassette
more radiodense structure are ______ and appear ______
radiopaque
white
less radiodense structure are ____ and appear ______
radiolucent
dark
you always need at least ____ projections for xray
2
how are anterior posterior radiographs named
for the way the beam is going
how are lateral and oblique radiographs named
for the side closest to the film cassette
ABCs of imaging
alignment
bone density
cartilage spaces
soft tissues
the anatomical part closest to the x-ray tube will appear _______
larger
what is the most commonly performed imaging
radiograph
primary indication for a radiograph
bone injury
contrast enhanced imaging
inject medium into an anatomical part and then perform a radiograph
what is a pro to contrast enhanced imaging?
improved visualization of pathology
arthrography
injection of a medium into a joint
myelography
injection of a medium into the spine
computerized tomography
- radiographs taken in a 360 degree fashion
- pt is placed on a table moving through a circular ring
when is a CT indicated
complex fractures/tumors (wrist, face, pelvis, spine)
T or F: CT scans eliminate superimposition of one anatomical part on another
t
what can CT scans not visualize
articular cartilage, ttendon rupture/tendonitis
this imaging is good for soft ttissue when MRI is contraindicated
CT (metal is not contraindicated)
this image is best for cortical bone
CT
magnetic resonance imaging
nuclei generate a magnetic moment, tissues are placed in a magnetic field, energy patterns develop an image
for an MRI pt usually has to lie still for at least ________
1 hour
what are some indications for MRI
soft tissue lesions
surgical/injection planning
stress fx
ligament injury
tumors
cartilage
head trauma/SCI
bone marrow edema
T1 weighted MRI… what is dark and what is bright?
bright = fat
dark = fluid and soft tissue
T2 weighted MRI… what is dark and what is bright?
bright = fluid (bright) and soft tissue (bright-ish)
dark - fat
fat sat/STIR MRI…. what is dark and what is bright
bright = water
dark = fat
_______ bone has no fatt or water, while ____ bone has fat
cortical
trabecular
2 benefits of MRI
1 - both sensitive and specific
2 - no radiation
bone scan
- agent is injected and pt is placed under a camera
- entire body is scanned and can be compared side to side
bone scans have ______ sensitivitty and _______ specificity
good
poor
in a bone scan, does normal bone appear lighter or darker than pathological bone?
light
indications for bone scan
- tumors
- metastatic disease
- infections
- stress reactions
- fractures
- avascular necrosis
what are diagnostic ultrasounds most commonly used for?
image soft tissue lesions in tendon and muscle
T or F: diagnostic ultrasound uses ionizing radiation
F: but image quality is not as good as CT/MRI
T or F: diagnostic ultrasound is efficient and cost-effective
T
what can PTs use diagnostic ultrasound for?
pre and post movement re-education
fluoroscopy is similar to what other imaging
plain films
T or F: with fluoroscopy images can be static or dynamic
T
indications for fluoroscopy
- in the OR for fracture reduction/fixation
- observe abnormal movement of a joint
what are 2 downsides to fluoroscopy
1 - increased radiation
2 - poor quality image
x-ray absorptiometry
evaluates bone density by using standard anatomical partts as a reference and compares these to a normative model
changes in bone density are termed ____ while _____ is a pathology
osteopenia
osteoporosis
quantative CT
takes a CT or 3 lumbar vertebrae and assesses bone density against a normative model
what 2 types of imaging have no radiation exposure
diagnostic ultrasound and MRI
