Diagnostic Imaging Intro Flashcards
5 different types of imaging
radiographs, MRI, CT, bone scan, and ultrasound
Why should we care about imaging?
Our pts often come armed with a diagnosis based off imaging, it’s the language that physicians speak, and it’s another piece of potentially critical information
a posterior to anterior view is best for scoliosis, because it will have a ______ reduction in lifetime ionizing radiation and it reduces the risk of breast cancer by ________ and thyroid cancer by _________
3-7X; 3-4X; 2X
Radiographs are most common and are the favorite because they are ____________, but they also use _______________
easy, cheap, and quick; ionizing radiation
key components to reading radiographs
get good quality images, know your anatomy, realize difference with age, be able to interpret and react to your findings, and know your limits
X-ray film: black without absorption - ________________ - less dense material
radiolucent
X-ray film: white with absorption (without penetration) - ___________________ - more dense material
radiopaque
Osteoblastic activity
bone becomes more dense because of calcium deposition to the area – so it gets stronger and thicker
Osteoclastic activity
when you have depletion of calcium, bone becomes weakened or more brittle and thinner
Radiopaque, opacity, sclerosis, hypertrophic bone, increased radiodensity, and blastic lesions (reparative or reactive) are all ______________ activity
Osteoblastic
Radiolucent, lucency, osteopenia, decreased radiodensity, and lytic lesion or lysis are all _____________ activity
osteoclastic
From _____________ to ______________, it’s air, fat, water, bone, contrast media, and heavy metals
radiolucent, radiopaque
What are the ABCs of radiographic evaluation
alignment, bone density, cartilage spaces, and soft tissue
Don’t immediately focus on the _____________
obvious
What should you consider when looking at alignment?
size of bone, number of bones, shape and contour of bones, and bone and joint position
One view is _____________
no view
critical questions to ask when looking at imaging
is there enough pictures (importance of two views)? are they the right pictures (importance of correct views, capture all areas of concerns)? are they good pictures (Structures well visualized, identification and orientation)?
2 examples of trauma we should look for
dislocation and fracture
Salter-Harris
System of classifying physial fractures in kids
Salter-Harris Grade 1
Fracture through the physis only
Salter-Harris Grade 2
Fracture through the physis and metaphysis
Salter-Harris Grade 3
Fracture through the physis and Epiphysis
Salter-Harris Grade 4
Fracture through the physis, Metaphysis, and epiphysis
Salter-Harris Grade 5
Crush/compression injury to the physis
Fractures are classified by ___________________
description or mechanism of injury
Some descriptions of fractures are __________
open vs closed, type, location, deformity, and number of fragments/pieces
Fracture description: types
transverse, oblique, spiral, compression/impacted, torus/buckle, and epiphyseal
locations of fractures
relational or anatomical
Fracture description: deformities
Angulation, displacement, shortened, roatation
Examples of non-traumatic things that imaging can be used for
arthritis, infections, neoplasms, metabolic bone disease, and pathologic fractures
remember to look at ___________ of the affected area and look at joints/area ____________ to the area of concern
stability; proximal and distal
MRI uses ___________________ impulses in a magnetic field
radiofrequency (RF)
MRI aligns nuclei with an odd # of pro/neutrons ______________ to magnetic field
parallel
RF pulses cause _____________ of nuclei resulting in MRI images
Deflections
T1 MRI
best demonstrate anatomic structure
T2 MRI
most helpful in contrasting normal and abnormal tissue
Water, CSF, acute hemorrhage, and soft tissue tumors appear ________ on T1 and _________ on T2 studies
dark, bright
MRI uses
most sensitive method for detection of early osteonecrosis, infection and trauma, excellent for occult fractures, neoplasms, disc disease and herniation, bone marrow changes, ACL, best radiologic test for PCL, and Shoulders (90%) for RC tears, equal to Ct on labral pathology
28% of subjects over 40 years old have abnormality in their ___________ on MRI
C-spine
20-30% of subjects under 40 years old show evidence of _______________________
lumbar disc herniation
__________% of subjects over 60 years old show evidence of degeneration and bulging of one or more lumbar disc
93
MRI disadvantages
Expensive, 10% of pts can’t tolerate it due to claustrophobia, Subject to artifact from metallic objects, can interfere with cardiac pacemakers, and can cause shifting of foreign metallic objects in the eye/brain
Computed tomography uses __________, is computer enhanced, gives a great increase in tissue ___________, can use _____________ agents (arthrography), and is great for spinal lesions
X-ray; contrast; contrasting
CTs demonstrate ____________ better than any other study
bony abnormalities
CTs are used in conjunction with _______, such as in arthrogram CT and myelogram CT
contrast
CTs are useful in measuring ____________ for cervical stenosis
cross sectional dural area
CT is valuable for evaluating subtaler ________ & subtaler ____________
joint and coalitions
Dynamic CT is the best test available for diagnosis of ______________ subluxation
atlantoaxial rotary
Bone scan
uses markers to reflect increased blood flow and metabolism
In a bone scan, the marker is absorbed by hydroxyapatite crystals in bone in areas of _____________
infection, trauma, or neoplasm, etc.
Bone scans are very useful in the diagnosis of ______________________
subtle fractures, avascular necrosis, decreased blood flow, osteomyelitis, and THA/TKA loosening
Ultrasonography of the shoudler
useful in diagnosis of RC tears
Ultrasonography of the hip
useful in diagnosis and follow-up on congenital hip dysplasia, and diagnosis of iliopsoas bursitis
Ultrasonography of the knee
Assess articular cartilage thickness and identify intra-articular fluid/effusion
Ultrasonography of fractures
used for fracture healing progression
Other than the shoulder, hip, knee, and fractures, ultrasonography can also be used for _____________________
soft tissue masses, hematoma, tendon rupture, abscesses, and foreign body location
types of transducers
linear, curved linear, and compact linear
Linear transducers transducers
look at midrange/average depth
Curved linear transducers
look at much deeper structures
Compact linear transducers
look at very superficial structures; good for tendons of fingers
What type of transducer is used for pregnancies?
curved linear transducers
