Intro Flashcards
Another word for increased opacity is:
sclerosis
Another word for decreased opacity is:
lucency
What are the ABCs for plain film?
Alignment
Bone/bone density
Cartilage (space)
Soft tissue
Air or contrast injected into joint is a process called:
Arthrography
When radiopharmaceuticals are injected for bone scan, areas of uptake indicate:
increased metabolic activity
What is a myelogram?
injection of contrast dye to subarachnoid space; CT/radiograph taken
What is a myelogram used to assess?
SC
nerve roots
meninges
cysts
MRI is based on excitability of __ atoms in human tissues.
H+
T1 is good for detecting ____; fat and bone marrow appear ___; fluids like CSF, urine, edema appear ____
good anatomical detail
fat bright
fluid dark
T2 is good for detecting ____; fat and bone marrow appear ___; fluids like CSF, urine, edema appear ____
inflammation and fluid ddx
fat dark
dark bright
Proton density imaging is helpful for observation of:
tendon, meniscus, ligament, cartilage
STIR = short tau inversion recovery; emphasizes what kind of structures?
fluid-rich (similar to T2); suppresses fat;
best for detecting occult fx’s
*What normal structures appear black in all sequences?
tendons, meniscus, labrum, ligaments
What are the transient effects of strong magnetic field?
dizziness, vertigo, nausea, concentration
What causes a radio frequency burn?
the energy is released as heat
What can you see/do/measure with RUSI ?
Muscle length Muscle depth Muscle diameter Muscle cross sectional area Muscle volume Muscle contraction/ timing of contractions Tissue deformation with contraction Qualitative assessment of muscle/tissue density (i.e. fatty infiltrate) Muscle discontinuity / tears
Hyperechoic structures include:
hyperechoic (light)
Cortical bone, tendons, ligaments, hyaline cartilage, nerve
Hypoechoic structures include:
hypoechoic (less bright)
muscle, bursa
What’s good about US? Saf
e, Real time, Cost effective, Portable, Clinically accessible, No ionizing radiation
What sucks about US?
Needs skill/training to run - $$$ to purchase - Limited evidence for PT practice - Limited training available for PTs
Curvilinear US
Lower freqs, see deeper structures
Linear US
Higher freqs, more superficial and linear structures (tendon)
Limitation of US for joints and bones?
Limited in showing joint surfaces and intra-articular structures; Can only show cortical outline of bone
What is CT great at showing?
Lung, Bone, Organs, Vessels
What is CT radiation dose?
3x background radiation
Pro’s of CT
Can work w/ metal implants > availability < \$\$ < claustrophobia faster
Con’s of CT
MRI > for fine detail
not good for non-displaced Fx’s
Images only in Axial plane
How is Myelogram done?
Dye injected into Subarachnoid space, assessed with PF or CT
What is Myelogram used to assess?
Spinal cord, Nerve roots, Meninges, Cysts
How many imaging sequences does MRI use, and how long to they take?
2-6 sequences, at 2-15 minutes/sequences
This subtype of imaging has both T1 & T2 properties: _____. What’s it good for?
Proton Density Imaging.
Good with tendon, meniscus, & cartilage
What is STIR similar to? What is bad about it?
T2. Poor resolution
What’s good about STIR?
Emphasizes fluid-rich stuff
Detects occult Fx’s like a boss
Top 5 things about MRI
- Great at ST fine details 2. Contrast has fewer allergic reactions 3. No radiation 4. Great view of changes in bone marrow (CA & AVN) 5. Diff sequences incr Sn for finding disease
Top 5 ways MRI stinks
- No pacemakers 2. No ferromagnetic implants 3. Metal ~safe, but distorts 4. Too slow for unstable pts 5. Can’t tell betw CA & edema
