Exam 2- Final Review Cumulative Stuff

How does MRI work

Large external magnet aligns hydrogen protons in the same direction

Common MRI strength

1.5 Tesla

MRI inputs radio frequency signal (radio waves) do what

Move protons out of position by turning the other smaller magnet called a gradient coil on

Does an MIR utilize ionizing radiation

No

Images that have white signal on MRI

Hyper intense or high signal intensities

Images that are black on MRI

Hypointense or low signal intensities

Contrast study for MRI

White signal within artery

Non contrast study for MRI

Black signal within artery

What MRI has fat white, and fluid dark

T1`

What MRI has CSF bright white

T2

What MRI is it when we eliminate any high signal within fat that may represent water so anything on the imaging that is white is very high in water content like inflammation or CSF

STIR/SPIR/T2 Fat Sat

What MRI is best for looking at general anatomy overall

PD

What MRI is best for edema or inflammation

T2

STIR/T2 Fat Sat

What MRI is best for assign marrow changes seen with infections and tumors

T1

What is a "3-D X ray"

CT

If it would look radiodense on X ray then what would it look like on Ct

Hyperattenuating

If it would look radiolucent on X-ray then what would it look like on Ct

Hypoattenuating

What are the units for measuring attenuation on CT

Hounsfield Units (HU)

How do you look for fracture on CT

Bone windowing

What is bone windowing on CT

Clear differentiation of osseous anatomy, soft tissues are blurry

Bone scans uses

Technetium 99 MDP

Bone scans are good for

Osteolytic metastasis

Positron Emission Tomography (PET) uses

F18-FDG (fluorodextroglucose)

T score of a DEXA scan

Bone density compared to 30 year old same sex patient

A score DEXA scan

Bone density compared to similar age and sex patient

A score below what is diagnostic for osteoporosis

-2.5

Echoes on ultrasound

Hyperechoic echogenicity (echogenic)

No echo on ultrasound

Hypoechoic echogenicity (hypoechonic/anechoic)

Ultrasound is great for looking at

Soft tissue anatomy

Bone is_______ on CT

White