Wk 3: Intro to Diagnostic Imaging

Question 1

X Ray how it works

Answer 1

-electrons accelerated at target
-works on grey scale (black/transparent=non dense objects; white= dense objects)
-looks past air, fat, water, and muscle
-3D presented as 2D
-minimum of 2 views perpendicular, optional oblique 3rd view

Question 2

X ray imaging

Answer 2

-documents bony defects
-chest x ray for viewing thoracic cavity

Question 3

CT how it works

Answer 3

-moving x ray axially
-circles pt abdomen to create detailed planar images by progressive visual slices
-cross sectional images
-better sensitivity than film x ray but less sensitive than MRI

Question 4

MRI how it works

Answer 4

-applies magnetic field & detects rate of magnetization
-produces slice images in any plane
-grey scale does not apply, no radiation exposure

Question 5

MRI Imaging

Answer 5

-highly sensitive to tissue differences
-images through bone

Question 6

Ultrasound how it works

Answer 6

-sends in signals and receives timing and amplitude of reflections for echo
-sends in signals and examines frequency change for doppler
-2D image in real time, can be moving

Question 7

Ultrasound imaging

Answer 7

-distinguishes solid from fluid
-does not penetrate bone, air, or gas
-images well fetus, children, abdominal organs, aorta, blood flow (doppler)

Question 8

Bone scan how it works

Answer 8

-small amount of radioactive drug injected into veins
-radioactive substance travels to areas of bone damage
-once settled, dark spots on image indicates damage

Question 9

Bone scan imaging

Answer 9

-problems with bone metabolism, how bone is healing if damaged
-used to diagnose metastatic disease, arthritis, stress fx, osteomyelitis, loosening of implants, multiple trauma

Question 10

Nuclear Imaging how it works

Answer 10

-injects radioactive material and PET/CT/MRI

Question 11

Nuclear imaging

Answer 11

-thyroid masses
-bone metastases
-lung circulation and ventilation
-cancer
-GI and endocrine diseases