radiology

Question 1

Canadian C spine rules

Answer 1

1. > =65, dangerous MOI, paresthesia’s in extremities (yes=radiography)
2. simple MVA, sitting in ED, ambulatory, delayed onset neck pain, absence of midline tenderness (no=radiography)
3. able to AROM 45 L and R (no=radiography)

Question 2

What is ALARA

Answer 2

increases safety awareness and regulations
individual dose as low as possible

Question 3

Different energy for medical purposes (5)

Answer 3

mechanical (US)
thermal (IR lamp)
electrical
nuclear (gamma rays)
electromagnetic (xrays)

Question 4

Soft vs Hard xrays

Answer 4

shorter wl = high energy = greater penetration

soft: long wl, used to tx superficial malignancies

hard: short wl, dx imaging

Question 5

Good things about plain film

Answer 5

low cost
reliable
relatively good quality
ease of use

Question 6

Fluoroscopy
what is it

Answer 6

dynamic/continuous radiograph
allows real time image and view for later

Question 7

Computed and digital radiography

Answer 7

CR: phosphor screen replaces film w/ digital image

DR: flat panel detectors replace film, xray energy converted to electronic signal

Question 8

Radiodensity

Answer 8

determines attenuation
product of composition and thickness
density: blackening
radiopaque: harder to penetrate with xrays
radiolucent: easier to penetrate

Question 9

colors on radiograph

Answer 9

air- black
fat- gray/black
water- gray
bone - white

positive contrast -bright white (barium)
negative contrast- darker (gas)
heavy metal= solid white

Question 10

what is decubitus position

Answer 10

body on horizontal surface w/ horizontal beam

Question 11

Projections rules

Answer 11

min 2 views at right angles
3D: length, width, depth
common AP and lateral w/ long bones
.>=2 info markers

Question 12

arthrography

Answer 12

inject contrast within joint space
distends capsule
outlines internal surfaces

Question 13

myelography

Answer 13

pertains to sc, dura, nerve root
injected in CSF
column oof radiopaque fluid

Question 14

CT indics
how it works

Answer 14

xray beam and detector within circular scanner-moves around pt

bone and ST tumors, frx, intra-artic abnorms, bone frag detection, bone mineral analysis, neuroimaging

Question 15

Nuclear imaging
how it works

Answer 15

pharmaceuticals: targets organ
radionuclide: gamma ray emission
-indics metabolic activity
-gamma rays detected, recorded

static image or viewing over period of time

Question 16

MRI
how it works
indics

Answer 16

radiofrx waves within magnetic field, relies on detection of reemitted radiofrx waves absorbed

indics: ST trauma, internal joint derangement, tumors, stress frxs

Question 17

US
how it works
indics

Answer 17

image from reflected sound waves, diff by acoustic quality

indics: muscle/tendon/lig lesions, cysts, ST tumor, bf, muscle func