Lecture 1- Intro to Radiology Imaging Flashcards

1
Q

Terminology

CXR

A

chest xray = chest radiograph = chest plain film

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Terminology

image

A

any singular image (doesn’t matter type)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Terminology

study/examination

A

collection of images

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Terminology

wet reading

A

archaic term for immediate or “stat” intercreptation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Terminology

PACS

A

Picture Archiving, Communications, and Storage System (the system that archives and stores images for later retrieval)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Terminology

Films vs Computed Radiography

A
  • films: printed
  • computed: electronic (almost everything now)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Radiographs/CT

what are the 5 radiographic densities

A
  1. air (least dense, black)
  2. fat
  3. water
  4. bone
  5. metal (most dense, white)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Radiographs/CT

differentiate radiolucent and radiopaque

A
  • radiolucent: least dense (air); black
  • radiopaque: most dense (bone); white
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Film Quality

3 factors that affect quality of CXR?

A
  1. penetration
  2. inspiration
  3. rotation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Film Quality

differentiate underpenetrated and overpenetrated

A
  • underpenetrated: too white
  • overpenetrated: too black
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Film Quality

how to know if CXR is penetrated correctly?

A

you can see the thoracic spine faintly through the heart shadow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Film Quality

how to evaluate for rotation

A
  • R & L clavicle heads are equally distant from the spinous process
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

why are 2 views often required for xrays

A

because they are 2D pictures of 3D objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

describe silhouette sign

A

when 2 structures of the same density are in anatomical contact, their margins cannot be seen on film
* ex: the heart rests on the diaphragm, so you cannot see where one starts and the other ends.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

describe CTs

A
  • digital image generated by multiple xrays which are generated into a slice of the body
  • generated to be axial, coronal, sagittal, and 3D images
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

CT

denser structures have higher what?

measurement

A

hounsfield units (more white)

17
Q

CT

describe windowing

A

manipulating images to maximize the display of different densities (ex: bone windowing, soft tissue windowing)

18
Q

CT

why is contrast administered

A

to increase density differences between tissues

19
Q

CT

describe IV Iodinated contrast

A
  • opacifies tissues and organs w/ high blood flow
  • excreted by the kidneys
20
Q

CT

potential adverse effects of iodine contrast

A
  • mild reaction: n/v, itching, hives, irritation at injection site
  • rare: severe anaphylaxis, death
21
Q

CT

which patients are at a higher likelihood of a contrast rxn?

3

A
  • asthma
  • severe atopy
  • hx of prior rxns
22
Q

CT

which renal conditions should contrast be used in caution with?

A

renal insufficiency (diabetes, multiple myeloma)

23
Q

CT

what tests do you order to clear someone with renal insufficiency for contrast?

A
  • BUN (> 21)
  • Creatinine (> 1.5 mg/dL)
24
Q

CT

what to do with patients taking metformin?

A

stop metformin for 48 hrs after contrast dye due to increased risk of lactic acidosis

25
Q

CT

describe barium contrast

A
  • oral or enema contrast used to visualize GI tract
  • this is not absorbed by the body
26
Q

CT

contraindication of barium contrast

A
  • suspected bowel perforation
  • before bowel surgery
27
Q

CT

what is a double contrast study (GI)

A

air + barium

28
Q

MRI

differentiate T1 and T2 imaging

A
  • water is dark on T1
  • water is bright on T2
29
Q

MRI

contraindications

A
  • pregnancy
  • presence of ferromagnetic object
30
Q

MRI

most common contrast agent for MRI?

A

gadolinium

31
Q

MRI

contraindications of gadolinium?

A
  • severe renal disease
  • caution in moderate renal disease

due to risk of nephrogenic systemic fibrosis (rare)

32
Q

CT vs MRI

A
  1. CT more readily available, faster, cheaper
  2. MRI has better soft tissue contrast, no radiation, no iodinated contrast, but can be problematic for pts with claustrophobia
33
Q

US

advantages

6

A
  • low cost
  • tolerable
  • readily available
  • safe (no rad)
  • portable
  • real time imaging
34
Q

US

disadvantages

4

A
  • operator skill dependent
  • more difficult to interpret
  • not good for bone or lung imaging
  • may be difficult to see in obese patients
35
Q

US

types of US

A
  1. gray scale (B mode)
  2. color doppler (blood flow in vessels)
  3. spectral doppler (determines direction, velocity, and acceleration of blood flow in vessels)