Radiology Exam #1 (Topics 6 Thru 8)

Front 1

Intensity of the x-ray beam as it emerges from a patient is directly proportional to _____________ and inversely proportional to ______________ and ____________.

Back 1

-original intensity of the beam

-thickness of the object and absorption coefficient of the tissue

Front 2

What is the difference in the way water, blood and exudates look like on a radiograph?

Back 2

no difference

Front 3

Interaction of x-rays with the subject is dependant on what four things?

Back 3

(1) number of x-rays in beam
(2) energy of x-ray beam
(3) thickness of object
(4) composition of object

Front 4

What are the five image principles?

Back 4

(1) density, opacity, and contrast
(2) differential interface
(3) silhouette sign
(4) summation effect
(5) fluid-air interface

Front 5

What does radioopacity mean?

Back 5

-white image and fewer x-rays reached the film due to greater absorption (bone)

Front 6

What is one factor that affects contrast, but not radioopacity?

Back 6

scatter

Front 7

What type of contrast does the thorax normally have?
The abdomen?

Back 7

-high (short scale
-low (long scale)

Front 8

What is differential density Interface?

Back 8

-specific structures are visible radiographically IF surrounded by tissue of a different density

Front 9

What is silhouette sign?

Back 9

-margins of objects of the same density that are in contact can not be visualized separately (loose the differential interface)

Front 10

What is summation effect?

Back 10

radiographic opacities are additive - may then create an artificial opacity that appear as structures that are not really present

Front 11

What is the fluid-air interface?

Back 11

-if both fluid and air are present, the resultant view of a vertical x-ray beam will be a shade of grey (lighter than air, darker than fluid because they are superimposed)
-must shoot a horizontal beam so air will be at the top and fluid at the bottom

Front 12

What are radiographic signs used for and what are the three major categories?

Back 12

-are a vocabulary that provides an objective, analytic means of evaluating structures on radiographs and verbalizing those findings
(1) density
(2) geometry
(3) function

Front 13

What does density refer to as a radiographic sign?

Back 13

-inherent tissue density
can increase or decrease

Front 14

What are the five categories of geometry in a radiographic sign?

Back 14

-Size
-Shape
-Number
-Position
-Margination

Front 15

What are the four categories of function in a radiographic sign?

Back 15

(1) integrity
(2) motility
(3) patency
(4) excretion

Front 16

How is a lateral radiograph viewed?

Back 16

-viewed as a right lateral (head to left, and tail to right)

Front 17

How is a VD/DV radiograph viewed?

Back 17

As a VD - want to shake hands with the patient

Front 18

What are the five factors that contribute to making a radiograph of diagnostic quality?

Back 18

(1) patient prep
(2) exposure
(3) interactions
(4) recording
(5) processing

Front 19

What will over and under exposure do for you?

Back 19

overexposure: burn out subtle lesions

underexposure: provides insufficient distinction of structures and can obscure some lesions

-both dependent on equipment capabilities and technical settings

Front 20

What is the min amount of views you should take?

Back 20

2

Front 21

While positioning a patient you should mind two things - what are they?

Back 21

(1) include entire body part
(2) accuracy - true laterals, ect.; degree of obliquity

Front 22

Interpretation of a radiograph is based on three steps - they are....

Back 22

(1) method
(2) psychological
(3) results

Front 23

How should cranio-caudal caudo-cranial views be looked at?

Back 23

cranio-caudal

Front 24

What should be the first thing evaluated when looking at a radiograph?

Back 24

-film quality

Front 25

What are the five legal requirements of a film?

Back 25

(1) permanent
(2) before development
(3) ownership of radiograph
(4) date
(5) patient ID

Front 26

What are three main types of radiographic film ID?

Back 26

(1) leaded tape
(2) marker sets
(3) photoprinter - BEST

Front 27

What are disadvantages to using lead tape?

Back 27

-difficult to read
-must be included in x-ray field, limiting collimation
-often overexposed and too dark

Front 28

What are disadvantages to using marker sets?

Back 28

-time consuming
-must be included in x-ray field, limiting collimation

Front 29

How does a photoprinter work?

Back 29

-blocks the intensifying screen
-blocked portion of thee film is then imprinted by exposure to a light source thru a card

Front 30

Why would you want to use CM?

Back 30

-to overcome silhouette sign
-to see small sized structures or structures with low density or superimposed structures

Front 31

How does using CM work?

Back 31

-changes the radiographic density of the structure and enhances contrast

Front 32

How does a vet go about choosing the right contrast media?

Back 32

(1) organ studied
(2) suspected abnormality

Also: safety, specificity, radioopacity, reproducibility, cost

Front 33

What are two types of negative contrast media?

Back 33

-air and CO2
-makes less radioopaque

Front 34

What are two types of positive contrast media?

Back 34

-Barium Sulfate and Organic Iodinated CM
-makes more radioopaque
-attenuation coefficients of Ba and I are greater than other tissues

Front 35

What are they pysical classes of Barium Sulfate Product?

Back 35

(1) Powder
(2) Paste
(3) Liquid

Front 36

What would you use a Ba paste for?

Back 36

esophagram to demonstrate postion and mucosa of the esophagus

Front 37

What is liquid Ba contrast media used for?

Back 37

-routine upper and lower GI in cats and dogs

Front 38

When would you use negative contrast media?

Back 38

-pnemocytography, pneumocolon

Front 39

What are negatives to using Ba powder?

Back 39

inconsistent, poor quality, extra time

Front 40

What are factors when considering a liquid Ba CM?

Back 40

(1) particle size (small is better-micronized!)
(2) suspending agents: aids in stability
(3) flavoring agents
(4) concentration

Front 41

What is a prefered concentration when buying a liquid Ba CM?

Back 41

-40 w/w - don't want too concentrated

Front 42

What would happen if Barium Sulfate leaked into the bowel due to a preforation?

Back 42

-chronic, granulomatous inflammation

Front 43

When would you use a organic, iodinated contrast medium for the alimentary tract?

Back 43

-if a perforation is suspected

Front 44

What type of contrast medium would you use for urographic or angiographic study?

Back 44

-Organic Iodinated CM

Front 45

How is toxicity diminished in an organic iodinated CM??

Back 45

by binding to a less toxic molecule

Front 46

What type of agents are organic iodinated (urographicand angiographic) CM?

Back 46

-water-soluble, tri-iodinated, benzoic acid derivatives (Ag Org I)

Front 47

What are the two most common anions for urographic and angiographic CM?

-cations?

Back 47

(1) Iothalamate and (2) Diatrizoate

(1) Na and (2) methlyglucamine

Front 48

List two types of urographic and angiographic CM?

Back 48

conray 400 (Na Iothalamate) 400 mg I/cc (pick one that is concentrated and dilute it)
renographin -76

Front 49

Why should Iodinated CM not be used for routine alimentary tract studies?

Back 49

(1) expensive
(2) adverse effects (very hypertonic and pulls fluid into lumen causing dehydration AND irritates bowel

Front 50

What is the newest thing in development of CM?

Back 50

non-ionic media - less hypertonic and have fewer side effects
-derivatives from glucose
-EXPENSIVE

Front 51

What is used for myelographic CM?

Back 51

non-ionic media

Front 52

What is the only iodinated CM approved for VET MED?

Back 52

Renographin 76