Diagnostic imaging

Question 1

what are the five radiographic opacities?

Answer 1

air (black)
fat
soft tissue/fluid
mineral (bone)
metallic (white)

Question 2

what are the five basic radiographic signs of abnormalities looked for in a systematic evaluation?

Answer 2

number
size
shape
location
opacity

Question 3

what must be assessed to ensure completeness of a radiographic study?

Answer 3

correct patient and region
complete study (two orthogonal views)
identify and label radiographs
assess image quality

Question 4

what is assessed for when looking at imagine quality?

Answer 4

exposure
collimation (all four edges)
position (straight and well centred)
contrast
artefacts

Question 5

what is the first stage of assessing the radiograph?

Answer 5

searching the radiograph for lesions

Question 6

what is the second part of assessing the radiographic image?

Answer 6

descriptions (report findings)

Question 7

how in depth description of a radiograph have to be?

Answer 7

sufficient enough for someone to mentally reconstruct the image
significant aspects systematically described

Question 8

do normal features on a radiographic imagine need describing?

Answer 8

no, if it isn’t described its considered normal

Question 9

when assessing the shape of a lesion, what must be described?

Answer 9

overall shape
shape of margins
definition of margins

Question 10

what interpretive principles can be applied to radiographs?

Answer 10

mass effect - if something changes in size it will have an effect on the surrounding structures
effacement - loss of normal contrasting opacity
multiple lesions - single lesions are rare
specific signs

Question 11

what are some limitations of radiographic imaging?

Answer 11

2D representation of 3D structure
only shows change in anatomy no other information
only a small snapshot in time (lesion might not appear at some times)
no information about function

Question 12

what property of an ultrasound wave determines how well it penetrates tissue?

Answer 12

wavelength (frequency)

Question 13

what does the amount of reflection of ultrasound waves by tissue depend on?

Answer 13

echo-density of the tissue (bone reflects fully)

Question 14

what are the three types of head of an ultrasound probe?

Answer 14

linear
convex
sector

Question 15

what does high ultrasound wave frequency correlate to?

Answer 15

higher resolution

Question 16

what are artefact due to reflection called on ultrasound?

Answer 16

reverberation

Question 17

when is reverberation on ultrasound useful?

Answer 17

useful to tell the widest part of a tube

Question 18

what are the artefacts due to refraction of ultrasounds effect?

Answer 18

position a structure is viewed

Question 19

what are the three possible outcomes of a dominant follicle in a cow?

Answer 19

ovulate
turnover (regress then grow again)
cystic

Question 20

what is the first diagnostic information to determine when ultra sounding cattle ovaries?

Answer 20

is there a CL, cyst or follicle

Question 21

when do we ultrasound scan cows for reproductive purposes?

Answer 21

earlier the better but later is more accurate as to whether the animal will produce a live calf

Question 22

where will the uterus be found if the animal is pregnant?

Answer 22

over the pelvic brim

Question 23

what are clues in the cattle uterus that the animal is pregnant?

Answer 23

CL on ovary that last ovulated
fetus in uterine horn
fluid in the horn

Question 24

roughly what ages is the amniotic vesicle visible in cattle ultrasound?

Answer 24

day 40

Question 25

what ways can foetuses be ages?

Answer 25

crown-rump length biparietal distance trunk diameter

Question 26

how can cattle foetuses be sexed?

Answer 26

genital tubercle migrates at around day 56 | just behind umbilicus in males and between hind legs and tail in females

Question 27

what are some common uterine abnormalities that cause cloudy fluid?

Answer 27

mucometra endometritis pyometra

Question 28

what types of imaging modalities can be used in equine?

Answer 28

``` radiography nuclear scintigraphy ultrasonography MRI CT ```

Question 29

what is radiography mainly used to image?

Answer 29

``` bone articular and periarticular structure soft tissue (swelling and mineralisation) ```

Question 30

what is kVp on a radiography machine?

Answer 30

speed of electrons

Question 31

what is mA on a radiography machine?

Answer 31

number of electrons release

Question 32

what is S on a radiography machine?

Answer 32

time

Question 33

what should be reported first when reading radiographic films, before the report?

Answer 33

area that has been imaged | quality of the film

Question 34

what are the three phases of a film report?

Answer 34

recognition (search) descriptive (report) interpretation (differential diagnosis)

Question 35

what should be analysed when discussing film quality?

Answer 35

``` positioning collimation contrast exposure labelling artefacts (Pink Camels Collect Extra Large Apples) ```

Question 36

what is the recognition phase of a film report?

Answer 36

systematic search to identify abnormal findings, normal findings and normal variations

Question 37

what is the descriptive phase of a film report?

Answer 37

categories finding according to radiographic signs

Question 38

what are the radiographic signs used to categorise the descriptive phase of radiographic findings?

Answer 38

``` size shape position number margination opacity ```

Question 39

what is described in the interpretation phase of a film report?

Answer 39

history signalment clinical signs diagnostic tests

Question 40

what is ultrasonography used to image mainly in equine medicine?

Answer 40

tendons and ligaments

Question 41

how can the contact area for ultrasound scanning be improved?

Answer 41

clip and clean skin ultrasound gel standoff alcohol (not clipped)

Question 42

what aspects of lesions are described when looking at ultrasound?

Answer 42

``` size shape position number margination echogenicity ```

Question 43

what is nuclear medicine (gamma scintigraphy) used for in equine medicine?

Answer 43

detect areas of actively turning over of bone

Question 44

how does gamma scintigraphy work?

Answer 44

polyphosphonate (body thinks of it as calcium) is labeled and put into body, the machine can then pick this up where it is being used

Question 45

what are the phases of scanning of gamma scintigraphy?

Answer 45

phase I - blood pool (rarely used) phase II - soft tissue phase III - bone

Question 46

what is the major issue of using MRI for horses?

Answer 46

MRI machines can't fit the whole horse through (mainly used for feet)

Question 47

what are the advantages of MRI use in equine medicine?

Answer 47

highly detailed | specific and sensitive diagnosis