Radiology

Question 1

When looking at an MRI picture what must you remember?

Answer 1

You are looking at the patient from feet up

the projection might distort the size (AP vs PA)

Question 2

what are limitations of x rays

Answer 2

2d representation
overlapping structures obstructed
no depth perception

Question 3

what are good things of x rays

Answer 3

great spatial resolution

immediate results

Question 4

what is a grey area on an x ray

Answer 4

soft tissues

Question 5

what is a dark area on an x ray

Answer 5

air. (low density)

Question 6

what is a white area on an xray

Answer 6

bone/metal

Question 7

3 fates of xrays

Answer 7

transmitted
absorbed
scattered

Question 8

trendelenburg body position

Answer 8

lying down with head lower than feet

Question 9

fowler’s body position

Answer 9

lying down head higher than feet

Question 10

radiographic density

Answer 10

amount of exposure or blackness on the radiograph

Question 11

radiographic contrast

Answer 11

difference in density between adjacent area of a radiographic image

Question 12

spatial resolution

Answer 12

recorded sharpness of structures on the image. clarity, sharpness or detail of an image

Question 13

what happens when there are 2 structures that are the same density next to each other on an xray

Answer 13

cant see margins they merge together

Question 14

contrast agent

Answer 14

substance used to increase the contrast between organs/ vessels/ fluids or other structures withn the body that do not have natural inherent contrast with surrounding tissues

Question 15

why iv contrast

Answer 15

improves sensitivity : detection
improves specificity: characterization
improves certainty
create ct and mri angiograms

Question 16

advantages of a ct

Answer 16

quick
motion not much of a problem
grey scale can be manipulated on viewing screen
excellent resolution in most areas
widely available and cheaper than mri

Question 17

disadvantages of ct

Answer 17

ionizing radiation
renal function must be evaluated if contrast is used
some patients are allergic to iodine contrast

Question 18

mri t1

Answer 18

csf dark

tr and te are short

Question 19

mri t2

Answer 19

csf white

tr and te are long

Question 20

advantages of mri

Answer 20

nonionizing
better soft tissue contrast
extremely versatile - can use variety of sequences fo rvisualizing specific tissue

Question 21

disadvantages of mri

Answer 21

longer time for sequences
more expensive
images cant be manpulate
gantry narrow - claustrophobia
no metal 
noisy

Question 22

transverse orientation (ultrasound)

Answer 22

probe marker towards patient’s right

Question 23

sagittal orientation (ulrasound)

Answer 23

probe marker towards patients head

Question 24

xray pros

Answer 24

easy,
available
less than 30 min
1-3 rad
cheap

Question 25

xray cons

Answer 25

often nondiagnostic | limited

Question 26

mri pros

Answer 26

high sensitivity and specificity best for soft tissue contrast 30-60 min no radiation

Question 27

mri cons

Answer 27

``` motion sensitive safety issues claustrophobia availibility expensive ```

Question 28

ct pros

Answer 28

fast available relatively motion resistant 30-60 min

Question 29

ct cons

Answer 29

3-4 rads | expensive

Question 30

ultrasound pros

Answer 30

no radiation cheap 30-45 mn fast, reliable, safe

Question 31

ultrsound cons

Answer 31

limited in obesity

Question 32

nuclear medicine pet/ct pros

Answer 32

targets specific tumors/disease

Question 33

nuclear medicine pet/ct cons

Answer 33

``` limited availability hours-days costly nonspecfic 3-4 rads ```

Question 34

xray densities black

Answer 34

gas

Question 35

xray densities dark grey

Answer 35

fat

Question 36

xray densities light grey

Answer 36

soft tissue/ fluid

Question 37

xray densities light white

Answer 37

bone/calcification

Question 38

xray densities pure white

Answer 38

metal

Question 39

anechoic

Answer 39

absence of echoes | looks dark

Question 40

hypoechoic

Answer 40

less echogenic than surrounding tissues | light grey

Question 41

isoechoic

Answer 41

same echogenicity as surrounding tissues | see no difference

Question 42

hyperechoic

Answer 42

more echogenic than surround tissues | looks lighter

Question 43

which use ionizing radiaton

Answer 43

xray / ct nuclear med pet

Question 44

which use nonionizing radiation

Answer 44

ultrasound | mri

Question 45

odontoid

Answer 45

dens

Question 46

jefferson fracture

Answer 46

break in multiple places | burst fracture of atlas

Question 47

hangman fracture

Answer 47

between superiot and nferior facets | hyperextension

Question 48

facet orientation cervical

Answer 48

oblique nearly horizontal facets

Question 49

thoracic facet orientation

Answer 49

nearly vertical

Question 50

lumbar facets orientation

Answer 50

nearly vertical

Question 51

where does spinal cord end

Answer 51

l3

Question 52

os terminate

Answer 52

tip of dens doesn't fuse | has smooth margin

Question 53

os odontoideum

Answer 53

doesn't ctabilize c1 c2 | doesnt fuse body and dens of c2

Question 54

type ii odontoid fracture

Answer 54

base of odontoid | sharp margins

Question 55

three things to line up looking at radiographs

Answer 55

anterior vertebral line posterior vertebral line spinolaminar line

Question 56

scotty dog nose

Answer 56

trasnverse process

Question 57

scotty dog eye

Answer 57

pedicle

Question 58

scotty dog front leg

Answer 58

nferior articular facet

Question 59

scotty dog ear

Answer 59

superior articular facet

Question 60

scotty dog neck

Answer 60

pars nterarticularis

Question 61

scotty dog body

Answer 61

lamina