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Flashcards in RADIOLOGY Deck (81):
1

what is an xray

form of electromagnetic energy with a very short wavelength which allows xrays to penetrate matter unlike light rays

2

How are xrays produced ?

xray tube consits of an evacuated glass tube with cathode and anode terminals; cathode tungsten filament in heated to incandescencce, giving off electron; electrons bombard positively charged anode target and xray are emitted

3

ionizing radiation

radiation that has enough energy to remove electrons from atoms or molecules; forms of ionization radiation include Xray, gamma rays, alpha particles, beta particles and neutrons

4

what involves ionizing radiation

xrays, nucleur medicne studis and fluroscopy

5

radioopaque tissue is

denser, absorbs more xrays and appears as white image on film

6

radiolucen tissue is

less dense, absorbs less xrays and appears as darker image on film

7

film cassette

patients cannot hold still long enough to obtain an image from x rays along; cassette contains flourescent screens which glow when activated by xrays and this light is used to expose the film; less radiation and exposure times are needed; the grid cuts down on scatter effect on film-like a lens

8

The close an object is to the film

the less magnified its image

9

advantages to digial radioagrphy

less storage space
multiple monitors can look at same image at the same time, difficult to Lose films, transmitted electronically, view generated can be altered by the computer

10

disadvantages of digital radiography

hospitals arealdy have fully functional film based imaging equipment, new equpment is expensive, may not be as sharp

11

flouroscopy

common radiological technique allows realtime visulaization; continous beam of xrays; common procedures used for are upper gi and lower gi, and many interventional procedures

12

types of GI contrast

barium sulfate or iodinated water; not absorbed

13

barium sulfate

dense, good images, slow to be excreted, not good is body cavity is posibile, must be dilute for CT scan

14

iodine based water soluble contrast

ok if spilled into cavities, less dense, less details, toxic to lung tissue,

15

intravenous contrast

imaging of blood vessels or urinary tract use iodinated compounds but they are toxic to kidneys

16

ultrasound

narrow beam of high frequency sound waves is procued by vibrating crystals; sound waves directed into the body and reflected back dependent upon tissues differing acoustic impedance

17

anechoic

echo-free due to absence of acoustic interfaces

18

sonolucent

cyst or fluid filled viscus shows as dark area

19

echogenic

based on internal echoes due to acoustic interfaces, solid tisues, tumors, fat or fibrous itssue show as LIGHT areas

20

advantages of ultrasound

no ionixing radiation safe, multiplanar imaging; ability to differentiate cystic, solid and complex tissue, cost effectv, portable and realtime analysis

21

disadvantages of ultrasound

air and bone produce extreme impendance; most sound is reflected prohibitng sound penetration; images not as clear as CT or MRI, and operator depedent

22

doppler ultrasound

can be used to calculate velocity of moving blod

23

computer tomography

cross sectional xray imaging

24

in computer tomography dense tissues are

white

25

in computer tomography lease dense tissues are

black

26

advantages of CT scanning

extremely sensitive to slight differenences in tissue, comparison screen or film radiography requires 5% difference, excellent images, available almost everywhere

27

disadvatnages of CT scann

expensive, high demand may mean long wait time, ionizing radiation, over utilized

28

IV contrast for CT

differentiate vascular form nonascular structures, and urinary tract

29

oral contrast for CT

delineates GI tract, must NOT be TOO DENSE

30

MRI

imaging of protons

31

lungs are what color in MRI

black

32

fat under skin in MRI is

white

33

image in MRI are determined by

number of hydrogen atoms not by tissue density

34

gandolinium contrast

magnetically active and used to enhance contrast between tissues especially T1, blood stream, helps with imaging strokes, tumors, infections

35

disadvantages

long scanning times, claustrophobia people with pacemakers, non-ferrous metals interefere with image quality, high cost

36

bone in CT appears

white

37

bone in MRI appears

black

38

CT is excelletn for

bone

39

MRI is excellent for

soft tissue

40

common indications for CT imaging

trauam, intracranial hemorrhage, fracture detetion, evaluation, spine alignment, foreign bodies in joints, neoplasm,s axial images

41

uses for MRI

non urgen imaging, musculoskeletal system injuries

42

radioisitope scanning

radioactive isotope is given intravenously or by mouth and uptake is imaged with gamma camera

43

heptobiliary iminodiacetic acid or HIDA scan

injected, excreted by the liver into a biliary tree, enters the GB and flows into the bowel

44

sentinel lymph node scan

used in malignant melanoma and breast cancer cases; allows removal fo the first lymph node that drains the tumor site

45

SPECT

specialized gamma camera rotates around patient to produce a tomographic image used in cardiac imaging and cerebral perfusion scans

46

PET Scan

evaluates how cells use glucose FDG is given to patient and it concentrates in the tissue accroding to METABOLIC rate

47

PET is used for

oncology, cardiology, neurology

48

what are the three cervical spine series

AP, lateral and odontoid view

49

what can you see in a AP cspine

normal degenerative changes, articular pillar changes, alignment of lateral masses and perhaps any cervical ribs

50

what is the highest visulaized vertebrae in C spine AP view

c3

51

lateral C spine what do you need to see

must see all 7 cervical and top of t1 used for prevertebral soft tissue analysis

52

lateral C spine you can use to see

alingment of vertebral segments, high of vertebral bodies and height of intervertebral dics

53

odontoid view

see the integrity of dens and the alignment of C1 and C2

54

what does the presence of lipping of vertebral bodies indicate

presence of osteophytes

55

AP lumboscral spine

count vertebral bodies, check alignment, evaluate bone density, pedicles cortices, transverse processes, examine sacrm and SI joints

56

spondyloisthesis

anterior slippage of vertebral segment; fracture or defect in the pars interarticularis, visslbe displacement on lateral view

57

T1 MRI images

excellent resolution used to procure anatomic information

58

T2 images

better contrast cause water to light up and shows pathology well

59

colors of things in T1 image

fat is white, soft tissue is grey

60

in a t2 image what are the colors of things

water is ligher grey, fat greyl used to look for pathology

61

cortical bone, calcium, air and fast flowing blood

all appear very dark in MRI

62

what is the test of choice for chornic conditions

MRI

63

what is the test of choice for acute conditions

CT

64

what type of scan is helpful in deciding whether or not surgery is necessary for fractures of vertebrae

CT

65

what are the different types of fractures

segmental
comminuted (pieces)
spiral
oblqiue
transverse

66

communuted fracture

broken into several pieces or crushed
high probability of damage to surrouding tissues
may heal with immobilization but frequenly requires ORIF

67

oblque fracture

likely due to shearing force along line of fracture, pointed ends make open fractures morel ikely

68

spiral fracture

result of fixed distal component with rotational force

69

greenstick farctures

pediatric fracture, bone is flexed breakage is only on one side

70

torus or buckle facture

bone id flexed not completely transected, comparable to folding a papertowel roll

71

95% of glenohumeral dislocations are

anterior and subcoracoid

72

what is the best technique for rotator cuff injuries

MRI

73

what is sail sign associated with

radial head fracture, MRI can confirm diagnosis

74

Smith's fracture

caused by falling on palmar flexed hand, reverse of colles fracture, distal radius fracture with palmar angulation of distal fragment

75

Colles fracture

caused by falling on dorsiflexed hand, distal radius fracture with dorsal angulation of distal fracment

76

perilunate dislocation

lunate is normal but rest of carpal bones dislocated posteirorly

77

lunate dislocation

lunate is rotated and dislocated toward palmar side

78

thickening around joints is called

herberdens nodes

79

ulnar deviation of digits is associated with

rheumatoid arthirits

80

MRI is test of choice for

medial meniscus tear

81

Mortise view of ankle

allows visualization of the relationship betweeen the distal tibia and fibula