Introduction to Radiology and Imaging Anatomy

Question 1

X-ray mechanism

Answer 1

X-ray photons interact with tissue and are either attenuated or pass through tissue

Question 2

X-rays have the ability to____

Answer 2

penetrate tissue

Question 3

Types of attentuation

Answer 3

Absorption

Scatter

Question 4

What changes the appearance of radiograph

Answer 4

Direction and orientation of the object imaged

Question 5

Radiography machine made of

Answer 5

Detector and X-ray source

Question 6

No penetration of x-ray

Answer 6

Radiopaque (white)

Question 7

Complete penetration of x-ray

Answer 7

Radiolucent (black)

Question 8

Degree of x-ray penetration depends on

Answer 8

Atomic Number

Thickness

Question 9

Higher atomic number means

Answer 9

More radiopaque, whiter, more absorption

Question 10

Thicker means

Answer 10

More radiopaque, whiter, more absorption

Question 11

What can x-ray not distinguish between

Answer 11

Water and soft tissue

Question 12

Radiography as a function of composition (radiopaque to radiolucent)

Answer 12

Metal, bone, soft tissue/water, fat, gas

Question 13

X-ray contrast agents and how they change

Answer 13

Iodine or barium
Attenuate the x-ray beam
Appear very radiopaque

Question 14

Barium (x-ray)

Answer 14

Only for enteric use

Question 15

Iodine (x-ray)

Answer 15

For enteric or vascular use

Question 16

Enteric contrast agents administered either

Answer 16

Oral or rectally

Question 17

Intravascular contrast agents (x-ray)

Answer 17

Iodine only

Venous or arterial

Question 18

Lipohemarthrosis

Answer 18

Joint effusion containing fat and blood/fluid

Fat gloats to the top because it is less dense

Question 19

Radiographic views of x-ray

Answer 19

Frontal (anteroposterior or posteroanterior)

Lateral

Question 20

Orientation of X-ray

Answer 20

As if you are looking straight at the patients face

Question 21

Way that lateral chest x-ray named

Answer 21

Side that is against the detector

Ex. left lateral

Question 22

Do you need more than one view with x-ray?

Answer 22

Yes

Question 23

Orthogonal views

Answer 23

Views at 90 degrees of each other

Question 24

What kind of image does CT give?

Answer 24

Axial slice through body

Question 25

Advantages of CT over radiography

Answer 25

CT eliminates superimposition of structures outside area of interest CT has high-contrast so can better differentiate things like water and soft tissue Data can be viewed in axial, coronal, or sagittal planes (multiplanar)

Question 26

CT uses _________

Answer 26

ionizing radiation

Question 27

Disadvantage of CT scan

Answer 27

Higher radiation dose

Question 28

2 components of CT

Answer 28

Gantry and table

Question 29

Mechanism of CT

Answer 29

X ray tube and detector rotate around the patient

Question 30

Orientation of CT images

Answer 30

As if you are looking at the patients feet on the bed

Question 31

CT units used

Answer 31

Attenuation

Question 32

Attenuation

Answer 32

Degree to which something blocks a photon

Question 33

Attenuation can be expressed how many ways?

Answer 33

2 - qual and quant

Question 34

Low attenuation to high attenuation of CT

Answer 34

Gas, fat, water, muscle, active blood, contrast, bone

Question 35

CT image composed of

Answer 35

voxels

Question 36

CT windows _____

Answer 36

refer to adjustment of gray scale to highlight areas of interest

Question 37

CT enteric contrast

Answer 37

Iodine or barium based solutions

Question 38

H2O soluble CT contrast agent

Answer 38

Iodine

Question 39

H2O insoluble CT contrast agent

Answer 39

Barium

Question 40

Intravenous contrast media

Answer 40

Iodine based | Will make all organs with large blood supply much brighter (aorta, kidneys, liver)

Question 41

Names for relative attenuation

Answer 41

Hypoattenuating Isoattenuating Hyperattenuating

Question 42

CT enhancement

Answer 42

Increase in attenuation of a tissue after contrast administration

Question 43

CT and metal

Answer 43

Can't handle metal and will create lines across the image

Question 44

Ultrasound mechanism

Answer 44

Based on acoustic sound waves No ionizing radiation Pulses emitted by transducer and reflected back by body tissues

Question 45

Why use gel?

Answer 45

Air and gas are highly reflective so if present, sound wave will not make it to the body

Question 46

Brightness of US depends on

Answer 46

Amplitude of signal

Question 47

Depth of US image depends on

Answer 47

Timing at which echo originated

Question 48

What will sound not travel through?

Answer 48

Gas and bone | Can only see cortex of bone because of this

Question 49

Orientations of US images

Answer 49

Longitudinal (sagittal)/transverse (axial)

Question 50

If target moving towad transducer...

Answer 50

FR>FT

Question 51

If target moving away from transducer...

Answer 51

FT

Question 52

Color doppler

Answer 52

Frequency info can be used to determine direction of flow in blood vessels Uses frequency shift

Question 53

Fluid in ultrasound

Answer 53

Doesn't show up

Question 54

Ultrasound terminology

Answer 54

Anechoic/Echolucent Hypoechoic Hyperechoic/echogenic

Question 55

MRI mechanism

Answer 55

Uses magnetic fields and radiofrequency waves to create images Imaging protons No ionizing radiation

Question 56

Disadvantages of MRI

Answer 56

Takes a lot longer

Question 57

MRI components

Answer 57

Magnet and table

Question 58

MRI T2 weighted

Answer 58

``` Fluid is bright Highlights pathology (edema) ```

Question 59

MRI T1 weighted

Answer 59

Fluid dark | Highlights anatomy

Question 60

Fluid in MRI

Answer 60

Stationary relative to how fast the scan takes place can be imaged

Question 61

In MRI, fat is typically

Answer 61

Bright

Question 62

MRI fat saturation

Answer 62

Fat signal is nulled

Question 63

Vascular contrast MRI

Answer 63

Vessels and organs will be high in signal intensity on T1 ONLY weighted images

Question 64

Advantages of fat saturation

Answer 64

Can help to highlight edema

Question 65

MRI terminology

Answer 65

``` Hypointense (low SI) Isointense Hyperintense (High SI) ```

Question 66

MRI contrast agents

Answer 66

Gadolinium based | Makes tissues bright on T1 weighted sequences

Question 67

DIfferences between MRI and CT

Answer 67

Bones much brighter in CT