Exam 1 Introduction to radiology

Question 1

Explain X-rays

Answer 1

Radiation passes through patient strikes cassette to create an image, rays don’t pass through dense tissues as easily creating the outlines

Question 2

What is Computed Radiography?

Answer 2

x-ray passes through patient strikes a sensitized plate which is read and digitized into a computer image

Question 3

What is digital radiography?

Answer 3

x-ray strikes a plate of sensors producing the computer image directly

Question 4

Which type of radiography sends the image directly to the computer: digital or computed?

Answer 4

digital

Question 5

Why are x-rays harmful to biological organisms?

Answer 5

can displace electrons from energy level, creating a free radical

Question 6

What are the different risks of radiation?

Answer 6

deterministic effects resulting in cell death: skin erythema, epilation, radiation burns or cataracts; stochastic effects: cancer/leukemia

Question 7

T/F: pediatric patients are at increased risk for stochastic effects

Answer 7

True; higher proportion of rapidly dividing cells

Question 8

What are examples of background radiation exposure?

Answer 8

radon, radioactivity from rocks, cosmic rays

Question 9

What accounts for 95% of all radiation exposure?

Answer 9

medical imaging

Question 10

What does the risk model look like that estimates lifetime risk of radiation induced cancer?

Answer 10

linear no-threshold dose response curve (dose and risk are directly proportional

Question 11

What questions should you ask to reduce the risk of radiation-induced cancer?

Answer 11

Is this test necessary? Will it change the management of the pt? Is there a better study that would answer the question?

Question 12

What are the technical factors that can be controlled to reduce the exposure to radiation?

Answer 12

decrease tube current/tube voltage, wider collimation or change speed table moves, automated methods

Question 13

What trimester is absolutely critical to avoid radiation exposure?

Answer 13

First trimester (organ exposure); after 2 gestational weeks it gets better

Question 14

What is the first line of study to look at lungs, heart and skeleton?

Answer 14

Plain films

Question 15

What are the main uses for plain films/x rays

Answer 15

CXR, spine films, skeletal films, abdoment films

Question 16

What should always be done when getting an x-ray

Answer 16

get more than 1 view to put it in more of a 3D

Question 17

What is basis of ultrasound?

Answer 17

high frequency sound waves reflect back based on distance/density

Question 18

Does ultrasound use ionizing radiation?

Answer 18

negatory

Question 19

What is the primary way of evaluation pregnancy?

Answer 19

ultrasound

Question 20

What are the best uses of ultrasound?

Answer 20

pregnancy, gallbladder, abdominal/pelvic pain in women and children

Question 21

T/F: ultrasound is good for evaluating veins for DVT?

Answer 21

False

Question 22

Do CT scans use IR?

Answer 22

yes; a lot

Question 23

How does CT work?

Answer 23

gantry moves around patient taking x-rays at many angles and computer puts them all together

Question 24

What is CT best used for?

Answer 24

acute hemorrhage of brain, mass effect or herniation of brain, chest imaging, PE, tumor, interstitial lung disease, abdominal screening (tumor, inflammation, obstruction), UTI and kidney stones

Question 25

T/F: CT can be used for non-hemorrhagic infarction?

Answer 25

false, it’s not good at that

Question 26

T/F: CT is good for gallbladder disease? Abdominal pain in young women?

Answer 26

False; False

Question 27

Can you use contrast for CT scans?

Answer 27

yes

Question 28

What are the risks of IV contrast for CT scans?

Answer 28

Allergic reactions, contrast-induced nephropathy

Question 29

What are risk factors for IV contrast reactions?

Answer 29

preexisting renal fxn ,DM, nephrotoxic drugs, reduced intravascular volume

Question 30

How can you prevent nephropathy due to contrast?

Answer 30

Hydration, Mucomist

Question 31

Does MRI have IR?

Answer 31

nope

Question 32

Explain idea behind MRI

Answer 32

magnetic lines up all dipoles and measures their relaxation at different rates

Question 33

What can MRIs damage?

Answer 33

pacemakers, aneurysm coils, other implants

Question 34

What are the primary uses of MRI?

Answer 34

Patients with inflammatory bowel disease, liver for cancer, very specific images of nearly everything in the body

Question 35

What is the contrast of MRI?

Answer 35

gadolinium

Question 36

T/F: MRI contrast (gadolinium) is nephrotoxic?

Answer 36

False

Question 37

What can gadolinium (MRI contrast) cause?

Answer 37

nephrogenic systemic fibrosis (NSF)

Question 38

What is nuclear medicine good at?

Answer 38

gallbladder and bone scans

Question 39

T/F: nuclear medicine is more of a functional test than giving a detailed anatomic representation?

Answer 39

True

Question 40

What are barium exams less common than endoscopy?

Answer 40

barium gives you just the information, endoscopy allows you to do something while in the area.

Question 41

What has CT replaced barium exams for diagnoses?

Answer 41

diverticulitis and small bowel obstruction

Question 42

What do PET scans use for “contrast”?

Answer 42

FDG (flourine 18 fluorodeoxyglucose)

Question 43

what is PET scans good for?

Answer 43

demonstrate abnormal metabolic activity in organs

Question 44

What have PET scans been coupled with? Why?

Answer 44

CT scans to make them more accurate in localizing regions of abnormal uptake