Intro to Radiology

Question 1

The following definition describes what modality:

Shadow-like 2D images of radiographic densities obtained from passing x-rays through the body

Answer 1

Radiograph

Question 2

X-rays are ___ energy, the same as radio waves, microwaves, or visible light - except their very low wavelength and high energy allow them to penetrate and interact with the body, and potentially cause ionization

Answer 2

electromagnetic

Question 3

A proper term for something that looks bright on an x-ray image is ____, while something that looks dark is ____

Answer 3

radiopaque; radiolucent

Question 4

List the 5 radiographic densities within the body and put them in order from least to greatest

Answer 4

Air, fat, water, bone, and metal

Question 5

True or false?

Density is affected by the thickness of what is being imaged

Answer 5

true

note: this concept is important because we cannot distinguish different anatomy shown on a radiograph unless the different structures have different radiographic densities

Question 6

What are the advantages of radiographs?

Answer 6

fast and relatively inexpensive ($200-500, also available nearly everywhere and demonstrate bone and metal very well

Question 7

What are the disadvantages of radiographs?

Answer 7

Use ionizing radiation, give limited information for soft tissues, shadows from other anatomy can become superimposed, magnification issues, blurring due to patient motion

Question 8

The following definition describes what modality:
A form of x-ray image, obtained by passing x-rays through the patient onto a fluoroscope, usually captured as a combination of video and still images

Answer 8

fluoroscopy

Question 9

What are the advantages of fluoroscopy?

Answer 9

can image anatomy in real-time, by using different contrasting agents, these can see inside body cavities, such as bowel, bladder, etc., relatively inexpensive

Question 10

What are the disadvantages of fluoroscopy?

Answer 10

sometimes can accumulate significant radiation exposure for patient or personnel. Contrast agents can be unpleasant or can cause allergy, nausea, or renal damage

Question 11

The following definition describes what modality:

All the minimally invasive procedures performed by radiologists using various modalities of imaging for guidance

Answer 11

intervential procedures

Question 12

What are the advantages of intervential procedures?

Answer 12

minimally invasive and less expensive than open surgeries, can make diagnosis from procedure, as well as treat condition

Question 13

What are the disadvantages of intervential procedures?

Answer 13

complications, blood product/body fluid exposure to personnel, radiation exposure

Question 14

The following definition describes what modality:
a radioactive substance is introduced into the body- designed to travel to the organ being studied. Gamma rays are emitted by the radiopharmaceutical as it enters and exits the organ of interest, which are imaged using a gamma camera

Answer 14

nuclear medicine

Question 15

In regards to nuclear medicine, the term for what shows on the image is ____ ___ or “hot”, relative to the other areas that may be ___ ___ or photopenic

Answer 15

increased uptake; decreased uptake

Question 16

An advantage of this modality is excellent at showing organ function

Answer 16

nuclear medicine

Question 17

What are the disadvantages of nuclear medicine?

Answer 17

do not image organ anatomy in great detail. Expensive, ionizing radiation

Question 18

The following definition describes what modality:

covered in ultrasound lab

Answer 18

ultrasound

Question 19

Something bright on an ultrasound image is termed ____, while something dark is ____

Answer 19

hyperechoic; hypoechoic

Question 20

The following is an advantage of what modality:
relatively inexpensive, zero ionizing radiation. Real-time imaging. can directly image in any plane. although IV contrast agents exist, they are seldom necessary to image vasculature

Answer 20

ultrasound

Question 21

What are the disadvantages of ultrasound?

Answer 21

hard to image deep structures, so it is often difficult to image obese patients or immobile patients who may be difficult to position ideally. ultrasound does not travel well through bone or air so certain anatomy is not seen well. anatomy is difficult to interpret without proper training

Question 22

Define the modality of computed tomography (CT)

Answer 22

a specialized modification of x-rays - where the x-ray tube and x-ray detectors are resolved/spiraled around the patient - as the patient is moved through the machine. x-rays striking the detectors are converted to images by computer. while passing through the body - some of the x-rays are attenuated (absorbed or lost)

Question 23

When looking at a CT, the proper term for something that looks bright is high ____, while something that is dark is low ____

Answer 23

attenuated; attenuated

Question 24

What are the advantages of CT?

Answer 24

excellent cross sectional anatomy, with tremendous radiographic density resolution. rapid. widely available. excellent guidance for interventional procedures. non-invasive vascular imaging

Question 25

What are the disadvantages of CT?

Answer 25

expensive. cumbersome for the very ill. ionizing radiation. metal causes artifact. Iodine-based IV contrast complications

Question 26

The following definition describes what modality:
by subjecting the body’s protons to very strong magnetic fields, the direction they are pointing and their rate of spinning can then be known. once the rate of spinning is known - radio waves of the same frequency can be applied to them. since their frequencies are matched - the protons absorb energy from those radio waves

Answer 26

magnetic resonance imaging (MRI)

Question 27

Advantages of MRI

Answer 27

excellent cross sectional anatomy, especially soft tissues. zero ionizing radiation. non-invasive vascular imaging. when needed, its IV contrast has fewer complications than Iodine-based contrast. provides good guidance for interventional procedures

Question 28

Disadvantages of MRI

Answer 28

expensive. contraindicated for some. artifact may be unavoidable because a patient cannot hold still, or because of certain kinds of metal within the patient. the very obese often do not fit. MRI is not often widely available