Introduction To Radiology

Question 1

What are the different modalities in radiology?

Answer 1

1-X-rays or flat plate or radiograph or digital radiography, or computed radiography
2-Fluoroscopy
3-Nuclear medicine or Scintigraphy
4-Ultrasound or sonography 
5-Computed tomography
6-Magnetic Resonance Imaging

Question 2

What are x-rays?

Answer 2

A form of electromagnetic wave photons traveling at the speed of light
The shorter the wavelength the greater the energy
Can cause ionization with causes damage
The higher the dose the higher the health risk

Question 3

What are the advantages of radiography?

Answer 3

Fast
Relatively inexpensive
Available everywhere
Demonstrates bone and metal very well

Question 4

what are the disadvantages of radiography?

Answer 4

Radiation level (1/5) exposure
Limited information for soft tissues
Artifacts such as superimposed shadows, magnification, blurring due to patient motion

Question 5

what is the term for something bright on a x-ray?

Answer 5

Radioopaque
Radiodense
High density

Question 6

What is the term for something dark on an X-ray?

Answer 6

Radiolucent

Low density

Question 7

What is fluoroscopy?

Answer 7

Continuous X-rays passed through the patient onto a fluoroscope
If radiography is a photograph, fluoroscopy is a movie
Exam is monitored on a video monitor then recorded on video or still images
Utilizes a contrast agent

Question 8

What are the advantages of fluoroscopy?

Answer 8

Can see inside a bowel, bladder or other cavities
Real time visualization
Moderate expense
Can be used for interventional procedures

Question 9

What are the disadvantages of fluoroscopy?

Answer 9

Can accumulate significant radiation exposure for patient and especially personnel (4/5)
Contrast agent maybe unpleasant (barium) or can cause allergy nausea

Question 10

What are interventional procedures?

Answer 10

All the minimally invasive procedures performed by radiologists, surgeons and cardiologists using imaging guidance
Examples treating stroke, drainage procedures, stopping hemorrhage

Question 11

What are the advantages of interventional procedures?

Answer 11

Both diagnostic as well as therapeutic

Minimally invasive compare and less expensive compare to open surgery

Question 12

What are the disadvantages of interventional procedures?

Answer 12

Complications(hémorragie, pain, embolus)
Blood product exposure to personnel
Radiation (2/5)

Question 13

What is nuclear medicine?

Answer 13

A radionuclide + a physiologic analog=radiopharmaceutical
Radiopharmaceutical usually given through IV but may be ingested, infused
Gamma rays project from radiopharmaceutical
Gamma camera detect rays and computer generates digital images
Examples:PET scan for metastasis, treadmill test of heart

Question 14

What is the advantage of nuclear medicine?

Answer 14

Excellent at showing the functions of organs

Question 15

What are the disadvantages of nuclear medicine?

Answer 15

Do not reveal organ anatomy in great detail
Expensive
Ionization radiation

Question 16

What is the term for a revealed anatomy in nuclear medicine?

Answer 16

Increased uptake
Hot
Photons rich

Question 17

What is the term for not revealed anatomy in nuclear medicine?

Answer 17

Decreased uptake
Cold
Photon poor
Photogenic

Question 18

What is the term for a revealed anatomy in ultrasound?
A more revealed anatomy?
A less revealed anatomy ?
A not revealed anatomy?

Answer 18

Echoegenic
Hyperechoic
Hypoechoic
Anechoic

Question 19

What are advantages in ultrasound?

Answer 19

Relatively inexpensive
No ionization radiation
Real time
Gives both anatomic and dynamic information (fetal movements)
No contrast agents needed
Imaging in any plane

Question 20

What are the disadvantages of ultrasound?

Answer 20

Hard to see deep structures
Difficult with obese or immobile patients
Cannot see well through bone or air
Looks like weather map to untrained eye

Question 21

What is Computed tomography(CT)

Answer 21

X-ray tube and multiple detectors are revolved around the patient
Detector plates measure attenuation of radiation that pass through patient
Digital images are produced and displayed by computer

Question 22

What is the term for something that is bright in CT?

Something that is dark?

Answer 22

High attenuation

Low attenuation

Question 23

What are the advantages of CT?

Answer 23

Excellent cross-sectional anatomy
Rapid
Widely available
Tremendous radiographic density resolution
Excellent guidance for interventional procedures

Question 24

What the disadvantages of CT?

Answer 24

Relatively costly
Cumbersome for the very ill
Ionization radiation(3/5)
Metal or bone artifact

Question 25

What is magnetic resonance imaging (MRI)

Answer 25

Strong magnetic fields are used to align body protons
Radio waves are transmitted to the protons
Protons absorb the radio wave energy then resonate it back
Detected the processed and displayed by computer

Question 26

What is the term for anatomy that appears bright on MRI?

Anatomy that appears dark?

Answer 26

High signal intensity

Low signal intensity

Question 27

What are the advantages of MRI?

Answer 27

Excellent cross sectional anatomy
No ionization radiation
Images directly in any plane
Non invasive vascular imaging
Generally available

Question 28

What are the disadvantages of MRI?

Answer 28

Costly
Contraindicated for some patients (pacemakers, défibrillations, claustrophobic patients)
Artifact from motion, metal