Radiology

Question 1

Who is the father of radiology?

Answer 1

Wilhelm Röntgen – Discovered it in 1895

Question 2

What is imaging?

Answer 2

Medical imaging is the technique and process of imaging the interior of a body for clinical analysis and medical intervention, as well as visual representation of the function of some organs or tissues.

Question 3

What are the four imaging tests?

Answer 3

-X-rays
-Ultrasound
-Magnetic resonance imaging (MRI)
-Nuclear medicine

Question 4

What are the three subdivisions of X-ray?

Answer 4

Plain radiography
Contrast studies (Barium enema, arthrography)
Computed tomography (CT)

Question 5

What are X-rays? (Scientific answer)

Answer 5

Electromagnetic radiation is produced by an electrical source that pass through body tissue to a degree dependent on its density

Question 6

What are the five steps of mechanics of producing an X-ray?

Answer 6

1. Electric current heats filament cathode
2. Electrons are emitted and strike the anode
3. Generated x-rays exit window in casing and beam is collimated
4. x-rays penetrate the patient and scatter
5. Only 1% of x-rays reach the film and contribute to the image

Question 7

What is PACS and what does it allow?

Answer 7

Picture archiving and communications system allow easier storage, access, and retrieval of digital images.

Question 8

How do X-rays interact with each tissue?

Answer 8

The denser a tissue, the fewer x-rays pass through it

air lets all x-rays pass through
soft tissue lets some x-rays pass through
cortical bone lets no x-rays pass through

Question 9

What are the three strengths of X-rays?

Answer 9

1. Good at showing things that are surrounded by black air.
2. Good at showing things that are surrounded by white bone.
3. Good at showing things that destroy white bone- Sclerotic lesion.

Question 10

What are the two weaknesses of X-rays?

Answer 10

1. An abnormality must be of very different density to the tissue that surrounds it.
2. A lot of pathologies, especially that affecting soft tissues, is of similar density to its surroundings and isn’t shown by simple x-rays

Question 11

What are contrast studies?

Answer 11

Contrast radiography is a method of studying organs using X-rays and the administration of a special dye, called a contrast medium.

Question 12

What are two examples of contrast mediums?

Answer 12

Barium and iodine

Question 13

Why can X-rays be dangerous and what is it relative to?

Answer 13

X-rays are radiation so can damage cell DNA leading to mutations that may kill the cell or make it turn cancerous
the risk is related to the x-ray dose

Question 14

What is computed tomography?

Answer 14

A procedure that uses a computer linked to an x-ray machine to make a series of detailed pictures of areas inside the body.

Question 15

Why is CT better than radiographs at times and what is it often used for?

Answer 15

It is more able than radiographs to distinguish between tissues of similar density and is often used to show soft tissue pathology

Question 16

What superior characteristic does CT have over X-rays?

Answer 16

Contrast resolution.
With CT, x-rays are ‘fired’ from all around the body and processed by a computer which produces a set of cross-sectional pictures with no superimposition

Question 17

Why are radiographs not sufficient to diagnose illness?

Answer 17

When obtaining a radiograph, the x-rays are ‘fired’ from only one direction producing an image where all structures between their source and the film are superimposed

Question 18

What does cross-sectional mean?

Answer 18

A discipline of radiology that encompasses the use of a number of advanced imaging techniques that feature in common the ability to image the body in cross-section

Question 19

So why don’t we just CT everybody?

Answer 19

-CT gives large doses of ionizing radiation
-Soft tissues of very similar density cannot be distinguished by CT
-CT cannot resolve bone marrow disease

Question 20

What soft tissues cannot be distinguished by CT?

Answer 20

Pelvic organs (uterus, ovaries, prostate)
Muscles and tendons
Joint cartilage and ligaments
Some areas of the brain

Question 21

What are the seven steps of the mechanics of ultrasound?

Answer 21

Piezoelectric crystals can convert electrical energy to acoustic energy
These crystals are housed in a transducer which has an electrical supply
The transducer produces pulses of sound waves
The skin is coated with jelly to assist sound transmission into the body
the ultrasound transducer alternately transmits sound pulses and then listens for reflected sound returning
The returning acoustic energy is converted back into an electrical impulse and fed into a computer
The computer ‘knows’ where the sound has come from by the time taken for it to return to the transducer
It uses this to create a cross-sectional picture of the soft tissues that are invisible to x-rays

Question 22

What is the interaction between ultrasound and body tissues?

Answer 22

Body tissues have different acoustic properties - some tend to transmit sound while others, such masses, tend to reflect it

Question 23

Is the diagnosis in an ultrasound done after the procedure?

Answer 23

Nope, during the procedure.

Question 24

What makes a good ultrasound exam? (5)

Answer 24

-Tissues that allow sound transmission
-Good skin – transducer contact, superficial structures, slim patients, and correct transducer selection
-Tissues that have different acoustic properties
-A well-trained and experienced sonographer
-Modern equipment

Question 25

What makes a poor ultrasound exam?

Answer 25

tissues that prevent sound transmission (gas, bone)
sound can’t reach the target or return to the transducer
poor skin – transducer contact (not enough jelly, hairy pt)
very deep structures
fat patients
incorrect transducer selection
tissues that have identical acoustic properties (reflect the same amount of sound)
an incompetent operator
antique equipment

Question 26

What are the four strengths of ultrasound?

Answer 26

1. ultrasound has a high spatial resolution, useful in imaging MSK soft tissue structures
2. body fluids readily transmit ultrasound whereas solid structures within the fluid reflect it
3. abnormal fluid collections are well shown by ultrasound as the surrounding tissues reflect more sound and contrast with the black fluid
4. soft tissues with different acoustic properties are well differentiated by ultrasound

Question 27

What are the three ultrasound weaknesses?

Answer 27

bone blocks the US, so it can’t see the brain, the spinal canal, inside joints, or assess bone marrow

gas blocks the US, so ‘windy’ patients are difficult to assess and gas-containing structures like the lungs or bowel can’t be assessed

very fat patients make poor US subjects

Question 28

What are the mechanics of the MRI?

Answer 28

-the scanner produces a burst of radio signal (RF pulse), which energizes the body’s protons
-the scanner waits
-the scanner listens for a return signal, produced by the protons
-the amount of signal produced depends on the molecular environment of —these protons
-using the returned signal, the scanner’s computer performs some amazingly complex calculations and creates an image

Question 29

What has MRI caused which makes it hostile?

Answer 29

Frostbite and thermal burns
Deafness
Disturbance of surgical and non-surgical ferrous material
Pacemakers
Heart valves
Mobile ferrous material eg shrapnel, intra-ocular foreign bodies
Missile injuries

Question 30

What two things should you do to prevent patient injury regarding the MRI?

Answer 30

request card safety questionnaire
patients must remove all ferrous metal

Question 31

MRI is time-consuming, how long does it take for the spine, knee and ankle?

Answer 31

spine 25-40 minutes
knee 25mins
ankle 30mins

Question 32

What are the four strengths of MRI?

Answer 32

-MRI provides the most complete assessment of the brain of any modality
-MRI is a sensitive way to assess acute muscle and tendon tears, especially in deep tissues where ultrasound is less accurate
-MRI provides excellent detail of spinal canal disease
-MRI allows the interior of joints to be imaged so that injuries to cartilage and ligaments can be seen

Question 33

What are the five weaknesses of MRI?

Answer 33

-MRI is expensive
-MRI could harm some patients and is therefore contraindicated
-Some patients find MRI too claustrophobic
-MRI scans take a long time so patients who are in pain or are restless, or those who are unstable or need monitoring can’t be scanned
-MRI is poor at showing detail of the lungs

Question 34

Tell me the five roles of imaging

Answer 34

To make or confirm a diagnosis
To help narrow a differential diagnosis
To ‘STAGE’ a known disease, eg cancer to inform treatment
To monitor the effects of treatment and follow up on a known disease
To aid intervention/deliver treatment eg image-guided procedures or interventional radiology

Question 35

What two fields are required in imaging?

Answer 35

Clinical medicine and anatomy

Question 36

How do you start X-ray interpretation?

Answer 36

Begin chest X-ray interpretation by checking the following details:

Patient details: name, date of birth, and unique identification number.
Date and time the film was taken
Previous imaging: useful for comparison.

Question 37

How do you assess image quality?

Answer 37

RIPE
-Rotation
-Inspiration
-Projection
-Exposure

Question 38

What is the golden standard regarding the position in CXR?

Answer 38

Posterior Anterior (PA)