4: Radiology - imaging modalities, advantages & disadvantages

Question 1

Which radiography method would be used to obtain a simple image of the heart?

Answer 1

Chest X-ray

Question 2

Give three different types of angiogram.

Answer 2

Catheter angiogram
CT angiogram
MRI angiogram

Question 3

Which imaging modality is used to obtain an echocardiogram?

Answer 3

Ultrasound

Question 4

Which two imaging modalities can be used to obtain a more detailed image of the heart than a normal CXR?

Answer 4

CT

MRI

Question 5

What are the advantages of taking a chest X-ray to obtain an image of the heart?

Answer 5

Very quick and easy to do

Image is immediately available

Question 6

What are a couple of disadvantages of using a chest X-ray to look at the heart?

Answer 6

Patient receives a dose of radiation

CXRs can be a bit non-specific sometimes

Question 7

What is the main investigation carried out in radiology departments?

Answer 7

CXR

Question 8

On a CXR, the outline of the heart should be ___.

Answer 8

sharp

Question 9

What is the cardiothoracic ratio?

Answer 9

Maximum diameter of the heart / Maximum diameter of the thorax

Question 10

A normal cardiothoracic ratio should be less than or equal to __%.

Answer 10

50%

Question 11

The cardiothoracic ratio can only be used when working with __ chest X-rays.

Answer 11

PA

Question 12

Why may heart size be falsely exaggerated on a CXR?

Answer 12

CXR is AP
Patient has not inspired fully
Patient has rotated

Question 13

On a poorly taken CXR, heart size may be ___ leading to a false diagnosis of ___.

Answer 13

enlarged , cardiomegaly

Question 14

Which imaging technique is used to assess the condition of the coronary arteries?

Answer 14

Angiogram

Question 15

What are some disadvantages of using an angiogram to assess a patient’s coronary arteries?

Answer 15

Patient receives a dose of radiation
Angiography is invasive
There may be complications
Angiography requires hospital admission
Patient may be allergic to the contrast (e.g iodine)

Question 16

Why may patients receiving a coronary angiogram require an admission to hospital?

Answer 16

Procedure is invasive

There may be vascular complications

Question 17

Which contrast, used in coronary angiography, may patients be allergic to?

Answer 17

Iodine

Question 18

What is an echocardiogram?

Answer 18

An ultrasound of the heart

Question 19

What structures can an echocardiogram be used to assess?

Answer 19

Cardiac valves

Cardiac chambers

Question 20

Does an echocardiogram emit any radiation?

Answer 20

No

Question 21

What are some disadvantages of using an echocardiogram to assess the structure of a patient’s heart?

Answer 21

Very operator dependent - expertise required
Patient dependent - weight concerns
Doesn’t offer the whole picture

Question 22

What imaging modality offers a very good, non-invasive view of the heart anatomy and coronary arteries?

Answer 22

Cardiac CT scan w/ IV contrast

Question 23

What imaging modality is very good at capturing the stroke fraction of the heart?

Answer 23

CT scan

Question 24

What are some disadvantages of using a cardiac CT scan to view the heart?

Answer 24

High radiation dose
Patient may be allergic to the contrast (e.g iodine)
Requires specialist CT equipment

Question 25

What imaging modalities can be used to assess vascular stenosis / patency?

Answer 25

Angiography

CT scan

Question 26

What is the gold standard investigation used to obtain images of the heart?

Answer 26

Cardiac MRI

Question 27

Which imaging modality gives an excellent view of the soft tissue and anatomy of the heart?

Answer 27

Cardiac MRI

Question 28

Which vessels cannot be seen particularly well on a cardiac MRI?

Answer 28

Coronary arteries

Question 29

What are some disadvantages of cardiac MRI scanning?

Answer 29

Long imaging times (patient has to lie still for ages)
Claustrophobia
MRI contraindications ( e.g PACEMAKERS)
Need specialist equipment and expertise to interpret images

Question 30

Which kind of patient may be unsuitable for a cardiac MRI scan?

Answer 30

Claustrophobic
Those with metal implants (mechanical stents, pacemakers particularly)
Those who cannot lie still for extended periods of time

Question 31

Do MRI scanners emit any radiation?

Answer 31

No

Question 32

Which imaging method can be used to determine the impact of coronary artery disease on muscle perfusion?

Answer 32

Nuclear cardiology

Question 33

In nuclear cardiology, patients undergo stress testing with a vasodilator such as ___ and are then given a radioisotope to obtain data about myocardial perfusion.

Answer 33

Adenosine

Dihydropyridine