Imaging of the thorax

Question 1

What is computed tomography?

Answer 1

• an X-ray applied as a single beam

- then quickly rotated around the body

Question 2

What type of rays does computed tomography use?

Answer 2

• ionising radiation

- downside of CT

Question 3

Everyone experiences some form of background radiation during routine day to day activities. What is the equivalent dosage from a CT scan?

Answer 3

• 1 years worth of radiation on a chest scan

Question 4

Are CT scans accessible and expensive?

Answer 4

• cheap

- accessible

Question 5

Do CT scans provide 2D or 3D images?

Answer 5

• 3D cross sectional

Question 6

Why is it difficult to detect specific tissue and abnormalities in CT imaging?

Answer 6

• images are superimposed on top of each other

- this makes it hard to detect things in its own anatomical space

Question 7

Why is ultrasound used so commonly in clinical proactice?

Answer 7

• cheap and accessible

- non ionising

Question 8

What is the biggest flaw of ultrasound?

Answer 8

• operator dependent

Question 9

What is radionuclide imaging?

Answer 9

• a radioactive dye is inserted into the body
• may be specific to a tissue or organ
• the dye can be detected on the imaging modality

Question 10

When using CT scans, why is reformatting important?

Answer 10

• aspects of images can be edited to enhance clarity

Question 11

Why is injecting patients with contrast a good thing?

Answer 11

• contrasts show up on images better

- allows abnormalities to be identified better

Question 12

When looking at images, which side is left and right?

Answer 12

• looking at the image the right = left
• left = right
• unless stated otherwise

Question 13

Instead of performing an operation blindly, what imaging technique may help with this?

Answer 13

• ultrasound

Question 14

Is X-ray or ultrasound better at detecting pleural effusions?

Answer 14

• ultrasound

- X-rays are pass straight through fluid

Question 15

What is echocardiogram?

Answer 15

• ultrasound imaging

- used to identify cardiac and vascular structural changes

Question 16

What is the normal direct a chest X-ray is performed?

Answer 16

• from back to front

- postero-anterior (PA)

Question 17

When would you change from a postero-anterior chest X-ray to an anterior-posterior X-ray?

Answer 17

• if the patient is unable to stand alone

Question 18

When analysing an X-ray what is one of the first things to check?

Answer 18

• was the patient aligned centrally in the image

- any annotations on the image align with?

Question 19

What checking to see if a patient has inspired on an X-ray, where should the 6th anterior rib align with?

Answer 19

• cross the diaphragm at the mid clavicular line

Question 20

When analysing an X-ray, what do each of the following words represent? ‘ Are There Many Lung Lesions Present’

Answer 20

• Are = Abdomen
• There = Thorax
• Many = Mediastinum
• Lung - Lung (right and then left)
• Lesions = Lungs comparison
• Present = Devices

Question 21

What are some common artefacts that can show up on an X-ray?

Answer 21

• bra-straps
• ECG leads
• pacemakers

Question 22

On X-rays a gas bubble can be present on the left side, just above the diaphragm. Why is this normal?

Answer 22

• this is the stomach

- the stomach contains air

Question 23

In a normal healthy X-ray what should the length of the mediastinum be roughly half of or less?

Answer 23

• the thorax

Question 24

If the width of the mediastinum is greater than half of the thorax, what does this indicate?

Answer 24

• patient has an enlarged heart

Question 25

What is the cardio thoracic ratio?

Answer 25

• width of mediastinum is compared with thorax

Question 26

If a patient has a feeding tube that is supposed to go to the stomach, but accidentally it enters the trachea, where is it like to be lodged?

Answer 26

• on right primary bronchi

- right aligns with trachea better at the carina

Question 27

When inserting a feeding tube for a patient, that is then check on an X-ray, how would you know this is in the correct place?

Answer 27

• tube should cross the diaphragm at the midline
• tube visible below the left hemisphere of diaphragm
• tube dissects the carina
• tube follows oesophagus and not trachea