Diagnostic Techniques

Question 1

In relation to the ribs, where can the heart be found in dogs?

Answer 1

around the third to sixth rib

Question 2

How would you position a dog to get diagnostic radiographic images of the heart? (7)

Answer 2

• Lie the dog laterally on the affected side
• Pull fore and hindlimb out of the collation area and tie
• Keep the head in a neutral position
• collimate to the heart
• Capture on inspiration
• lie the dog on its back or sternum, head spine and tail should be in line
• Repeat process
• head spine and tail should be in line

Question 3

What main structures can be seen on a cardiac radiograph? (5)

Answer 3

• Heart
• Aoritc arch
• Ascending aorta
• Tracheobronchial lymph nodes
• Pulmonary artery

Question 4

What is angiography?

Answer 4

Special type of radiograph using a contrast media used to visualise blood vessels in and around the heart

Question 5

When taking thoracic radiography should dogs be anaesthetised, sedated, or left as normal? and Why?

Answer 5

Sedated so they don’t move when the image is taken, unless severely dyspneic, not anaesthesia as it alters lung function, unless totally necessary

Question 6

What might cause an alveolar patter on a radiograph? (3)

Answer 6

• pulmonary oedema
• pneumonia
• haemorrage (anutoimmune)

Question 7

What causes bronchial pattern to show up on a radiograph? (2)

Answer 7

• Cells or fluid lining the bronchi

- Cells or fluid in the peribronchial space

Question 8

What might cause a vascular pattern to be seen on a radiograph?

Answer 8

abnormal amount of blood in the vessel causes a change in position or diameter

Question 9

What might cause an interstitial pattern on a radiograph? (3)

Answer 9

• nodular - accesses
• nodular - tumours
• diffuse - pleural effusion

Question 10

What is pneumothorax and how would it look on a radiograph?

Answer 10

collapsed lung

Question 11

In general how big should the heart be in a canine lateral radiograph?

Answer 11

3.5 rib spaces big

Question 12

In general how big should the heart be in a canine dorsoventral radiograph?

Answer 12

2/3 the width of the thorax and maximum 6 rib spaces long

Question 13

What are the limitation of a cardiac radiograph? (3)

Answer 13

• differences in breeds
• inspiration and expiration changes
• movements cause blur

Question 14

What are the limitation of angiography? (3)

Answer 14

• lesions can be underestimating
• general radiographic issues
• large variation in contrast concentration during systole and diastole

Question 15

What is pulse oximetry?

Answer 15

non-invasive way of measuring the amount of oxygen in the blood by measuring haemoglobin saturation

Question 16

What is capnography

Answer 16

The monitoring of PCO2 during anaesthesia

Question 17

What is a blood gas analyser?

Answer 17

A machine that measures pH, PO2, PCO2 and HCO3-

Question 18

What are the limitations of capnography? (2)

Answer 18

• The sampled air contains anaesthetic so must be returned to the circuit
• not as accurate as a blood gas analyser

Question 19

How is a direct arterial blood pressure measurement achieved?

Answer 19

Using a catheter which is inserted into an artery, and the machine plots a graph in real time

Question 20

How is an indirect arterial blood pressure measurement achieved?

Answer 20

Achieved by palpating the peripheral pulse

Question 21

What is a doppler flow probe?

Answer 21

ultrasound waves are reflected off pulsing blood vessels and turned into audible sound

Question 22

What is doppler sphygmomanometry?

Answer 22

Same method as a oscillometric method but uses a crystal to detect blood flow after the uff is released

Question 23

What is the oscillometric method for measuring blood pressure?

Answer 23

A cuff inflates to a higher pressure than the systolic pressure so that flow stops, when slowly the released, the pressure at which the first blood flow is heard is recorded.

Question 24

What piece of equipment can be used to measure central venous pressure?

Answer 24

Manometer

Question 25

How would you prepare and position for a thoracic ultrasound? (5)

Answer 25

• Clip the area
• rub with alcohol
• apply gel
• place in lateral recumbency
• scan both sides

Question 26

Where would you place an ultrasound probe to view the heart?

Answer 26

palpate the apex beat, place in a rib space, look longitudinal and transverse

Question 27

What are the limitations of cardiac ultrsound? (2)

Answer 27

• bone

- distance in large animals

Question 28

What does doppler ultraound show?

Answer 28

Shows the direction of blood flow because a change in frequency occurs when sound is reflected off a moving object. Approaching objects cause a frequency increase and retreating objects show a frequency decrease.

Question 29

What can M-mode on ultrasound show you?

Answer 29

Cardiac movemet

Question 30

What are the two most common ultrasound views of the heart?

Answer 30

• right parasternal short axis

- right parasternal long axis

Question 31

How do you record an ECG in a dog? (4)

Answer 31

• Place in right lateral recumbency
• Spray limbs with alcohol
• Apply gel to areas that the electrodes will be placed
• Apply electrodes to both hind limbs and the right forelimb

Question 32

What clinical information can you obtain from an ECG? (6)

Answer 32

• AVN function
• SAN function
• Tachycardia
• Bradycardia
• Heart rate
• heart rhythm