Cardiac Radiography Flashcards
(50 cards)
What are the indiciation for thoracic radiography? (3)
–Identification, location and quantification of lesions producing respiratory signs (coughing) (typically dyspnoea/cough)
–Identification of lesions too small to produce clinical signs
•E.g. Looking for metastasis
–Assess effectiveness once we have started a treatment
What does radiography NOT identify?
CAUSE of heart disease
What type of heart failure is radiography good for? How do you know it is this?
Left heart failure
Evidence of cardiac enlargement?
Identify fluid in the lungs or pleural space
Why might it be hard to generate radiographs of diagnostic quality? (5)
–Movement blur (respiratory)
–Wide radiographic contrast
–Interpretation! (New grads- malcolm doesn’t agree..)
–Breed normals/age normals
–Inspiratory/expiratory
How can we minimise movement blur? (3)
- Careful handling
- Sedation/GA
–Dyspnoeic cat may just sit there
•Reduce exposure time
Wha positions may we do for radiography? What are they good to show?
•Lateral - right (left) - heart
–BOTH LATERALS – LUNG METASTASES
–Whetehr left or right laterally will depend on the x ray machine
- Dorsoventral - heart
- Ventrodorsal - lungs
- Only time we put it on the back is a chronic cough and signs are stable! Never put a resp difficulty case on their back
Why do we no longer use the following positions?
- Standing lateral
- Standing erect
- Recumbent VD with horizontal beam
Danger of the xray beam
What can obscure the thorax in lateral view?
Triceps
Where do we centre and collimate for lateral x ray?
Centre – cd scapula
Include small amount cr abdo
Thoracic inlet cr
What is the risk during interpretation if there is rotation?
Do not want to over-interpret
Where do we centre for a DV?
Caudal border of scapula
When would you do a VD view?
ONLY – chronic cough as you can get a good inspiratory bag by using breathing bag
As you want to see any evidence of airway making
What should we assess in the technical quality of a radiograph? (7)
- Pink camels collect extra large apples on inspiration!
- Positioning
- Centring
- Collimation
- Exposure
- Labelling
- Artefacts
- Inspiratory or expiratory? (hard to get fully inspiratory unless Ga and would need to interpret the film. No inspiratory – look more white (radiopaque)
What are some common artefacts to watch out for? (5)
- Skin folds
- Nipples
- Cartilage mineralisation
- Size and shape of cardiac silhouette
- “Collapse” of dependent lung - do DV first!
Which X ray do we do first? Why?
Do DV first!
Lateral first means the one lung collapses slightly
This I the same dog – l (lateral first an lung collapsed) and right is lateral second.
If you take lateral first give a couple of breaths first
What does it mean to Assess “not the heart and lungs”.?
Peripheral soft tissue structures.
Anterior abdominal contents.
Thoracic skeleton.
Cranial mediastinum.
Caudal mediastinum.
Diaphragm.
Pleural space.
Then lungs – cardiac silhouette and then vessels
What is the normal cardiac silhouette? Both for lateral and DV?
Rules of thumb for lateral (3.5 rib spaces max)
Rules of thumb for DV (2/3 of width of thorax at rib 6 max)
How can you assess heart size?
Draw a line from trachea bifurcation to heart apex
Normally – 4 chambers should be distributed
DV – draw the line apex to base
If you have a 8 yo grade 4 systolic murmur no other signs CKCS
What do you look for?
Let side enlaargment
What is the normal height of the heart in lateral?
5th rib - 2/3 heart of thorax
What is the difference in deep vs narrow chest breeds with the heart silohouette?
Deep chest Narrow more upright chest
Narrow chest – chunkier, rounded cardiac silhouette
On a DV image - where is the aniaml LHS on the image?
RHS
If you have a Bulge 1-2 Enlarged RHS. Loud systolic murmur at heart base. What would you suspect?
Pulmonary stenosis?
Looking at a DV heart what is at the ollowing times on a clock face:
- 12-1?
- 1-2?
- 2-4?
- 3-5?
- 5-9?
- 8-11?
- Aorta
- PA
- LA
- LV
- RV
- RA
