Radiographic anatomy of the thorax Flashcards
Why take thoracic radiographs
- Respiratory disease
- Trauma
- Cardiovascular disease (particularly congestive heart failure)
- Staging of neoplasia
Why take multiple views
- 2d image of 3d structure
2. to get accurate representation of structures in thorax - those closer to the plate = larger
When taking radiographic anatomy of thorax what views?
- left lateral
- right lateral
- either ventrodorsal (on back) or dorsoventral
if take radiograph of lungs what position and why
- ventrodorsal as lungs sit dorsally and laterally to heart
what position for heart
- dorsal ventral as heart is ventral to lungs = close to plate
What is an X-ray
short wave electromagnetic radiation
Where is the scapula on a lateral thoracic radiograph?
Around about in line with base of heart
Why does the diaphragm appear solid?
D overlying liver and GI that is behind it
Lateral thoracic radiograph with letter R means
Right lateral recumbancy
If right lateral recumbency which lung is better represented?
Left as full of air, right is collapsed even if closer to plate
What are we seeing when we look at the heart
cardiac silhouette - pericardium and heart
when do you knwo if enlarged cardiac silhouette and what does it indicate
- 2/3rds of depth of thorax
- 3 rib spaces
- Trachea not parallel to sternum but pushed up
- fluid in pericardium
black tube
black = air = trachea
what si the large greyish tube that looks like it is leaving the CS and going towards Diaphragm
Caudal vena cava
On right lateral recumbancy what positioning is the heart in?
- Cranial vena cava = horizontally into base (harder to see)
- Caudal VC = horizontally, in line with cranial VC, out of heart towards diaphragm
- Aorta = structure at top curving up and back towards caudal thoracic vertebrae
- LHS of heart is towards right
- Left ventricle = bottom and closest to diaphragm
- Left auricle above LV
- bottom LHS = RV, directly above = feeds into pulmonary trunk
- Right auricle = just below start of aorta, most base of heart
What is the positioning of the heart on a DV/VD
Think of it as a clock face
- Cranial and caudal VC = branches coming out of top and bottom (slightly to side)
- 12/1 o’clock = aorta arch
- 1/2 o’clock = pulmonary artery
- 3 o’clock = left auricle
- 4 and 5 o’clock = LV
- 6-8 o’clock = RV
- 9-10 o’clock = Right auricle
What are right/left auricles/ appendages?
right = attached to the heart's right atrium. It's a small, cone-shaped pouch which comes out from the upper and front part of the atrium and overlaps the root of the aorta left = small, muscular pouch at the upper corner of the left atrium. It collects oxygenated blood as it leaves the lungs and moves the blood into the left ventricle
What do you see with left atrial enlargement?
The trachea looks like its jumping over something at the end
What would grey lungs indicate
fluid build up: pulmonary oedema
What about the lungs on a radiograph
Shouldn’t be able to distinguish the lobes- if can see = something abnormal = air (black) or fluid (grey)
1. bright outline = fluid in pleural cavity = pleural effusion = can’t inflate lungs
What are the lobes of the lung
RHS: 1. cranial, middle, caudal, accessory LHS: 1. cranial (subdivided into cranial and caudal) 2. Caudal
What is one way to identify if LHS or RHS on dorsal ventral/ VD?
- media stinum joins diaphragm slightly left of midline
- apex of heart, slightly left
- caudal vena cava on RHS to diaphragm
Where should the apex of the heart be
- touching sternum
2. close to diaphragm
sharp heart outline indicates what
pericardium effusion = free fluid in peri = need to ultrasound
