small animal thoracic Flashcards
kVp for thoracic
high kVp (80-120kVp)
*because largest, thickest part=thorax
mA for thorax
lower mA (1-5mAs)
exposure time (s) for thorax
lower to reduce motion blur from respiration
Standard radiographs for thorax
-Right and left lateral
-VD and DV
**at least 2 orthogonal views but all 4 best
right and left lateral views
-thoracic limbs pulled cranially; laying on side
-head to left side of table
-Field of view= cranial to thoracic inlet to a few cm caudal to the last rib
Why do you extend further down to the abdomen in a thoracic radiograph?
need to extend a bit into the abdomen because the lungs extend further towards the diaphragm
Radiographic markers
Used to indicate the recumbency or which side is down (in contact with the table)
How to distinguish R lateral from L lateral?
Right lateral
=dorsal crura of diaphragm is parallel
=heart slightly more elongated, not elevated from the sternum
How to distinguish L lateral from R lateral?
=dorsal crura of diaphragm deviates from each other (Y shaped)
= heart slightly more round and elevated from the sternum
VD view
-dorsal recumbency
-thoracic limbs pulled cranially
-Field of view: just cranial to the thoracic inlet to a few cm caudal to the last rib
DV view
-animal in sternal recumbency
-thoracic limbs pulled cranially
Radiographic markers on VD vs DV
Right side should always be on our left
Distinguishing VD from DV
-in DV= diaphragm cranially displaced, cardiac apex shifted to left, cardiac silhouette more rounded, caudal lobar vessels are more conspicuous
When should thoracic radiographs be taken?
Peak of inspiration
Lungs
-6 lung lobes
Left = cranial cranial, cranial caudal, caudal
Right= cranial, middle, caudal, accessory
What view is best used to identify lung lobe diseases?
The opposite view than the side where disease is present
eg. Right lung lobe disease best ID’d in left lateral view
Heart size in dogs vs cats
Dogs:
- Should be between 2.5 to 3.5 intercostal spaces
-Vertebral heart score (VHS)= between 8.7-10.7 (mean 9.7) but varies depending on breed
Cats:
-should be between 2-2.5 intercostal spaces
-VHS= mean of 7.8 (between 7-8)
Heart width in dogs and cats
Cardiac width should be less than 2/3rds of the chest width
Location of the cardiac chambers
Aorta
Caudal vena cava
Normal diameters of the caudal vena cava
-less than 1.5x the aorta
-less than length of T5 or T6
Pulmonary veins in lateral
-left lateral view is best to see them
-arteries should be approx the same diameter as veins
-both should be less than the diameter of the 4th proximal ribs
Pulmonary vessels
Pulmonary vessels in DV vs VD
-best view in DV
-arteries should be approx the same diameter as veins
-both= diameter of the 9th rib
pulmonary vessles
