Radiography 2 Flashcards
At what point of repsiration should a radiograph be taken? Why?
Maximum inspiration
During lateral caudodorsal lung reaches T12
During DV/VD Cupula of diaphragm reaches T8-T10
How are lateral radiographic views named?
Based on which side is recumbent
How are dorsoventral & ventrodorsal views named?
The point of entry to the point of exit of the beam
What is the minimal number of radiographic views?
2 orthogonal views are required
Describe characteristics of right lateral views
Cardiac silhouette is egg shaped
Diaphragmatic crura are parallel
Right crus of diaphragm is more cranial
Better for visualizing left lung lobes
Describe characteristics of left lateral views
Cardiac silhouette is round
Diaphragmatic crura diverge
Left crus is more cranial
Better for visualizing right lung lobes
Why is the opposing lateral better for visualizing a lung lobe?
Dependent (down) lung is compressed (atelectasis) and non-dependent (up) lung is more aerated
Better aeration makes better contrast
Describe characteristics of the dorsoventral view
Cardiac silhouette is round
Diaphragm has one dome (cupula)
Better view to see caudal lobar vessels
Describe characteristics of ventrodorsal view
Heart flops & looks elongated
Diaphragm has 2 - 3 lobes (cupula & crura)
What is the standard protocol for positioning during radiographs?
Head on left during lateral views
Left side on the right during VD/DV views
How to interpret film
Review extrathoracic structures first
- Soft tissues, bones, abdomen
Review thoracic wall Diaphragm Pleural space Mediastinum - Trachea, esophagus, lymph nodes, cranial vena cava Heart and vessels - cardiac silhouette, lobar/pulmonary vessels Lungs
Name the extrathoracic structures to review first
Cervical/thoracic soft tissues
Vertebral bodies
Ribs
Sternum
Long bones of thoracic limbs
Shoulders/Scapulae
Elbows
What are the characteristics of the diaphragm should be checked on radiographs?
Cupula, three thin muscular portions, three openings (aortic, esophageal, caudal vena cava)
What are interlobar fissures?
Very faint, thin lines that signals areas where lung lobes are in contact with each other
What may signify pleural fluid in pleural space?
More prevalent interlobar fissures
Describe the boundaries of the mediastinum
Midline of the thorax
Thoracic inlet to diaphragm
Communicates with fascial planes of neck cranially
Communicates with retroperitoneal space caudally
What structures are visible in the cranial medastinum?
Trachea
Esophagus
Major vessels)
Thymus
What structures are visible in the middle mediastinum?
Cardiac silhouette
Aortic arch
Esophagus
Terminal trachea
What structure is most visible in cranial mediastinum?
Trachea, thymus in young animals
What structure is most visible in middle mediastinum
Cardiac silhouette
Aortic arch
Tracheal bifurcation
What structures are present in the caudal mediastinum?
Caudal vena cava
Descending aorta
Esophagus
What structures are the most visible in the caudal mediastinum?
Descending aorta
Caudal vena cava
Esophagus is occasionally seen
Where is the mediastinal reflection seen?
Craniolateral and caudal portion of thorax
Are lymph nodes visible in radiograph/
Not in healthy animals but may be visible in diseased animals
What does the thoracic radiograph look like in a dog with intermediate chest projection? (Lab, Goldie)
Lateral projection: Base of heart is angled craniodorsally Heart takes up 3 intercostal spaces Heart is 2/3 the height of dorsoventral thorax Trachea deviates from spine
Ventrodorsal projection: More elongated and apex flops to left
What does the thoracic radiograph look like in a dog with deep chest projection? (Doberman, collie)
Lateral projection: Upright orientation of heart (perpendicular to spine) Heart is 2/3 DV height of thorax Heart takes up 2.5 intercostal spaces Trachea deviates from spine
Ventrodorsal:
Circular/ovoid (very circular in DV) heart with apex slightly to the left
What does the thoracic radiograph look like in a dog with barrel chest projection? (english bulldog)
Lateral projection: Short, round heart 2/3 or greater DV height 3 to 3.5 intercostal spaces Increased sternal contact Little tracheal deviation
Ventrodorsal projection:
Short distance from thoracic inlet to cupula
Apex of heart shifted left
What does the thoracic radiograph look like in a cat?
Lateral projection: Oval shaped heart 2 to 2.5 intercostal spaces 2/3 DV height Trachea deviates from spine
Ventrodorsal projection:
Apex leans slightly left of the midline
What are age related changes in the feline heart?
Cardiac silhouette becomes more horizontal
Aortic arch becomes prominent and can become tortuous
What can be seen on the cranial border of the heart in a lateral projection?
Top to bottom: Ascending aortic arch Right auricle Main pulmonary artery Right ventricle
What can be see on the caudal border of the heart in a lateral projection?
Left atrium
Left ventricle
What cardiac structure is located between 12:00 and 2:00 on a lateral projection?
Left atrium
What cardiac structure is located between 2:00 - 5:00 on a lateral projection?
Left ventricle
What cardiac structure is located between 5:00 - 9:00 on a lateral projection?
Right ventricle
What cardiac structure is located between 9:00 - 11:00 on a lateral projection?
Main pulmonary artery
Right auricle
Aortic arch
Define the cardiac structure in a VD/DV view using the clockface analogy
11: 00 - 1:00: Aortic arch
1: 00 - 2:00: Main pulmonary artery
2: 00 - 3:00: Left Auricle
3: 00 - 5:00: Left ventricle
5: 00 - 9:00: Right ventricle
9: 00 - 11:00: Right atrium
Is it possible to see the left atrium in a DV/VD view?
No, it is located between the mainstem bronchi and superimposed with the left ventricle
Use the clock analogy to describe the feline heart radiograph
2:00 - 3:00: Left atrium, left auricle
Where are the pulmonary arteries, bronchi, and veins positioned on a lateral radiograph (compared to 4th rib)?
Arteries (up & away) are positioned most dorsally
Bronchi are located below arteries and above veins
Veins are located ventrally (ventral & central)
Where are pulmonary arteries, bronchi and veins located on a DV/VD radiograph (compared to 9th rib)?
Arteries are most cranial (up & away)
Bronchi are located beneath arteries
Veins are located caudally (ventral & central)
Is it possible to see any of the left lung on a left lateral?
Yes, the cranial portion of the cranial lobe sticks out past the cranial right lobe a bit
