What is the diaphragm?
a musculocutaneous partition between the thorax and abdomen
What diaphragmatic structures can you distinctly visualize radiographically?
The right and left crura
The intercrural cleft
Where is the most dependent (lowest) crus usually displaced on lateral radiographs?
Cranial to the "Up" Crus
What factors will influence diaphragmatic position and shape?
What are the most frequent radiographic changes to the diaphragm?
general or focal outline loss of the thoracic diaphragmatic surface
changes in diaphragmatic shape and position
What is the most frequent radiographically observed diaphragmatic disease in the dog and cat?
Hernias (Traumatic and Congenital)
What information can radiographs help discover about a hernia?
location, extent, contents and secondary complications
What are the most consistent radiographic signs of a traumatic diaphragmatic hernia?
Abdominal viscera within the thorax
Displacement of the abdominal or thoracic organs (or both)
Partial or complete loss of the thoracic diaphragmatic surface outline
Asymmetry or altered slope to the diaphragm on a lateral view
The presence of pleural fluid
What are the types of Congenital diaphragmatic hernias?
Peritonealpericardial diaphragmatic hernia
and Diaphragmatic defects
When does a peritonealpericardial diaphragmatic hernia occur?
When abdominal viscera herniates into the pericardial sac through a congenital hiatus formed between the tendinous portion of the diaphragm and the pericardial sac.
When do Hiatal hernias occur?
When a portion of stomach enters thorax through the esophageal hiatus
What are the two types of hiatal hernias?
Sliding (the gastroesophageal junction itself slides through the defect into the thorax)
Paraesophageal (the gastro-esophageal junction remains where it belongs, but part of the stomach is squeezed up into the thorax beside the esophagus)
What is a gastroesophageal intussusception?
When the stomach invaginates through the esophageal hiatus into the caudal esophagus.