Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

Chapter Two The Thorax 81
Fig. 2-54 A 5-year-old male Yorkshire
Terrier was evaluated for an acute onset of
dyspnea. Right parasternal short-axis
views reveal the presence of liver (l) adjacent
to the heart (h). The diaphragm is
not visible. Diagnosis: Diaphragmatic
hernia.
detectable. In cats with congenital PDH, the presence of a dorsal peritoneopericardial
mesothelial remnant (a distinct curvilinear soft-tissue opacity between the cardiac silhouette
and diaphragm) is highly indicative of the diagnosis (Fig. 2-57). 104 Sonographically, PDH is
recognized by the presence of abdominal viscera within the pericardial sac (Fig. 2-58). This
condition is discussed more completely in the section on cardiac abnormalities.
G A S T R O E S O P H AG E A L I N T U S S U S C E P T I O N
Gastroesophageal intussusception is the invagination of the stomach into the caudal thoracic
esophagus. Radiographically, the caudal esophagus will appear to be fluid filled and
enlarged, and the stomach may not be identifiable within the abdomen. If the esophagus
cranial to the intussusception is dilated with gas, the rugal folds of the stomach may be
identifiable. An esophagram may be needed to confirm the diagnosis radiographically. 110-
113 Sonographically, a transesophageal study may reveal the tissue density extending cranially
and the rugal folds may be apparent.
H Y P E RT R O P H I C M U S C U L A R D Y S T R O P H Y
Thickening and irregularity of the diaphragmatic contour, megaesophagus, and cardiomegaly
have been described in dogs and cats with hypertrophic muscular dystrophy. 114 Decreased
liver echogenicity; peritoneal fluid; hepatic, splenic, and renal enlargement; increased renal
cortical echogenicity; and adrenal mineralization may be demonstrated on ultrasonographic