NAVLE Diagnostic Imaging Interpretation Questions and Answers — Questions and Answers
Question 1: A 7-year-old Great Dane presents with acute, non-productive retching, hypersalivation, and a distended, tympanic abdomen. A right lateral abdominal radiograph is taken. Which radiographic finding is most pathognomonic for gastric dilatation-volvulus (GDV)?
- Severe gaseous distention of the entire stomach with a normal pyloric position.
- A soft tissue opacity compartmentalizing the gas-filled stomach, creating a 'double bubble' appearance. (Correct answer)
- Displacement of the small intestines to the right cranial abdomen.
- The presence of gravel or foreign material within the gastric lumen.
Correct answer: A soft tissue opacity compartmentalizing the gas-filled stomach, creating a 'double bubble' appearance.
The classic radiographic sign for GDV on a right lateral view is the compartmentalization of the stomach by a soft tissue band, which is the pylorus folding over the fundus. This creates what is often described as a 'double bubble', 'Smurf hat', or 'Popeye arm' appearance and is pathognomonic for the condition.
Question 2: A 5-year-old Siamese cat is presented for a chronic, intermittent cough and occasional wheezing. Thoracic radiographs are performed. Which of the following radiographic patterns is most consistent with a diagnosis of feline asthma?
- A diffuse, unstructured interstitial pattern with prominent pulmonary veins.
- A patchy alveolar pattern concentrated in the cranioventral lung lobes.
- A prominent bronchial pattern, characterized by 'doughnuts' and 'tramlines', with evidence of lung hyperinflation. (Correct answer)
- Enlarged, tortuous pulmonary arteries and right-sided cardiomegaly.
Correct answer: A prominent bronchial pattern, characterized by 'doughnuts' and 'tramlines', with evidence of lung hyperinflation.
Feline asthma is an inflammatory condition of the lower airways. Radiographically, this manifests as a prominent bronchial pattern due to the accumulation of inflammatory cells around the airways. These thickened bronchial walls are seen as 'doughnuts' (end-on view) and 'tramlines' (long-axis view). Air trapping due to bronchoconstriction can also lead to lung hyperinflation.
Question 3: A 10-year-old Quarter Horse with chronic, bilateral forelimb lameness undergoes a radiographic examination of the feet. Which of the following radiographic findings is most indicative of navicular disease (podotrochleosis)?
- Rotation and sinking of the distal phalanx (P3) within the hoof capsule.
- Enlarged, flask-shaped synovial invaginations ('lollipops') on the distal border of the navicular bone. (Correct answer)
- Smooth, well-defined new bone formation on the extensor process of the distal phalanx.
- Narrowing of the distal interphalangeal joint space with extensive periarticular osteophytes.
Correct answer: Enlarged, flask-shaped synovial invaginations ('lollipops') on the distal border of the navicular bone.
While many radiographic changes can be seen with navicular disease, the presence of more than 6-7 enlarged, flask-shaped or branching synovial invaginations (vascular channels) on the distal border is a classic and significant finding. Other key signs include flexor cortex erosions and medullary sclerosis.
Question 4: Which of the following common canine uroliths is most likely to be radiolucent on survey abdominal radiographs, often requiring contrast cystography or ultrasonography for diagnosis?
- Calcium Oxalate Monohydrate
- Struvite (Magnesium Ammonium Phosphate)
- Silica
- Ammonium Urate (Correct answer)
Correct answer: Ammonium Urate
Ammonium urate and cystine uroliths are typically radiolucent or only faintly radiopaque, making them difficult to see on standard radiographs. In contrast, struvite and calcium oxalate uroliths are mineral-dense and almost always radiopaque.
Question 5: A veterinarian performs an abdominal ultrasound on a dog with acute vomiting and anorexia. Which finding is most specific for a mechanical small intestinal obstruction?
- Peristaltic waves are increased to 6-7 contractions per minute throughout the small intestine.
- The intestinal wall is diffusely thickened with preserved layering.
- A segment of intestine is severely dilated with fluid (>1.6 times the diameter of the aorta) proximal to a distinct transition point. (Correct answer)
- Hyperechoic mesenteric fat is noted surrounding the entire small bowel.
Correct answer: A segment of intestine is severely dilated with fluid (>1.6 times the diameter of the aorta) proximal to a distinct transition point.
The most reliable ultrasonographic sign of a mechanical small intestinal obstruction is segmental dilation of the intestine proximal to the obstruction. A commonly used objective criterion is a small intestinal diameter greater than 1.6 times the diameter of the aorta. Other signs include a visible foreign body, plication, or intussusception.
Question 6: A 9-year-old Miniature Schnauzer presents with vomiting, cranial abdominal pain, and a 'praying' posture. Abdominal radiographs are taken to rule out other causes. Which of the following radiographic signs would be most consistent with acute pancreatitis?
- Generalized loss of serosal detail throughout the entire abdomen.
- Focal loss of serosal detail and increased soft tissue opacity in the right cranial abdomen. (Correct answer)
- Mineralization within the soft tissue opacity of the liver.
- A gas-filled and distended gallbladder (emphysematous cholecystitis).
Correct answer: Focal loss of serosal detail and increased soft tissue opacity in the right cranial abdomen.
The radiographic signs of pancreatitis are often subtle and non-specific, but they reflect the focal inflammation and peritonitis in the area of the pancreas. The most common findings are a focal loss of serosal detail (a 'ground glass' appearance) and a soft tissue mass effect in the right cranial abdomen, which may cause widening of the pyloro-duodenal angle.
NAVLE Diagnostic Imaging Interpretation Questions and Answers
A 7-year-old Great Dane presents with acute, non-productive retching, hypersalivation, and a distended, tympanic abdomen.
A right lateral abdominal radiograph is taken.
Which radiographic finding is most pathognomonic for gastric dilatation-volvulus (GDV)?