Diagnostic Imaging Techniques Flashcards
7 cards from real VTNE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Diagnostic Imaging Techniques flashcards as text
Which artifact on MRI appears as alternating bright and dark bands and is caused by motion during image acquisition?
Answer: Ghosting (motion artifact)
Ghosting or motion artifact creates ghost images or banding in the phase-encode direction due to periodic motion (e.g., breathing, cardiac pulsation) during the MRI acquisition.
A double-contrast gastrogram is performed by introducing iodinated contrast followed by air. The purpose of the air is to:
Answer: Distend the stomach lumen to coat the mucosal surface with contrast
Air distends the stomach so that the positive contrast agent coats the mucosal folds, allowing mucosal detail and wall lesions (e.g., ulcers, masses) to be seen clearly.
Which radiographic sign indicates free gas in the peritoneal cavity (pneumoperitoneum)?
Answer: Gas opacity between the liver and diaphragm on a standing lateral or DV view
Free peritoneal gas rises to the highest point and is visible as a radiolucent stripe between the liver and diaphragm on a standing lateral or horizontal-beam view.
In ultrasound physics, 'resolution' refers to the ability to distinguish two structures as separate. Which type of resolution is MOST affected by transducer frequency?
Answer: Axial resolution
Axial resolution (along the beam axis) is determined by pulse length and wavelength, both of which improve with higher transducer frequency, allowing finer discrimination along the beam path.
A dog has a suspected portosystemic shunt. Which imaging modality provides the MOST definitive pre-surgical mapping of shunt vasculature?
Answer: CT angiography
CT angiography provides three-dimensional vascular mapping with high spatial resolution, allowing precise identification of shunt location, number, and anatomy critical for surgical planning.
When performing an upper GI series with barium in cats, contrast should reach the colon within approximately:
Answer: 3–5 hours
In cats barium typically reaches the colon within 3–5 hours under normal GI transit; slower transit may indicate obstruction, ileus, or motility disorder.
Which of the following is a contraindication to the use of barium sulfate as a GI contrast agent?
Answer: Suspected esophageal or GI perforation
Barium leaking into the mediastinum or peritoneal cavity causes severe granulomatous inflammation and is potentially fatal; water-soluble contrast is used when perforation is suspected.