BCSE Diagnostic Imaging Interpretation 2 — Questions and Answers
Question 1: On a chest X-ray, a 'silhouette sign' is created when two structures of similar density are adjacent. Which finding indicates right middle lobe consolidation?
- Loss of the right heart border (Correct answer)
- Loss of the left heart border
- Loss of the aortic knob
- Blunting of the right costophrenic angle
Correct answer: Loss of the right heart border
The right middle lobe is adjacent to the right heart border, so consolidation there obliterates that border on PA chest X-ray.
Question 2: On CT of the abdomen, which finding is most characteristic of acute appendicitis?
- Appendiceal diameter >6 mm with periappendiceal fat stranding (Correct answer)
- Free air under the diaphragm
- Thickening of the terminal ileum
- Calcification within the appendix lumen
Correct answer: Appendiceal diameter >6 mm with periappendiceal fat stranding
An appendiceal diameter greater than 6 mm combined with periappendiceal fat stranding indicates acute appendicitis on CT.
Question 3: A lateral skull X-ray shows a biconvex (lenticular) hyperdense collection. What is the most likely diagnosis on CT head?
- Epidural hematoma (Correct answer)
- Subdural hematoma
- Subarachnoid hemorrhage
- Contusion
Correct answer: Epidural hematoma
Epidural hematomas appear as biconvex hyperdense collections because blood accumulates between the dura and inner table of the skull.
Question 4: Which MRI sequence is most sensitive for detecting acute ischemic stroke within the first few hours?
- Diffusion-weighted imaging (DWI) (Correct answer)
- T1-weighted imaging
- T2-weighted imaging
- FLAIR
Correct answer: Diffusion-weighted imaging (DWI)
DWI detects restricted diffusion within minutes of ischemic stroke onset, far earlier than T2 or FLAIR sequences.
Question 5: On an abdominal X-ray, 'thumbprinting' of the colon wall is most associated with which condition?
- Ischemic colitis (Correct answer)
- Irritable bowel syndrome
- Colon polyps
- Diverticulosis
Correct answer: Ischemic colitis
Thumbprinting represents submucosal edema and hemorrhage causing nodular indentations of the bowel wall, classic for ischemic colitis.
Question 6: Which ultrasound finding is most consistent with acute cholecystitis rather than chronic cholecystitis?
- Positive sonographic Murphy's sign with gallstones and gallbladder wall thickening >3 mm (Correct answer)
- Gallstones alone without wall thickening
- Gallbladder polyps <5 mm
- Echogenic bile sludge without tenderness
Correct answer: Positive sonographic Murphy's sign with gallstones and gallbladder wall thickening >3 mm
Acute cholecystitis is indicated by the combination of sonographic Murphy's sign, gallstones, and wall thickening over 3 mm.
Question 7: On a chest X-ray, Kerley B lines appear as short horizontal lines at the lung periphery and indicate which underlying process?
- Pulmonary interstitial edema causing lymphatic distension (Correct answer)
- Pulmonary embolism
- Pleural effusion
- Pneumothorax
Correct answer: Pulmonary interstitial edema causing lymphatic distension
Kerley B lines represent edema in the interlobular septa due to elevated pulmonary venous pressure, characteristic of interstitial pulmonary edema.
BCSE Diagnostic Imaging Interpretation 2
On a chest X-ray, a 'silhouette sign' is created when two structures of similar density are adjacent.
Which finding indicates right middle lobe consolidation?