BCSE Diagnostic Imaging Interpretation 4 — Questions and Answers
Question 1: On a plain radiograph of the hand, which finding is most characteristic of rheumatoid arthritis rather than osteoarthritis?
- Periarticular osteopenia with marginal erosions at the MCP joints (Correct answer)
- Osteophyte formation at DIP joints
- Subchondral sclerosis at weight-bearing surfaces
- Chondrocalcinosis in fibrocartilage
Correct answer: Periarticular osteopenia with marginal erosions at the MCP joints
Rheumatoid arthritis causes periarticular osteopenia and marginal erosions preferentially at the MCPs and PIPs due to synovial pannus formation.
Question 2: A CT scan shows a hypodense area in the right middle cerebral artery territory with loss of the gray-white matter differentiation. This finding is most consistent with:
- Acute ischemic infarct (Correct answer)
- Glioblastoma multiforme
- Multiple sclerosis plaque
- Cerebral abscess
Correct answer: Acute ischemic infarct
Loss of gray-white differentiation in an arterial territory on CT indicates acute ischemic infarction due to cytotoxic edema.
Question 3: On MRI of the spine, which imaging finding is most concerning for spinal cord compression requiring urgent evaluation?
- T2 hyperintensity within the cord at the level of disc herniation with cord edema (Correct answer)
- Modic type 1 endplate changes
- Disc desiccation at multiple levels
- Mild facet joint arthrosis
Correct answer: T2 hyperintensity within the cord at the level of disc herniation with cord edema
Intramedullary T2 hyperintensity indicates myelomalacia or edema from cord compression, signaling a neurological emergency.
Question 4: On a plain abdominal radiograph, which pattern of bowel gas distribution is most consistent with small bowel obstruction?
- Multiple dilated loops of small bowel centrally with a paucity of colonic gas (Correct answer)
- Dilated colon with haustral markings throughout
- Free air under the diaphragm
- Diffuse gasless abdomen
Correct answer: Multiple dilated loops of small bowel centrally with a paucity of colonic gas
Small bowel obstruction produces centrally located dilated loops (>3 cm) with a step-ladder pattern and absent distal colonic gas.
Question 5: On ultrasound, which characteristic of a thyroid nodule most strongly indicates the need for fine-needle aspiration biopsy?
- Microcalcifications within a solid hypoechoic nodule >1 cm (Correct answer)
- A nodule with a peripheral halo and isoechoic texture
- A purely cystic nodule with posterior acoustic enhancement
- Spongiform appearance with small cystic spaces
Correct answer: Microcalcifications within a solid hypoechoic nodule >1 cm
Microcalcifications in a solid hypoechoic nodule >1 cm are high-risk features per ACR TI-RADS and warrant fine-needle aspiration.
Question 6: On echocardiography, an M-mode finding of paradoxical septal motion is most commonly associated with which condition?
- Right bundle branch block or volume overload of the right ventricle (Correct answer)
- Left ventricular hypertrophy
- Mitral stenosis
- Pericardial effusion
Correct answer: Right bundle branch block or volume overload of the right ventricle
Paradoxical septal motion (septal moving anteriorly in systole) occurs with RBBB and right ventricular volume overload conditions like atrial septal defect.
Question 7: On a mammogram, which feature is most associated with malignancy in a breast mass?
- Spiculated margins with architectural distortion (Correct answer)
- Circumscribed smooth margins
- Low density compared to surrounding tissue
- Round shape with a halo sign
Correct answer: Spiculated margins with architectural distortion
Spiculated margins indicate desmoplastic reaction and tethering, hallmarks of invasive breast carcinoma on mammography.
BCSE Diagnostic Imaging Interpretation 4
On a plain radiograph of the hand, which finding is most characteristic of rheumatoid arthritis rather than osteoarthritis?