FRCR FRCR Pediatric Radiology 2 — Questions and Answers
Question 1: The 'sail sign' on pediatric chest radiograph most commonly represents:
- Normal thymus (Correct answer)
- Anterior pneumomediastinum
- Pericardial effusion
- Mediastinal mass
Correct answer: Normal thymus
The sail sign is the triangular right-sided thymic shadow that can mimic a right upper lobe opacity or mediastinal mass in infants and young children.
Question 2: In pediatric head trauma, which imaging finding on CT is most suggestive of non-accidental injury (NAI)?
- Bilateral subdural hematomas of different ages (Correct answer)
- Isolated epidural hematoma
- Single parietal skull fracture
- Solitary subarachnoid hemorrhage
Correct answer: Bilateral subdural hematomas of different ages
Bilateral subdural hematomas at different stages of evolution (mixed density), especially with retinal hemorrhages, are highly suspicious for non-accidental injury in infants.
Question 3: Hirschsprung disease is definitively diagnosed by:
- Rectal suction biopsy showing absence of ganglion cells (Correct answer)
- Contrast enema alone
- Anorectal manometry
- Abdominal ultrasound
Correct answer: Rectal suction biopsy showing absence of ganglion cells
The gold standard for Hirschsprung disease diagnosis is rectal suction biopsy demonstrating the absence of submucosal ganglion cells and hypertrophied acetylcholinesterase-positive nerve fibers.
Question 4: Which condition causes the 'corkscrew' appearance of the duodenum and small bowel on upper GI series in neonates?
- Midgut volvulus (Correct answer)
- Duodenal web
- Jejunal atresia
- Meconium ileus
Correct answer: Midgut volvulus
Midgut volvulus, a complication of intestinal malrotation, causes the duodenum and proximal jejunum to spiral around the superior mesenteric artery, producing the corkscrew or 'Z' configuration.
Question 5: Osteogenesis imperfecta on skeletal survey is characterized by:
- Multiple fractures of varying ages with osteopenia and wormian bones (Correct answer)
- Dense metaphyseal bands
- Cortical thickening
- Wide growth plates
Correct answer: Multiple fractures of varying ages with osteopenia and wormian bones
OI shows diffuse osteopenia, multiple fractures at various stages of healing, wormian bones in the skull, and blue sclerae, distinguishing it from NAI.
Question 6: The most appropriate initial imaging for a child with suspected pyloric stenosis is:
- Ultrasound (Correct answer)
- Upper GI contrast study
- Plain abdominal radiograph
- CT abdomen
Correct answer: Ultrasound
Ultrasound is the first-line investigation for pyloric stenosis, demonstrating hypertrophied pyloric muscle with length >17 mm and thickness >3–4 mm.
FRCR FRCR Pediatric Radiology 2
The 'sail sign' on pediatric chest radiograph most commonly represents: