FRCR MCQ 2 — Questions and Answers
Question 1: On a chest X-ray, which of the following is a typical feature of left lower lobe collapse?
- Elevation of the left hemidiaphragm with a triangular opacity behind the heart (Correct answer)
- Tracheal deviation to the right
- Horizontal fissure displacement downward
- Hyperinflation of the left lung
Correct answer: Elevation of the left hemidiaphragm with a triangular opacity behind the heart
Left lower lobe collapse produces a triangular retrocardiac opacity and elevation of the left hemidiaphragm, with mediastinal shift to the left.
Question 2: Which MRI sequence is most sensitive for detecting acute subarachnoid hemorrhage within the first 24 hours?
- T2-weighted FLAIR
- T1-weighted post-contrast
- DWI with ADC map
- Gradient echo (T2*) (Correct answer)
Correct answer: Gradient echo (T2*)
Gradient echo (T2*) sequences detect blood products by exploiting susceptibility effects, making them most sensitive for acute SAH, particularly small amounts.
Question 3: A patient undergoes CT urography showing a filling defect in the right renal pelvis. Which diagnosis must be excluded first?
- Urothelial carcinoma (Correct answer)
- Renal calculus
- Blood clot
- Fungal ball
Correct answer: Urothelial carcinoma
Urothelial carcinoma of the renal pelvis is the most important diagnosis to exclude, as it requires prompt surgical management and carries significant morbidity.
Question 4: Which of the following best describes the radiological appearance of pulmonary alveolar proteinosis on HRCT?
- Crazy-paving pattern with ground-glass opacification and interlobular septal thickening (Correct answer)
- Bilateral lower lobe reticular pattern with honeycombing
- Centriacinar nodules with tree-in-bud pattern
- Multiple bilateral cavitating nodules
Correct answer: Crazy-paving pattern with ground-glass opacification and interlobular septal thickening
Pulmonary alveolar proteinosis classically shows the 'crazy-paving' pattern on HRCT, representing geographic ground-glass opacities overlaid by interlobular septal thickening.
Question 5: On ultrasound, which feature is most useful in distinguishing a simple from a complex renal cyst?
- Internal echoes, septations, or wall irregularity (Correct answer)
- Size greater than 3 cm
- Posterior acoustic enhancement
- Anechoic appearance
Correct answer: Internal echoes, septations, or wall irregularity
Internal echoes, thick septations, nodularity, or irregular walls indicate complexity and warrant further evaluation with CT for possible malignancy (Bosniak classification).
Question 6: A barium swallow shows a posterior indentation at the level of T4 causing dysphagia in an elderly man. What is the most likely diagnosis?
- Aberrant right subclavian artery (dysphagia lusoria) (Correct answer)
- Oesophageal carcinoma
- Pharyngeal pouch
- Achalasia
Correct answer: Aberrant right subclavian artery (dysphagia lusoria)
An aberrant right subclavian artery (arteria lusoria) passes posterior to the oesophagus, causing a characteristic posterior oblique filling defect at T4, known as dysphagia lusoria.
Question 7: Which bone tumour most commonly undergoes malignant transformation in Paget's disease?
- Osteosarcoma (Correct answer)
- Chondrosarcoma
- Fibrosarcoma
- Giant cell tumour
Correct answer: Osteosarcoma
Osteosarcoma is the most common malignant transformation in Paget's disease, occurring in approximately 1% of patients and carrying a very poor prognosis.
FRCR MCQ 2
On a chest X-ray, which of the following is a typical feature of left lower lobe collapse?