Urinary Obstruction, Calculi and Infection
Evaluate haematuria, colic, obstruction, infection and urothelial disease across the urinary tract.
How to prepare for the current Final FRCR Part A
Build general-radiology breadth, then practise integrating clinical context, anatomy, multimodality findings, technique and management to select the single best answer.
Core concepts
Concept 1
Localise obstruction, define cause and level, and assess renal function, infection, urinoma and surrounding inflammation.
Exam cue: Localise the abnormality and identify the organ, compartment, tissue or vessel before naming a diagnosis.
Concept 2
Choose ultrasound, non-contrast CT, CT urography, fluoroscopy or nuclear renography according to age, pregnancy, haematuria and function.
Exam cue: Use age, clinical setting, tempo and the complete multimodality pattern to rank the most likely explanation.
Concept 3
Recognise an infected obstructed system, forniceal rupture, emphysematous infection and other findings requiring urgent decompression.
Exam cue: Select the examination or intervention that changes management while accounting for contrast, radiation, access and urgency.
Concept 4
Apply normal and variant anatomy, modality technique, image quality and relevant imaging science to urinary obstruction, calculi and infection.
Risk pitfalls and guardrails
Equating collecting-system dilatation with obstruction without functional, temporal and anatomical context.
Guardrail: Do not anchor on one remembered sign; verify age, localisation, distribution, technique, alternatives and management consequence.
Do not choose a merely plausible SBA option before comparing every option with the full clinical and imaging context.
Guardrail: Re-read the command word and compare every option; the task is to select the best available answer, not the first plausible one.
Memory anchors
Renal colic CT
Non-contrast CT detects most calculi and alternative diagnoses; dose should be tailored to patient and question.
Infected obstruction
Obstruction plus sepsis is an emergency requiring prompt drainage, not observation for stone passage.
Haematuria imaging
The pathway depends on age, risk and suspected upper versus lower tract disease; CT urography uses purposeful phases.
Hydronephrosis caveat
Dilatation may persist or be non-obstructive; combine anatomy, ureteric findings, symptoms and functional evidence.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
A patient has severe flank pain. Non-contrast CT shows a 5 mm distal ureteric calculus with upstream hydroureteronephrosis. Why is non-contrast CT appropriate?
A ureteric calculus is not visible on a plain radiograph but is seen on CT. Which composition is classically radiolucent on radiography?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
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