Stone Evaluation (Metabolic Workup & Imaging)
Evaluating a stone former is two separate jobs: the acute one (image and decide if it's an emergency) and the long-term one (the 24-hour urine that tells you why this patient makes stones).
The big picture
Evaluating a stone former is two separate jobs that often get confused. The acute job is to image the stone and decide whether it's an emergency. The long-term job is the metabolic workup — the 24-hour urine that tells you why this patient makes stones, so you can stop the next one. Stones recur relentlessly if you only treat the rock and never ask why it formed.
The framework: acute imaging (non-contrast CT), then risk-stratified metabolic evaluation (basic for everyone, full 24-hour urine for recurrent/high-risk), interpreted alongside stone analysis.
Mechanism pathway
Tap any step to see why it happens.
Diagnostic algorithm
Each step answers one question. Tap to expand.
Board traps
Non-contrast CT is the gold-standard stone imaging; HU predicts composition (low HU → uric acid). US first in pregnancy/children.
A first stone carries ~50% recurrence over 10 years — the reason to do metabolic workup.
Basic workup for everyone; full 24-hour urine for recurrent/high-risk/single-kidney.
Always send the stone for analysis — composition directs prevention.
A high serum calcium → think hyperparathyroidism.