“She had a normal CT yesterday. Why another?” I asked the physician.
“That scan was enhanced. Contrast obscures small kidney stones. We need an unenhanced CT to rule out a stone,” he reasoned.
“A small kidney stone is unlikely to explain her pain. There was no hydronephrosis or perinephric stranding. You will advise ‘avoid dehydration.’ This is good advice regardless of the presence of a 2-mm nonobstructing calculus,” I explained.
“We need to know why she has pain. You don’t know that a small stone is not the cause of her pain. You can’t rule that out,” he concluded.
Jha S. Uncertainty and the Diagnostic Leviathan. JAMA Intern Med. 2015;175(7):1085–1086. doi:10.1001/jamainternmed.2015.1103