Choledocholithiasis: Likelihood Ratios

Introduction: Stones in the common bile duct, causing obstruction of bile flow out of the liver. Consequences of this include - besides simply Extrahepatic Biliary Obstruction - Acute Pancreatitis and acute cholangitis.

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Tags: Hepatic Tag this Diagnosis.

Differential Diagnoses include: Extrahepatic Biliary Obstruction

The likelihood ratios of findings for Choledocholithiasis are listed below. See the left navigation bar to change the display.

Pre-Test Probability (Prevalence): %.	Post-Test Probability (Predictive Value): %.	Switch to display mode.
Note that calculating probabilities from more than one** finding is inherently inaccurate because findings are not independent. (For example, using two positive findings that share a common pathogenesis is likely to overestimate the true probability.)

Good Positive Likelihood Ratio
Finding	Result	+LR	-LR
[ + ] Elevated LFTs	+ 0 -	23	0.6
at least 2 of: bilirubin, AP, ALT Study: Br J Surg. 1995 Oct;82(10):1371-3 PMID: 7489169
[ + ] MRCP	+ 0 -	2	0.8
MRCP with >= 5mm slices Differential Diagnosis: Extrahepatic Biliary Obstruction Study: Abdom Imaging. 2008 Jan-Feb;33(1):6-9. PMID: 17874159

Good Positive and Negative Likelihood Ratios
Finding	Result	+LR	-LR
[ + ] Endoscopic Ultrasound	+ 0 -	19.2	0
Differential Diagnosis: Extrahepatic Biliary Obstruction Study: Abdom Imaging. 2008 Jan-Feb;33(1):6-9. PMID: 17874159
[ + ] MRCP	+ 0 -	17.4	0.1
MRCP done with slices <= 3 mm or 3D MRCP Differential Diagnosis: Extrahepatic Biliary Obstruction Study: Abdom Imaging. 2008 Jan-Feb;33(1):6-9. PMID: 17874159
[ + ] Bile Duct Dilatation	+ 0 -	8.1	0.1
internal bile duct diameter on ultrasonography of less than or equal to 5 mm up to age 50 years, increasing by 1 mm per decade, was considered normal Study: Br J Surg. 1995 Oct;82(10):1371-3 PMID: 7489169
[ + ] Bile Duct Dilatation or Any Elevated LFT	+ 0 -	4.4	0.1
bile duct >5mm (+1 / decade over 50); LFTs: bilirubin, ALT, or AP Study: Br J Surg. 1995 Oct;82(10):1371-3 PMID: 7489169