Biliary Sludge Is Formed by Modification of Hepatic Bile by the Gallbladder Mucosa  Cynthia W. Ko, Scott J. Schulte, Sum P. Lee  Clinical Gastroenterology and Hepatology  Volume 3, Issue 7, Pages 672-678 (July 2005) DOI: 10.1016/S1542-3565(05)00369-1 Copyright © 2005 American Gastroenterological Association Terms and Conditions

Figure 1 Polarizing microscopy of biliary sludge (microlithiasis). This sample was the only hepatic bile sample in this study positive for cholesterol crystals (original magnification, ×200). Figure shows typical birefringent plates of cholesterol crystals clumped together with a center marked by the deposition of pigment (calcium-bilirubin complex). Clinical Gastroenterology and Hepatology 2005 3, 672-678DOI: (10.1016/S1542-3565(05)00369-1) Copyright © 2005 American Gastroenterological Association Terms and Conditions

Figure 2 Relationship between CSI and nucleation time in paired gallbladder bile (○) and hepatic bile samples (•). Note the clear separation of the 2 groups. Gallbladder bile samples have lower CSI but faster nucleation time, with CSI inversely correlated to nucleation time (y = .006x2 − .1062x + 1.5905, r = .7, P < .01). Hepatic bile samples, despite having higher CSI, have longer nucleation time, which are widely scattered, and there is no correlation between the 2 parameters (y = −.0065x2 + .1318x + 1.9885, r = .3, P > .05). One hepatic bile sample (CSI 2.51, nucleation time 4 days, arrow) was conspicuously outside the range of nucleation time of other 21 samples. This sample was positive for microlithiasis when studied with biliary microscopy (Figure 1). Clinical Gastroenterology and Hepatology 2005 3, 672-678DOI: (10.1016/S1542-3565(05)00369-1) Copyright © 2005 American Gastroenterological Association Terms and Conditions