Gallstones
Updates to Article Attributes
Gallstones, also called cholelithiasis,are concretions that may occur anywhere within the biliary system, most commonly within the gallbladder.
Terminology
Gallstones (cholelithiasis) describe stone formation at any point along the biliary tree. Specific names can be given to gallstones depending on their location:
-
cholecystolithiasis: gallstones within the gallbladder
the terms cholelithiasis or gallstones have been largely used in clinical practice by their own to refer to stones in the gallbladder
choledocholithiasis: gallstones within the bile ducts
Biliary microlithiasis refers to gallstones <3 mm in diameter. The term biliary microlithiasis is occasionally used as a synonym for sludge, however, this is not strictly correct. Sludge may include these microliths in its composition, but these are only one element of a variable mixture of crystals, proteinaceous debris, lysed cells and mucin 12.
Epidemiology
Gallstones occur in ~10% of the population with a predominance in women (F: M = 2:1). The prevalence increases with age in both sexes 3.
Genetics may have an important role in gallstone formation. Several studies have shown an association between age-adjusted prevalence of gallstone, ethnicity 4 and family history of gallstones:
highest age-adjusted prevalence (~50%): Pima Indians, some North and South American Indians
intermediate age-adjusted prevalence (up to 20%): Caucasians (20%), and Asian population (5-20%)
lowest age-adjusted prevalence (≤5%): Africans
Risk factors
Cholesterol gallstones
female sex
middle age
obesity
positive family history
recent rapid weight loss
Also see 5-F rule.
Pigment gallstones
-
black pigment stones
chronic haemolysis (e.g. sickle cell disease)
intestinal malabsorption (e.g. Crohn disease)
-
brown pigment stones
-
infection
bacterial
parasitic (e.g. Clonorchis sinensis)
-
Clinical presentation
Gallstones may be symptomatic in only 25% of cases. The most common presentation is with biliary colic (right upper quadrant or epigastric abdominal pain or discomfort, especially after a fat-rich meal). Other symptoms include belching, bloating, flatulence, heartburn, and nausea.
Abdominal pain is often referred to the right shoulder. Patients may demonstrate this radiation to the tip of the scapula by placing their hand behind the back and thumb pointing upwards: "Collins sign". This may be useful in distinguishing gallstone pain from oesophagitis, gastritis, or duodenal ulcer in ~50% of patients 5.
Pathology
There are three types of gallstones 3,4,7-10:
-
cholesterol (10%)
>50% cholesterol contents; form with supersaturation of bile, nucleation and stone growth
-
predisposing factors
diet, sedentary lifestyle, the rapid loss of weight, obesity, oral contraceptive pill, total parenteral nutrition (TPN)
ethnicity, genetic predisposition, older age, female sex
-
mixed (80%)
20-50% cholesterol content
predisposing factor: similar to cholesterol stones
-
pigment stones (10%)
<20% cholesterol content; high bilirubin content and occur when there is supersaturation of unconjugated bilirubin
-
two subtypes each with their own predisposing factors:
black pigment stones: chronic haemolysis, cirrhosis, intestinal malabsorption
brown pigment stones: infections (bacterial/parasitic) and biliary stasis
Complications
cholecystoduodenal fistula leading to a gallstone ileus or Bouveret syndrome
increased risk of cholangiocarcinoma
Radiographic features
Plain radiograph
Some radiopaque gallstones may be seen on plain film:
gallstones are radiopaque only in 15-20% of cases 3
may be laminated (a.k.a. lamellated): radiopaque outline with lucent centre
may have a faceted outline
may show a Mercedes-Benz sign: triradiate pattern of gas lucency
Ultrasound
Ultrasound is considered the gold standard for detecting gallstones 6:
-
greyscale ultrasound
highly reflective echogenic focus within gallbladder lumen, normally with prominent posterior acoustic shadowing regardless of pathological type (acoustic shadowing is independent of the composition and calcium content) 11
gravity
-dependant-dependent movement is often seen with a change of patient position (the rolling stone sign)
-
colour Doppler
may demonstrate a twinkling artifact and is particularly useful for identification of small stones
CT
Calcified gallbladder stones are hyperattenuating to bile, making them the only type to be clearly visualised on CT scan images. On CT, a high percentage of cholesterol stones are hypoattenuating relative to bile 15, and other gallstones are isodense to bile and these may not be clearly identified on CT.
MRI
-
T1-weighted 3D fast spoiled gradient echo (3D FSPGR):
pigmented stones (hyperintense) 14
cholesterol stones (hypointense) 14
T2: signal void or low signal outlined by markedly hyperintense bile within the gallbladder
MRCP: focus of signal void inside the gallbladder
Differential diagnosis
Possible imaging differential considerations in selected situations include
ingested iron tablets (pseudogallstones) on plain radiograph 13
echogenic bile (sludge) and tumefactive sludge: non-shadowing
pneumobilia on MRCP
Practical points
-
gallstone acoustic shadowing is prominent with
larger size stones (usually >3 mm for shadowing)
higher transducer frequency
focal zone at the level of gallstone
a gallbladder full of stones may paradoxically be hard to visualise (wall-echo-shadow sign)
-<a href="/articles/gallstones-1">cholecystolithiasis</a>: gallstones within the gallbladder<ul><li>the terms cholelithiasis or gallstones have been largely used in clinical practice by their own to refer to stones in the gallbladder </li></ul>- +<p><a href="/articles/gallstones-1">cholecystolithiasis</a>: gallstones within the gallbladder</p>
- +<ul><li><p>the terms cholelithiasis or gallstones have been largely used in clinical practice by their own to refer to stones in the gallbladder </p></li></ul>
-<li>-<a href="/articles/choledocholithiasis">choledocholithiasis</a>: gallstones within the bile ducts</li>- +<li><p><a href="/articles/choledocholithiasis">choledocholithiasis</a>: gallstones within the bile ducts</p></li>
-<li>highest age-adjusted prevalence (~50%): Pima Indians, some North and South American Indians</li>-<li>intermediate age-adjusted prevalence (up to 20%): Caucasians (20%), and Asian population (5-20%)</li>-<li>lowest age-adjusted prevalence (≤5%): Africans</li>- +<li><p>highest age-adjusted prevalence (~50%): Pima Indians, some North and South American Indians</p></li>
- +<li><p>intermediate age-adjusted prevalence (up to 20%): Caucasians (20%), and Asian population (5-20%)</p></li>
- +<li><p>lowest age-adjusted prevalence (≤5%): Africans</p></li>
-<li>female sex</li>-<li>middle age</li>-<li>obesity</li>-<li>positive family history</li>-<li>recent rapid weight loss</li>- +<li><p>female sex</p></li>
- +<li><p>middle age</p></li>
- +<li><p>obesity</p></li>
- +<li><p>positive family history</p></li>
- +<li><p>recent rapid weight loss</p></li>
-<li>black pigment stones<ul>-<li>chronic haemolysis (e.g. <a href="/articles/sickle-cell-disease">sickle cell disease</a>)</li>-<li><a href="/articles/cirrhosis">liver cirrhosis</a></li>-<li>intestinal malabsorption (e.g. <a href="/articles/crohn-disease-1">Crohn disease</a>)</li>- +<li>
- +<p>black pigment stones</p>
- +<ul>
- +<li><p>chronic haemolysis (e.g. <a href="/articles/sickle-cell-disease">sickle cell disease</a>)</p></li>
- +<li><p><a href="/articles/cirrhosis">liver cirrhosis</a></p></li>
- +<li><p>intestinal malabsorption (e.g. <a href="/articles/crohn-disease-1">Crohn disease</a>)</p></li>
-<li>brown pigment stones<ul>-<li>infection<ul>-<li>bacterial</li>-<li>parasitic (e.g. <a href="/articles/clonorchis-sinensis"><em>Clonorchis sinensis</em></a>)</li>- +<li>
- +<p>brown pigment stones</p>
- +<ul>
- +<li>
- +<p>infection</p>
- +<ul>
- +<li><p>bacterial</p></li>
- +<li><p>parasitic (e.g. <a href="/articles/clonorchis-sinensis"><em>Clonorchis sinensis</em></a>)</p></li>
-<li><a title="biliary stasis" href="/articles/biliary-stasis">biliary stasis</a></li>- +<li><p><a href="/articles/biliary-stasis" title="biliary stasis">biliary stasis</a></p></li>
-<strong>cholesterol </strong>(10%)<ul>-<li>>50% cholesterol contents; form with supersaturation of bile, nucleation and stone growth</li>-<li>predisposing factors<ul>-<li>diet, sedentary lifestyle, the rapid loss of weight, <a href="/articles/obesity">obesity</a>, oral contraceptive pill, total parenteral nutrition (TPN)</li>-<li>ethnicity, genetic predisposition, older age, female sex</li>- +<p><strong>cholesterol </strong>(10%)</p>
- +<ul>
- +<li><p>>50% cholesterol contents; form with supersaturation of bile, nucleation and stone growth</p></li>
- +<li>
- +<p>predisposing factors</p>
- +<ul>
- +<li><p>diet, sedentary lifestyle, the rapid loss of weight, <a href="/articles/obesity">obesity</a>, oral contraceptive pill, total parenteral nutrition (TPN)</p></li>
- +<li><p>ethnicity, genetic predisposition, older age, female sex</p></li>
-<strong>mixed </strong>(80%)<ul>-<li>20-50% cholesterol content</li>-<li>predisposing factor: similar to cholesterol stones</li>- +<p><strong>mixed </strong>(80%)</p>
- +<ul>
- +<li><p>20-50% cholesterol content</p></li>
- +<li><p>predisposing factor: similar to cholesterol stones</p></li>
-<strong>pigment stones</strong> (10%)<ul>-<li><20% cholesterol content; high bilirubin content and occur when there is supersaturation of unconjugated bilirubin</li>-<li>two subtypes each with their own predisposing factors:<ul>-<li>black pigment stones: chronic haemolysis, <a href="/articles/cirrhosis">cirrhosis</a>, intestinal malabsorption</li>-<li>brown pigment stones: infections (bacterial/parasitic) and biliary stasis</li>- +<p><strong>pigment stones</strong> (10%)</p>
- +<ul>
- +<li><p><20% cholesterol content; high bilirubin content and occur when there is supersaturation of unconjugated bilirubin</p></li>
- +<li>
- +<p>two subtypes each with their own predisposing factors:</p>
- +<ul>
- +<li><p>black pigment stones: chronic haemolysis, <a href="/articles/cirrhosis">cirrhosis</a>, intestinal malabsorption</p></li>
- +<li><p>brown pigment stones: infections (bacterial/parasitic) and biliary stasis</p></li>
-<li><a title="biliary colic" href="/articles/biliary-colic">biliary colic</a></li>-<li><a href="/articles/cholecystitis">cholecystitis</a></li>-<li><a href="/articles/acute-cholangitis">acute cholangitis</a></li>-<li><a href="/articles/pancreatitis">pancreatitis</a></li>-<li><a href="/articles/jaundice">obstructive jaundice</a></li>-<li><a href="/articles/gallbladder-empyema">gallbladder empyema</a></li>-<li>-<a href="/articles/gallbladder-hydrops">gallbladder hydrops</a>/<a href="/articles/gallbladder-mucocele">mucocele</a>-</li>-<li>-<a href="/articles/cholecystoduodenal-fistula">cholecystoduodenal fistula</a> leading to a <a href="/articles/gallstone-ileus">gallstone ileus</a> or <a href="/articles/bouveret-syndrome-1">Bouveret syndrome</a>-</li>-<li><a href="/articles/mirizzi-syndrome">Mirizzi syndrome</a></li>-<li>increased risk of <a href="/articles/cholangiocarcinoma">cholangiocarcinoma</a>-</li>- +<li><p><a href="/articles/biliary-colic" title="biliary colic">biliary colic</a></p></li>
- +<li><p><a href="/articles/cholecystitis">cholecystitis</a></p></li>
- +<li><p><a href="/articles/acute-cholangitis">acute cholangitis</a></p></li>
- +<li><p><a href="/articles/pancreatitis">pancreatitis</a></p></li>
- +<li><p><a href="/articles/jaundice">obstructive jaundice</a></p></li>
- +<li><p><a href="/articles/gallbladder-empyema">gallbladder empyema</a></p></li>
- +<li><p><a href="/articles/gallbladder-hydrops">gallbladder hydrops</a>/<a href="/articles/gallbladder-mucocele">mucocele</a></p></li>
- +<li><p><a href="/articles/cholecystoduodenal-fistula">cholecystoduodenal fistula</a> leading to a <a href="/articles/gallstone-ileus">gallstone ileus</a> or <a href="/articles/bouveret-syndrome-1">Bouveret syndrome</a></p></li>
- +<li><p><a href="/articles/mirizzi-syndrome">Mirizzi syndrome</a></p></li>
- +<li><p>increased risk of <a href="/articles/cholangiocarcinoma">cholangiocarcinoma</a></p></li>
-<li>gallstones are radiopaque only in 15-20% of cases <sup>3</sup>-</li>-<li>may be <a href="/articles/lamellated-1">laminated (a.k.a. lamellated)</a>: radiopaque outline with lucent centre</li>-<li>may have a faceted outline </li>-<li>may show a <a href="/articles/mercedes-benz-sign-gallbladder">Mercedes-Benz sign</a>: triradiate pattern of gas lucency</li>- +<li><p>gallstones are radiopaque only in 15-20% of cases <sup>3</sup></p></li>
- +<li><p>may be <a href="/articles/lamellated-1">laminated (a.k.a. lamellated)</a>: radiopaque outline with lucent centre</p></li>
- +<li><p>may have a faceted outline </p></li>
- +<li><p>may show a <a href="/articles/mercedes-benz-sign-gallbladder">Mercedes-Benz sign</a>: triradiate pattern of gas lucency</p></li>
-<li>greyscale ultrasound<ul>-<li>highly reflective echogenic focus within gallbladder lumen, normally with prominent posterior acoustic shadowing regardless of pathological type (acoustic shadowing is independent of the composition and calcium content) <sup>11</sup>-</li>-<li>gravity-dependant movement is often seen with a change of patient position (the <a href="/articles/rolling-stonesign">rolling stone sign</a>)</li>- +<li>
- +<p>greyscale ultrasound</p>
- +<ul>
- +<li><p>highly reflective echogenic focus within gallbladder lumen, normally with prominent posterior acoustic shadowing regardless of pathological type (acoustic shadowing is independent of the composition and calcium content) <sup>11</sup></p></li>
- +<li><p>gravity-dependent movement is often seen with a change of patient position (the <a href="/articles/rolling-stonesign">rolling stone sign</a>)</p></li>
-<li>colour Doppler<ul><li>may demonstrate a <a href="/articles/twinkling-artifact">twinkling artifact</a> and is particularly useful for identification of small stones</li></ul>- +<li>
- +<p>colour Doppler</p>
- +<ul><li><p>may demonstrate a <a href="/articles/twinkling-artifact">twinkling artifact</a> and is particularly useful for identification of small stones</p></li></ul>
-<strong>T1-weighted 3D fast spoiled gradient echo (3D FSPGR):</strong> <ul>-<li>pigmented stones (hyperintense) <sup>14</sup>-</li>-<li>cholesterol stones (hypointense) <sup>14</sup>-</li>- +<p><strong>T1-weighted 3D fast spoiled gradient echo (3D FSPGR):</strong> </p>
- +<ul>
- +<li><p>pigmented stones (hyperintense) <sup>14</sup></p></li>
- +<li><p>cholesterol stones (hypointense) <sup>14</sup></p></li>
-<li>-<strong>T2:</strong> signal void or low signal outlined by markedly hyperintense bile within the gallbladder</li>-<li>-<strong>MRCP:</strong> focus of signal void inside the gallbladder</li>- +<li><p><strong>T2:</strong> signal void or low signal outlined by markedly hyperintense bile within the gallbladder</p></li>
- +<li><p><strong>MRCP:</strong> focus of signal void inside the gallbladder</p></li>
-<li>ingested iron tablets (<a href="/articles/pseudogallstones">pseudogallstones</a>) on plain radiograph <sup>13</sup>-</li>-<li><a href="/articles/gallbladder-polyp">gallbladder polyp</a></li>-<li>-<a href="/articles/gallbladder-sludge">echogenic bile (sludge) and tumefactive sludge</a>: non-shadowing</li>-<li><a href="/articles/gallbladder-carcinoma-1">gallbladder carcinoma</a></li>-<li>-<a href="/articles/pneumobilia">pneumobilia</a> on <a href="/articles/magnetic-resonance-cholangiopancreatography-mrcp-2">MRCP</a>-</li>- +<li><p>ingested iron tablets (<a href="/articles/pseudogallstones">pseudogallstones</a>) on plain radiograph <sup>13</sup></p></li>
- +<li><p><a href="/articles/gallbladder-polyp">gallbladder polyp</a></p></li>
- +<li><p><a href="/articles/gallbladder-sludge">echogenic bile (sludge) and tumefactive sludge</a>: non-shadowing</p></li>
- +<li><p><a href="/articles/gallbladder-carcinoma-1">gallbladder carcinoma</a></p></li>
- +<li><p><a href="/articles/pneumobilia">pneumobilia</a> on <a href="/articles/magnetic-resonance-cholangiopancreatography-mrcp-2">MRCP</a></p></li>
-<li>gallstone acoustic shadowing is prominent with<ul>-<li>larger size stones (usually >3 mm for shadowing)</li>-<li>higher transducer frequency</li>-<li>focal zone at the level of gallstone</li>- +<li>
- +<p>gallstone acoustic shadowing is prominent with</p>
- +<ul>
- +<li><p>larger size stones (usually >3 mm for shadowing)</p></li>
- +<li><p>higher transducer frequency</p></li>
- +<li><p>focal zone at the level of gallstone</p></li>
-<li>a gallbladder full of stones may paradoxically be hard to visualise (<a href="/articles/wall-echo-shadow-sign-ultrasound">wall-echo-shadow sign</a>)</li>- +<li><p>a gallbladder full of stones may paradoxically be hard to visualise (<a href="/articles/wall-echo-shadow-sign-ultrasound">wall-echo-shadow sign</a>)</p></li>
Unable to process the form. Check for errors and try again.