Cholelithiasis (ancient Greek chole, “bile” and líthos, “stone”) is a deposit in the gallbladder caused by an imbalance of soluble substances in the bile. Depending on their location and size, gallstones can cause pain – from moderate discomfort in the right upper abdomen to severe biliary colic.
Cholelithiasis describes the presence of calculi in the gallbladder (cholecystolithiasis) and/or bile ducts (intra/extrahepatic) as choledocholithiasis. About 50% of women and 15% of men are stone carriers, and the cholesterol stone: pigment stone ratio is 9:1 [3]. Cholesterol stones are formed by crystallization of cholesterol around a nidation point, and pigment stones are formed by precipitation of bilirubin. The precursor of gallstones is sludge, usually an expression of a hypomotile gallbladder. Overview 1 lists the risk factors (6 f rule) of gallstone formation. Other risk factors may include diabetes mellitus, liver cirrhosis, hemolysis, estrogen therapy, and terminal ileum disease. About 80% of gallstones do not cause any symptoms. Nonspecific symptoms may occur.
Biliary colic as a very painful course can sometimes last for hours, usually increasing in frequency. Radiation of pain to the right shoulder may occur. Pain, fever, fatigue and chills indicate acute cholecystitis. Laboratory diagnostics should confirm acute inflammation.
Laparoscopic cholecystectomy is the therapy of choice, and ERCP is the therapeutic goal in choledocholithiasis. Drug-induced litholysis is possible for stones less than 2 cm, but has a high recurrence rate. The consequence of lithotrypsia is often the provocation of colic by the stone debris. Recurrent intraductal calculi formation after cholecystectomy has been described [2].
If symptomatic cholelithiasis is not adequately treated, serious complications may result (Overview 3).
Radiographic examinations are no longer of value in the imaging diagnosis of cholecystolithiasis. In rare cases, larger and more severely calcified gallstones may be visible as incidental findings on abdominal radiographs or radiographic examinations of the lumbar spine. In the period before sonography became widespread, “oral bile” with swallowing of bile-permeable contrast medium was the standard imaging examination in combination with slice imaging and stimulus meal (raw egg) to provoke emptying of the gallbladder and rule out functional disorders. If contrast was inadequate, “i.v. bile” often followed, but this was relatively frequently associated with contrast intolerance.
Sonography is the standard imaging method in the detection of cholecystoliths, regardless of the extent of calcification. Inflammatory concomitant reactions of the gallbladder wall and the width of the bile ducts can be determined reliably. However, the sensitivity in detecting bile duct calculi is only 64% [4].
Computed tomography can verify calcified calculi of the gallbladder and bile ducts very well. Depending on the biochemical composition and lack of calcification of the stones, they may be isodense to the bile fluid and thus masked [4]. CT is of great importance in the detection of inflammatory and tumorous changes of the biliary system.
Magnetic resonance imaging is classified as a complementary examination to sonography for specific questions in the imaging of the biliary system, with MRCP (magnetic resonance cholangiopancreatography) as a noninvasive imaging, especially of the draining bile ducts [1]. The method is considered equal to ERCP in diagnostic terms [5]. Normal intrahepatic bile ducts less than 3 mm in diameter are usually not delineable in standard sequences. The ductus choledochus has a diameter of about 8 mm; larger calibers indicate outflow obstruction. Normal bile juice has a signal hyperintense in T2w, sublayers with bile concentrated basally in the supine position can cause a heterogeneous signal, as can sludge with thickened/initially small-corpuscular bile. Gallstones present hypointense. Usually asymptomatic, gallstones are often incisional findings on MRI of the upper abdomen. The symptomatic cases are mostly found in the 5. and 6th decade of life with female predominance (3:1).
Case studies
In case report 1 (Fig. 1), numerous minute corpuscular structures are discernible in the gallbladder, compatible with sludge, with otherwise unremarkable gallbladder and ducts. The 45-year-old patient complained of recurrent mild upper abdominal pain
Case 2 demonstrates increasing cholecystolithiasis in the course (Figs. 2A and 2B) with lithiasis detected on CT in 2012 and an incomplete stone-filled gallbladder in recurrent progressive upper abdominal symptoms in the examination performed after seven years. So far, the patient could not decide to undergo cholecystectomy.
Case report 3 shows a completely stone-filled gallbladder (Fig. 3) on CT (annular calcified concretions).
Case report 4 demonstrates cholecystolithiasis and a prepapillary concretion with biliary outflow obstruction (Figs. 4A to 4C). The 58-year-old patient had crampy back and upper abdominal pain, pale stools, and elevated liver enzymes for 4 weeks.
Case report 5 documents MRCP (Fig. 5) in a 47-year-old female patient with recurrent upper abdominal symptoms secondary to cholecystectomy 2 years ago, demonstrating unremarkable drainage with normal dilatation of the hepatocholedochal duct and bile ducts near the aorta. The D. Wirsungianus is partially included.
Case report 6 shows normal findings on MRCP with a regularly filled gallbladder and unremarkable bile ducts. In the pancreas, small side-branch IPMN requiring control can be seen in the presence of unremarkable D. Wirsungianus.
Take-Home Messages
- Cholelithiasis is relatively common, affecting about 50% of women and 15% of men.
- The disease is clinically silent in about 80% of cases.
- The 6 f rule describes the main risk factors for gallstone formation.
- The standard imaging procedure is sonography, CT and MRI can be
provide additional information when the question is extended. - Laparoscopic cholecystectomy is now considered a standard procedure in the treatment of symptomatic cholelithiasis.
Literature:
- Burgener FA, et al: Differential diagnostics in MRI. Georg Thieme Verlag: Stuttgart, New York; 2002, 518-524.
- Dam van PMEL, et al: Symptomatic cholecystolithiasis after cholecystectomy. BMJ Case Rep 2013 Jan 28; 2013:bcr2012007692.
- Cholelithiasis, https://flexikon.doccheck.com/de,(last accessed Mar. 14, 2023).
- Juchems M, Brambs HJ: Diagnosis and differential diagnosis of biliary tract diseases. Radiology up2date 3; 2009: 255-268.
- Kinner S, Lauenstein T: MRCP – magnetic resonance cholangiopancreatography. Radiology up2date 2, 2016: 147-156.
- Opherk JP, Wiesner W, Kirchhoff TD: Differential diagnosis of acute abdomen. Part I. Radiology up2date 3, 2008: 259-271.
HAUSARZT PRAXIS 2023; 18(4): 40-42
