Gallstone disease ultrasound
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Hadeel Maksoud M.D.[2]
Overview
Generally transabdominal ultrasound (TAUS) is considered to be the most useful test to detect gallstones. TAUS is noninvasive, readily available, low cost and doesn't expose patients to ionizing radiation. The patient should fast for at least eight hours before the examination this is to ensure that the gallbladder is distended with bile, which is best for visualizing stones.[1]
Transabdominal ultrasound
The initial imaging study of choice in patients with suspected common bile duct stones is a transabdominal ultrasound of the right upper quadrant.
Ultrasound may be helpful in the diagnosis of gallstones. Findings on an ultrasound suggestive of gallstones include:
- Gallstones - echogenic foci that cast an acoustic shadow
- Gravel - multiple, small echogenic foci and cast shadows
- Sludge - microlithiasis that is echogenic but doesn't cast a shadow[2]
False-negative or misleading results may be obtained if the gallbladder is completely filled with stones or if it is contracted around many stones.[3] A systematic review estimated that the sensitivity was 84 percent and specificity was 99 percent.The accuracy is, however, operator dependent.[1] In patients who complain of biliary colic but have not shown evidence of gallstones on ultrasound, the examination is usually repeated a few weeks later. If the repeated TAUS is still negative then this patient may have sludge in the gallbladder and invasive procedures are considered on an individual case basis.
Endoscopic ultrasound
The gallbladder can be visualised through an endoscopic ultrasound (EUS). During EUS, an ultrasound endoscope is placed at the gastric antrum, which is in close proximity to the gallbladder. This allows for imaging free of bowel gases or the liver. Consequently, EUS is more sensitive than transabdominal ultrasound for the detection of gallstones, particularly in obese patients, in cases of microlithiasis or in patients that have other anatomic considerations that limit gallbladder visualization with a conventional transabdominal ultrasound.[4][5]
References
- ↑ 1.0 1.1 Shea JA, Berlin JA, Escarce JJ, Clarke JR, Kinosian BP, Cabana MD, Tsai WW, Horangic N, Malet PF, Schwartz JS (1994). "Revised estimates of diagnostic test sensitivity and specificity in suspected biliary tract disease". Arch. Intern. Med. 154 (22): 2573–81. PMID 7979854.
- ↑ Conrad MR, Janes JO, Dietchy J (1979). "Significance of low level echoes within the gallbladder". AJR Am J Roentgenol. 132 (6): 967–72. doi:10.2214/ajr.132.6.967. PMID 108978.
- ↑ Leopold GR, Amberg J, Gosink BB, Mittelstaedt C (1976). "Gray scale ultrasonic cholecystography: a comparison with conventional radiographic techniques". Radiology. 121 (2): 445–8. doi:10.1148/121.2.445. PMID 981625.
- ↑ Dahan P, Andant C, Lévy P, Amouyal P, Amouyal G, Dumont M, Erlinger S, Sauvanet A, Belghiti J, Zins M, Vilgrain V, Bernades P (1996). "Prospective evaluation of endoscopic ultrasonography and microscopic examination of duodenal bile in the diagnosis of cholecystolithiasis in 45 patients with normal conventional ultrasonography". Gut. 38 (2): 277–81. PMC 1383037. PMID 8801211.
- ↑ Liu CL, Lo CM, Chan JK, Poon RT, Fan ST (2000). "EUS for detection of occult cholelithiasis in patients with idiopathic pancreatitis". Gastrointest. Endosc. 51 (1): 28–32. PMID 10625791.
- ↑ "Morris-Stiff G, et al. Does Endoscopic Ultrasound Have Anything to Offer in the Diagnosis of Idiopathic Acute Pancreatitis?. JOP. J Pancreas (Online) 2009 Mar 9; 10(2):143-146. [Full text]".