Gallstone disease ultrasound: Difference between revisions
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False-negative or misleading results may be obtained if the gallbladder is completely filled with stones or if it is contracted around many stones.<ref name="pmid981625">{{cite journal |vauthors=Leopold GR, Amberg J, Gosink BB, Mittelstaedt C |title=Gray scale ultrasonic cholecystography: a comparison with conventional radiographic techniques |journal=Radiology |volume=121 |issue=2 |pages=445–8 |year=1976 |pmid=981625 |doi=10.1148/121.2.445 |url=}}</ref> | False-negative or misleading results may be obtained if the gallbladder is completely filled with stones or if it is contracted around many stones.<ref name="pmid981625">{{cite journal |vauthors=Leopold GR, Amberg J, Gosink BB, Mittelstaedt C |title=Gray scale ultrasonic cholecystography: a comparison with conventional radiographic techniques |journal=Radiology |volume=121 |issue=2 |pages=445–8 |year=1976 |pmid=981625 |doi=10.1148/121.2.445 |url=}}</ref> | ||
A systematic review estimated that the sensitivity was 84 percent and specificity was 99 percent.The accuracy is, however, operator dependent.<ref name="pmid7979854">{{cite journal |vauthors=Shea JA, Berlin JA, Escarce JJ, Clarke JR, Kinosian BP, Cabana MD, Tsai WW, Horangic N, Malet PF, Schwartz JS |title=Revised estimates of diagnostic test sensitivity and specificity in suspected biliary tract disease |journal=Arch. Intern. Med. |volume=154 |issue=22 |pages=2573–81 |year=1994 |pmid=7979854 |doi= |url=}}</ref> | |||
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. | |||
[[Image:gallstonesus.jpg|thumb|center|500px|Source:radiopedia.org <ref name="urlGallstones | Radiology Reference Article | Radiopaedia.org">{{cite web |url=https://radiopaedia.org/articles/gallstones-1 |title=Gallstones | Radiology Reference Article | Radiopaedia.org |format= |work= |accessdate=}}</ref>]] | [[Image:gallstonesus.jpg|thumb|center|500px|Source:radiopedia.org <ref name="urlGallstones | Radiology Reference Article | Radiopaedia.org">{{cite web |url=https://radiopaedia.org/articles/gallstones-1 |title=Gallstones | Radiology Reference Article | Radiopaedia.org |format= |work= |accessdate=}}</ref>]] | ||
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Revision as of 16:50, 1 December 2017
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Gallstone disease Microchapters |
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Gallstone disease ultrasound On the Web |
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American Roentgen Ray Society Images of Gallstone disease ultrasound |
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Risk calculators and risk factors for Gallstone disease ultrasound |
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, relatively inexpensive 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
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 — Imaging of the gallbladder can be obtained by EUS. During EUS, an ultrasound transducer on the tip of an endoscope is placed into contact with the gastric antrum, which is in close proximity to the gallbladder. This permits gallbladder visualization without interference from bowel gas, subcutaneous tissue, or the liver. As a result, EUS is more sensitive than transabdominal ultrasound for the detection of gallstones, particularly in patients who are obese or have other anatomic considerations that limit gallbladder visualization with transabdominal ultrasound [40,41].
Several studies have demonstrated that EUS is useful for the detection of small stones and microlithiasis [40-43]. In one study of 45 patients in whom there was a clinical suspicion of cholelithiasis but with at least two normal transabdominal ultrasound examinations, EUS detected evidence of cholelithiasis in 26 patients (58 percent). The sensitivity and specificity of EUS for detecting cholelithiasis were 96 and 86 percent, respectively [40].
In a second study of 89 patients with acute pancreatitis, EUS revealed small gallbladder stones (1 to 9 mm) in 14 of 18 patients who had otherwise negative standard imaging studies, including transabdominal ultrasound [41]. Subsequent endoscopic retrograde cholangiopancreatography (ERCP) and cholecystectomy confirmed the presence of stones in all 14 patients. None of the remaining four patients developed evidence of cholelithiasis during a median follow-up of 22 months.
The initial imaging study of choice in patients with suspected common bile duct stones is a transabdominal ultrasound of the right upper quadrant. Transabdominal ultrasound can evaluate for cholelithiasis, choledocholithiasis, and common bile duct dilation. It is readily available, noninvasive, permits bedside evaluation, and provides a low-cost means of evaluating the common bile duct for stones. (See "Ultrasonography of the hepatobiliary tract".)
The sensitivity of transabdominal ultrasound for choledocholithiasis ranges from 20 to 90 percent [14]. In a meta-analysis of five studies, the pooled sensitivity of ultrasound for detecting a common bile duct stone was 73 percent, with a specificity of 91 percent [20]. Transabdominal ultrasound has poor sensitivity for stones in the distal common bile duct because the distal common bile duct is often obscured by bowel gas in the imaging field [21-25]. Occasionally, a definite common bile duct stone (one that casts a shadow) can be imaged by transabdominal ultrasound (image 1).
A dilated common bile duct on transabdominal ultrasound is suggestive of, but not specific for, choledocholithiasis [6,8,10]. A cutoff of 6 mm is often used to classify a duct as being dilated [14]. However, using a cutoff of 6 mm may miss stones [26]. One study of 870 patients undergoing cholecystectomy found that stones were often detected in patients whose ducts would have been classified as "nondilated" using the 6 mm cutoff [27]. In addition, the probability of a stone in the common bile duct increased with increasing common bile duct diameter:
●0 to 4 mm: 3.9 percent ●4.1 to 6 mm: 9.4 percent ●6.1 to 8 mm: 28 percent ●8.1 to 10 mm: 32 percent ●>10 mm: 50 percent Conversely, because the diameter of the common bile duct increases with age, older adults may have a nolder adults may have a normal duct with a diameter that is >6 mm. (See "Ultrasonography of the hepatobiliary tract", section on 'Normal measurements on ultrasound'.)
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.
- ↑ "Gallstones | Radiology Reference Article | Radiopaedia.org".