Trans abdominal ultrasound is the most frequently used imaging method for the diagnosis of choledocholithiasis.
Dr Steffen Rickes and colleagues from Germany evaluated the diagnostic accuracy of high-resolution ultrasound in the diagnosis of common bile duct stones.
The research team assessed whether the diagnostic accuracy depended on the operator's experience.
The researchers also compared high-resolution ultrasound in comparison with endoscopic retrograde cholangiography as the gold standard.
The team included 126 patients that were referred because of clinically and biochemically suspected common bile duct stones from 2003 to 2004.
The researchers excluded 2 patients because they refused to undergo endoscopic retrograde cholangiography.
| Bile duct stones were correctly found by ultrasound in 22 out of 27 patients|
|Scandanavian Journal of Gastroenterology|
Consequently, the study comprised 124 patients, of which 86 were female with a mean age of 63 years.
High-resolution ultrasound was performed by operators who were unaware of the results of other imaging procedures.
The definitive diagnosis was established by means of endoscopic retrograde cholangiography.
Experienced examiners investigated 35 out of 124 patients.
The team found that 77% had stones at endoscopic retrograde cholangiography.
Bile duct stones were correctly found by ultrasound in 22 out of 27 patients.
The team noted that of the 8 patients without stones at endoscopic retrograde cholangiography, 1 false-positive diagnosis was made with ultrasound.
Correct diagnoses were made in 29 out of 35 patients investigated by experienced examiners.
The researchers reported that 89 out of 124 patients were investigated by less-experienced examiners.
About 61% were found to have stones at endoscopic retrograde cholangiography.
Choledocholithiasis was found correctly in only 25 out of 54 patients.
Of the 35 patients without stones at endoscopic retrograde cholangiography, 3 false-positive diagnoses were made with ultrasound.
The team observed correct diagnoses in 57 of 89 patients investigated by less-experienced examiners.
Dr Rickes' concluded, “High-resolution ultrasound carried out by experienced examiners has a high diagnostic accuracy in the diagnosis of choledocholithiasis.”
“Therefore, good training and continued experience are prerequisites for successful sonographic detection of bile duct stones using ultrasound.”
“Under these conditions, further expensive and invasive methods such as endoscopic retrograde cholangiography, and magnetic resonance cholangiopancreatography."
"Endoscopic ultrasonography may not be necessary in cases with a clear sonographic diagnosis”