Short- versus long-sequence MRI cholangiography for the preoperative imaging of the common bile duct in patients with cholecystolithiasis.

BACKGROUND

This study aimed to compare an 18-s fast spin echo magnetic resonance image sequence (coronal thick-section two-dimensional breathhold) with a three-dimensional axial and coronal thin-section sequence and its secondary reconstruction, and to assess its value in the diagnosis of bile duct pathologies, particularly common bile duct stones (CBDS) before laparoscopic cholecystectomy.

METHODS

This study prospectively included 72 patients. Because of protocol violations, 14 of these patients had to be excluded. Thus, 58 patients (29 Man and 29 women with a mean age of 51 years) who had cholecystolithiasis or suspected choledocholithiasis were evaluated. Magnetic resonance cholangiopancreatography (MRCP) was performed for all patients with a fast sequence (18 s) and a long sequence (coronal oblique and axial respiratory triggered; 16 min). Two radiologists, blinded with respect to diagnosis, evaluated all the radiographic images. The MRCP results were confirmed for all the patients: 20 by endoscopic retrograde cholangiopancreatography, 46 by intraoperative cholangiography, and 2 by percutaneous transhepatic cholangiography.

RESULTS

According to the findings, 16 patients (28%) had CBDS, 6 patients (10%) had common bile duct stenosis, and 36 patients (62%) had a clear bile duct. With regard to CBDS, the short sequence had 100% specificity, 94% sensitivity, and an overall accuracy of 98%. Its negative predictive value was 98%, and its positive predictive value was 100%. The long sequence had a specificity of 100% and a sensitivity of 100%.

CONCLUSION

Because of its high sensitivity and specifity, MRCP has the potential to be the diagnostic method of choice for CBD evaluation. The short sequence is not suitable for the diagnosis of all CBD pathologies, but in cases of suspected CBDS, more than 80% of the patients could be diagnosed correctly, and the complete sequence could be dropped.