Preoperative staging of gallbladder carcinoma using biliary MR imaging

To evaluate the performance of biliary MRI, including unenhanced imaging, gadolinium-enhanced (Gd-E) dynamic imaging, and MR cholangiography, for the preoperative staging of gallbladder cancer (GBC).

Our institutional review board approved this retrospective study. Eighty-six, consecutive patients with surgically resected and pathologically confirmed GBCs and who underwent preoperative MRI, including unenhanced T1- and T2-weighted images, MR cholangiography, and dynamic imaging, were enrolled in this study. Two observers independently evaluated the biliary MR images regarding the T- and N-staging of GBCs and graded their diagnostic confidence for the staging using a 5-point scale. Receiver operating curve analysis was performed to evaluate the diagnostic performance of MR in the staging of GBC. Interobserver agreement was evaluated using kappa statistics.

The overall accuracy of T- and N-staging using biliary MRI was 84.9% and 77.9% for observer 1 and 69.8% and 74.4% for observer 2. There was good interobserver agreement regarding the T stage (k = 0.828). The Az (AUC: area under the curve) values of the diagnostic ability of MRI to differentiate ≥ T1b from ≤ T1a lesions, were 0.979 and 0.955 for both observers (P < 0.0001).

Biliary MRI with MR cholangiography allows moderately accurate preoperative T staging and N staging of GBCs. It also shows an excellent diagnostic ability for differentiating ≥ T1b lesions from ≤ T1a lesions, which can be helpful for preoperative planning.