Detection and localization of post-operative and post-traumatic bile leak: hybrid SPECT-CT with 99mTc-Mebrofenin.

PURPOSE: To evaluate the role of single photon emission tomography-computed tomography (SPECT-CT) with 99mTc-N-(3-bromo-2,4,6-trimethylacetanilide) iminodiacetic acid (Mebrofenin) for detection and localisation of post-operative and post-traumatic bile leak and compare the same with planar hepatobiliary scintigraphy (HBS).

METHODS: Data of 32 consecutive patients (Age--35.7 ± !15.3 years; Female--53.2%) who underwent 99mTc-Mebrofenin planar HBS and SPECT-CT for suspected bile leak was prospectively collected and retrospectively analyzed. Twenty-six patients were post-operative and six had history of abdominal trauma. Planar HBS and SPECTCT images were evaluated by two experienced nuclear medicine physicians. Sensitivity, specificity and predictive values, were calculated for planar HBS and SPECT-CT. Final diagnosis was established based on a combination of re-operative findings, follow up imaging and clinical follow up (1-4 week).For evaluation of observer confidence a third observer used a scoring scale of 1-5, with 1 being definite bile leak and 5 being no leak. Receiver operating characteristic (ROC) curves were drawn and the areas under the curves were compared.

RESULTS: The sensitivity, specificity and accuracy of SPECT-CT were 88.8%, 100% and 96.8% while that of planar HBS were 77.7%, 60.8% and 65.6%, respectively. Planar HBS showed very low diagnostic accuracy compared to SPECT-CT (65.6%vs. 96.8%; P = 0.021). It was false positive in nine patients. SPECT-CT also correctly localised the site of bile leak in eight of nine patients. On ROC analysis the observer confidence for SPECT-CT was significantly better than that for planar scintigraphy (P = 0.045).

CONCLUSION: 99mTc-Mebrofenin hybrid SPECT-CT is highly sensitive and specific for detection and localisation of post-operative and post-traumatic bile leak. It is more accurate than planar HBS and should be routinely done in such patients.