Novel Mathematical Diagnostic Analysis of Malignant Biliary Stenosis Using Magnetic Resonance Cholangiography in Patients Undergoing Pancreaticoduodenectomy.

BACKGROUND/AIM:A novel mathematical diagnostic analysis using Fourier transform (FT) algorithm of the extrahepatic bile duct (BD) using magnetic resonance-cholangiography (MRC) was performed to evaluate irregularities of the bile duct lumen indicating BD cancer (BDC) extension compared to pancreatic head malignancies controls. PATIENTS AND METHODS:BD lumen was automatically traced, and a 2D-diagram cross-section was measured and a FT-based integrated-power-spectral-density-function value (FTV) of both diameter and area (mm 2  and mm 4 /Hz) was calculated for cancerous and non-cancerous parts utilizing a computer workstation. RESULTS:FT analysis that was achieved in 59 patients consisted of BDC in 31, pancreatic cancer with biliary stenosis (PC) in 10 and pancreatic neoplasm without stenosis (PN) in 18. FTV-diameter and -area of non-tumorous proximal BD were larger compared to tumor involving BD (p<0.01), and those of the entire BD in BDCs were significantly larger than those in PN (p<0.01). FTV-diameter and -area in proximal BDC-positive were smaller than those in BDC-negative (p<0.05). BDC part was significantly discriminated by the cutoff value (286 mm 2 Hz -1  in diameter and 10,311 mm 4 Hz -1 in area) compared to PC and diagnostic accuracy was over 70% (p<0.01). CONCLUSION:Novel mathematical MRC FT-analysis is promising for differentiating between BDC and PC with biliary stenosis and can be utilized as an objective diagnostic tool in the future.