Perfusion CT – Can it resolve the pancreatic carcinoma versus mass forming chronic pancreatitis conundrum?

Abstract

ObjectivesTo evaluate the utility of perfusion CT (PCT) in differentiating pancreatic adenocarcinoma from mass forming chronic pancreatitis (MFCP). MethodsIn this ethically approved study, PCT was performed in 122 patients with pancreatic masses of which 42 patients had pancreatic adenocarcinoma and 13 had MFCP on histopathology. Perfusion parameters studied included blood flow (BF), blood volume (BV), permeability surface area product (PS), time to peak (TTP), peak enhancement intensity (PEI) and mean transit time (MTT). Twenty five controls with no pancreatic pathology were also studied. ResultsAmongst the perfusion parameters BF and BV were found to be the most reliable for differentiating between adenocarcinoma and mass forming pancreatitis. Although they were reduced in both pancreatic adenocarcinoma (BF- 16.6 ± 13.1 ml/100 ml/min and BV- 5 ± 3.5 ml/100 ml) and MFCP (BF- 30.4 ± 8.7 ml/100 ml/min and BV- 8.9 ± 3.1 ml/100 ml) as compared to normal controls (BF- 94.1 ± 24 ml/100 ml/min and BV- 36 ± 10.7 ml/100 ml) but the extent of reduction was greater in pancreatic adenocarcinoma than in MFCP. Based on ROC analysis cut off values of 19.1 ml/100 ml/min for BF and 5 ml/100 ml for BV yielded optimal sensitivity and specificity for differentiating pancreatic adenocarcinoma from MFCP. ConclusionsPCT may serve as an additional paradigm for differentiating pancreatic adenocarcinoma from mass forming chronic pancreatitis and a useful tool for detecting masses which are isodense on conventional CT.