Quantitative Analysis Of CT-perfusion Parameters With Open Two-compartment Model: Initial Experience In Rectal Tumor

ObjectiveQuantitative analysis of CT-perfusion parameter in patients with rectal tumor for characterizing microcirculation of malignant tissue with open two-compartment model, and determing whether perfusion CT parameters differ between tumor grades.Methods36patients with pathologically confirmed rectal adenocarcinoma underwent a 300-second axial-scan perfusion CT examination with 6 seconds interval,1 ml/kg of non-ionic contrast agent was injected in 30 seconds followed with 30ml saline. CT perfusion data were analyzed to calculate relative volume fraction of the plasma compartment (fp), relative volume fraction of the interstitial compartment (fi) and permeability-surface area product (PS). All patients were divided into groups according to the Duke's classification. CT perfusion parameters were compared with the Duke's classification by using Mann-Whitney tests with significance assigned at the 5% level.ResultsThe relative volume fraction of the plasma compartment, relative volume fraction of the interstitial compartment and permeability-surface area product values were 17.3±7.4%,34.3±11.6%,43.2±18.8mL/min/100ml,141±47.8 ml/min/100ml respect-ively. There was no significant difference between these parameters according to the Duke's classification (P>0.05) due to less cases.Conclusion Our preliminary findings suggest that Perfusion CT with open two-compartment model is feasible in patients with rectal tumors, and the parameters may reflect the microvascularity of rectal tumors warranting further study.