Correlation Between Dual-Phase Dual-Energy CT Iodine Uptake And Perfusion CT Measurements In Patients With Lung Cancer

Objective To evaluate the correlation between quantitative dual-phase iodine parameters derived from DECT and perfusion parameters in lung cancer patients.Method(1)From July 2018 to June 2019,144 patients with suspected lung cancer who were admitted to our hospital were collected and randomly divided into PCT & arterial-phase DECT group(Group A)and PCT & venous-phase DECT group(Group B).According to the inclusion and exclusion criteria,35 patients were enrolled in group A and 36 in group B.There was no statistically significant difference in gender,age or pathological subtype between the two groups.Written informed consent was obtained from all patients.(2)ROI was drawn in evidently enhanced areas of lung cancer lesions.PCT parameters included blood volume(BV),blood flow(BF),permeability surface(PS)were calculated.DECT parameters included iodine concentration(IC),normalized iodine concentration(NIC),slope of spectral attenuation curves(λHU).Dose-length product(DLP)were recorded to calculate effective dose(ED)of DECT and PCT.Pearson R and Spearman correlation coefficients were calculated to analyze the correlation between dual-phase iodine uptake and perfusion parameters.(3)Wilcoxon rank sum test were used to compare ED of the two scanning protocols.Results(1)Mean arterial λHU,IC and NIC were 1.55±0.84,1.48±0.95 mg/m L and 0.14±0.09,respectively.Mean venous λHU,IC and NIC were 1.82±0.87,1.72±0.85 mg/m L and 0.32±0.16,respectively.Mean BF,BV and PS were 35.30±15.50 ml/(min·100g),7.71±2.73 ml/100 g and 24.00 ± 11.54 ml/(min·100g)in group A,respectively.Median BF,BV and PS were 36.78(25.84,47.55)ml/(min·100g),7.56(6.00,9.70)ml/100 g and 23.08(12.98,36.45)ml/(min·100g)in Group B,respectively.(2)BV was significantly related to arterial λHU(r=0.51,P﹤0.05),IC(r=0.48,P﹤0.05)and NIC(r=0.45,P﹤0.05),and venous λHU(r=0.53,P﹤0.05),IC(r=0.44,P﹤ 0.05)and NIC(r=0.46,P ﹤ 0.05).BF was significantly related to arterial λHU(r=0.40,P ﹤0.05),venous λHU(r=0.45,P ﹤0.05)and IC(r=0.0.35,P ﹤0.05).PS was significantly related to arterial λHU(r=0.61,P﹤0.05),IC(r=0.55,P﹤0.05)and NIC(r=0.50,P﹤0.05).No further significant correlations were found.(3)The ED(3.89±0.39 m Sv)of dual-energy CT was lower than that of the PCT(7.45±0.02 m Sv)(P﹤0.05).Conclusion(1)DECT quantitative iodine analysis,similar to PCT,can be used to evaluate the tumor angiogenesis in lung cancer patients non-invasively.This study shows that the iodine parameters during the arterial and venous phase in lung cancer patients are associated with BV,and iodine parameters in the arterial phase are associated with PS.(2)DECT required a lower radiation dose than PCT,which contributed to reduce the burden of radiation damage in lung cancer patients.