Correlation of microvessel and mature vessel in hepatocellular carcinoma with tumor metabolism quantized noninvasively by using in-vivo ~(31)P-MRS at 3.0 Tesla

Objective To probe the influence of angiogenesis and its maturation in hepatocellular carcinoma(HCC)over cell metabolism with in-vivo ~(31)P-MRS at 3.0 Tesla.Methods ~(31)P-MRS scanning with a single voxel on lesion and hepatic parenchyma respectively was carried out in 31 patients with pathologically proved HCC.Intracellular pH value(pHi),and some metabolites including phosphomonoester(PME),phosphodiester(PDE),inorganic phosphate(Pi),γ-,β-and α-ATP,lower energetic phosphate(LEP),and the ratios of PME/ATP,Pi/ATP,PME/PDE,PME/Pi,PDE/Pi and PDE/ATP were calculated.After surgery,the continuous slices of lesion were stained with hematoxylin-eosin(HE)and immunohistochemical staining of vascular endothelial growth factor(VEGF),Flk-1,PCNA,CD34 and alpha smooth muscle actin(SMA).Extracellular space(ES)and extracellular extravascular space(EES)by HE staining,and the expressions of the VEGF and the Flk-1,and PCNA index(PI)were evaluated.According to CD34 and SMA staining,some vascular parameters were counted in a computed analysis system including number,mean vessel area,total vessel area,circumference,diameter,distance between adjacent vessels(DAV),variety index and the expression position of microvessel and mature vessel.In addition,the number of arterioles and vein-lets,mature vessel index and mean perfused fraction(mPF)were also recorded.All vessel parameters were compared with the metabolites.Results ~(31)P-MRS showed an increase in Pi,β-ATP,pHi and PME/PDE,and a decrease in PDE/ATP and PDE/Pi in HCC when compared with normal hepatic parenchyma(P＜0.05).Pi/ATP was significantly increased in lesions with positive VEGF expression(P=0.047,t=2.135),and an increase in PDE/Pi was also detected in positive expression group of Flk-1(P=0.001,t=2.13).Among three patterns of CD34 expression position,the highest pHi was in type Ⅱ,whereas the lowest in type Ⅰ(P=0.01,F=7.493).pHi was correlated positively with the increased number of veinlets(P=0.003,r=0.749),and an inverse correlation of PME with EES was gotten(P = 0.029,r=-0.583).Positive correlations between microvessel total area and Pi,and between γ-ATP and the number of arterioles were showed(P＜0.05).Except ES,microvessel diameter,circumference,mean area and PI were positively correlated with β-ATP(P＜0.05).In addition,PME/Pi was inversely correlated with microvessel variety index,whereas positively with PI(P＜0.05).Some parameters including the number,diameter,and circumference of mature vessel,and the arteriolar number were correlated positively with PME/ATP(P＜0.05).There were positive correlations between PDE/Pi and mature DAV(P=0.041,r=0.533),and between mPF,microvessel total area and LEP,whereas an inverse correlation between EES and LEP was gotten(P＜0.05).Conclusion Pi,phi,β-ATP and PME/PDE in HCC are higher than those in liver.However,PDE/ATP,PDE/Pi are inverse.Metabolites in HCC detected with in-vivo ~(31)P-MRS may be influenced by the heterogeneity of angiogenesis. Key words: Carcinoma hepatocellular; Magnetic resonance spectrum; Angiogenesis