Recently clinical MR contrast media consists mainly of gadolinium based small molecule complexes,such as Gd-dTPA,Gd dOTA,etc,but small molecule complexes are defective in the relaxation and early diagnosis.With the development of nanotechnology,molecular nanoprobes not only have the advantages of small particle size,good biocompatibility,enhanced penetration and retention (EPR) effect and long half-life,but also their relaxation rates are higher than that of common gadolinium contrast media.The application of current MR molecular probe,such as liposomes,dendrimers,mesoporous silica,polymer micelles,carbon nanotubes,nano-gold and paramagnetic nanoparticles were mainly introduced in this paper.

Objective To investigate the correlation between tumor perfusion parameters and tumor volume and Child-Pugh classification in CT of hepatocellular carcinoma (HCC).Methods Fifty-six patients with hepatocellular carcinoma were selected to perform CT perfusion imaging.The parameters of the total tumor perfusion such as hepatic artery perfusion (HAP),portal vein perfusion (PVP)and hepatic perfusion index (HAPI)were calculated according to the degree of hepatic encephalopathy,albumin,bilirubin, clotting time,ascites for liver Child-Pugh classification.The relationship between the tumor or peritumoral perfusion parameters with tumor volume and Child-Pugh classification were analyzed.Results (1)There was no correlation between tumor or peritumoral perfusion with the tumor volume.(2)The difference of HAP,PVP and HAPI between the different Child-Pugh classification groups was statistically significant (P<0.000 1).(3)With the reduction of Child-Pugh classification,the tumor body HAP and HAPI values gradually decreased, while the PVP value increased gradually.Conclusion There is no correlation between the tumor volume of hepatocellular carcinoma with total tumor perfusion parameters.The differences in perfusion measurements between different Child-Pugh classification can intuitively and quantitatively reflect the reserve function of the liver.

Objective To investigate the association between heme oxygenase-1 (HO-1) gene rs2071746 polymorphism and long-term clinical outcome in patients with ischemic stroke.Methods Between July 2015 and June 2017,consecutive patients with acute ischemic stroke admitted to the Department of Neurology,the Third Affiliated Hospital of Soochow University were enrolled prospectively.TOAST classification was performed for all patients.Genotyping of the HO-1 gene rs2071746 polymorphism was performed using a modified multiplex ligase detection reaction technique.The patients were followed up.The primary endpoint events included ischemic stroke,vascular death,and myocardial infarction.Multivariate Cox proportional hazard regression model was used to analyze the independent influencing factors for primary endpoint events.Results A total of 1 698 patients with successful genotyping and follow-up information were enrolled.Genotyping showed that the frequency of rs2071746 A allelewas 44.91％.They were followed up for 15.21 ± 7.39 months,and 168 patients (9.89％) had primary endpoint events.The incidence of primary endpoint events in A allele carriers was significantly lower than that in non-A allele carriers (8.80％ vs.12.40％;P =0.018).Multivariate Cox proportional risk regression model showed that after adjusting for age,gender,hypertension,diabetes mellitus,smoking,alcohol consumption,and genotype,A allele was an independent protective factor for primary endpoint events in patients with acute ischemic stroke (hazard risk [HR] 0.693,95％ confidence interval [CI]0.506-0.949;P=0.022).Subgroup analysis showed that carrying the A allele was an independent protective factor for primary endpoint events in patients with large atherosclerotic stroke (HR 0.651,95％ CI 0.425-0.997;P=0.048),while rs2071746 polymorphism was not associated with long-term outcome in other etiological subtypes.Conclusion The HO-1 gene rs2071746 A allele may be a protective factor for the long-term outcome in patients with acute ischemic stroke and large atherosclerotic stroke.