16-Slice Spiral CT Study Of The Inflammatory Pseudotumor Of The Liver

【Objective】1.To discuss the CT characteristics of the inflammatory pseudotumor of the liver(IPL) on rabbit.1.1 To establishe animal models with IPL;1.2 To analyze the CT manifestations of IPL model before and after administration of iopamidol,to measure the CT value of the IPL lesions and the surrounding liver tissue the lesions,and analysis the CT value changes of the two areas by using SPSS 13.0 statistical software,1.3 To study the CT perfusion imaging characteristics of IPL.To measure the perfusion parameters such as CBV,CBF and MTT,in the IPL lesions and the liver tissue surrounding the lesions.To analysis the perfusion parameters changes of the three parts by using SPSS 13.0 statistical software.1.4 Experimental animals were sacrificed and anatomy had live IPL tissues taken for histologic examination.2,To discuss the CT characteristics of human inflammatory pseudotumor of the liver(IPL).2.1 To discuss the CT characteristics of IPL confirmed pathologically through operation or biopsy guided by B-ultrasound or CT. 2.2 To measure the CT values of the IPL lesions and the surrounding liver tissues of the lesions.To analysis the changes of CT values in the two areas by SPSS13.0 statistical software.2.3 To proposed the diagnoses and differential diagnoses of IPL combining the previous reports in literature and our study.【Materials and Methods】1.Experiment group1.1 Experimental reagents①Freund's Complete Adjuvant(FCA),10ml,sigma company,American;②Contrast Agent:Iopamidol,100ml,bracco company,American;③Anaesthetic:Sumianxin Injection,1.5ml,Changchun Academy of Military Medical Sciences military Veterinary Institute;Atropine Sulfate Injection,1.0ml,Guangdong Lizhu Pharmaceutical;Pelltobarbitalum Natricum Injection,5ml,China Pharmaceutical Corporation Shanghai Chemical Reagent.1.2 Experimental Animals12 New Zealand rabbits,gender unlimited does not limit female or male, 2.5-3.0kg weight.1.3 Preparation of the animal modelsNarcotic the rabbits,teke whole liver scan,and selected the thickest parts of the left lobe,then inject 1.5ml complete Freund's adjuvant into the liver using CT-guided puncture technology.1.4 CT scanLiver lesions on CT perfusion scanning and the whole liver on CT plain scans, dynamic contrast-enhanced scan after 28 days the preparation of the animal model.1.5 Pathologic examinationTo sacrifice and dissect the animals,then slice and stain the IPL lesions. 1.6 CT image analysisTo observe the CT characteristics of the IPL lesions,measure the CT value of the IPL lesions and the liver tissue surrounding the lesions,and calculate the perfusion parameters:CBV,CBF and MTT of the lesion,the surrounding liver tissues of the lesions and the normal liver tissue.1.7 Statistical methodsSPSS13.0 statistical analysis software was used for comparing the CT values of the lesions and the surrounding liver tissue during different periods;and for comparing the CBV,CBF,MTT of the lesions,the surrounding liver tissue and the normal liver by factorial design,P＜0.05 for statistical significance.2,Clinic Group2.1 Experiment objectsChoose 16 cases of IPL pathologically confirmed,the common clinical manifestations were fever,fatigue and abdominal discomfort,most of whom were alpha-fetoprotein(AFP) and the liver surface antigen(HbsAg) negative.2.2 CT scanUsing the GE LightSpeed Z/Xi 16-slice CT,dynamic contrast-enhanced CT-scanning after plain scanning,then all the data transmitted to the independent workstations(GE Advantage Workstation 4.2) for processing.2.3 CT image analysisTo Observe the CT image before and after enhancement,and to measure the CT values of the IPL lesions and the surrounding liver tissue during different phases.2.4 Statistical analysisSPSS13.0 statistical software was used for statistical analysis,the CT values comparison of different period in the lesions and the surrounding liver tissues of the lesions by statistical methods of factorial design,P＜0.05 for statistical significance. 【Results】1,Experiment group1.1 IPL occurred Overview12 New Zealand rabbits underwent Freund's complete adjuvant injecting into the left liver lobe,one of whom died for narcotic accident.13 IPL lesions were detected in the rest 11 rabbits(incidence rate was 91.7%),with tumor size of 1.5±0.6cm.Based on the planting site,some tumors situated in the liver parenchyma,some protruded behind the liver capsule.1.2 CT findings of IPLThe lesions were generally single,round or round-like,or abnormal in sharp low density phantom with unclear boundary on plain CT scan imagesDynamic enhanced CT scan:the lesions showed slow enhancement in the artery phase,moderate reinforcement in the portal-vein phase,and ring enhancement surrounding the lesions.The partial infections may see nodular or textile fiber strip funicular strengthening in the infection center,and the portal vein passes through the infection,statistics confirmed that in IPL lesion,it has no statistics difference between plain phase and artery phase(P=0.186),but it has statistics difference between portal-venous phase and plain phase(P＜0.01),it also has statistics difference between portal-venous phase and artery phase(P＜0.01);In liver organization around the IPL lesion,it has statistics difference compared with plain phase,artery phase and portal-vein phase(P＜0.01).CT perfusion scan:compared with normal liver tissue,the lesion showed hypoperfusion on CT perfusion images,and the liver tissue surrounding lesions showed as annular hyperperfusion region.Perfusion scan showed that the CBV and CBF in lesions were lower than in normal hepatic parenchyma,MTT is shorter than normal hepatic parenchyma,in addition,the CBV and CBF in the liver tissue surrounding the lesions are higher than normal hepatic parenchyma,MTT is longer than normal hepatic parenchyma(P＜0.01).1.3 The pathologic manifestations of IPLDue to the planting sites,some IPL lesions located in the liver parenchyma, some protruded below the liver capsule,section observation for gray nodules,size and shape vary,round or round-like,or irregular in sharp with low density phantom, the boundary is clear.Unstructured area showed under the microscope,partial liver cells edema,liver cell nuclei concentration,cracking,with lymphocytes,plasma cells, multinucleated cells invasion,and a large amount of fibrous tissue hyperplasia,small hepatic artery degeneration and necrosis,cell shedding,thrombus formation.2.Clinic Group2.1 IPL occurred OverviewThere were 18 lesions detected in 16 cases,and most of them(16 lesions) located in the right lobes of liver,the lesions were roundness or round-like,or abnormal in sharp,size range from 0.6cm to 5.5cm2.2 CT findings of IPLIt showed round or round-like,or irrigular lesions with low-density.Dynamic enhanced CT scan showed slowly reinforcement during the artery phase,then moderatly reinforcement in the portal vein time.The partial infections may see ring enhancement surrounding the lesions,nodular or textile fiber strip funicular strengthening in the infection center,and the portal vein passes through the infection, these can be used as a characteristic of IPL.Statistics confirmed that in IPL lesion, there are no statistics difference between plain phase and artery phase(P=0.117),but it has statistics difference between portal-venous phase and plain phase(P＜0.01),it also has statistics difference between portal-venous phase and artery phase(P＜0.01); In liver organization around the IPL lesion,it has statistics difference compared with plain phase,artery phase and portal-vein phase(P＜0.01).【Conclusions】1.The improved model bearing of IPL in rabbits induced by Freund's complete adjuvant is outstanding for its facility,high incidence rate,high repetition rate and short latent period.Compared with the abdomen surgery to pour into or to implant the adjuvant in the liver,this method is simpler with fewer bleeding,less infection and higher success rate,it also have the pathologic feature of necrotic constitution,fibrous proliferation and inflammatory cells infiltrated.It is also proved that the model could be served as ideal experimental animal model for further study of IPL's etiopathology and imaging features.2.Iopamidol could enhance the density contrast ratio between the IPL and the normal liver,improved it's conspicuity.IPL are hypovasculary and enhanced slowly, and the enhancement is lower than the the liver in same phase,the portal-venous phase and the delayed phase scanning details the lesion best,hence they are the key to the diagnosis of IPL.3.CT features of the IPL in human:①)Most IPL lesions are located in the right lobes of the liver,with the shape of roundness,round-like or abnormity;②Dynamic enhanced CT revealed that most IPL lesions poor in arteri-blood supply,and enhanced insignificantly in the artery phase scanning;③During portal-venous phase, some lesions showed slightly to intermediate enhancement,and some show round-ring or(and) nodes reinforcement in the center,and some had the portal-venous cross through.The above signs may be the characteristic CT experiences and are important in the diagnosis and differential diagnosis of IPL.4.CT perfusion scan showed that the CBV,CBF in lesions were lower than that in the normal liver,MTT shortening,the CBV,CBF in the liver tissue surrounding the lesions were higher than that in the normal liver,MTT extended. 5.Statistics analysis confirmed that in IPL lesion,there is no statistics difference between plain phase and artery phase,but the difference between portal-venous phase and plain phase are statistic significant,there is statistics difference between portal-venous phase and artery phase;In liver organization around the IPL lesion, there is statistics difference compared with plain phase,artery phase and portal-vein phase.