The Value Of Spectral Computed Tomography Application In Diagnosis The Cystic Hydatid

Objective: To explore the value of spectral CT in diagnosis different hepatic cystic hydatid.Method: 36 cases of granulosus echinococcos liver space-occupying lesions patients were retrospectively analyzed,in total of 71 hydatid.There were 21 cases of male and 15 cases of female;Ages 18 to 83 years,the average age(48.67±18.43),BMI(22.34±3.32)kg/m2,36 cases of cystic hydatid patients according to clinical data,ultrasound and screw CT and routine MRI diagnosis and Casoni's test results to ensure the reliability of the diagnosis.26 cases in total of 54 hydatid(13 simple cyst type,11 mother daughter cyst type,3 collapse of the internal capsule type,14 solid variant type,13 calcification type)were confirmed by surgery(20 cases of cystic echinococcosis treated by sub advititalpericystectom,6 cases of cystic echinococcosis underwent most ectocyst resection),the postoperative pathology were accord with echinococcus granulosustin disease.Using GE Discovery 750 HD 64 gems CT,Told the patients finished drunk 600-1000 ml water before check begin 10 min to full the stomach.Determine the scope of the lesions scanning and adopt the GSI mode in non-contrast scan and triphase phase contrast-enhanced scan.The scanning parameters as follows: energy-spectrum scanning,ball tube rotation speed of 0.8 seconds per week,with a thick layer of 5 mm,pitch coefficients: 0.983:1,Auto-milliampere technique,high and low energy instantaneous switch(140 KVP and 80 KVP),ASIR 30%,DFOV 35 cm.After scanning to produce hybrid energy of 120 kev QC images and its layer thickness and spacing are 1.25 mm thick;Then use the image restructuring standard algorithm,restructuring the 40-140 ke V single energy image,layer thickness and spacing are 1.25 mm thick.Application the software of GSI General to analysis.By measuring cystic hydatid and subcutaneous fat Contrast to Noise Ratio(CNR)obtained the best ratio at about 65 ke V level.The lesions can be divided into average of 10 levels,placed circular ROI as large as possible including fluid,as far as possible avoid calcifications and daughter cyst.The value of CT(65ke V),Effective-Z,calcium(water),water(ca)concentration,phosphorus(water),water(p)concentration were measured in hydatid cyst contents at 65 ke V.The ROI area of hydatid cyst wall is thinner and lesser,for this reason the measurement error is bigger,but the maximum value of hydatid cyst wall measurement error was little,then select the maximum as its average value.Select 25mm2 ROI area measuring the value of CT(65ke V),Effective-Z,calcium(water),water(ca)concentration,phosphorus(water),water(p)concentration in hydatid cyst wall at 65 ke V,and calculate the spectral curve of the slope,slope = CT(40 ke V)-CT(100 ke V)/ 60 ke V;CT(40 ke V)and CT(100 ke V)represent the value in 40 ke V and the value in 100 ke V respectively.Result: All indicators of hydatid liquid have significant different between each type in GSI scan(P < 0.05).But water(ca)concentration of ectocyst have no difference between each type(P > 0.05).Besides water(ca)concentration and the concentration of water(P),other indicators of the four type hydatid liquid have a significant correlation with the natural evolution process of echinococcos(P < 0.05),while all the indicators of ectocyst are related(P < 0.05).GSI scan in 65 ke V the CT value less than15.54±4.30,the average concentration of calcium(water)less than1.57±0.90mg/cm3,phosphorus(water)the average concentration of less than3.04±1.16mg/cm3,energy spectrum curve slope is less than0.12±0.17,the activity of hydatid were higher,whereas the activity was lower;GSI scan in 65 ke V the CT value is greater than37.83±4.36,the average concentration of calcium(water)greater than 5.33±1.78mg/cm3,the average concentration of phosphorus(water)is greater than10.34±2.02mg/cm3,energy spectrum curve slope is greater than0.42±0.37 have no activity;Each indicators of the ROC curve of solid variant hydatid type diagnosis efficiency is highest,the simple cyst type diagnosis efficiency is lowest.Hydatid liquid and ectocyst of calcium(water),phosphorus(water)concentration exists significant correlation respectively,Pearson correlation coefficients were 0.999.Conclusion: Spectral CT multi-parameter analysis and spectral curve have obvious advantages than traditional CT,it can be further popularized application in clinic.Especially in the judgment of hydatid development stage of the disease and its activity,for drugs or surgical treatment has important guiding significance.