Energy Spectrum CT Features Research Of Rabbit Inflammatory Node

Object: To study the spectral imaging of New Zealand white rabbits’ inflammatorylymph glands of different sizes by applying CT spectral imaging technology and analyzespectral curves of plain CT scan, arterial and venous phases, as well as to explore curveslope during plain scan, arterial phase and venous phase and changes of iodineconcentration and water concentration of different groups so as to discusses the features ofthe rabbit model of inflammatory lymph node of CT spectral imaging.Methods: Select10New Zealand white rabbits cultured at the Animal ExperimentalCenter of Jilin University and establish an animal mode of axillary inflammatory lymphglands. After the application of spectral unenhanced CT and dynamic contrast-enhancedscan of inflammatory lymph glands of different sizes, spectral curves are observed byplain scan, arterial and venous phases. Analysis and Measurement of all images areperformed on a professional workstation GE AW4.5. The GSI Mono images of thespectral CT scan at every phases are transferred to spectral imaging browser software (GSIviewer). The maximum cross-section of the abnormal lymph gland chooses region ofinterest (ROI); The best KeV images are generated by the software automatically,including the spectral curve of ROI and calculate the slope of the spectral curve i.e. slope=(40KeV CT value~100KeV CT value)/60. Measure the iodine concentration andwater concentration of ROIs’ and explore spectral curve of two groups of lymph glands ofdifferent sizes during plain CT scan, arterial phase and venous phase and distinctionbetween iodine concentration and water concentration through corresponding statisticalanalysis, with P <0.05, which is considered statistically significant.Results:24lymph glands, including12ones smaller than5mm,12ones larger than5mm, of which the smallest was about2.4mm and the largest about7.6mm, were found inthe10New Zealand white rabbits.Analysis the24lymph nodes and found that: Spectral curve average slope of plainCT scan is-0.4177±0.134. Spectral curve average slope of arterial phase is-1.874±0.461. Spectral curve average slope of venous phase is-1.740±0.403. Plain CTscan of average iodine concentration is4.198±1.029mg/mL. Average iodine concentration of arterial phase is18.38±2.578mg/mL. Average iodine concentration ofvenous phase is16.77±3.327mg/mL. Plain CT scan of average water concentration is1040.61±25.94mg/mL. Average water concentration of arterial phase is1028.74±13.275mg/mL. Average water concentration of venous phase is1029.86±11.397mg/mL.Two groups were formed, with one group larger than5mm and the other smallerthan5mm. Comparing spectral curves of plain CT scan, arterial and venous phases,iodine maps and water maps of ROIs of the data of two groups showed that:1. spectralcurve slope of plain CT scan(λHU): the group smaller than5mm was-0.535±0.197, thegroup larger than5mm was-0.431±0.128, p=0.141, hence the difference was notstatistically significant (P>0.05);2. spectral curve slope of arterial phase: the groupsmaller than5mm was-1.709±1.317, the group larger than5mm was-2.199±0.255,P=0.219, hence the difference was not statistically significant (P>0.05);3. spectralcurve slope of venous phase: the group smaller than5mm was-1.934±0.443, the grouplarger than5mm was-2.066±0.424，P=0.464, hence the difference was not statisticallysignificant (P>0.05);4. plain CT scan of iodine concentration: the group smaller than5mm was4.520±1.630mg/ml, the group larger than5mm was3.685±1.064mg/ml，P=0.152, hence the difference was not statistically significant (P>0.05);5. iodineconcentration of arterial phase: the group smaller than5mm was18.349±2.973mg/ml,the group larger than5mm was18.418±2.214mg/ml, P=0.950，hence the difference wasnot statistically significant (P>0.05);6. iodine concentration of venous phase: the groupsmaller than5mm was16.676±3.75mg/ml, the group larger than5mmwas16.858±3.058mg/ml，P=0.898, hence the difference was not statistically significant(P>0.05);7. plain CT scan of water concentration: the group smaller than5mm was1032.813±19.482mg/ml, the group larger than5mm was1048.398±28.901mg/ml，P=0.136, hence the difference was not statistically significant (P>0.05):8.waterconcentration of arterial phase: the group smaller than5mm was1025.767±16.384mg/ml, the group larger than5mm was1033.708±6.163mg/ml，P=0.101，hence thedifference was not statistically significant(P>0.05);9. water concentration of venousphase: the group smaller than5mm was1025.767±16.384mg/ml, the group larger than 5mm was1034.030±9.855mg/ml，P=0.149, hence the difference was not statisticallysignificant(P>0.05).Conclution:1、Rabbit inflammatory lymph glands have characteristic appearanceof energy spectrum CT.2、It hasn’t close relationship with lymph gland size. It can obtain quantitativeimaging data of inflammatory lymph glands, and provide a reference for imaging toidentify different lymph glands.3、It can provide further information of lymph glands imaging differential diagnosisof scientific research.