Study On Value Of320-slice Volume CT Orbit Subtraction Imaging In Evaluating Efficacy Atfer TACE For Primary Liver Cancer

Objective：To study the value of320-slice volume CT orbit subtraction imagingin evaluating the efficacy after TACE for primary liver cancer.Materials and Methods：35TACE-treated patients were randomly selected. Within1weekafter1-month treatment, the follow-up examinations of320-slice volumeCT perfusion scan, orbit subtraction scan and MRI enhanced scan wereperformed. The MRI and CT orbit subtraction images were evaluated forresidual enhancement areas by two radiologists with under adouble-blinded state. In order to improve the evaluation accuracy, twogroups of images were assessed by each radiologist at an interval of2weeks and scored according to the5-point evaluation standard(1score: noresidual enhancement areas;2scores: possibly no residual enhancementareas;3scores:uncertainly residual enhancement areas;4scores: possiblyresidual enhancement areas;5scores: residual enhancement areas). Themaximum diameter and minimum diameter of CT subtraction images andMRI images of lesion-residual enhancement areas with4and5scoreswere measured by two observers, respectively; and the inter-observeragreement and the evaluation consistency of residual enhancement areas between two imaging methods were both analyzed using Kappa test. Thex2test and t test were used for inter-group comparisons. P<0.05suggested that there was a statistical difference.Results：In35patients,2cases died during follow-up,3cases lost follow-up atthe specified time, and30cases (42lesions) were followed up. MRIenhanced scan: the image score was4.12±0.36, the average maximumdiameter of residual enhancement areas in the arterial phase was3.43±0.12cm and the average minimum diameter was1.11±0.56cm. CTorbit subtraction scan: the image score was4.05±0.44, the averagemaximum diameter of residual enhancement areas in the arterial phasewas3.22±0.08cm and the average minimum diameter was1.33±0.24cmThere was inter-observer agreement (k=0.89) and evaluation consistencyof residual enhancement areas between two imaging methods (k=0.50).As measured, there were no differences in the maximum diameter ofresidual enhancement areas（P=0.065） and there were difference in theminimum diameter of residual enhancement areas in the arterial phase（p=0.034）.Conclusion:320-slice volume CT orbit subtraction imaging and MRI enhanced imaging have consistency in evaluating the tumor residual areas afterTACE for primary liver cancer.