Preliminary Study On The Application Of Spectral Ct Imaging Characteristics For Histopathologic Differentiation Of Hepatocellular Carcinoma

Objective:To investigate the application of spectral CT imaging characteristics for histopathologic differentiation of hepatocellular carcinoma by using spectral CT and multi-parameter quantitative measurement such as Iodine content,water content and spectrum energy curve.Materials and Methods:A total of57patients who went to see a doctor in Qianfoshan Hospital of Shandong Province because of hepatocellular carcinoma from September2012to March2014were collected, including male35cases, female22cases who were aged between30and70years old, and mean age was58years old. All cases had been proved as hepatocellular carcinoma by surgery or biopsy pathology. Among the56cases, histopathologic results showed high differentiated HCC in19, moderate differentiated HCC in20, poor differentiated HCC in18.They were scanned by using spectral CT (Discovery CT750HD), including plain scan, arterial, portal venous and lag phase enhancement scanning. The plain scan and lag phase enhancement scanning were in routine scan mode,and arterial and portal venous phase enhancement scanning were in GSI mode. The non-ionic contrast medical lohexol (300mg I/ml) at the dose of1.5ml/kg was injected with power injector at a rate of3ml per second through median cubital vein, thickness:5.0mm,collimation:40mm, screw pitch:0.985, FOV:36.Arterial enhancement scanning was triggered by monitoring, and the region of interest (ROI) was set in the abdominal aorta. We started scanning after8s when the threshold was up to100HU, and the portal venous phase scan was conducted after30s when the arterial phase was over.And the lag phase scan lag phase was conducted after50s when the portal venous phase scan was over.All patients were signed informed consent themselves before the inspection.Reform conventional polychromatic images into0.625mm thicken monochromatic ones and send them to GE AW44work-station. All data was analyzed by GSI Viewer software. The maximum level of lesion was selected and ROI which located in the center of lesions accounted for1/2-1/3of the lesion, avoiding necrotic tissue, calcification, and blood vessels. Then measure Iodine content, water content and calculate the corresponding spectrum energy curve slope.56cases were divided into three groups:high differentiated,moderate differentiated and poor differentiated based on the pathologic results. A contrast analysis was conducted between various spectral CT parameters and histopathologic differentiation of hepatocellular carcinoma in three groups. SPSS17.0software with ANOVA method was used for statistic analysis in the three groups and P<0.05was considered statistically significant difference.Results:In57cases of patients with hepatocellular carcinoma,there were19high differentiated cases,including3cases with obvious enhancement in AP and16cases with light enhancement in AP;20moderate differentiated cases, including12cases with obvious enhancement in AP and8cases with light enhancement in AP;18poor differentiated cases, including17cases with obvious enhancement in AP and1cases with light enhancement.The spectrum energy curve slope in high, moderate and poor differentiated group were (0.52±0.05),(1.17±0.16).(1.72±0.15)(F=130.22, P<0.05) respectively; the Iodine content in the three groups were (6.69±0.9)、(15.24±2.03)、(22.68±2.33)(F=106.27, P<0.05), which indicated difference existed in spectrum energy curve slope and Iodine content between the three groups, while water content were found no difference(F=0.2, P>0.05), the water content were (1023.56±10.78)、(1021.32±8、59).(1024.35±11.67) respectively.Conclusion:The spectrum energy curve slope and Iodine content in high differentiated group were significantly lower than the poor differentiated group, and moderate differentiated group fell in between the two groups (P<0.05), which indicated the correlation of spectral CT imaging characteristics in arterial phase with histopathologic differentiation of hepatocellular carcinoma. Spectral CT with multi-parameter quantitative measurement such as Iodine content, water content and spectrum energy curve offers a mensurable analysis, which can distinguish grade malignancy of hepatocellular carcinoma on a pathological level. And it will provide more theoretical basis for clinical treatment and prognosis evaluation of hepatocellular carcinoma.