Evaluation Of Preoperative Resectability Of Pancreatic Cancer By Energy Spectrum

Part1The multi-parameter imaging of spectral CT to evaluate pancreatic cancerObj ective To explore the value of spectral CT multi-parameter imaging to evaluate pancreatic cancer.Methods Forty-six patients included in this study underwent spectral CT imaging from Oct.2012to Dec.2013. All the patients had diagnosis confirmed by pathology.Using GSI can gain monochromatic images and observe the imaging features of the lesions in optimal monochromatic images. Measure the spectral parameters (CT values, iodine-water concentration, water-iodine concentration and Effective.Z) of dual-phase pancreatic cancer and adjacent normal pancreatic tissue, calculate the spectrum curve slope of pancreatic cancer and adjacent normal pancreatic tissue and dispose the data for statistical analysis.Results In the arterial phase(AP), the range of optimal monochromatic value is53-72Kev, mean is62±6Kev, and in the portal vein phase(PP), the range is53Kev-72Kev, mean is63±7Kev.Pancreatic head cancer24cases, pancreatic cervical cancer6cases, pancreatic body cancer9cases, pancreatic tail carcinoma5cases, pancreatic head and body increased1case, one case involved the whole pancreas. The tumor size ranges from1.0cm×0.7cm×1.0cm to7.4cm×5.6cm×7.5cm, the average size is3.8cm×3.0cm×4.0cm. Pancreatic cancer mostly low-density lesion, no significant enhancement. The lesions is isodense or slightly hypodense on the water-based image, hypodense on the iodine-based image and the border of mass is often unclear in the arterial phase, while iodine uptake can be seen around lesions and showed a slightly higher density changes in the portal vein phase. In the arterial phase, the spectral parameters(CT values, iodine-water concentration, water-iodine concentration, effective.Z and curve slope) of pancreatic cancer are52.0±14.7HU,6.7±2.9mg/ml,1027±8.7mg/ml,8±0.2,0.8±0.3HU/Kev respectively in the62Kev monochromatic images,and the spectral parameters of adjacent normal pancreatic tissue are100.7±21.8HU,19.3±5.3mg/ml,1029±8.8mg/ml,8.7±0.3, 2.3±0.6HU/Kev respectively; in the portal vein phase, the spectral parameters of pancreatic cancer are61.4±17.1HU,10.6±4.6mg/ml,1026±9.2mg/ml,8.3±0.3,1.2±0.5HU/Kev respectively in the63Kev monochromatic images and the spectral parameters of adjacent normal pancreatic tissue are121.5±21.2HU,26±5.6mg/ml,1029±9.4mg/ml,9.0±0.2,3.1±0.7HU/Kev respectively.Conclusion In the dual-phase, spectral parameters of pancreatic cancer were lower than normal pancreatic tissue. There were significant differences among the CT values, iodine-water concentration, water-iodine concentration, effective.Z and curve slope of pancreatic cancer and normal pancreatic tissue, while no significant differences among the water concentration. Part2. Preoperative resectable Evaluation of Pancreatic cancer with spectral CTObjective To study the value of spectral CT in the preoperative assessment of resectability in patients with carcinoma of pancreas.Methods: Forty-six patients included in this study underwent spectral CT imaging from Oct.2012to Dec.2013. All the patients had diagnosis confirmed by pathology. Application of optimal monochromatic image and mutiple planar reformation (MPR), curve planar reformation (CPR), maximum intensity projection (MIP) volume rendering (VR) of four methods of three-dimensional reconstruction of peripancreatic vessels. According to Li Hui, Lu and other studies of vascular invasion grading standards violations per pancreatic vascular evaluation, assessment of main blood vessels were: hepatic artery (HA), celiac (CA), superior mesenteric artery (SMA), portal vein (PV), superior mesenteric vein (SMV).Application of spectrum curve, scatter plots, histograms, Effective-Z determine the existence of metastases. Statistical analysis using SPSS17.0statistical analysis software to calculate the overall vascular spectral CTA evaluate the specificity and sensitivity, and compared with surgical findings.Using the x2test compare the difference spectral CTA findings and surgical outcomes.Results46cases of pancreatic cancer patients,8cases were liver metastases, all8cases of metastases were confirmed by puncture biopsy or exploratory laparotomy.The optimal monochromatic value of peripancreatic arteries are52KeV to62KeV, mean are55±3Kev, peripancreatic vein are50Kev to57KeV,mean are53±2Kev. Analyze with38patients without liver metastases,celiac (CA) invasion5cases, superior mesenteric artery (SMA) invasion11cases, hepatic artery (HA) invasion5cases, portal vein (PV) invasion14cases,superior mesenteric vein (SMV) invasion15cases; lymphadenectasis10cases,of which9cases origin from pancreas, one case is different from pancreas, and another two cases with small lymph nodes origin from pancreas. With statistical analysis,the specificity of their assessment of arterial invasion is98.9%, sensitivity95.2%; the specificity of vein invasion specificity100%, sensitivity90.6%; the specificity of overall vascular invasion99.2%, sensitivity94.2%.Conclusion spectral CT can determine cancer liver metastasis and lymph node metastasis accurately, improve specificity and sensitivity of peripancreatic vascular invasion and accuracy of preoperative resectable Evaluation.