Multi-imaging Study Of Pancreatic Cancer

Objective: By synthesizing imaging comparative studies and comparing with postoperative pathology, to evaluate the value of routine multi-detector CT noncontrast enhanced scan, multi-phase enhanced scan and CT perfusion imaging, conventional MRI and correlated new imaging technology for early diagnosis of pancreatic cancer, differential diagnosis and preoperative staging, curative effect and prognosis assessment.Methods: Forty-five patients underwentCT and MRI examination from December 2008 to December 2009. Pancreas was taken routine scan, multi-phase enhancement scan and CT perfusion imaging by GE Light Speed Pro32 multi- detector CT, and take routine scan, MRI perfusion and delayed enhanced scan by Siemens Avanto 1.5T superconducting MRI , applying the body phased-array coil. CT and MRI routine scan model and sequence; CT enhance scan and perfusion used high-pressure injector, bolus injected non-ionic iodine contrast agent 50ml (Ultravist 300 mgI/s ml) through elbow vein, at speed of 5.0ml /s, using the film mode (0.55 per lap), analyzed blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PS) mean of lesions and normal pancreatic tissue. Scan phase of Routine enhanced scan was divided into: arterial phase 25 seconds, pancreas phase 45 seconds, portal phase 70 seconds. Scan at interval of 5mm, images was reconstructed at section thickness of 0.625mm or 1.25mm; MRI perfusion scan with T1WI sequence, using high-pressure injector injected Magnevist 20 ml through the back of the hand vein, or median cubital vein, at speed of 2.5 ml/s, applied manual mode. The mean of perfusion parameters enhanced signal of lesions and normal pancreatic tissue was analyzed. Taking delayed scan to observe the signal strength of lesion and normal pancreatic tissue.SPSS 11.5 was used as statistical analysis software. Percentage method was used to analyze detection rate of lesions. Every phase parameters of normal pancreatic tissue and pancreatic tumor tissue and the mean of the every perfusion parameters were analyzed to test the significance of the difference. Chi-square test, t test, single factor analysis of variance, and non-parametric rank sum test and so on was used. Z test of The area under ROC curve, P> 0.05 regard as no significant difference statistically; P <0.05 regard as significant difference statistically; P <0.01 regard as highly significant difference statistically.Results:Part One1. In 45 case of patients, 17 patients with pancreatic head carcinoma, 2 cases with pancreatic neck carcinoma, 6 cases with uncinate process carcinoma, 8 cases with pancreatic body carcinoma, 7 cases with pancreatic tail carcinoma, 5 cases with pancreatic cancer involved both pancreatic body and tail; The maximum diameter of tumor range 0.9cm from 12cm, average diameter was 3.44cm size. 2 cases were less than 1cm, 9 cases were in 1-3cm, 24 cases were in 3-5cm, 10 cases were greater than 5cm.2. A total of 31 cases got pathological results (including 25 cases underwent surgery, biopsy in 6 cases): 17 cases were pancreatic adenocarcinoma, 2 cases were cystadenoma, 5 cases was solid pseudopapillary tumor, of which 3 cases showed malignant invasive growth, 1 case was gland atypical hyperplasia, 1 case puncture results were negative, adenocarcinoma was found in pleural effusion in 1 case. adenocarcinoma nodules was found in liver in 2 cases, omental adenocarcinoma metastasis nodules was found in 2 cases.3. 16 cases showed equal attenuation at unenhanced phase; 8 cases showed equal attenuation at arterial phase; 1 case showed equal attenuation at pancreas phase; 2 cases showed equal attenuation at portal phase. At unenhanced, arterial phase, pancreatic phase and portal phase, the detection rate of pancreatic lesions are different (χ2 = 24.880, P = 0.000). The detection rate was 64.44%, 82.22%, 97.78% and 95.56% respectively, at pancreas phase is highest. The CT value and T value dCifference of Arterial phase, pancreatic phase, portal phase of lesions and normal pancreatic tissue and was significant statistically (P <0.05,P*<0.05).4. BF, BV, MTT and PS values between carcinoma tissue and normal pancreatic tissue has significant difference statistically (P <0.05), BF, BV, MTT and PS values of pancreatic cancer was lower than the normal pancreatic tissue, while the MTT values were higher than normal pancreatic tissue.Part Two1. 8 cases in T1WI sequence, 6 cases in T2WI sequence, 4 cases in T1WI with FS sequence, and 3 cases in T2WI with FS was equal signal, lesions both can be found at enhance and DWI sequences; Detection rate of pancreatic lesion in every sequence (χ2 =16.299, P = 0.000) was statistically significant. The detection rate of T1WI, T2WI, T1WI with FS, T2WI with FS, DWI sequences and enhance were 64.44%, 82.22%, 97.78%, 95.56%, 100% and 100% respectively.2. The ADC value measurements of Pancreatic lesions and normal pancreatic tissue showed that pancreatic cancer lesion ADC value was 1.236±3.53×10-3mm2/s, The ADC value of normal pancreatic tissue was 1.565±3.71×10-3mm2/s, (u =-3.995, P = 0.000) the difference between them was significant statistically.3. Average enhanced signal of Pancreatic cancer and normal pancreatic tissue perfusion parameters measurements showed that: Average enhanced signal of Pancreatic cancer and normal pancreatic tissue measurement results showed that pancreatic cancer lesions was 25.65±9.03, and normal pancreatic tissue was 45.79±7.36 , (u =-4.815, P = 0.000) the difference between them two was significant statistically.Part Three1.The detection rate difference among CT and MRI two kinds of examination for pancreatic cancer has significant statistically difference (n=33,χ2=60.099,P=0.000), were 87.88% and 66.67% respectively.2. Diagnose efficiency of the pancreatic cancer diagnosis by CT, MRI and CT / MRI (serial test) contrast with pathological results (n=33). Diagnose sensitivity pancreatic cancer of CT was 96.29%, specificity was 50.00%, accuracy was 87.88%, positive predictive value was 89.66%, negative predictive value was 75.00%. Diagnose sensitivity for pancreatic cancer of MRI was 77.78%, specificity was 83.33%, accuracy was 78.79%, positive predictive value was 95.45%, negative predictive value was 45.45%. Diagnose sensitivity for pancreatic cancer of CT/MRI was 77.78%, specificity was 100%, accuracy was 78.79%, positive predictive value was 100%, negative predictive value was 45.45%.3. The area under ROC curve CT(0.731,CI:0.466-0.997),MRI(0.806,CI:0.607-1.004),CT/MRI(0.889,CI:0.778-0.999);The area under ROC curve for diagnosis with combination of CT and MRI 0.449 was unsignificantly, CT and CT/MRI 0.3587 was unsignificantly, MRI and CT/MRI 0.4944 was unsignificantly, the three imaging methods was no significant differene.Part Four1. 29 cases of patients underwent surgical resection, in which 21 cases were judged asⅠandⅡphase, resectability rate was 72.41%, 8 cases were judged as stageⅢ,Ⅳphase, non-resection rate was 100% by multi-slice spiral CT. Accuracy rate of preoperative staging of I phase was 50%; II phase was 36.36%; III phase was 85.71%: IV phase was 100%. The unresectable sensitivity was 100%, specificity was 50%, accuracy was 72.41%, positive predictive value was 61.90%, negative predictive value was 100%. Conclusion:Part One1. Detection rate of multi-slice spiral CT routine scan and multi-phase enhanced scanning for pancreatic lesions,pancreatic phase has highest, multi-phase enhanced scan was significantly higher than routine scan.2. multi-slice spiral CT perfusion imaging results showed that pancreatic lesions perfusion parameters BF, BV and PS values were lower than the normal pancreatic tissue, while the MTT values were higher than normal pancreatic tissue. Part Two1. The detection rate of pancreatic lesions of MRI normal sequence detection T1WI with FS sequence is higher than other routine sequence; While detection rate of enhanced scan or MRI diffusion-weighted imaging for pancreatic lesions were both higher than routine MRI.2. ADC value of pancreatic cancer was less than normal pancreatic tissue, the average enhanced the signal value of pancreatic cancer was less than normal pancreatic tissue.Part Three1. The efficiency of CT and MRI two kinds of inspection methods for detection of pancreatic cancer ranked from high to low as CT,MRI.2.Tpe-B Ultrasonography can be used for screening, CT or MRI for the qualitative diagnosis, At first ,we can chooses combination of Ultrasoun and CT, If have CT contraindication that it is necessary Supplemented by MRI examinationPart Four1. Multi-slice spiral CT for pancreatic cancer has higher resectable sensitivity, but has lower accuracy and positive predictive value. unresectable sensitivity with high accuracy.2. Multislice spiral CT for pancreatic cancer staging and guiding appropriate clinical treatment plan has significant value.