Clinical Study Of MR Perfusion Weighted Imaging In Pancreatic Disease

Objective:To determine which one is better at MR perfusion weighted imaging in normal pancreas by comparing sequence FLASH 2D and VIBE. To investigate the difference of perfusion between head,neck,body and tail of normal pancreas.To evaluate the diagnosis and differential diagnosis value of MR PWI in pancreas diseases.Methods:1.A group of 28 healthy volunteers were studied.They underwent MR perfusion with sequence FLASH 2D and VIBE.The interval of the two sequences was 24 hours.Compared the value of signal-to-noise rate(SNR) in the two sequences and a statistical analysis was done.Drew a region of interest(ROI) in aorta,head,neck,body and tail of pancreas respectively,then got their time-intensity curves(TIC).Calculated the time to peak(TTP) and the steepest slope(SS).Then the following statistical analysis were performed:Perfusion gained with different sequences and perfusion gained from head,neck,body and tail of pancreas.2.A group of 38 patients with pancreatitis underwent MR perfusion with sequence VIBE,including acute pancreatitis(AP)(n=15)and chronic pancreatitis(CP)(n=23).Drew a region of interest(ROI) in 38pancreatitis respectively,then got their time-intensity curves(TIC).Calculated the time to peak(TTP) and the steepest slope(SS).The results of these pancreatitis and normal pancreas were statisticaly analyzed. 3.A group of 67 patients with lumps in pancreas underwent MR perfusion with sequence VIBE,including pancreas carcinoma(n=34),serous cystadenoma(n=6),solid-pseudopapilla tumors(SPT)(n=9),islet cell tumor(n=4),pseudocyst(n=10),and tumor-forming pancreatitis(n=4).Drew a region of interest(ROI) in lumps of pancreas respectively,then got their time-intensity curves(TIC).Calculated the time to peak(TTP) and the steepest slope(SS).The results of these lumps and normal pancreas were statisticaly analyzed.Results:1.TTP of normal pancreas were 23.71±3.15s,24.84±3.80s respectively,and SS 30.34±3.59,30.48,3.28.There was no difference between the results of sequence FLASH 2D and VIBE(P＞0.05).SNR of FLASH 2D and VIBE were 55.71±11.44,111.52±29.35(P＜0.05).2.The TTP of head,neck,body and tail of normal pancreas were 24.33±3.74s,23.82±2.14s,23.75±3.94s,23.47±2.40s respectively,and the SS 30.23±4.66,29.69±3.39,31.02±2.54,30.83±2.60.There was no difference between perfusion of pancreas head,neck,body and tail.3.The TTP of AP and CP were 36.80±3.48s,79.67±13.55s,SS分别为24.07±0.86,19.32±5.37.There was a significant difference between each two groups(P＜0.05).4.The curve of pseudocyst showed an approximately horizontal straight line,and no calculation was given.There was only 2 neuroendocrine carcinoma,and the sample size was too small to do statistical analysis.The TTP of serous cystadenoma,solid-pseudopapilla tumors(SPT),islet cell tumor,pancreascarcinomaandtumor-formingpancreatitiswere 57.74±15.23s,8 6.46±35.23s20.70±5.36s,140.24±24.14s and 82.66±20.5 srespectively, and the SS 7.65±3.07,20.73±5.36,53.64±5.60,16.10±2.20,19.14±6.05.The difference between each 2 groups were significant except the TTP between normal pancreas and islet cell tumor,and the TTP and SS between SPT and tumor-forming pancreatitis(P＞0.05).Conclusion:Sequence VIBE can be applied in whole-pancreas MR perfusion,and the images has higher SNR.Its results are reliable.PWI has potential clinical application value in the diagnosis and differential diagnosis of pancreatic diseases..