,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,*,MRI of Pancreatitis and Its Complications:Chronic,Pancreatitis,宋承汝 2013,.6.5,慢,性胰腺炎及其并发症的MRI表现,MRI of Pancreatitis and Its Co,1,Chronic pancreatitis is an inflammatory disease characterized by progressive and irreversible structural damage to the pancreas resulting in permanent impairment of both exocrine and endocrine functions.ERCP is the gold standard for early chronic pancreatitis,but it is invasive.MRI may be an alternative for patients in whom CT or ERCP is contraindicated or not tolerated.,MRI provides noninvasive biliary and pancreatic duct imaging and accurate characterization of pancreatic and peripancreatic pathology.慢性胰腺炎是一种炎症性疾病，其特征,是对,胰腺逐步和不可逆转的结构性损坏，导致外分泌和内分泌功能的永久性,受损,。ERCP是,诊断,早期慢性胰腺炎的金标准，但它是侵入,性检查,。在CT或ERCP,为,禁忌或不能耐受,时，,MRI可,作为,替代。MRI提供非侵入性胆胰管成像和胰腺及胰周病变的,征象,。,Chronic pancreatitis is an in,2,The diagnosis of chronic pancreatitis on MRI is based on signal intensity and enhancement changes as well as on morphologic abnormalities in the pancreatic parenchyma,pancreatic duct,and biliary tract.The imaging features of chronic pancreatitis can be divided into early and late findings.,慢性胰腺炎MRI诊断是基于信号强度和增强的变化，以及胰腺实质，胰管和胆道形态的异常。慢性胰腺炎的影像特征可分为早期,表现,和晚期表现。,The diagnosis of chronic pancr,3,Early findings include low-signal-intensity pancreas on T1-weighted fat-suppressed images,decreased and delayed enhancement after IV contrast administration,and dilated side branches.Late findings include parenchymal atrophy or enlargement,pseudocysts,and dilatation and beading of the pancreatic duct often with intraductal calcifications.,早期,表现,包括T1加权脂肪抑制图像,上呈,低信号，,延迟强化或强化程度减低,，侧支,扩张,。晚,期表现,包括实质萎缩或肿大，假性,囊肿，,胰管,扩张或呈串珠样，,导管内,常伴,钙化。,Early findings include low-sig,4,MRI allows early recognition of chronic pancreatitis based on changes in pancreatic signal intensity;these changes are best visualized on unenhanced and gadolinium-enhanced T1-weighted fat-suppressed images(Fig.,1A,1B,1C,1D,).,MRI可以早期识别慢性胰腺炎胰腺信号强度的变化，平扫和增强T1加权脂肪抑制图像,显示信号变化最佳,（图1A，1B，1C，1D）。,MRI allows early recognition o,5,Fig.1A.1B.,Fig.1A.24-year-old woman with small pancreatic duct stone causing duct obstruction and segmental pancreatitis.Axial T2-weighted HASTE image shows slightly increased signal intensity of pancreatic tail(,arrow,)with mild dilatation of pancreatic duct.Axial T1-weighted fat-suppressed spoiled gradient-echo image shows abnormal low signal intensity of pancreatic tail(,arrow,)while remainder of pancreas has normal bright signal intensity.,24岁,，,女,。,小胰管结石引起胆道梗阻和节段性胰腺炎。,T2WI胰尾信号轻度升高，胰管轻度扩张,（箭头）。,T1WI,显示胰尾,异常低信号,（箭头），,胰腺其余部分,信号强度正常,，为高信号。,Fig.1A.1B.Fig.1A.24-year-o,6,Axial enhanced T1-weighted fat-suppressed spoiled gradient-echo image obtained during arterial phase shows delayed enhancement of pancreatic tail(,arrow,)relative to normal pancreas due to fibrosis.Patient later developed atrophic changes in this area that led to resection of pancreatic tail.Contrast-enhanced CT scan shows punctate high-density focus(,arrow,)in pancreatic duct representing small intraductal stone.This example illustrates the advantage of CT in showing tiny intraductal stone that was not seen on MRI.It,however,also illustrates the advantage of MRI in showing changes of signal intensity associated with chronic pancreatitis that are not visible on CT.,动脉期,增强T1WI,示因纤维化胰尾,较正常胰腺,强,化,延迟（箭头），,此处后来呈萎缩性改变，,导致,实行,胰尾切除术。对比增强CT扫描显示,胰管内,小结石。这个例子说明了CT的优势在于显示微小的管内结石，而在MRI未显示。然而，它也,显,示出磁共振成像的优点,：可显,示出慢性胰腺炎信号强度的变化与关系，,此,在CT上是不可见的。,Fig.1C.1D.,Axial enhanced T1-weighted fat,7,Chronic inflammation and fibrosis diminish the proteinaceous fluid content of the pancreas,resulting in the loss of the usual high signal intensity on T1-weighted fat-suppressed images.The normal pancreas enhances uniformly and intensely on early arterial phase contrast-enhanced T1-weighted images and exhibits rapid washout of gadolinium on subsequent images.,慢性炎症和纤维化减少胰腺的蛋白质含量，,使得,在T1加权脂肪抑制图像,上高,信号,消失,。正常胰腺,动脉期,均匀,明显强化，并快速廓清,。,Chronic inflammation and fibro,8,In contrast,a pancreas with chronic fibrosis and glandular atrophy exhibits decreased and heterogeneous enhancement on early arterial phase images and increased relative enhancement on delayed images(Fig.,2A,2B,2C,).,相比之下，慢性纤维化,并,腺体萎缩,的胰腺在早动脉期强化程度减低并强化不均匀，延迟图像上强化程度相对升高,（图2A，2B，2C）,In contrast,a pancreas with c,9,Fig.2A.,2B.,Fig.2A.,46-year-old man with history of chronic pancreatitis due to alcohol abuse.Axial T1-weighted fat-suppressed spoiled gradient-echo image shows atrophy of pancreatic parenchyma and irregular dilatation of main pancreatic duct(,arrows,),changes suggestive of chronic pancreatitis.Calcifications are not as well seen on MRI as on CT.Axial enhanced T1-weighted fat-suppressed spoiled gradient-echo image obtained during arterial phase shows diffusely decreased pancreatic enhancement relative to marked enhancement seen normally.This decreased enhancement relates to fibrosis due to chronic pancre