慢性胰腺炎與并發(fā)癥

1、慢性胰腺炎與并發(fā)癥 慢性胰腺炎MRI診斷是基于信號(hào)強(qiáng)度和增強(qiáng)的變化，以及胰腺實(shí)質(zhì)，胰管和膽道形態(tài)的異常。慢性胰腺炎的影像特征可分為早期表現(xiàn)和晚期表現(xiàn)。 早期表現(xiàn)包括T1加權(quán)脂肪抑制圖像上呈低信號(hào)，延遲強(qiáng)化或強(qiáng)化程度減低，側(cè)支擴(kuò)張。晚期表現(xiàn)包括實(shí)質(zhì)萎縮或腫大，假性囊腫，胰管擴(kuò)張或呈串珠樣，導(dǎo)管內(nèi)常伴鈣化。 MRI可以早期識(shí)別慢性胰腺炎胰腺信號(hào)強(qiáng)度的變化，平掃和增強(qiáng)T1加權(quán)脂肪抑制圖像顯示信號(hào)變化最佳（圖1A，1B，1C，1D）。 Fig. 1A. 24-year-old woman with small pancreatic duct stone causing duct obstruction

2、 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 re

3、mainder of pancreas has normal bright signal intensity.24歲，女。小胰管結(jié)石引起膽道梗阻和節(jié)段性胰腺炎。T2WI胰尾信號(hào)輕度升高，胰管輕度擴(kuò)張（箭頭）。 T1WI顯示胰尾異常低信號(hào)（箭頭），胰腺其余部分信號(hào)強(qiáng)度正常，為高信號(hào)。Axial enhanced T1-weighted fat-suppressed spoiled gradient-echo image obtained during arterial phase shows delayed enhancement of pancreatic tail (arrow) relat

4、ive 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 o

5、f 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.動(dòng)脈期增強(qiáng)T1WI示因纖維化胰尾較正常胰腺?gòu)?qiáng)化延遲（箭頭），此處后來(lái)呈萎縮性改變，導(dǎo)致實(shí)行胰尾切除術(shù)。對(duì)比增強(qiáng)CT掃描顯示胰管內(nèi)小結(jié)石。這個(gè)例子說(shuō)明了CT的優(yōu)勢(shì)在

6、于顯示微小的管內(nèi)結(jié)石，而在MRI未顯示。然而，它也顯示出磁共振成像的優(yōu)點(diǎn)：可顯示出慢性胰腺炎信號(hào)強(qiáng)度的變化與關(guān)系，此在CT上是不可見(jiàn)的。 慢性炎癥和纖維化減少胰腺的蛋白質(zhì)含量，使得在T1加權(quán)脂肪抑制圖像上高信號(hào)消失。正常胰腺動(dòng)脈期均勻明顯強(qiáng)化，并快速廓清。 相比之下，慢性纖維化并腺體萎縮的胰腺在早動(dòng)脈期強(qiáng)化程度減低并強(qiáng)化不均勻，延遲圖像上強(qiáng)化程度相對(duì)升高（圖2A，2B，2C）Fig. 2A. 46-year-old man with history of chronic pancreatitis due to alcohol abuse. Axial T1-weighted fat-suppr

7、essed 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 ob

8、tained during arterial phase shows diffusely decreased pancreatic enhancement relative to marked enhancement seen normally. This decreased enhancement relates to fibrosis due to chronic pancreatitis. Dilated pancreatic duct (arrows) is visualized more clearly after contrast administration.46歲，男，因酗酒致

9、慢性胰腺炎。T1WI顯示胰腺實(shí)質(zhì)的萎縮和不規(guī)則擴(kuò)張的主胰管（箭頭），提示慢性胰腺炎的變化。鈣化在MRI和CT上都沒(méi)有看到。 動(dòng)脈期增強(qiáng)T1WI顯示胰腺因慢性炎癥引起的纖維化而強(qiáng)化彌漫性降低，而非通常看到的顯著增強(qiáng)。胰管擴(kuò)張（箭頭）顯示更清。 MRCP is highly accurate for identifying pancreas divisum (Fig. 6). However, its association with pancreatitis remains controversial. Duct abnormalities such as dilatation, irregul

10、arity, and stones and complications of chronic pancreatitis such as pseudocysts are best depicted by thin-section T2-weighted HASTE or single-shot fast spin-echo and thick-slab T2-weighted half-Fourier RARE MRCP images. MRCP發(fā)現(xiàn)胰腺分裂的準(zhǔn)確度很高（圖6）。然而，它與胰腺炎的關(guān)系仍存在爭(zhēng)議。胰管異常，如擴(kuò)張，不規(guī)則，結(jié)石和并發(fā)癥如假性囊腫，在薄層T2加權(quán)HASTE或MRCP

11、顯示最佳。Fig. 6. 53-year-old woman with history of cholecystectomy who presented with jaundice, abnormal results on liver function tests, and pancreas divisum. Axial T2-weighted image shows noncommunicating main pancreatic duct (straight arrow) and accessory duct (curved arrow) draining separately into

12、duodenum.圖6， 53，女。膽囊切除術(shù)后，黃疸，肝功能異常，胰腺分裂癥。軸位T2WI顯示軸向T2加權(quán)圖像顯示，互不溝通的主胰管（直箭頭）和配胰管（彎箭頭）分別進(jìn)入十二指腸引流。MRCP is accurate in depicting strictures of the pancreatic duct or biliary tract (Fig. 7). In equivocal cases, ductal distention by contrast injection during ERCP may be helpful. The beaded main pancreatic du

13、ct with its dilated side branches may have a chain-of-lakes appearance when more extensive (Fig. 8). MRCP可準(zhǔn)確的描繪胰管或膽管的狹窄（圖7）。在模棱兩可的情況下，在ERCP過(guò)程中導(dǎo)管注射造影劑擴(kuò)張胰膽管可能會(huì)有幫助。當(dāng)病變廣泛時(shí)，串珠樣主胰管和擴(kuò)張的側(cè)枝，可能有連鎖湖樣改變。 Fig. 7. 62-year-old woman with history of chronic pancreatitis and pseudocysts. Coronal T2-weighted thick-sl

14、ab RARE image shows stricture (straight arrow) of pancreatic duct at level of pancreatic head. Upstream pancreatic duct is dilated and irregular, and there is mild dilatation of side branches. Note diverticulum (curved arrow) arising from duodenum. 圖7。 62，女。慢性胰腺炎，假性囊腫。冠狀T2WI顯示胰頭水平胰管狹窄（直箭頭）。上游胰管不規(guī)則擴(kuò)張

15、，側(cè)枝輕度擴(kuò)張。注意十二指腸憩室（彎箭頭）。Fig. 8. 69-year-old man with chronic pancreatitis. Axial T2-weighted HASTE image shows irregular dilated main pancreatic duct and side branches giving chain-of-lakes appearance. Note atrophic changes in pancreas and signal-void areas (arrows) related to calcifications from chro

16、nic pancreatitis.圖8。69歲，男。慢性胰腺炎。軸向T2WI顯示不規(guī)則擴(kuò)張的主胰管和側(cè)枝，連鎖湖外觀?？梢?jiàn)胰腺萎縮及無(wú)信號(hào)鈣化區(qū)（箭頭）。CT is more sensitive than MRI for the detection of calcifications associated with chronic pancreatitis; however, MRI best depicts intraductal stones and duct obstruction (Figs. 9A, 9B and 10). Unlike ERCP, MRCP can show the

17、 dilated duct upstream from an obstructing stone. Nevertheless, visualizing intraductal stones not surrounded by fluid may be difficult on MRI (Fig. 1A, 1B, 1C, 1D).對(duì)慢性胰腺炎的鈣化檢測(cè)，CT比MRI敏感，然而，MRI顯示管內(nèi)結(jié)石和胰膽管阻塞最佳（圖9A，9B和10）。不同于ERCP，MRCP能顯示上游擴(kuò)張導(dǎo)管。然而，MRI診斷不被液體包圍的導(dǎo)管內(nèi)結(jié)石困難（圖1A，1B，1C，1D）。Fig. 9A. 46-year-old ma

18、n with history of chronic pancreatitis due to alcohol abuse. Axial contrast-enhanced CT scan shows multiple calcifications in pancreatic head. It is difficult to determine that a stone is in pancreatic duct. Calcifications are seen commonly in chronic alcohol-related pancreatitis, as in this patient

19、.Axial T2-weighted HASTE image shows stone (arrow) in main pancreatic duct delineated by high-signal-intensity fluid.圖9A。 男，46歲。酗酒史，慢性胰腺炎。軸向增強(qiáng)CT掃描顯示胰頭多發(fā)鈣化。從CT很難確定胰管內(nèi)有無(wú)結(jié)石。鈣化在慢性酒精相關(guān)性胰腺炎中很常見(jiàn)，此例即如此。軸向T2WI的顯示主胰管內(nèi)結(jié)石（箭頭）被高信號(hào)液體包繞。Fig. 10. 45-year-old woman with history of abdominal pain. Coronal T2-weighted

20、 HASTE image shows pancreatic duct stone (straight arrow) and gallstone (curved arrow). GB = gallbladder, CBD = common bile duct, PD = pancreatic duct, DUOD = duodenum.圖10。 45歲，女，腹痛。冠狀T2WI的顯示胰管內(nèi)結(jié)石（直箭頭）和膽結(jié)石（彎箭頭）。 GB =膽囊，CBD =膽總管，PD =的胰管，DUOD =十二指腸。1.Pseudocysts 假性囊腫2.Vascular 血管相關(guān)并發(fā)癥3.Biliary 膽管相關(guān)并發(fā)癥

21、Pseudocysts are encapsulated collections of pancreatic secretions that occur in or around the pancreas. Although most resolve spontaneously, complications such as infection, hemorrhage, and gastric or biliary obstruction may occur (Fig. 11A, 11B). Pseudocysts can be communicating with the main pancr

22、eatic duct (Fig. 12) or noncommunicating . MRI can depict pseudocysts and can be used to characterize their content and thus to guide drainage.假性囊腫是發(fā)生在胰腺內(nèi)或胰腺周圍被包裹的胰腺分泌物。雖然大多數(shù)可自發(fā)吸收，但也可發(fā)生并發(fā)癥，如感染，出血，胃或膽道梗阻（圖11A，11B）。假性囊腫與主胰管可連通（圖12）或不連通（圖13）。MRI可以描繪假性囊腫并檢測(cè)內(nèi)容物成分以指導(dǎo)引流。52-year-old man with history of recu

23、rrent pancreatitis. Axial T2-weighted HASTE image shows large thick-walled multiloculated cystic collection located primarily in lesser sac, representing pseudocyst (P). It does not communicate with pancreatic duct.Axial T1-weighted fat-suppressed spoiled gradient-echo image shows high-signal-intens

24、ity fluid within pseudocyst, suggestive of complicated pseudocyst (P). Internal consistency of pseudocysts may be altered because of presence of proteinaceous material, hemorrhage, or infection, and it may require prompt drainage.52歲，男，復(fù)發(fā)性胰腺炎。軸向T2WI的顯示主要位于小網(wǎng)膜囊的巨大厚壁多房假性囊腫 (P)。不與胰管溝通。 軸位T1WI顯示囊腫內(nèi)為高信號(hào)，

25、提示其為復(fù)雜性假性囊腫（P）。因存在蛋白性物質(zhì)，出血，或感染，假性囊腫內(nèi)部一致性可被改變，提示需要盡快引流。Fig. 12. 55-year-old woman with abdominal pain, weight loss, and history of pancreatitis. Axial T2-weighted HASTE image shows high-signal-intensity pseudocyst (P) in pancreatic head with dilated and irregular pancreatic duct. Pseudocyst can be se

26、en communicating with main pancreatic duct (arrow).圖12。 55歲，女。腹痛，體重減輕，胰腺炎。軸位T2WI顯示胰頭部高信號(hào)假性囊腫（P）及不規(guī)則擴(kuò)張的胰管?？梢钥闯黾傩阅夷[與主胰管（箭頭所示）連通。Arterial pseudoaneurysms, hemorrhage into pseudocysts, arterial bleeding, and splenic or portal vein thrombosis are vascular complications of chronic pancreatitis that may be

27、 seen on MRI. In patients with chronic splenic vein thrombosis, the vein may not be visualized. (Fig. 14A, 14B).假性動(dòng)脈瘤，假性囊腫內(nèi)出血，出血，脾靜脈或門靜脈血栓為慢性胰腺炎的血管相關(guān)并發(fā)癥，MRI可檢測(cè)出。但當(dāng)有慢性脾靜脈血栓時(shí)，靜脈可能無(wú)法顯示（圖14A，14B）Fig. 14A. 46-year-old man with history of chronic pancreatitis due to alcohol abuse. Axial enhanced T1-weight

28、ed fat-suppressed spoiled gradient-echo image obtained during venous phase shows chronic occlusion of portal vein with collaterals (arrow): cavernous transformation of portal vein. Fig.B shows collateral vessels (arrows), which is suggestive of splenic vein occlusion.46歲，男，慢性胰腺炎，酗酒史。靜脈期軸向增強(qiáng)T1WI示門靜脈慢

29、性閉塞（箭頭）呈海綿樣變。圖B顯示側(cè)支循環(huán)形成（箭頭），提示脾靜脈阻塞。The biliary complications of chronic pancreatitis include choledocholithiasis, fistulas, and dilatation of the common bile duct due to inflammatory strictures. The typical appearance of benign strictures on MRCP is gradual tapering with a funnellike narrowed segme

30、nt (Fig. 15).慢性胰腺炎的膽道并發(fā)癥，包括膽總管結(jié)石，瘺管，由于炎性狹窄而致的膽總管擴(kuò)張。 良性狹窄的典型MRCP表現(xiàn)為逐漸變細(xì)的漏斗樣狹窄（圖15）。Fig. 15. 59-year-old man with history of chronic pancreatitis. MR image was obtained to evaluate biliary tract and complex pseudocysts seen on prior CT scan (not shown). Coronal T2-weighted thick-slab RARE image shows

31、dilated common bile duct with funnel-shaped narrowing (arrowhead). Pancreatic duct is dilated and contains calculus (arrow) at pancreatic head level. Also seen are multiple pseudocysts (P) extending both superior and inferior to pancreas. GB = gallbladder.男，59歲，明顯胰腺炎。行MRI檢測(cè)以明確CT所示復(fù)雜假性囊腫并評(píng)價(jià)膽道情況。冠狀T2W

32、I顯示擴(kuò)張的膽總管、漏斗樣狹窄（箭頭）。胰管擴(kuò)張、胰頭處可見(jiàn)結(jié)石。并可見(jiàn)多發(fā)假性囊腫（P）延伸至胰腺前后方。 GB =膽囊。Differentiating between an inflammatory mass due to chronic pancreatitis and pancreatic carcinoma on the basis of imaging criteria remains difficult. Decreased T1 signal intensity with delayed enhancement after gadolinium administration a

33、s well as dilatation and obstruction of the pancreaticobiliary ducts can be seen in both diseases . Irregularity of the pancreatic duct, intraductal or parenchymal calcifications, diffuse pancreatic involvement, and normal or smoothly stenotic pancreatic duct penetrating through the mass (“duct pene

34、trating sign”) favor the diagnosis of chronic pancreatitis over cancer (Fig. 16A, 16B, 16C). In distinction, a smoothly dilated pancreatic duct with an abrupt interruption, dilatation of both biliary and pancreatic ducts (“double-duct sign”), and obliteration of the perivascular fat planes favor the

35、 diagnosis of cancer.鑒別慢性胰腺炎引發(fā)的炎性包塊和胰腺腫瘤，從影像學(xué)上尚屬困難。兩者均可出現(xiàn)延遲強(qiáng)化和胰膽管的阻塞擴(kuò)張。不規(guī)則的胰管，胰管內(nèi)或?qū)嵸|(zhì)內(nèi)鈣化，彌漫性胰腺受累，光滑狹窄的胰管從腫塊內(nèi)穿過(guò)（“穿透癥”）更支持慢性胰腺炎的診斷（圖16A，16B ，16C）。相反的，平滑擴(kuò)張的胰管突然中斷，膽管和胰管同時(shí)擴(kuò)張（“雙管征”），以及血管周圍脂肪間隙消失則支持腫瘤的診斷。Fig. 16A. 58-year-old woman with breast cancer and chronic pancreatitis related to alcohol abuse. Patie

36、nt had 50-lb (23-kg) weight loss. ERCP image (not shown) revealed stone in pancreatic duct, which was removed. Fine-needle aspiration was suggestive of adenocarcinoma. Whipple procedure indicated chronic pancreatitis without cancer. Axial T1 fat-suppressed spoiled gradient-echo image shows low-signa

37、l-intensity pancreas due to chronic pancreatitis.Axial enhanced T1-weighted fat-suppressed spoiled gradient-echo image obtained during arterial phase shows diffusely decreased enhancement of pancreas due to chronic pancreatitis. Note dilated pancreatic duct.圖16A。 58歲，女，乳腺癌、酗酒相關(guān)的慢性胰腺炎。發(fā)病以來(lái)體重下降23kg。 E

38、RCP圖像（圖中未示出）顯示胰管石并去除。細(xì)針穿刺提示腺癌。胰十二指腸切除術(shù)提示慢性胰腺炎無(wú)癌變。軸向T1WI顯示因慢性胰腺炎而呈低信號(hào)的胰腺。 動(dòng)脈期增強(qiáng)T1WI示胰腺?gòu)浡詮?qiáng)化減低。注意胰管擴(kuò)張。Fig. 16C. Axial T2-weighted HASTE image shows markedly dilated main pancreatic duct (arrow) penetrating through pancreas with chronic inflammatory and fibrotic changes: “duct penetrating sign.” This f

39、inding suggests chronic pancreatitis over adenocarcinoma.圖16C。同一病例。軸向T2WI示明顯擴(kuò)張的主胰管（箭頭），穿過(guò)具有慢性炎癥和纖維化的胰腺：“穿透征”。這一征象提示慢性胰腺炎可能性大。MRI may be superior to MDCT for the evaluation of pancreatic adenocarcinoma, especially if the lesion is small and non-contour-deforming. The tumor is best delineated on unenh

40、anced T1-weighted fat-suppressed images and multiphasic enhanced sequences (Fig. 17A, 17B, 17C, 17D).MRI在對(duì)胰腺腺癌的診斷上優(yōu)于MDCT，特別是病變較小且胰腺外形沒(méi)有異常時(shí)。平掃T1WI及多期增強(qiáng)序列上圖17A，17B，17C，17D）顯示最佳。71-year-old woman with weight loss due to adenocarcinoma of pancreas with associated chronic pancreatitis. Axial contrast-enh

41、anced CT scan shows atrophy of pancreatic tail and duct dilatation (arrow) to level of suspected mass, which is difficult to see.Axial T2-weighted HASTE image shows dilatation of pancreatic duct with abrupt termination (arrow) due to tumor. 71歲，女。慢性胰腺炎并腺癌。軸向增強(qiáng)CT示胰尾萎縮和胰管擴(kuò)張（箭頭），無(wú)法判斷是否有腫塊。軸向T2WI示由于腫瘤擴(kuò)張

42、的胰管突然終止（箭頭）。Fig. 17C. Axial T1-weighted fat-suppressed spoiled gradient-echo image shows low-signal-intensity mass (arrowhead), measuring less than 1 cm. Note atrophy and decreased signal intensity of pancreatic tail (curved arrow) related to associated chronic pancreatitis. Normally high signal int

43、ensity of pancreatic head (straight arrow) is preserved.Axial enhanced T1-weighted fat-suppressed spoiled gradient-echo image obtained during late venous phase shows delayed enhancement of tumor (arrowhead). This example shows value of MRI to depict nondeforming pancreatic mass .同一病例，軸向T1WI示低信號(hào)腫塊（箭頭

44、），小于1厘米。注意慢性胰腺炎引起的胰尾信號(hào)減低并萎縮（彎箭頭）。胰頭仍為正常高信號(hào)（直箭頭）。靜脈期軸向增強(qiáng)T1WI示延遲強(qiáng)化的腫瘤（箭頭）。這個(gè)例子顯示MRI在診斷不伴有胰腺外形失常的胰腺腫瘤中的價(jià)值。Groove pancreatitis is a type of focal chronic pancreatitis affecting the groove between the head of the pancreas, duodenum, and common bile duct. The predominant MRI finding of groove pancreatitis

45、 is a sheetlike fibrotic mass between the pancreatic head and thickened duodenal wall associated with duodenal stenosis and cystic changes in the duodenal wall (Fig. 18A, 18B, 18C, 18D). The recognition of groove pancreatitis is important for differentiation from pancreatic and duodenal carcinomas .溝部胰腺炎（胰頭部慢性局限性胰腺炎）是一種局灶性慢性胰腺炎，發(fā)生于胰頭、十二指腸、膽總管之間的凹槽內(nèi)。溝部胰腺炎的主要MRI為胰頭及增厚的十二指腸壁之間片狀的纖維化腫塊，同時(shí)伴有十二指腸狹窄和十二指腸壁的囊性改變（圖18A，18B，18C，18D）。提高對(duì)溝部胰腺炎的認(rèn)識(shí)在胰腺和十二指腸腫瘤的鑒別診斷中是非常