Magnetic resonance imaging of extrahepatic bile duct disruption

Blunt injury of the extrahepatic bile duct is rare and hence a large series of scientific study of its MRI is difficult to perform. We present the MRI and MR cholangiography of a case of blunt extrahepatic bile duct injury proven at surgery. The diagnosis could be established based on MRI findings of an abrupt tapering of the extrahepatic bile duct with a retracted end, a discordant small-caliber proximal duct, massive ascites, and a hematoma in proximity to the bile duct injury. This non-invasive MRI study is a promising imaging modality to evaluate biliary tract injury. Electronic Publication     

Magnetic resonance findings of bile duct adenoma with calcification

Computed tomographic (CT) and magnetic resonance (MR) appearances of bile duct adenoma (BDA in a patient who underwent partial hepatectomy of segment 8 are presented. BDA showed a ring-shaped hyperdense area suggesting calcification and ring enhancement on CT. It appeared hypointense on both T1- and T2-weighted MR images. Preoperatively, the diagnoses considered included metastatic carcinoma, cholangiocarcinoma, tuberculosis, and rare tumors such as epithelioid hemangioendothelioma. The radiological findings were confirmed by pathological investigation.     

MR imaging findings of early bile duct cancer

Purpose

To retrospectively evaluate the MR imaging features of early bile duct cancer and to correlate them with the clinicopathologic findings.

Materials and Methods

This retrospective study was approved by our institutional review board, and informed consent was waived. Seventeen patients with surgically proven early bile duct cancer who had undergone preoperative MR cholangiopancreatography with gadolinium‐enhanced MR imaging, were included in this study. Two, experienced radiologists evaluated the MR images in consensus regarding the following findings: tumor number and morphology; signal intensity of the tumor; sharpness of the outer border of the bile duct wall; enhancement pattern of the tumor; and the presence of enlarged peribiliary lymph nodes. Another radiologist measured the SNR of the tumor and bile duct wall on gadolinium‐enhanced MRI during the dynamic phases to evaluate the tumor enhancement degree.

Results

In all patients, MR imaging demonstrated single or multiple intraluminal bile duct masses showing a sharply defined outer margin. The most common enhancement pattern of the biliary lesions showed heterogeneous amorphous enhancement or heterogeneous enhancement with central, dot‐like structures or vascular structures (76.5%, 13/17 patients). The difference of SNR between bile duct and tumor was greatest in the equilibrium phase (P < 0.05).

Conclusion

MRCP combined with dynamic contrast‐enhanced MRI can be useful for detecting early bile duct cancers. Common MR findings of early bile duct cancer include one or more inhomogeneously enhancing intraductal masses with clear outer margins and preservation of the bile duct wall. J. Magn. Reson. Imaging 2008;28:1466–1475. © 2008 Wiley‐Liss, Inc.     

磁共振扩散加权成像在胆管癌及肝占位性病变鉴别诊断中的应用价值

目的 探讨磁共振扩散加权成像在胆管癌及肝良、恶性占位性病变鉴别诊断中的应用价值。方法 采用DWI技术对胆管癌患者及肝良、恶性占位性病变患者进行了鉴别和诊断,探讨DWI对胆管癌定性诊断中的作用,及其与肝其他占位性病变进行鉴别比较研究过程中的特点。结果 肝细胞癌组、肝转移瘤组的ADC值与胆管癌组比较无明显差异。肝血管瘤组、肝囊肿组及正常肝组织的ADC值则明显高于胆管癌组,且差异具有统计学意义。胆管癌组的ADC值与与肝恶性病变比较无明显差异;但是胆管癌组的ADC值明显低于肝良性病变组,且差异具有统计学意义。结论 DWI序列速度快,通过DWI图像特点及量化分析ADC值,对胆管癌及肝良、恶性占位性病变可提供定量的诊断信息,可作为上腹部平扫的补充检查序列,应列为MRI常规序列之一。     

肝外胆管梗阻的磁共振胆胰管造影诊断

目的 评价磁共振胆胰管造影（ＭＲＣＰ）对肝外胆管梗阻性疾病的临床诊断价值。方法 对５４例肝外胆管梗阻性疾病（肝外胆管结石３０例,恶性胆管梗阻２４例）进行ＭＲＣＰ检查,并与临床诊断或手术和病理结果对照分析。ＭＲＣＰ采用不屏气快速自旋回波（ＴＳＥ）序列重工Ｔ２ＷＩ扫描,结合呼吸触发及脂护抑制技术,原始图像以最大信号强度投影（ＭＩＰ）法进行三维重建。结果 全部５４例ＭＲＣＰ检查均一次成功,５２例胆胰管显     

磁共振胆道造影在胆道梗阻定位和定性诊断中的价值

目的：通过ＭＲＩ胆道造影（ＭＲｃｈｏｌａｎｇｉｏｇｒａｐｈｙ，ＭＲＣ）与ＣＴ、ＵＳ、经皮穿刺胆道造影术（ＰＴＣ）或内窥镜逆行胰胆管造影术（ＥＲＣＰ）及手术、病理的对照研究，评价ＭＲＣ显示胆道梗阻部位，确定梗阻原因的能力。材料与方法：３０例梗阻性黄疸的患者在ＧＥＳｉｇｎａ１．５Ｔ超导系统上进行了ＭＲＣ检查，并与ＰＴＣ或ＥＲＣＰ、ＣＴ、ＵＳ、手术及病理对照。结果：本组资料中，ＭＲＣ显示胆道梗阻的部位准确性达１００％，优于有损伤性的ＰＴＣ或ＥＲＣＰ。ＭＲＣ确定梗阻原因的准确性达７０％，类似于ＰＴＣ或ＥＲＣＰ、ＣＴ、ＵＳ。结论：初步研究结果表明，无损伤性的ＭＲ胆道造影在梗阻性黄疸的定位和定性上具有很高的敏感性、准确性，对于梗阻性黄疸，特别是行ＥＲＣＰ失败和不宜行ＰＴＣ或ＥＲＣＰ的病人是最有效的替代方法。     

Hepatocellular carcinoma with bile duct tumor thrombi: Correlation of magnetic resonance imaging features to histopathologic manifestations

Purpose

This study was to analyze the magnetic resonance imaging (MRI) features of hepatocellular carcinoma (HCC) with bile duct tumor thrombi, and explore their correlations to histopathology to improve the accuracy of diagnosis.

Materials and methods

21 patients with pathologically confirmed HCC with bile duct tumor thrombi was performed with a superconducting 1.5-T MR imager within two weeks before operation. Magnetic resonance cholangiopancreatography (MRCP) was performed on 18 patients. Images were retrospectively assessed for the size, location and MRI manifestations of HCC lesions and associated bile duct tumor thrombi. The differentiation of HCC lesions and the pathologic changes of bile duct tumor thrombi were retrospectively analyzed under microscope.

Results

The average diameter of HCC lesions was 5.8 ± 2.8 cm, and ≤5.0 cm in nine cases. Capsule formation was observed on MRI or pathology in 4 cases of HCC (19%). Of the 21 cases with bile duct tumor thrombi, 20 were clearly presented on MRI as cord-like or columnar masses in the bile duct with proximal cholangiectasis. The tumor thrombi showed slightly hypointense on T1WI and slightly hyperintense on T2WI. On enhanced scan, three cases of tumor thrombi, which were mainly consisted of necrotic tissue, did not show enhancement; 17 cases, which were mainly consisted of cancer cells, showed mild or moderate enhancement. On magnetic resonance cholangiopancreatogram (MRCP), 14 cases of tumor thrombi presented as filling defect in the bile duct, abrupt obstruction of the bile duct, and cholangiectasis above the obstruction; four presented as dilated intra-hepatic bile ducts with missing common bile duct. Of the 21 patients, 16 had biliary hemorrhage; three also had tumor thrombi in the portal vein. Seventeen of the 21 HCC with biliary thrombi were poorly differentiated, unencapsulated and with an invasive growth. Nineteen of 21 bile duct tumor thrombi did not invade the bile duct wall and could be easily extracted.

Conclusion

MRI plays a valuable role in diagnosing HCC with bile duct tumor thrombi and identifying the extent of the thrombi; the MRI features of HCC with bile duct tumor thrombi are associated with its pathologic changes.     

Magnetic resonance imaging in the assessment of cystic pancreatic lesions: differentiation of benign and malignant lesion status

Purpose: To characterize cystic pancreatic lesions and tumors with magnetic resonance imaging (MRI), and to assess the value of morphological criteria in differentiating pseudocysts versus cystic tumors and benign versus malignant cystic tumors.

Material and Methods: Twenty-three patients with cystic pancreatic tumors or lesions underwent plain and contrast-material-enhanced MRI, including magnetic resonance cholangiopancreatography (MRCP). The MR findings were characterized and analyzed by two readers, and the role of various imaging criteria and combinations thereof for final lesion assignment were assessed. Final diagnoses were obtained from the results of open surgery (n = 19) and/or biopsy (n = 4).

Results: Final diagnoses included cystic tumors (n = 11) and pseudocysts (n = 12). The lesions were located in the head (56%) and body or tail (44%). Lesion diameters ranged from 7 to 50 mm. Various lesion contrast enhancement patterns were observed for both benign and malignant lesions. Serous cystadenomas were located in the head, they were lobulated, and had wall diameters≤2 mm; with the combination of these characteristics all patients with serous cystadenoma could be identified, whereas in no other patient was this constellation observed.

Conclusion: MRI facilitated the diagnosis of serous cystadenomas, although no definite morphologic criterion for the differentiation between pseudocysts and mucinous cystadenomas was identified. In consideration of the substantial therapeutic consequences, either diagnostics in unclear cystic pancreatic lesions should comprise cyst fluid analysis if necessary, or eligible patients should be referred for surgical resection.     

Magnetic resonance imaging findings of the mass-forming type of autoimmune pancreatitis: comparison with pancreatic adenocarcinoma

Purpose:

To determine the characteristic magnetic resonance imaging (MRI) features of mass‐forming autoimmune pancreatitis (AIP), which allow its differentiation from pancreatic adenocarcinoma (PAC).

Materials and Methods:

MR images of 37 patients with either pathologically proven, mass‐forming AIPs (n = 9) or PACs (n = 28) were retrospectively reviewed. The pancreatic MR protocol included unenhanced images, contrast‐enhanced dynamic images, diffusion‐weighted imaging (DWI), and MR‐cholangiopancreatography (MRCP). Two reviewers analyzed the MR images regarding the number, location, morphologic features, and enhancement degree and pattern of the lesions as well as secondary changes of the pancreatic parenchyma, the biliary and pancreatic ducts. The size and apparent diffusion coefficient (ADC) values of the lesions were measured.

Results:

Although sensitivities were low (28.6%–44.4%), specificities of multiplicity, capsule‐like rim enhancement, and skipped stricture of the biliary or pancreatic duct in mass‐forming AIP were high (100%). Sensitivities and specificities of irregular or geographic shape, delayed enhancement, and a low ADC value <1.26 × 10^?3 mm²/s in mass‐forming AIP were favorable (71.4%–83.3% and 78.5%–89.3%).

Conclusion:

Although to differentiate mass‐forming AIP from pancreatic cancer is difficult, the combination of MRI findings including contrast‐enhanced dynamic images, MRCP, and DWI can be a help. J. Magn. Reson. Imaging 2012;36:188–197. © 2012 Wiley Periodicals, Inc.

     

MRI of slow flow in artificial duct in swine

Our aim was to evaluate whether it is possible to visualize slow flow within a small catheter placed inside a living animal. We used a flow-sensitive, single-shot turbo spin-echo (SS-TSE) MRI sequence, developed in house, based on diffusion-weighted (DW) techniques. Four anesthetized pigs were used as models. A plastic catheter was surgically placed within the common bile duct (CBD). To mimic flow, the catheter was filled with Ringers acetate and connected to a pump. b factors (s/m²) of 0, 6, and 12, with flow velocities raging from 0 to 1.32 cm/s, were used. A total of 375 images were obtained and examined. After correction for bowel movement artifacts, all images displayed the catheter on zero flow. With a flow of 0.66 cm/s or higher, no images displayed the catheter with a b factor of 6 or 12. On the slower flow velocities, it was variable whether the catheter was visible or not, but at b=6 and flow 0.17 cm/s all catheters were viewable. This method made it possible to perform a semiquantitative evaluation of flow velocities in vivo, dividing flow into three groups.     

胆管导管内乳头状黏液性肿瘤的影像表现和形态分型

目的 探讨胆管导管内乳头状黏液性肿瘤(IPMN-B)的CT、MRI特征及其形态分型.方法 回顾性分析经病理证实的IPMN-B患者18例,16例行CT平扫+增强扫描,13例行MR增强扫描,其中11例同时行CT和MR检查.观察分析其影像和病理表现,结合影像及病理表现将IPMN-B分为典型IPMN-B、囊性IPMN-B、无肿块型IPMN-B和侵袭性IPMN-B共4种类型,确定其分型.结果 典型IPMN-B 9例,表现为沿胆管壁的肿瘤灶,肿瘤上游、下游胆管均明显且广泛扩张.囊性IPMN-B5例,胆管呈动脉瘤样扩张,内可见单发或多发瘤灶.无肿块型IPMN-B 2例,胆管呈广泛明显扩张,未见明确肿瘤病灶,胆管壁光滑.侵袭性IPMN-B 2例,病灶所在节段胆管扩张,肿瘤突向胆管腔内使胆管壁呈锯齿状,伴随胆管外异常密度或信号灶.18例均有胆管扩张,其中16例可见扩张胆管内肿瘤病灶,2例未见明确瘤体显示,仅表现为胆管扩张.CT扫描可见肿瘤密度低于肝实质,并高于胆汁和胆管内黏液.MR T2WI可见肿瘤信号高于结石,并低于胆汁和黏液.DWI肿瘤均表现为高信号.增强扫描肿瘤呈轻中度强化,三期增强扫描可见肿瘤的密度或信号均低于肝实质.结论 IPMN-B的CT和MRI表现具有一定特征性并有助于分型.     

磁共振仿真内镜在胆总管梗阻性病变中的应用

目的：评价MR仿真内镜（MRVE）对胆总管梗阻性病变的诊断作用。方法：将61例行3D TSE MRCP检查的胆总管梗阻病例的原始图像资料传送至工作站，利用专用的仿真内镜软件进行仿真内镜，观察不同病变的仿真内镜表现。结果：所有61例均得到较好的仿真内镜图像，32例结石及7例壶腹癌基础上合并结石、壶腹癌11例、十二指肠乳头炎6例、胰头癌6例、胰腺炎4例均得到清楚的显示，同时有12例泥沙样结石MIP图像未见显示而仿真内镜上得到清楚的显示，但有1例胆道乳头状癌的诊断需结合平扫图像；MRVE的空间分辨率低、无法真正显示病变的色彩改变及无法显示粘膜的细微改变为MRVE的应用局限性。结论：MRVE能直观地显示扩张胆总管内表现及病变情况，MRVE结合MRCP可提高胆总管梗阻性病变的诊断准确性。     

磁共振弥散加权成像观察胰腺癌冷冻术后近期疗效的应用价值

目的 探讨采用磁共振弥散加权成像(MRI-DWI)评估胰腺癌冷冻术后肿瘤坏死及肿瘤残存的应用价值.方法 对接受冷冻治疗的26例胰腺癌患者行T1WI、T2WI常规MRI平扫、DWI序列及动态增强扫描.观察胰腺癌冷冻前后MRI信号改变.测量并比较正常胰腺、术前肿瘤组织及术后残存、坏死组织的表现弥散系数(ADC)值.评价肿瘤组织ADC值与肿瘤大小的相关性,不同肿瘤直径、肿瘤位置及分期表现ADC值的差异.结果 26例患者中16例肿瘤完全坏死,冷冻坏死的胰腺肿瘤组织在T1WI图像上呈低信号,T2WI呈高信号,DWI呈低信号,动态增强无强化.活性肿瘤组织残留9例(其中7例肿瘤直径＞5.0 cm),残留率为34.6％.ADC值由低到高依次为:术前胰腺肿瘤组织(1.022±0.126)×10-3 mm2/s、术后残存肿瘤组织(1.130±0.155)×10-3 mm2/s、正常胰腺组织(1.924±0.124)×10-3 mm2/s及术后坏死组织(2.312±0.214)×10-3 mm2/s.术前胰腺肿瘤组织ADC值与术后残存肿瘤组织相比,差异无统计学意义(P=0.452),与正常胰腺组织、术后坏死组织相比,差异有显著统计学意义(P＜0.001).胰腺肿瘤ADC值与肿瘤大小呈负相关(R=-0.43,P=0.027 2),与肿瘤位置、肿瘤分期无关(P=0.738 8,P=0.089 5).结论 DWI能有效鉴别胰腺癌冷冻治疗后的病灶坏死及残存,为进一步临床诊治提供依据.     

利用磁共振胰胆管成像对晚期医原性肝外胆管狭窄进行术前评估

目的：探讨磁共振胰胆管成像（MRCP）对晚期医源性肝外胆管狭窄的磁共振胆胰管成像的术前评估价值。方法：对18例MRCP诊断为晚期医源性肝外胆管狭窄并经手术病理证实的患者进行分型及术后手术方式选择，并与手术记录对照分析。结果：18例中能够按照Bismuth分型法进行分型者17例，其中I型3例，Ⅱ型7例，Ⅲ型3例，Ⅳ型3例，1例Ⅱ型狭窄被误分为Ⅲ型，MRCP分型准确16例。根据术前MRCP提供的信息，术中16例采取了正确的手术方法，2例未能采用预期的手术方式。MRCP术前手术方式选择准确16例。结论：MRCP对晚期医源性外胆管狭窄的术前评估有重要价值。     

Detection of common bile duct stones before laparoscopic cholecystectomy. Evaluation with MR cholangiography

Purpose:
To assess the diagnostic value of MR cholangiography (MRC) for detecting common bile duct (CBD) stones in candidates for laparoscopic cholecystectomy (LC). Material and Methods:
A series of 95 selected patients with gallstones and suspected CBD lithiasis (abnormal serum liver tests and/or CBD size ≥6.5 mm at US) were referred to our institution for MRC, before LC. MRC was performed on a 0.5 T magnet through a non-breath-hold, respiratory-triggered, fat-suppressed, thin-slab, heavily T2-weighted fast spin-echo sequence and through a breath-hold, thick-slab, single-shot T2-weighted sequence in the coronal plane. Axial T1- and T2-weighted sequences were first obtained. Two observers in conference reviewed source images and maximum intensity projections to determine the presence or absence of choledocholithiasis. MR findings were compared with endoscopic retrograde cholangiography and intraoperative cholangiography (IOC); IOC was always performed during LC. Results:
CBD calculi (single or multiple) were identified in 41 out of 95 patients (43%). Two false-positive and 4 false-negative cases were found on MRC. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of MRC for choledocholithiasis were 90%, 96%, 94%, 95%, and 93%, respectively. Conclusion:
MRC is a highly effective diagnostic modality for evaluation of patients with risk factors for CBD stones prior to LC.     

肝细胞癌合并胆管癌栓的影像表现

目的 探讨胆管癌栓的影像表现,以提高影像诊断水平.方法 回顾性分析经手术病理证实的肝细胞癌(HCC)胆管癌栓13例患者资料,其中3例进行了CT和MR检查,2例仅行CT检查,8例仅行MR检查,7例进行了MR胰胆管成像检查,13例均进行了超声检查.采用四格表Fisher 确切概率检验方法比较超声与CT、MR诊断HCC胆管癌栓的准确性.结果 13例HCC肿瘤及胆管癌栓均在CT或MRI上显示.4例胆管癌栓在CT上表现为胆管内软组织块影,动脉期可见癌栓轻度增强,癌栓远端胆管扩张.11例胆管癌栓在T1 WI上均呈稍低信号,T2 WI为稍高信号,增强后可见轻、中度强化.MR胰胆管成像上胆管癌栓表现为:胆管阻塞中断、狭窄或不规则充盈缺损伴有梗阻上方胆管扩张,胆管突然截断或呈"鼠尾"状(5例);肝内胆管扩张,癌栓充满整个胆总管.胆总管不显示(2例).超声检查准确诊断胆管癌栓7例,误、漏诊6例.CT、MRI准确诊断12例,误诊4例,超声与CT、MRI诊断胆管癌栓差异无统计学意义(P=0.270).结论 CT或MRI对诊断HCC合并胆管癌栓及明确癌栓范围有价值.     

3.0T磁共振钆塞酸二钠磁共振胆管造影术在胆管疾病中应用

目的探讨3.0T磁共振钆塞酸二钠(Gd-EOB-DTPA)磁共振胆管造影术(MRC)在胆管疾病中的诊断价值。方法选取2016年7—12月解放军309医院收治的20例患胆道梗阻或其他病变需行Gd-EOB-DTPA MRC检查的患者,采用3.0T超导磁共振扫描仪,对所有20例患者行常规上腹部平扫+磁共振胰胆管造影(MRCP)+Gd-EOB-DTPA动态增强扫描,以及肝胆特异期、T1容积内插体部检查(VIBE)冠状位+轴位扫描,并将冠状位图像进行最大密度投影(MIP)重建,获得胆管树图像。对各序列的影像学特征做出诊断,并与穿刺、手术病理、内镜下逆行胰胆管造影术及相关临床资料进行对照。结果本组20例患者中,胆管解剖变异者7例。其中,胆囊管经胆总管前方汇入胆总管左侧壁1例,经胆总管后方汇入胆总管左侧壁3例,胆囊管开口于肝外胆管下1/3处2例,胆囊管汇入右肝管1例。胆管梗阻11例,其中,完全性梗阻8例(肝门部胆管恶性占位5例、胆总管恶性占位1例、胆总管下端结石1例,胆总管周围淋巴结转移1例);部分梗阻3例(胰头占位1例,胆总管结石1例,胃窦癌侵及胆总管1例)。胆漏2例。硬化性胆管炎1例。其中,1例患者同时有胆漏及胆囊管汇入右肝管变异。结论 Gd-EOB-DTPA MRC检查能够直接显示肝内外胆管系统解剖结构以及胆管通畅情况,能为胆管疾病的诊断提供更多的信息,可以进一步应用于胆管疾病的检查。     

Diagnostic imaging of carcinomas of the gallbladder and the bile ducts

Early diagnosis and accurate staging of carcinomas of the gallbladder and the bile ducts are helpful in improving the prognosis. Ultrasonography (US), a useful initial modality when exploring the background of jaundice or non-specific gastrointestinal complaints, sensitively reveals bile duct obstruction in particular. In unclear cases, or if US suggests a resectable biliary malignancy, computed tomography (CT), magnetic resonance imaging (MRI) with magnetic resonance cholangiography (MRC) and / or traditional cholangiography often provide additional information, and imaging-guided fine-needle biopsy or an endoscopic brush sample may verify the malignant nature of the tumor. Complementary modalities are usually needed for accurate staging, and traditional cholangiography is often performed for therapeutic purposes as well. Comparative studies of MRI with MRC and multidetector CT in biliary cancers would be welcome.     

胆汁流动伪影的MR胆胰管成像表现

目的：探讨MR胆胰管成像(MRCP)上胆汁流动伪影的影像表现。方法 回顾性分析85例胆总管正常和95例胆总管扩张患者的MRCP资料,在MRCP原始薄层图像上观察记录胆汁流动伪影的表现,采用x2检验对各组胆汁流动伪影的发生率进行比较,采用Spearman等级相关分析检验胆总管直径和伪影表现形式的关系。结果 胆总管正常组流动伪影发生率38.8％ (33/85),扩张组流动伪影发牛率83.2％( 79/95),差异有统计学意义(x2 ＝37.512,P＝0.000)。胆总管直径(ψ)≤4mm时无流动伪影,4 mm ＜ψ≤8 mm时,流动伪影主要表现为单线征(52.6％,30/57)。胆总管轻度扩张时,流动伪影主要表现为三线征(85.7％,36/42);中度扩张时主要表现为多线征(84.6％,22/26),各组间表现差异有统计学意义(x2＝284.561,P＝0.000)。随胆总管直径增加,伪影的表现形式不同,二者有相关性(r ＝0.553,P＝0.000)。结论 胆总管正常组可以发生流动伪影;胆总管扩张组流动伪影发生率高于正常组;胆汁流动伪影的表现形式与胆总管直径有相关性。     

Contrast-enhanced MRI combined with MR cholangiopancreatography for the evaluation of patients with biliary strictures: differentiation of malignant from benign bile duct strictures

PURPOSE: To determine imaging criteria for the combined use of contrast-enhanced (CE)-MRI and MR cholangiopancreatography (MRCP) to differentiate malignant from benign biliary strictures. MATERIALS AND METHODS: A total of 44 patients with biliary stricture who had undergone unenhanced, MRCP, and dynamic MRI were identified from radiological and surgical databases. Two radiologists analyzed MR features for asymmetry, luminal irregularity, abrupt narrowing, outer margin, signal intensity (SI) on T2-weighted (T2W) images, and hyperenhancement relative to liver parenchyma during portal phase. The wall thickness and length of the narrowed segment were measured. MR findings relevant as predictors were identified using a Chi-square or Fisher's exact test and the odds ratio (OR). RESULTS: The presence of hyperenhancement relative to liver parenchyma, length > 12 mm, wall thickness > 3 mm, indistinct outer margin, luminal irregularity, and asymmetry of strictured bile duct were significant factors for malignancy (P < 0.05). Malignant strictures were significantly thicker (5.0 +/- 2.0 mm) and longer (27.0 +/- 13.6 mm) than benign strictures. When any three or more of these six criteria were used in combination, we could identify 100% of malignant strictures and 87.0% of benign strictures. CONCLUSION: The combined use of CE-MRI and MRCP helped to define the criteria for differentiating malignant from benign biliary strictures in our data.