Evaluation of the biliary and pancreatic system with 2D SSFSE, breathhold 3D FRFSE and respiratory-triggered 3D FRFSE sequences

Purpose

The authors compared biliary and pancreatic imaging obtained through 2D single-shot fast spin-echo (SSFSE), breath-hold 3D fast recovery fast spin-echo (FRFSE) and respiratory-triggered 3D FRFSE sequences.

Materials and methods

A total of 106 magnetic resonance cholangiopancreatography (MRCP) examinations performed between December 2007 and September 2008 were evaluated with a comparison of 2D SSFSE (thin section and thick slab), breath-hold 3D FRFSE and respiratory-triggered 3D FRFSE sequences. The biliary tract was divided into seven segments: right hepatic duct, left hepatic duct, common hepatic duct, cystic duct, common bile duct, cystic duct junction and biliarypancreatic confluence. The main pancreatic duct was divided into three segments (head, body and tail). Visualisation of biliary variants was also compared. Two blinded radiologists evaluated segment visibility using a quantitative scale. The Student’s t test for paired samples was used for statistical analysis.

Results

Compared with 2D SSFSE, respiratory-triggered 3D FRFSE sequences showed better visibility of the right hepatic duct (p=0.0277), the cystic duct (p=0.0081), the cystic duct junction (p=0.0010), the biliary-pancreatic confluence (p=0.0334) and biliary variants (p=0.0198). In the comparison between breath-hold 3D FRFSE and 2D SSFSE, a significant statistical difference was found in visualisation of the cystic duct (p=0.027), the cystic duct junction (p=0.020), the biliary-pancreatic confluence (p=0.0338) and biliary variants (p=0.0311).

Conclusions

Three-dimensional FRFSE offers a significant benefit over conventional 2D imaging.     

Comparative diagnostic evaluation with MR cholangiopancreatography, ultrasonography and CT in patients with pancreatobiliary disease

Purpose

The aim of this study was to directly compare the results of magnetic resonance cholangiopancreatography (MRCP) with those of ultrasonography (US) and multislice computed tomography (MSCT) in the diagnosis of pancreaticobiliary diseases.

Materials and methods

A total of 70 patients (41 men, 29 women) aged 22-89 years were studied either before (n=59) or after cholecystectomy (n=11) for biliary lithiasis. Clinical signs and symptoms were jaundice (n=15), abdominal pain (n=37) and proven biliary lithiasis (n=18). MRCP was performed in all patients, whereas abdominal US was performed in 55 (group 1) and MSCT in 37 (group 2) patients. A regional evaluation of the main structures of the pancreaticobiliary system was performed: gallbladder and cystic duct, intra- and extrahepatic bile ducts and main pancreatic duct. Histology (n=27), biopsy (n=5), endoscopic retrograde cholangiopancreatography (ERCP) (n=28) and/or clinical-imaging follow-up (n=10) were considered standards of reference. In particular, patients were classified as showing benign (n=47) or malignant (n=12) lesions or normal biliary anatomy (n=11).

Results

In group 1, the results of MRCP and US were concordant in the majority (92%) of cases; however, statistically significant discordance (p<0.01) was found in the evaluation of the extrahepatic ducts, with nine cases (16%) of middle-distal common bile duct stones being detected on MRCP only. In group 2, the results of MRCP and MSCT were also concordant in most cases (87%). However, findings were significantly discordant when the intra- and extrahepatic ducts were analysed, with seven (19%) and six (16%) cases, respectively, of lithiasis being detected on MRCP only (p<0.01 for both).

Conclusions

The results of our study confirm the diagnostic potential of MRCP in the study of the pancreaticobiliary duct system. In particular, the comparison between MRCP and US and MSCT indicates the superiority of MRCP in evaluating bile ducts and detecting stones in the common bile duct.     

Multifocal branch-duct intraductal papillary mucinous neoplasms (IPMNs) of the pancreas: magnetic resonance (MR) imaging pattern and evolution over time

Purpose

The aim of our study was to follow the evolution over time of multifocal intraductal papillary mucinous neoplasms (IPMN) of the pancreatic duct side branches by means of magnetic resonance imaging (MRI).

Materials and methods

A total of 155 patients with multifocal IPMN of the side branches were examined with MRI and MR cholangiopancreatography (MRI/MRCP). Inclusion criteria were patients with ≥2 dilated side branches involving any site of the parenchyma; presence of communication with the main pancreatic duct and previous investigations by MRI/MRCP within at least six months. Median follow-up was 25.8 months (range, 12–217). Patients with a follow-up period shorter than 12 months (n=33) and those with a diagnosis of multifocal IPMN of the side branches without any follow-up (n=14) were excluded from the study. The final study population thus comprised 108 patients. A double, quantitative and qualitative, analysis was carried out. The quantitative image analysis included: number of dilated side branches in the head-uncinate process and body-tail; maximum diameter of lesions in the head-uncinate process; maximum diameter in the body-tail; maximum diameter of the main pancreatic duct in the head and body-tail. The qualitative image analysis included: presence of malformations or anatomical variants of the pancreatic ductal system; site of the lesions (head-uncinate process, body-tail, ubiquitous, bridge morphology); presence of gravity-dependent intraluminal filling defects; presence of enhancing mural nodules.

Results

At diagnosis, the mean number of cystic lesions of the side branches was 7.09. The mean diameter of the cystic lesions was 13.7 mm. The mean diameter of the main pancreatic duct was 3.6 mm. At follow-up, the mean number of cystic lesions was 7.76. The mean diameter of the cystic lesions was 13.9 mm. The mean diameter of the main pancreatic duct was 3.7 mm. Intraluminal filling defects in the side branches were seen in 18/108 patients (16.6%); enhancing mural nodules were seen in 3/108 patients (2.7%).

Conclusions

Multifocal IPMN of the branch ducts shows a very slow growth and evolution over time. In our study, only 3/108 patients showed mural nodules which, however, did not require any surgical procedure, indicating that careful nonoperative management may be safe and effective in asymptomatic patients.     

胆囊管解剖变异的MRCP诊断

目的:探讨磁共振胰胆管成像(MRCP)对胆囊管解剖变异的诊断价值及临床意义.方法:搜集2002年8月～2006年8月期间行MRCP检查的900例病例进行分析,对显示不清的胆囊管视为正常.所有病例经胆囊切除术(783例)或逆行胰胆管造影术(117例)证实.结果:MRCP清晰显示胆囊管801例(89%),根据Taoureal胆囊管解剖变异分型标准:胆囊管变异53例,变异率为5.9%,其中胆囊管汇入左右肝管分叉处21例(2.3%),汇入右肝管10例(1.1%),与肝总管并行9例(1.0%),胆囊管低位插入8例(0.9%),旋前插入肝总管7例(0.8%),旋后插入肝总管3例(0.3%),过短1例(0.1%),囊状扩张1例(0.1%),合并胆囊分隔6例(0.7%),先天性胆总管囊肿6例(0.7%).部分患者合并2种或2种以上的变异.其中假阴性2例,显示不清2例.结论:MRCP能显示各种胆囊管解剖变异,术前了解这些变异有助于减少腹腔镜胆囊切除术中的胆道损伤.     

MRCP在评价肝内胆管变异与肝内胆管结石相关性中的应用

目的应用磁共振胰胆管成像(MRCP)分析肝内胆管变异与肝内胆管结石的相关性。资料与方法搜集429例胆石症患者的MRCP检查资料,评价肝内胆管的解剖类型,并分析其与肝内胆管结石的关系。结果MRCP资料显示肝内胆管变异占总病例数的31.7%,肝内胆管常型占68.3%。在肝内胆管变异的病例中,有肝内胆管结石者58例(42.6%),无肝内胆管结石78例(57.4%);肝内胆管常型的病例中,有肝内胆管结石者77例(26.3%),无肝内胆管结石216例(73.7%)。两组病例发生肝内胆管结石概率的χ2检验结果为:χ2=11.538,P<0.005,差异有显著统计学意义。结论肝内胆管变异者有更高的肝内胆管结石发生率。     

HASTE MR cholangiopancreatography in the evaluation of intraductal papillary-mucinous tumors of the pancreas

PURPOSE: The aim of this study was to determine the usefulness of MR cholangiopancreatography (MRCP) of intraductal papillary-mucinous tumors. METHOD: Thirteen patients with intraductal papillary-mucinous tumors were examined by breath-hold MRCP using a half-Fourier acquisition single-shot turbo spin echo (HASTE) sequence with a body phased-array coil. RESULTS: Endoscopic retrograde cholangiopancreatography (ERCP) and MRCP completely imaged the entire main pancreatic duct in 12 and in all 13 patients, respectively. ERCP demonstrated the whole opacification of the cystic lesion in only one patient. MRCP depicted the whole of the cystic lesion in all 11 patients who had cystic lesions. ERCP and MRCP source images depicted a communicating duct between the main pancreatic duct and the cystic lesion in 8 and in all 11 patients, respectively. ERCP depicted papillary projections in the main pancreatic ducts in two patients. MRCP source images depicted papillary projections in the main pancreatic ducts or cystic lesions in five patients. CONCLUSION: MRCP may be more useful to reveal the main pancreatic duct, cystic lesion, communicating duct between the main pancreatic duct and cystic lesion, and papillary projections than ERCP in patients with intraductal papillary-mucinous tumors of the pancreas.     

单次激发磁共振胰胆管造影的临床应用

目的：探讨单次激发快速自旋回波（ＳＳＦＳＥ）序列磁共振胰胆管造影的临床应用价值。方法：采用屏气、重Ｔ２ 加权、单次激发快速自旋回波（ＳＳＦＳＥ）序列、二维多平面成像技术做ＭＲ胰胆管造影８０ 例,其中３０ 例为正常者,５０例疑为胰胆系疾病的病人。结果：３０例正常者的胰胆管和胆囊的显示率为１００％ 。５０例疑为胰胆系疾病的病人,ＭＲＣＰ良好显示胰胆系病变部位及扩张的胰胆管,结合腹部常规ＭＲ,获得理想的综合影像诊断。结论：ＳＳＦＳＥ序列ＭＲＣＰ是一种安全简便、无创伤性的胰胆管影像学检查新技术,快速成像,图像清晰,具有重要的临床应用价值。     

Preoperative evaluation of the cystic duct for laparoscopic cholecystectomy: comparison of navigator-gated prospective acquisition correction- and conventional respiratory-triggered techniques at free-breathing 3D MR cholangiopancreatography

Objective

To evaluate the quality of magnetic resonance cholangiopancreatography (MRCP) images obtained with a three-dimensional navigator-gated (NG) technique and compare findings with conventional respiratory-triggered (RT) images in pre-laparoscopic cholecystectomy patients.

Methods

Turbo-spin-echo (TSE) RT-MRCP (average 242 s) and balanced turbo-field-echo (bTFE) NG-MRCP (average 263 s) were acquired at 1.5-T MRI for 49 pre-laparoscopic cholecystectomy patients. Two radiologists independently assessed image quality, visibility of anatomical structures, common bile duct (CBD) stones, and signal-to-noise ratios (SNRs). Interobserver agreement was also evaluated.

Results

The anatomical details of the cystic duct were clearly demonstrated in 33 (67.3 %, reader A) and 35 (71.4 %, reader B) patients on RT-MRCP, and in 45 (91.8 %) and 44 (89.7 %) patients on NG-MRCP. On NG-MRCP, visualisation of the cystic duct (3.22/3.12), its origin (3.57/3.55), and the gallbladder(3.61/3.59) was statistically better than on RT-MRCP (2.90/2.78, 3.29/3.12, 2.98/2.88, respectively). The overall image quality was statistically better on NG-MRCP than RT-MRCP. Each technique identified the presence of CBD stones in all affected patients. The SNR was significantly higher on NG-MRCP (CHD 22.40, gallbladder 17.13) than RT-MRCP (CHD 17.05, gallbladder 9.30). Interobserver agreement was fair to perfect.

Conclusion

Navigator-gated MRCP is more useful than respiratory-triggered MRCP for evaluating the gallbladder and cystic duct in patients scheduled for laparoscopic cholecystectomy.

Key Points

? Magnetic resonance cholangiopancreatography (MRCP) provides important cystic duct information before laparoscopic cholecystectomy. ? Navigator-gated (NG) MRCP images were better than conventional respiratory-triggered (RT) MRCP. ? The signal-to-noise ratio was significantly higher for NG-MRCP than for conventional RT-MRCP. ? Balanced turbo-field-echo NG-MRCP is useful for evaluating the gallbladder and cystic duct.     

CT and MR cholangiography: advantages and pitfalls in perioperative evaluation of biliary tree

Recent developments in imaging technology have enabled CT and MR cholangiopancreatography (MRCP) to provide minimally invasive alternatives to endoscopic retrograde cholangiopancreatography for the pre- and post-operative assessment of biliary disease. This article describes anatomical variants of the biliary tree with surgical significance, followed by comparison of CT and MR cholangiographies. Drip infusion cholangiography with CT (DIC-CT) enables high-resolution three-dimensional anatomical representation of very small bile ducts (e.g. aberrant branches, the caudate branch and the cystic duct), which are potential causes of surgical complications. The disadvantages of DIC-CT include the possibility of adverse reactions to biliary contrast media and insufficient depiction of bile ducts caused by liver dysfunction or obstructive jaundice. Conventional MRCP is a standard, non-invasive method for evaluating the biliary tree. MRCP provides useful information, especially regarding the extrahepatic bile ducts and dilated intrahepatic bile ducts. Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced MRCP may facilitate the evaluation of biliary structure and excretory function. Understanding the characteristics of each type of cholangiography is important to ensure sufficient perioperative evaluation of the biliary system.     

胰胆管疾病的ERCP影像诊断

目的评价内窥镜逆行胰胆管造影(ERCP)对胰胆管疾病的诊断价值。方法回顾性分析了经手术或病理及临床证实胰胆管疾病480例的ERCP表现,并与CT,MRI,MRCP,超声及透皮肝穿刺胆道造影(PTC)等检查方法进行对比。结果正常胰胆管75例,先天性胆管囊肿14例,胆系结石292例,奥狄括约肌狭窄症46例,壶腹癌、胆管癌52例,胰管癌4例,胰腺炎2例,胰管结石3例,胆道蛔虫症9例,肝内胆管发育变异2例,胆囊管异位开口6例,胆道-腹腔漏2例,十二指肠乳头旁憩室9例,十二指肠乳头开口于憩室内2例,肝移植后吻合口狭窄2例,肝移植后吻合口狭窄并胆漏1例,肝移植后肝外胆管条状结石2例。结论ERCP及MRCP检查同为诊断胰胆管疾病的“金标准”,但每种影像学方法均有其优缺点,应根据患者情况选择。ERCP虽有一定的创伤性,但检查同时可行内镜下乳头括约肌切开术(EST)等微创治疗。     

胆石症胆囊管MRCP分析及临床意义

目的:利用MRCP观察胆囊管在肝总管的开口部位及其变异,探讨其临床价值。方法:应用MRCP检查240例拟行腹腔镜胆囊切除术的胆石症病例,重建后观察胆囊管在肝总管的开口部位并对其变异予以分析。结果:MRCP像上胆囊管显示154例(64.2%),胆囊管正常开口于肝总管右侧壁96例(62.3%)、变异开口于肝总管左侧壁、前壁、后壁及低位分别为8例(5.2%)、8例(5.2%)、22例(14.3%)及4例(2.6%),另有16例(10.4%)胆囊管部分显示,其开口部位未显示。结论:MRCP可以观察胆囊管在肝总管的开口部位,对于腹腔镜胆囊切除术前了解胆囊管的变异有一定的临床价值。     

Anatomic variants of the pancreatic duct and their clinical relevance: an MR-guided study in the general population

Objectives

To investigate the frequency of pancreatic duct (PD) variants and their effect on pancreatic exocrine function in a population-based study using non-invasive secretin-stimulated magnetic resonance cholangiopancreatography (sMRCP).

Methods

Nine hundred and ninety-five volunteers, 457 women and 538 men, aged 51.9?±?13.4 years, underwent navigator-triggered, T2-weighted, 3D turbo spin echo MRCP on a 1.5 T system after 1 unit/kg secretin administration. Two readers evaluated images for PD variants. Pancreatic exocrine function and morphological signs of chronic pancreatitis such as abnormalities of the main PD, side branch dilatation, and pancreatic cysts were evaluated and related to PD variants using a Kruskal-Wallis test and post hoc analysis.

Results

Of all sMRCP, 93.2 % were of diagnostic quality. Interobserver reliability for detection of PD variants was found to be kappa 0.752 (95 %CI, 0.733 – 0.771). Normal PD variants were observed in 90.4 % (n?=?838/927). Variants of pancreas divisum was identified in 9.6 % (n?=?89/927). Abnormalities of the main PD, side branch dilatation, and pancreatic cysts were observed in 2.4 %, 16.6 %, and 27.7 %, respectively, and were not significantly different between pancreas divisum and non-divisum group (P?=?0.122; P?=?0.152; P?=?0.741). There was no association between PD variants and pancreatic exocrine function (P?=?0.367).

Conclusion

PD variants including pancreas divisum are not associated with morphological signs of chronic pancreatitis or restriction of pancreatic exocrine function.

Key Points

? MRCP allows the evaluation of pancreatic duct variants and morphological change. ? Pancreatic duct variants are not associated with morphological signs of chronic pancreatitis. ? Pancreas divisum is not accompanied by restriction of pancreatic exocrine function. ? Pancreatic duct variants including pancreas divisum are limited in their clinical relevance.     

Pseudo-obstruction of the extrahepatic bile duct due to artifact from arterial pulsatile compression: a diagnostic pitfall of MR cholangiopancreatography

PURPOSE: To evaluate the frequency of artifact from arterial pulsatile compression as the cause of pseudo-obstruction of the extrahepatic bile duct at magnetic resonance (MR) cholangiopancreatography (MRCP) and specify the causative vessels. MATERIALS AND METHODS: In 234 patients (102 men, 132 women; age range, 25-80 years), MRCP images obtained by using a single-shot turbo spin-echo sequence were reviewed to assess pseudo-obstruction of the extrahepatic bile duct caused by vascular compression. Dual-phase spiral computed tomography, contrast material-enhanced three-dimensional MR angiography, and/or digital subtraction angiography also were performed to determine the vessel that caused the pseudo-obstruction. RESULTS: Thirty-six pseudo-obstructions due to vascular compression were found in 33 (14%) patients. The common hepatic duct (27 [75%] sites) was the most common pseudo-obstruction site, followed by the left hepatic duct (four [11%] sites), proximal common bile duct (three [8%] sites), and right hepatic duct (two [6%] sites). The causative vessels were identified as the right hepatic artery at 24 (67%) sites; gastroduodenal artery, two (6%) sites; cystic artery, two (6%) sites; proper hepatic artery, one (3%) site; and an unspecified branch of the common hepatic artery, seven (19%) sites. CONCLUSION: At MRCP, pseudo-obstruction of the extrahepatic bile duct can be caused by pulsatile vascular compression of the hepatic and gastroduodenal arteries, and it should not be misdiagnosed as a bile duct tumor or biliary stone.     

Anatomic Variation in Intrahepatic Bile Ducts: an Analysis of Intraoperative Cholangiograms in 300 Consecutive Donors for Living Donor Liver Transplantation

Objective

To describe the anatomical variation occurring in intrahepatic bile ducts (IHDs) in terms of their branching patterns, and to determine the frequency of each variation.

Materials and Methods

The study group consisted of 300 consecutive donors for liver transplantation who underwent intraoperative cholangiography. Anatomical variation in IHDs was classified according to the branching pattern of the right anterior and right posterior segmental duct (RASD and RPSD, respectively), and the presence or absence of the first-order branch of the left hepatic duct (LHD), and of an accessory hepatic duct.

Results

The anatomy of the intrahepatic bile ducts was typical in 63% of cases (n=188), showed triple confluence in 10% (n=29), anomalous drainage of the RPSD into the LHD in 11% (n=34), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 6% (n=19), anomalous drainage of the RPSD into the cystic duct in 2% (n=6), drainage of the right hepatic duct (RHD) into the cystic duct (n=1), the presence of an accessory duct leading to the CHD or RHD in 5% (n=16), individual drainage of the LHD into the RHD or CHD in 1% (n=4), and unclassified or complex variation in 1% (n=3).

Conclusion

The branching pattern of IHDs was atypical in 37% of cases. The two most common variations were drainage of the RPSD into the LHD (11%) and triple confluence of the RASD, RPSD and LHD (10%).     

单次激发放射状MRCP临床应用

目的　探讨单次激发放射状磁共振胰胆管水成像 (SSH/MRCP/RAD)序列的临床应用价值。方法　对 42例均经手术或病理证实的胰胆管疾病患者的MRCP资料进行回顾性分析 ,MRCP采用单次激发放射状自旋回波序列技术。其中包括结石 19例、炎症 3例、先天囊肿 6例、胆管癌 12例、十二指肠降段憩室炎引起黄疸 1例、Mirizzi综合征 1例。结果　 42例MRCP检查均一次成功 ,肝内外胆管显示率 10 0 % ,主胰管显示率 80 .5 8%。定位诊断为 10 0 % ,定性诊断 88.2 %。结论　对胰胆管病变的检查 ,SSH/MR CP/RAD是较为理想的成像技术 ,在临床上有较大的应用价值。     

Biliary anatomy in potential right hepatic lobe living donor liver transplantation (LDLT): the utility of CT cholangiography in the setting of inconclusive MRCP

Objective

To determine the utility of CT cholangiography (CT-Ch) in preoperative evaluation of the biliary anatomy of living-donor liver transplantation (LDLT) donors when magnetic resonance cholangiopancreatography (MRCP) is inconclusive.

Materials and methods

Over a 2-year period, 22 potential living liver donors underwent contrast-enhanced CT-Ch for preoperative evaluating biliary anatomy due to inconclusive results on MRCP and subsequently donated their right hepatic lobe. Nineteen of them underwent intraoperative cholangiography and were included in this study. Two radiologists retrospectively reviewed both MRCP and CT-Ch with 1-month interval and documented the types of bile duct branching patterns and visualization score of intrahepatic bile ducts (4-point scale).

Results

There were no complications associated with CT-Ch examinations. CT-Ch was concordant with the reference standard in 18/19 (95%) including 7/8 typical branching type and 11/11 anomalous branching types. MRCP was concordant with the reference standard in 14/19 (74%) including 4/8 typical branching types and 10/11 anomalous branching types. The discordant case by CT-Ch was the identification of a tiny accessory right intrahepatic duct joining the common bile duct which was not visualized on intraoperative cholangiography. CT-Ch showed higher visualization score (mean, 3.9) than MRCP (mean, 2.6) (P < .001).

Conclusion

CT-Ch can be effectively used for the depiction of the branching pattern of the bile duct at the hepatic hilum when MRCP is inconclusive.     

Magnetic resonance cholangiopancreatography and contrast-enhanced magnetic resonance cholangiopancreatography versus endoscopic ultrasonography in the diagnosis of extrahepatic biliary pathology

Purpose

This study compared the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasonography (EUS) in evaluating the cause of extrahepatic bile duct dilatation.

Materials and methods

Forty-five patients (26 men, mean age 57 years) with extrahepatic biliary dilatation, as shown by transabdominal ultrasound, with or without elevated biliary and pancreatic serum indices, were prospectively studied with MRCP and EUS between September 2007 and October 2008. EUS and MRCP were performed within no more than 24 h of each other to reduce the possibility of changes due to stone migration. Image analysis was carried out in a double-blind fashion.

Results

MRCP had 88.9% diagnostic accuracy, 91.9% sensitivity and 75% specificity, with 94.4% positive predictive value and 66.7% negative predictive value. EUS had 93.3% diagnostic accuracy, 97.3% sensitivity and 75% specificity; the positive and negative predictive values were 94.7% and 85.7%, respectively.

Conclusions

MRCP and EUS do not show significant statistical differences in diagnostic accuracy. MRCP is an accurate, noninvasive modality in the study of extrahepatic biliary pathology. EUS is especially reliable in patients with extrahepatic biliary obstruction caused by endoluminal sludge.     

Magnetic resonance cholangiopancreatography

Magnetic resonance cholangiopancreatography (MRCP) uses MR imaging to visualize fluid in the biliary and pancreatic ducts as high signal intensity on T2-weighted sequences; it is the newest modality for biliary and pancreatic duct imaging. MRCP is of proven utility in a variety of biliary and pancreatic diseases, including choledocholithiasis, congenital anatomic variants, chronic pancreatitis, post-cholecystectomy disorders, and neoplastic duct obstruction. MRCP is an evolving technique, but it has reached the stage of development where it is clinically useful and of comparable accuracy to conventional cholangiography. With further progress, it is likely that by the start of the new millennium MRCP will replace diagnostic endoscopic retrograde cholangiopancreatography as the modality of choice for imaging the biliary and pancreatic ducts.     

MRI for evaluating congenital bile duct abnormalities

Congenital bile duct diseases consist of ductal plate development abnormalities and are genetically determined. These biliary abnormalities are encountered mainly in congenital fibrocystic diseases, represented by congenital hepatic fibrosis and different forms of Caroli disease. On the other hand, polycystic hepatic diseases also present cystic abnormalities, which could be confused with biliary dilatations, especially in the perihilar area. Further, intricate forms between Caroli and polycystic hepatic diseases are possible. In congenital bile duct paucity, which is extremely rare, the biliary tree, located on the opposite, is not visible. MRI modalities for the analysis of the biliary tree are mainly represented by T -weighted sequence, also known as MR cholangiography (MRCP), and T gadolinium-enhanced sequences. Familiarity with the most common appearances of congenital bile duct dilations, its variants, and related complex diseases facilitates accurate diagnosis and allows and helps avoid misinterpretation.     

Role of MRCP in assessment of biliary variants in living donor liver transplantation

Introduction

Liver transplantation can be done by three different methods: Cadaveric, heterotopic and living donor liver transplantation (LDLT). In LDLT usually the right lobe of a donor liver is transplanted into the patient after proper volumetric studies. The native patient bile ducts are connected to the biliary tree of the transplanted liver segment.

Patients and methods

From January 2010 to August 2011, 50 potential LDLT donors were evaluated with preoperative MRCP.

Results

The radiologist evaluated the visualization of the common duct, right and left intra-hepatic ducts, and insertion of the right posterior lobe duct. The data were classified according to Huang and Hakki classifications. According to the more detailed classification of Hakki 13 patients (26%) were Type K1; 15 patients (30%) were Type K2a; three patients (6%) were Type K2b; 11 patients (22%) Type K3a; four patients (8%) were Type K3b; two patients (4%) were Type K4 and no patients were Type K5. Two patients with unclassified anatomical biliary pattern were encountered. In conclusion, this study has shown an extremely high accuracy of MRCP in preoperative assessment of live hepatic donors, which aided in the style and procedure of the operation and ultimately to a high success rate of the transplantation procedures.