High-grade pancreatic intraepithelial neoplasia diagnosed based on changes in magnetic resonance cholangiopancreatography findings:A case report

BACKGROUND High-grade pancreatic intraepithelial neoplasia(PanIN)exhibits no mass and is not detected by any examination modalities.However,it can be diagnosed by pancreatic juice cytology from indirect findings.Most previous cases were diagnosed based on findings of a focal stricture of the main pancreatic duct(MPD)and caudal MPD dilatation and subsequent pancreatic juice cytology using endoscopic retrograde cholangiopancreatography(ERCP).We experienced a case of high-grade PanIN with an unclear MPD over a 20-mm range,but without caudal MPD dilatation on magnetic resonance cholangiopancreatography(MRCP).CASE SUMMARY A 60-year-old female patient underwent computed tomography for a follow-up of uterine cancer post-excision,which revealed pancreatic cysts.MRCP revealed an unclear MPD of the pancreatic body at a 20-mm length without caudal MPD dilatation.Thus,course observation was performed.After 24 mo,MRCP revealed an increased caudal MPD caliber and a larger pancreatic cyst.We performed ERCP and detected atypical cells suspected of adenocarcinoma by serial pancreatic juice aspiration cytology examination.We performed a distal pancreatectomy and obtained a histopathological diagnosis of high-grade PanIN.Pancreatic parenchyma invasion was not observed,and curative resection was achieved.CONCLUSION High-grade Pan-IN may cause MPD narrowing in a long range without caudal MPD dilatation.

Biliary complications after liver transplantation:A computed tomography and magnetic resonance imaging pictorial review

Biliary complications are the most common complications after liver transplantation.Computed tomography(CT)and magnetic resonance imaging(MRI)are cornerstones for timely diagnosis of biliary complications after liver transplantation.The diagnosis of these complications by CT and MRI requires expertise,mainly with respect to identifying subtle early signs to avoid missed or incorrect diagnoses.For example,biliary strictures may be misdiagnosed on MRI due to size mismatch of the common ducts of the donor and recipient,postoperative edema,pneumobilia,or susceptibility artifacts caused by surgical clips.Proper and prompt diagnosis of biliary complications after transplantation allows the timely initiation of appropriate management.The aim of this pictorial review is to illustrate various CT and MRI findings related to biliary complications after liver transplantation,based on time of presentation after surgery and frequency of occurrence.

Role of magnetic resonance cholangiopancreatography in diagnosing choledochal cysts: Case series and review

AIM:To determine the merits of magnetic resonance cholangiopancreatography(MRCP) as the primary diagnostic test for choledochal cysts(CC’s).METHODS:Between 2009 and 2012,patients who underwent MRCP for perioperative diagnosis were identified.Demographic information,clinical characteristics,and radiographic findings were recorded.MRCP results were compared with intraoperative findings.A PubMed search identified studies published between 1996-2012,employing MRCP as the primary preoperative imaging and comparing results with either endoscopic retrograde cholangiopancreatography(ERCP) or operative findings.Detection rates for CC’s and abnormal pancreaticobiliary junction(APBJ) were calculated.In addition detection rates for clinically related biliary pathology like choledocholithiasis and cholangiocarcinomas in patients diagnosed with CC’s were also evaluated.RESULTS:Eight patients were identified with CC’s.Six patients out of them had typeⅣCC’s,1 had type I and 1 had a new variant of choledochal cyst with confluent dilatation of the common bile duct(CBD) and cystic duct.Seven patients had an APBJ and 3 of those had a long common-channel.Gallstones were found in 2 patients,1 had a CBD stone,and 1 pancreatic-duct stone was also detected.In all cases,MRCP successfully identified the type of CC’s,as well as APBJ with ductal stones.From analyzing the literature,we found that MRCP has 96%-100% detection rate for CC’s.Additionally,we found that the range for sensitivity,specificity,and diagnostic accuracy was 53%-100%,90%-100% and 56%-100% in diagnosing APBJ.MRCP’s detection rate was 100% for choledocholithiasis and 87% for cholangiocarcinomas with concurrent CC’s.CONCLUSION:After initial ultrasound and computed tomography scan,MRCP should be the next diagnostic test in both adult and pediatric patients.ERCP should be reserved for patients where therapeutic intervention is needed.

Diagnosis of mild chronic pancreatitis (Cambridge classification):Comparative study using secretin injection-magnetic resonance cholangiopancreatography and endoscopic retrograde pancreatography

AIM： To investigate the usefulness of secretin injection- MRCP for the diagnosis of mild chronic pancreatitis.METHODS： Sixteen patients having mild chronic pancreatitis according to the Cambridge classification and 12 control subjects with no abnormal findings on the pancreatogram were examined for the diagnostic accuracy of secretin injection-MRCP regarding abnormal branch pancreatic ducts associated with mild chronic pancreatitis （Cambridge Classification）, using endoscopic retrograde cholangiopancreatography （ERCP） for comparison.RESULTS： The sensitivity and specificity for abnormal branch pancreatic ducts determined by two reviewers were respectively 55%-63% and 75%-83% in the head, 57%-64% and 82%-83% in the body, and 44%-44% and 72%-76% in the tail of the pancreas. The sensitivity and specificity for mild chronic pancreatitis were 56%-63% and 92%-92%, respectively. Interobserver agreement （K statistics） concerning the diagnosis of an abnormal branch pancreatic duct and of mild chronic pancreatitis was good to excellent.CONCLUSION： Secretin injection-MRCP might be useful for the diagnosis of mild chronic pancreatitis.

Magnetic resonance cholangiopancreatography study of pancreaticobiliary maljunction and pancreaticobiliary diseases

AIM: To discuss the imaging anatomy about pancreaticobiliary ductal union, occurrence rate of pancreaticobiliary maljunction (PBM) and associated diseases in a Chinese population by using magnetic resonance cholangiopancreatography (MRCP).

Use of carbon dioxide as negative contrast agent for magnetic resonance cholangiopancreatography

AIM: To evaluate the effects of using CO2 as negative contrast agent in decreasing the overlapping on the pancreaticobiliary system from intestinal fluids.METHODS:We evaluated the magnetic resonance cholangiopancreatography(MRCP) images in 117 patients divided into two groups(group 1,without taking gas producing crystals to produce CO2,n=64;group 2,with CO2,n=53)in a 1.5T unit using MRCP sequence.Anatomic locations of intestinal fluids distribution,overlapping with common bile duct(CBD)and pancreatic duct(PD),were evaluated.RESULTS:In the group with CO2,the decrease in distribution of intestinal fluids was significant in the gastric antrum(P=0.001)and duodenal bulb(P<0.001),but not in the gastric fundus and body and in the second portion of the duodenum(P=1.000,P=0.171,and P=0.584 respectively).In the group with CO2,the decrease in overlapping with CBD was significant(P< 0.001),but the decrease in overlapping with PD was not (P=0.106).CONCLUSION:MRCP with carbon dioxide as negative contrast agent would decrease intestinal fluids in the gastric antrum and duodenal bulb,thereby decreasing overlapping with the CBD.

Magnetic resonance cholangiopancreatography for the detection of pancreatic duct stones in patients with chronic pancreatitis

AIM:To assess the role of magnetic resonance cholangiopancreatography(MRCP) in detection of pancreatic duct stones(PDS) in patients with chronic pancreatitis(CP).METHODS:Clinical data of 78 CP patients who were treated at the First Affi liated Hospital of Xi'an Jiaotong University(China) between January 2004 and July 2008 were retrospectively analyzed.A predictive model of pancreatic duct stones was established through logistic regression and its effectiveness was verifi ed.Among these patients, MRCP was performed in 60 patients who served as a control group, while 44 patients with a higher predictive value than the entry threshold of the predictive model served as an experimental group.RESULTS:The positive rate of PDS in the 78 patients with CP was 19.2%(15/78).The predictive entry threshold of the predictive model was 5%(P < 0.05).The possibility of existence of PDS could be predicted according to the following 4 indexes:gastrointestinal symptoms, intermittent abdominal pain, diabetes mellitus(DM)/impaired glucose tolerance(IGT) and positive B-mode ultrasound results.The incidence of PDS in the experimental group was higher than that in the control group(P < 0.05).CONCLUSION:MRCP is strongly suggested for the detection of PDS in patients with gastrointestinal symptoms, intermittent abdominal pain, DM/IGT and positive B-mode ultrasound results.

MRI联合MRCP在胆道梗阻性疾病诊断中的应用价值

目的 探究MRI及MRCP在胆道梗阻性疾病定位和定性诊断的应用价值。方法 回顾性分析2017年11月至2019年11月在上海中医药大学附属岳阳中西医结合医院经手术病理或临床证实的72例胆道梗阻性疾病患者的临床资料,所有患者均行MRI及MRCP检查,其中42例加行CT检查,对不同影像学检查结果进行对比分析。结果 MRI联合MRCP、MRI、CT检查的定位诊断准确率分别为100%(72/72)、94.4%(68/72)、78.6%(33/42),定性诊断准确率分别为95.8%(69/72)、86.1%(62/72)、66.7%(28/42)。上述3种影像学检查均做的42例中,MRI联合MRCP检查较CT检查的定位诊断[100%(42/42) vs 78.6%(33/42),χ^(2)=10.080,P<0.05]和定性诊断[90.5%(38/42) vs 66.7%(28/42),χ^(2)=7.071,P<0.05]的准确率差异均有统计学意义,MRI联合MRCP与MRI、MRI与CT检查比较,定位诊断和定性诊断的准确率差异均无统计学意义(P>0.05)。结论 MRI联合MRCP可显著提高对胆道梗阻性病变的检出率和确诊率。

Clinical significance of magnetic resonance cholangiopancreatography utilizing half-Fourier acquisition single-shot fast spin-echo in diagnosing bile duct diseases

Objective: To investigate the clinical significance of magnetic resonance cholangiopancreatography (MRCP) utilizing half-Fourier acquisition single-shot fast spin-echo (HASTE) in the diagnosis of bile duct diseases. Methods: Forty-three patients with obstructive jaundice and 4 without were enrolled in this study. The underlying diseases included bile duct calculi ( 13 cases) , chronic cholangitis ( 14 cases) malignant tumors (18 cases) and congenital biliary cysts (2 cases). All patients underwent examinations with magnetic resonance imaging (MRI) and MRCP, and 39 were also examined with B-type ultrasonography, 33 with CT and 25 with ERCP and PTC. Three-dimensional image reconstruction was performed using volume-rendered technique ( VRE) on the basis of the data obtained by MRCP. Results: The biliary calculi were displayed as circular filling defects in MRCP images, with the proximal end of dilated bile duct taking the form of the mouth of a cup. The bile duct of patients with chronic cholangitis showed distal end dilation and thinner proximal end without discontinuity. Interception of the bile ducts was most frequent (72. 2% ) in cases of malignant bile duct obstruction, in which the ducts may also be mastoid or resembling rat tails. 72. 2% of the cases had severe dilation of the bile ducts, which occur in only 16. 0% of the benign cases, with significant difference between them (P <0. 01) . In images of intrahepatic biliary cyst, intrahepatic duct dilated in the shape of a bursa in connection with the duct. By MRCP, 20 malignant obstructions of the bile ducts were identified with 2 misdiagnoses, and in 25 cases of benign obstructions identified by MRCP, only 1 misdiagnoses occurred. Thus MRCP had the sensitivity, specificity and accuracy of 90.0% , 96.3% and 93.6% respectively in discriminating benign and malignant diseases of the bile ducts, showing a total diagnostic accuracy of 94. 0% that was similar to that of ERCP (92.0% ) but significantly higher than those of both CT (75. 0% ) and B-type ultrasonic examination (74. 0% ). Conclusion: In diagnosing obstructive jaundice, HASTE MRCP is similar to ERCP but better than CT and B-type ultrasonography , with the merits of fast imaging and high resolution as an ideal sequence for MRCP imaging.

Magnetic resonance cholangiopancreatography image enhancement for automatic disease detection

AIM:To sufficiently improve magnetic resonance cholangiopancreatography(MRCP) quality to enable reliable computer-aided diagnosis(CAD).METHODS:A set of image enhancement strategies that included filters(i.e.Gaussian,median,Wiener and Perona-Malik),wavelets(i.e.contourlet,ridgelet and a non-orthogonal noise compensation implementation),graph-cut approaches using lazy-snapping and Phase Unwrapping MAxflow,and binary thresholding using a fixed threshold and dynamic thresholding via histogram analysis were implemented to overcome the adverse characteristics of MRCP images such as acquisition noise,artifacts,partial volume effect and large inter-and intra-patient image intensity variations,all of which pose problems in application development.Subjective evaluation of several popular pre-processing techniques was undertaken to improve the quality of the 2D MRCP images and enhance the detection of the significant biliary structures within them,with the purpose of biliary disease detection.RESULTS:The results varied as expected since each algorithm capitalized on different characteristics of the images.For denoising,the Perona-Malik and contourlet approaches were found to be the most suitable.In terms of extraction of the significant biliary structures and removal of background,the thresholding approaches performed well.The interactive scheme performed the best,especially by using the strengths of the graphcut algorithm enhanced by user-friendly lazy-snapping for foreground and background marker selection.CONCLUSION:Tests show promising results for some techniques,but not others,as viable image enhancement modules for automatic CAD systems for biliary and liver diseases.

Evolution of incidental branch-duct intraductal papillary mucinous neoplasms of the pancreas: A study with magnetic resonance imaging cholangiopancreatography

AIM To investigate the type and timing of evolution of incidentally found branch-duct intraductal papillary mucinous neoplasms(bd-IPMN) of the pancreas addressed to magnetic resonance imaging cholangiopancreatography(MRCP) follow-up.METHODS We retrospectively evaluated 72 patients who underwent, over the period 2006-2016, a total of 318 MRCPs(mean 4.4) to follow-up incidental, presumed bdIPMN without signs of malignancy, found or confirmedat a baseline MRCP examination. Median follow-up time was 48.5 mo(range 13-95 mo). MRCPs were acquired on 1.5T and/or 3.0T systems using 2D and/or 3D technique. Image analysis assessed the rates of occurrence over the follow-up of the following outcomes:(1) imaging evolution, defined as any change in cysts number and/or size and/or appearance; and(2) alert findings, defined as worrisome features and/or high risk stigmata(e.g., thick septa, parietal thickening, mural nodules and involvement of the main pancreatic duct). Time to outcomes was described with the Kaplan-Meir approach. Cox regression model was used to investigate clinical or initial MRCP findings predicting cysts changes.RESULTS We found a total of 343 cysts(per-patient mean 5.1) with average size of 8.5 mm(range 5-25 mm). Imaging evolution was observed in 32/72 patients(44.4%; 95%CI: 32-9-56.6), involving 47/343 cysts(13.7%). There was a main trend towards small(< 10 mm) increase and/or decrease of cysts size at a median time of 22.5 mo. Alert findings developed in 6/72 patients(8.3%; 95%CI: 3.4-17.9) over a wide interval of time(13-63 mo). No malignancy was found on endoscopic ultrasound with fine-needle aspiration(5/6 cases) or surgery(1/6 cases). No clinical or initial MRCP features were significantly associated with changes in bd-IPMN appearance(P > 0.01).CONCLUSION Changes in MRCP appearance of incidental bd-IPNM were frequent over the follow-up(44.4%), with relatively rare(8.3%) occurrence of non-malignant alert findings that prompted further diagnostic steps. Changes occurred at a wide interval of time and were unpredictable, suggesting that imaging followup should be not discontinued, though MRCPs might be considerably delayed without a significant risk of missing malignancy.

Oral Gd-DTPA as a negative gastrointestinal contrast agent in magnetic resonance cholangiopancreatography

Objective: To evaluate the value of oral Gd-DTPA as a negative contrast agent during magnetic resonance cholangiopancreatography (MRCP) to eliminate the high signals of the gastrointestinal tract. Methods: To select the optimal concentration of oral Gd-DTPA for MRCP, a phantom study was performed followed by clinical trial in 15 cases undergoing MRCP before and after oral Gd-DTPA (in a total volume of 250 ml 1∶5 diluted Gd-DTPA, 1.488 g/L). MRCP images were acquired using two-dimensional single slice fast spin-echo (SSTSE) sequence and half-Fourier acquisition single slice fast spin-echo (HASTE) sequence. Results: The phantom study showed that the 1∶5 diluted oral Gd-DTPA was best in decreasing the signal intensity both in T2-weighted imaging (59.5%) and in HASTE sequence (82.45%). The high signal intensity of the stomach and intestinal fluid was completely suppressed in all the cases. The depictions of the common bile duct and pancreatic duct were markedly improved by using the oral contrast agent (P<0.05). Conclusion: Oral Gd-DTPA is effective and safe for eliminating the high signal of the gastrointestinal tract to improve the depiction of the biliary system by MRCP.

MRCP联合荧光胆道造影在腹腔镜胆囊切除术中识别胆囊床胆管的应用价值

目的探讨磁共振胆胰管成像(MRCP)联合吲哚箐绿(ICG)近红外荧光成像胆道造影技术在腹腔镜胆囊切除术(LC)中识别胆囊床胆管的可行性及临床应用价值。方法回顾性分析2021年7月至2023年12月淄博市市立医院术前完善MRCP评估、术中应用荧光胆道造影技术行LC术的160例患者的临床资料(研究组),同时收集2020年1月至2023年12月本院应用传统腹腔镜标准白光模式下行胆囊切除术的180例患者的临床资料(对照组),比较两组患者术中、术后相关指标。结果研究组术中出血量与对照组差异无统计学意义[(10.3±1.7)mL vs(11.9±1.4)mL,P>0.05],手术时间较对照组短[(30.6±10.3)min vs(45.7±9.6)min,P<0.05]。研究组共7.5%(12/160)患者术中荧光胆道造影发现存在胆囊床胆管。研究组出现1例胆囊床胆管损伤,术中给予缝扎,术后无胆漏发生;对照组出现2例胆囊床胆管漏,行内镜逆行胆胰管造影(ERCP)证实。研究组较对照组住院时间短[2.0(1.0,2.0)d vs 3.0(2.0,4.0)d,P<0.05]、置管率较对照组低[2.50%(4/160)vs 8.33%(15/180),P<0.05]。两组术后胆漏发生率、置管时间差异无统计学意义(均P>0.05)。MRCP对诊断胆囊床胆管敏感性为58.3%,特异性为61.0%。结论术前完善MRCP评估,术中应用ICG荧光成像技术有利于胆囊床胆管的发现,可缩短手术时间、提高手术安全性,减少术后并后症发生。

经腹超声、腹部CT和MRCP在胆总管结石诊断中的比较分析

目的 探讨经腹超声、腹部CT和磁共振胰胆管成像(MRCP)3种检查方法对胆总管结石诊断的效能。方法 回顾性分析2020年1月至2020年12月在我院消化科住院的84例可疑胆总管结石患者的临床资料,包括年龄、性别、经腹超声、腹部CT和MRCP检查结果等。比较3种方法对胆总管结石的诊断灵敏度、特异度、阳性预测值、阴性预测值、准确率及对胆总管扩张的检出率。结果 84例可疑胆总管结石患者中,通过内镜下逆行胰胆管造影(ERCP)检查(金标准)及相关治疗明确诊断为胆总管结石的患者76例,经腹超声检查、腹部CT检查及磁共振胰胆管成像(MRCP)检查的灵敏度分别为(55.26%、77.63%、93.42%),准确率分别为(57.14%、76.19%、92.85%)。3种检查方法对胆总管结石(CBDS)的诊断灵敏度、准确率不同,差异有统计学意义(P <0.05);3种检查方法的诊断特异度(75.00%、62.50%、87.50%)、阳性预测值(95.45%、95.16%、98.61%)、阴性预测值(15.00%、22.72%、58.33%)和对胆管扩张的检出率(61.90%、71.43%、73.81%)之间无明显差异(P> 0.05)。结论 3种检查方法对胆总管结石的诊断能力结果显示MRCP>腹部CT>经腹超声。

DCE-MRI、DWI和MRCP联合诊断肝外胆管癌临床价值研究

目的探讨采用磁共振动态增强成像(DCE-MRI)、磁共振弥散加权成像(DWI)与磁共振胰胆管造影成像(MRCP)联合诊断肝外胆管癌(CC)的临床价值。方法2019年3月~2022年3月我院诊治的64例疑似肝外CC患者,经穿刺或手术病理学检查为金标准,评估DCE-MRI、DWI和MRCP联合诊断的效能。结果经组织病理学检查诊断,在64例疑似肝外CC患者中,诊断肝外CC 45例;DCE-MRI诊断检出肝外CC 46例,其中41例阳性和14例阴性与病理学检查诊断一致(Kappa=0.658,P<0.05);DWI诊断检出肝外CC 45例,其中38例阳性和12例阴性与病理学检查诊断一致(Kappa=0.476,P<0.05);MRCP诊断检出肝外CC 44例,其中40例阳性和15例阴性与病理学检查诊断一致(Kappa=0.668,P<0.05);DCE-MRI、DWI和MRCP联合诊断检出肝外CC 45例,其中43例阳性和17例阴性与病理学检查诊断一致(Kappa=0.850,P<0.05);DCE-MRI、DWI和MRCP联合诊断的灵敏度、特异度和正确性分别为95.6%%、89.5%和93.8%,显著优于任一检查的单独诊断。结论DCE-MRI、DWI和MRCP联合诊断肝外CC的效能更高,能够为临床诊断提供重要的依据。

Accuracy of magnetic resonance cholangiography compared to operative endoscopy in detecting biliary stones, a single center experience and review of literature

AIM: To compare diagnostic sensitivity, specificity and accuracy of magnetic resonance cholangiopancreatography(MRCP) without contrast medium and endoscopic ultrasound(EUS)/endoscopic retrograde cholangiopancreatography(ERCP) for biliary calculi. METHODS: From January 2012 to December 2013, two-hundred-sixty-three patients underwent MRCP at our institution, all MRCP procedure were performed with the same machinery. In two-hundred MRCP was done for pure hepatobiliary symptoms and these patients are the subjects of this study. Among these two-hundred patients, one-hundred-eleven(55.5%) underwent ERCP after MRCP. The retrospective study design consisted in the systematic revision of all images from MRCP and EUS/ERCP performed by two radiologist with a long experience in biliary imaging, an experienced endoscopist and a senior consultant in Hepatobiliopancreatic surgery. A false positive was defined an MRCP showing calculi with no findings at EUS/ERCP; a true positive was defined as a concordance between MRCP and EUS/ERCP findings; a false negative was defined as the absence of images suggesting calculi at MRCP with calculi localization/extraction at EUS/ERCP and a true negative was defined as a patient with nocalculi at MRCP ad at least 6 mo of asymptomatic followup. Biliary tree dilatation was defined as a common bile duct diameter larger than 6 mm in a patient who had an in situ gallbladder. A third blinded radiologist who examined the MRCP and ERCP data reviewed misdiagnosed cases. Once obtained overall data on sensitivity, specificity, accuracy, positive predictive value(PPV) and negative predictive value(NPV) we divided patients in two groups composed of those having concordant MRCP and EUS/ERCP(Group A, 72 patients) and those having discordant MRCP and EUS/ERCP(Group B, 20 patients). Dataset comparisons had been made by the Student's t-test and χ2 when appropriate.RESULTS: Two-hundred patients(91 men, 109 women, mean age 67.6 years, and range 25-98 years) underwent MRCP. All patients attended regular follow-up for at least 6 mo. Morbidity and mortality related to MRCP were null. MRCP was the only exam performed in 89 patients because it did show only calculi into the gallbladder with no signs of the presence of calculi into the bile duct and symptoms resolved within a few days or after colecistectomy. The patients remained asymptomatic for at least 6 mo, and we assumed they were true negatives. One hundred eleven(53 men, 58 women, mean age 69 years, range 25-98 years) underwent ERCP following MRCP. We did not find any difference between the two groups in terms of race, age, and sex. The overall median interval between MRCP and ERCP was 9 d. In detecting biliary stones MRCP Sensitivity was 77.4%, Specificity 100% and Accuracy 80.5% with a PPV of 100% and NPV of 85%; EUS showed 95% sensitivity, 100% specificity, 95.5% accuracy with 100% PPV and 57.1% NPV. The association of EUS with ERCP performed at 100% in all the evaluated parameters. When comparing the two groups, we did not find any statistically significant difference regarding age, sex, and race. Similarly, we did not find any differences regarding the number of extracted stones: 116 stones in Group A(median 2, range 1 to 9) and 27 in Group B(median 2, range 1 to 4). When we compared the size of the extracted stones we found that the patients in Group B had significantly smaller stones: 14.16 ± 8.11 mm in Group A and 5.15 ± 2.09 mm in Group B; 95% confidence interval = 5.89-12.13, standard error = 1.577; P < 0.05. We also found that in Group B there was a significantly higher incidence of stones smaller than 5 mm: 36 in Group A and 18 in Group B, P < 0.05.CONCLUSION: Major finding of the present study is that choledocholithiasis is still under-diagnosed in MRCP. Smaller stones(< 5 mm diameter) are hardly visualized on MRCP.

Role of diffusion-weighted magnetic resonance imaging in the diagnosis of extrahepatic cholangiocarcinoma

AIM: To determine the clinical value of diffusion-weight- ed imaging (DWI) for the diagnosis of extrahepatic cholangiocarcinoma (EHCC) by comparing the diagnostic sensitivity of DWI and magnetic resonance cholan-giopancreatography (MRCP). METHODS: Magnetic resonance imaging examination was performed in 56 patients with suspected EHCC. T1- weighted imaging, T2-weighted imaging, MRCP and DWI sequence, DWI using single-shot spin-echo echoplanar imaging sequence with different b values (100, 300, 500, 800 and 1000 s/mm2), were performed. All cases were further confirmed by surgery or histopathological diagnosis. Two radiologists jointly performed the analysis of the DWI and MRCP images. Apparent diffusion coefficient (ADC) value and signal-noise ratio were calculated for EHCC. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value were tested using DWI with a b value of 500 s/mm2 and MRCP images, respectively. RESULTS: Histopathological diagnosis confirmed that among the 56 cases, 35 were EHCC (20 hilar and 15 distal extrahepatic), 16 were cholangitis, and 5 were cal-culus of bile duct. Thirty-three out of the 35 EHCC cases were detected by DWI. EHCC exhibited differential levels of high signal intensity in DWI and low signal intensity in the ADC map. The mean value for ADC was (1.31 ± 0.29) × 10-3 mm2/s. The detection rate of EHCC was significantly higher by DWI (94.3%) than by MRCP (74.3%) (P < 0.05). There was a significant difference in sensitivity (94.3% vs 74.3%), specificity (100% vs 71.4%), accu- racy (96.4% vs 73.2%), positive predictive value (100% vs 81.3%), and negative predictive value (91.3% vs 62.5%) between DWI and MRCP in diagnosing EHCC. CONCLUSION: DWI has a high sensitivity for the detection of EHCC as it shows the EHCC lesion more unambiguously than MRCP does. DWI can also provide additional clinically important information in EHCC patients when added to routine bile duct MR imaging protocols.

Gd-EOB-DTPA-enhanced magnetic resonance imaging for bile duct intraductal papillary mucinous neoplasms

AIM: To investigate gadolinium-ethoxybenzyldiethylenetriamine-pentaacetic acid(Gd-EOB-DTPA)-enhanced magnetic resonance imaging(MRI) of intraductal papillary mucinous neoplasms of the bile duct(IPMN-B). METHODS: The imaging findings of five cases of IPMN-B which were pathologically confirmed at our hospital between March 2012 and May 2013 were retrospectively analyzed. Three of these cases were diagnosed by duodenal endoscopy and biopsy pathology, and two cases were diagnosed by surgical pathology. All five patients underwent enhanced and non-enhanced computed tomography(CT), magnetic resonance cholangiopancreatography, and Gd-EOB-DTPA-enhanced MRI; one case underwent both Gd-EOB-DTPA-enhanced MRI and positron emission tomography-CT. The clinical data and imaging results for these cases were compared and are presented.RESULTS: Conventional imaging showed diffusedilatation of bile ducts and multiple intraductal polypoid and papillary neoplasms or serrated changes along the bile ducts. In two cases, Gd-EOB-DTPA-enhanced MRI revealed dilated biliary ducts and intraductal tumors, as well as filling defects caused by mucin in the dilated bile ducts in the hepatobiliary phase. GdEOB-DTPA-enhanced MRI in one case clearly showed a low-signal tumor in the hepatobiliary phase, similar to what was seen by positron emission tomographyCT. In two patients, routine inspection was unable to discern whether the lesions were inflammation or tumors. However, Gd-EOB-DTPA-enhanced MRI revealed a pattern of gradual enhancement during the hepatobiliary phase, and the signal intensity of the lesions was lower than the surrounding liver parenchyma, suggesting tissue inflammation in both cases, which were confirmed by surgical pathology. CONCLUSION: Gd-EOB-DTPA-enhanced MRI reveals the intraductal mucin component of IPMN-B in some cases and the extent of tumor infiltration beyond the bile ducts in invasive cases.

Exocrine pancreatic function assessed by secretin cholangio-Wirsung magnetic resonance imaging

BACKGROUND:Magnetic resonance cholangiopancreato-graphy (MRCP) is useful to assess exocrine pancreatic function by combining rapid imaging acquisition with the administration of secretin, a gastrointestinal hormone that stimulates the secretion of bile and pancreatic juice. However, extensive data on this method are lacking. This study aimed to determine whether MRCP with secretin administration is able to simultaneously detect alterations of both the pancreatic ducts and exocrine pancreatic function. METHODS:All subjects older than 18 years who underwent magnetic resonance imaging (MRI) and cholangio-Wirsung magnetic resonance imaging (CWMRI) for suspicion of benign or malignant pancreatic diseases from January 2006 to December 2006 were enrolled in the study. MRI and CWMRI were carried out using a dedicated apparatus. RESULTS:Eighty-seven patients (46 males, 41 females, mean age 59.7±14.6, range 27-87 years) were enrolled. Of the 87 patients, 39 had a normal pancreas on imaging, 20 had an intrapapillary mucinous tumor (IPMT), and the rest had chronic pancreatitis (7), serous cystadenoma (6), a previous attack of acute biliary pancreatitis (5), congenital ductal abnormalities (5), mucinous cystadenoma (3), previous pancreatic head resection for autoimmune pancreatitis (1), or cholangiocarcinoma (1). Morphologically, we found two pseudocysts (one of the 7 patients with chronic pancreatitis, and one of the 5 patients after an attack of acute pancreatitis;the latter pseudocyst communicated with the main pancreatic duct). Calcifications were found in 3 of the 7 patients with chronic pancreatitis. All patients with IPMT and mucinous cystadenoma and 3 patients with serous cystadenoma were histologically confirmed. The remaining patients were followed up adequately to confirm the diagnosis by imaging. According to the Matos criteria, 73 patients (83.9%) were of grade 3, 8 grade 2, 4 grade 1, and 2 grade 0. The only pancreatic diseases which impaired the exocrine pancreatic secretion stimulated by secretin were chronic pancreatitis (57.1% of the patients, grade 0-1) and the IPMT mixed type in 2 of the 4 patients was grade 1. CONCLUSION:Secretin MRCP is a useful technique to simultaneously detect the presence of alterations of the pancreatic ducts and exocrine pancreatic function.

Magnetic resonance cholangiography in the assessment and management of biliary complications after OLT

Despite advances in patient and graft management,biliary complications(BC)still represent a challenge both in the early and delayed period after orthotopic liver transplantation(OLT).Because of unspecific clinical presentation,imaging is often mandatory in order to diagnose BC.Among imaging modalities,magnetic resonance cholangiography(MRC)has gained widespread acceptance as a tool to represent the reconstructed biliary tree noninvasively,using both the conventional technique(based on heavily T2-weighted sequences)and contrast-enhanced MRC(based on the acquisition of T1-weighted sequences after the administration of hepatobiliary contrast agents).On this basis,MRC is generally indicated to:(1)avoid unnecessary procedures of direct cholangiography in patients with a negative examination and/or identify alternative complications;and(2)provide a road map for interventional procedures or surgery.As illustrated in the review,MRC is accurate in the diagnosis of different types of biliarycomplications,including anastomotic strictures,nonanastomotic strictures,leakage and stones.