Contrast-enhanced MR cholangiography (MRCP) with GD-EOB-DTPA in evaluating biliary complications after surgery. Radiol Med. 2012;117:354-368. [PMID: 22020424 DOI: 10.1007/s11547-011-0731-4]

Magnetic Resonance Cholangiography Diagnosing Post-cholecystectomy Biliary Injuries

OBJECTIVE

This study aimed to determine the diagnostic performance of contrasted magnetic resonance cholangiography for detecting bile duct lesions following cholecystectomy.

MATERIALS AND METHODS

A retrospective case series study was conducted that included patients over 18 years of age with suspected bile duct injury after cholecystectomy, who underwent contrasted magnetic resonance cholangiography, and who also had endoscopic retrograde cholangiopancreatography, surgery, or subsequent clinical follow-up. The images were interpreted by two radiologists who assigned the type of lesion according to the Strasberg classification. Qualitative variables were represented by frequencies and proportions, while quantitative variables were described using measures of central tendency and dispersion. Sensitivity, specificity, and predictive values were assessed, along with interobserver variability, using the kappa index.

RESULTS

We included 20 patients with a median age of 51.5 years (interquartile range: 35), and 14 (70%) were women. In all 20 patients, lesions were identified on magnetic resonance cholangiography, of which 19 were confirmed with the gold standard for a positive predictive value of 100% (hepatobiliary-specific contrast agents) and 92% (extracellular contrast). The most frequent lesions were Strasberg E2 and E4 in five patients each. The kappa index was 1 in determining the presence or absence of bile duct injury and 0.9 in the Strasberg classification.

CONCLUSION

Contrasted magnetic resonance cholangiography is a method with high positive predictive value and almost perfect interobserver agreement for diagnosing bile duct lesions after cholecystectomy.

Gd-EOB-DTPA-MRCP to localize bile leakage after liver trauma and surgery: impact on treatment and outcome

OBJECTIVES

Bile leakage (BL) is a challenging complication after hepatobiliary surgery and liver trauma. Gadolinium ethoxybenzyl (Gd-EOB-DTPA)-enhanced magnetic resonance cholangiopancreatography (MRCP) is used to diagnose BL non-invasively. We assessed the value of Gd-EOB-DTPA-MRCP in the detection of postoperative and post-traumatic BL hypothesizing that exact identification of the leakage site is pivotal for treatment planning and outcome.

METHODS

We retrospectively enrolled 39 trauma and postoperative patients who underwent Gd-EOB-DTPA-MRCP for suspected BL. Three readers rated the presence of BL and leakage site (intraparenchymal, central, peripheral ± aberrant or disconnected ducts). Imaging findings were compared to subsequent interventional procedures and their complexity and outcome.

RESULTS

BL was detected in Gd-EOB-DTPA-MRCP in 25 of patients and was subsequently confirmed. Sites of BL differed significantly between postoperative (central [58%] and peripheral [42%]) and trauma patients (intraparenchymal [100%]; p < 0.001). Aberrant or disconnected ducts were diagnosed in 8%/26% of cases in the postoperative subgroup. Inter-rater agreement for the detection and localization of BL was almost perfect (Κ = 0.85 and 0.88; p < 0.001). Intraparenchymal BL required significantly less complex interventional procedures (p = 0.002), whereas hospitalization and mortality did not differ between the subgroups (p > 0.05).

CONCLUSIONS

Gd-EOB-DTPA-MRCP reliably detects and exactly locates BL in postoperative and trauma patients. Exact localization of biliary injuries enables specific treatment planning, as intraparenchymal leakages, which occur more frequently after trauma, require less complex interventions than central or peripheral leaks in the postoperative setting. As a result of specific treatment based on exact BL localization, there was no difference in the duration of hospitalization or mortality.

CLINICAL RELEVANCE STATEMENT

Gd-EOB-DTPA-MRCP is a reliable diagnostic tool for exactly localizing iatrogenic and post-traumatic biliary leakage. Its precise localization helps tailor local therapies for different injury patterns, resulting in comparable clinical outcomes despite varying treatments.

KEY POINTS

• Gd-EOB-DTPA-MRCP enables adequate detection and localization of bile leakages in both postoperative and post-traumatic patients. • The site of bile leakage significantly impacts the complexity of required additional interventions. • Intraparenchymal bile leakage is commonly seen in patients with a history of liver trauma and requires less complex interventions than postoperative central or peripheral bile leakages, while hospitalization and mortality are similar.

Liver-Specific Contrast-Enhanced Magnetic Resonance Cholangio-Pancreatography (Ce-MRCP) in Non-Invasive Diagnosis of Iatrogenic Biliary Leakage

Current non-invasive diagnostic modalities of iatrogenic bile leak (BL) are not particularly sensitive and often fail to localise the BL origin. Percutaneous transhepatic cholangiography (PTC) and endoscopic retrograde cholangiopancreatography (ERCP) are considered the gold standard, yet are invasive studies with potential complications. Ce-MRCP has been not comprehensively studied in this setting but may prove particularly helpful given its non-invasive nature and the anatomical dynamic detail. This paper reports a monocentric retrospective study of BL patients referred between January 2018 and November 2022 submitted to Ce-MRCP followed by PTC. The primary outcome was the accuracy of Ce-MRCP in detecting and localising BL compared to PTC and ERCP. Blood tests, coexisting cholangitis features and time for leak resolution were also investigated. Thirty-nine patients were included. Liver-specific contrast-enhanced MRCP detected BL in 69% of cases. The BL localisation was 100% accurate. Total bilirubin above 4 mg/dL was significantly associated with false negative results of Ce-MRCP. Ce-MRCP is highly accurate in detecting and localising BL, but sensitivity is significantly reduced by a high bilirubin level. Ce-MRCP may be very useful in early BL diagnosis and in accurate pre-treatment planning, but can only be reliably used in selected patients with TB < 4 mg/dL. Non-surgical techniques, both radiological and endoscopic, are proven to be effective in terms of leak resolution.

Biliary complications in pediatric liver transplantation: findings of percutaneous transhepatic cholangiography in a large single-center cohort

BACKGROUND

Although biliary complications after orthotopic liver transplantation represent a common source of morbidity and mortality, decreasing graft survival, consensus is lacking on their management in the pediatric population.

OBJECTIVE

The aim of this study was to present the prevalence of such biliary complications and their interventional radiologic management with representative images.

MATERIALS AND METHODS

This retrospective study reports our experience with percutaneous transhepatic cholangiography in the management of biliary complications after orthotopic liver transplantation in pediatric patients. This study enrolled all pediatric patients (<18 years old) who underwent percutaneous transhepatic cholangiography for the management of biliary complications after orthotopic liver transplantation at a tertiary care center between January 2010 and December 2020. Diagnosis of biliary complications and indication to perform percutaneous transhepatic cholangiography were based on clinical, laboratory or radiologic data.

RESULTS

Among the 301 orthotopic liver transplantations, 78 (26%) developed biliary complications that were managed by interventional radiology: these included 52 (17.3%) biliary strictures, 19 (6.3%) bile leaks, 5 (1.7%) biliary stones, 1 (0.3%) iatrogenic biliary obstruction and 1 (0.3%) vanishing syndrome. The median time interval between orthotopic liver transplantation and the diagnosis of biliary complications was 6.0 years (interquartile range [IQR] 8.2 years). Percutaneous transhepatic cholangiography and biliary duct catheterization were successful in all cases, with low rates of complications that were variable among subgroups.

CONCLUSION

A wide spectrum of biliary complications can occur after pediatric orthotopic liver transplantation. In this large single-center experience, we highlight the value of percutaneous transhepatic cholangiography in their diagnosis and management. Percutaneous treatments in pediatric patients are safe and effective, providing resolution or serving as a bridge to surgery, including re-transplantation.

Liver Transplantation in Malignancies: A Comprehensive and Systematic Review on Oncological Outcome

Introduction

Liver transplantation (LT) is today's standard treatment for both end-stage liver disease and tumors; however, suitable grafts for LT are a scarce resource and outcome after LT is highly dependent on its underlying indication. Thus, patients must be carefully selected to optimize the number of life years gained per graft. This comprehensive and systematic review critically reflects the most recently published oncological outcome data after LT in malignancies based on the preoperative radiological findings.

Methods

A systematic literature search was conducted to detect preferentially most recent high-volume series or large database analysis on oncological outcomes after LT for both primary liver cancer and liver metastases between January 1, 2019, and November 14, 2020. A comprehensive review on the radiological assessment of the reviewed liver malignancies is included and its preoperative value for an outcome-driven indication reflected.

Results

Twenty most recent high-volume or relevant studies including a total number of 2,521 patients were identified including 4, 4, 4, 4, 3, and 1 publications on oncological outcome after LT for hepatocellular carcinoma, cholangiocellular carcinoma, hepatic epitheloid hemangioendothelioma, hepatoblastoma, and both metastatic neuroendocrine tumors and colorectal cancer, respectively. The overall survival is comparable to patients without tumors if patients with malignancies are well selected for LT; however, this is highly dependent on tumor entity, tumor stage, and both neoadjuvant and concomitant treatment.

Discussion/Conclusion

LT is a promising option for better survival in patients with malignant liver tumors in selected patients; however, the indication must be critically discussed prior to LT in every single case in the context of organ shortage.

Modern imaging of cholangitis

Cholangitis refers to inflammation of the bile ducts with or without accompanying infection. When intermittent or persistent inflammation lasts 6 months or more, the condition is classified as chronic cholangitis. Otherwise, it is considered an acute cholangitis. Cholangitis can also be classified according to the inciting agent, e.g. complete mechanical obstruction, which is the leading cause of acute cholangitis, longstanding partial mechanical blockage, or immune-mediated bile duct damage that results in chronic cholangitis.The work-up for cholangitis is based upon medical history, clinical presentation, and initial laboratory tests. Whereas ultrasound is the first-line imaging modality used to identify bile duct dilatation in patients with colicky abdominal pain, cross-sectional imaging is preferable when symptoms cannot be primarily localised to the hepatobiliary system. CT is very useful in oncologic, trauma, or postoperative patients. Otherwise, magnetic resonance cholangiopancreatography is the method of choice to diagnose acute and chronic biliary disorders, providing an excellent anatomic overview and, if gadoxetic acid is injected, simultaneously delivering morphological and functional information about the hepatobiliary system. If brush cytology, biopsy, assessment of the prepapillary common bile duct, stricture dilatation, or stenting is necessary, then endoscopic ultrasound and/or retrograde cholangiography are performed. Finally, when the pathologic duct is inaccessible from the duodenum or stomach, percutaneous transhepatic cholangiography is an option. The pace of the work-up depends upon the severity of cholestasis on presentation. Whereas sepsis, hypotension, and/or Charcot's triad warrant immediate investigation and management, chronic cholestasis can be electively evaluated.This overview article will cover the common cholangitides, emphasising our clinical experience with the chronic cholestatic liver diseases.

MRI evaluation of bile duct injuries and other post-cholecystectomy complications

Laparoscopic cholecystectomy is one of the most common procedures performed each year and can be associated with various post-operative complications. Imaging is integral to diagnosis and management of patients with suspected cholecystectomy complications, and a thorough understanding of normal and abnormal biliary anatomy, risk factors for biliary injury, and the spectrum of adverse events is crucial for interpretation of imaging studies. Magnetic resonance cholangiography (MRC) enhanced with hepatobiliary contrast agent is useful in delineating biliary anatomy and pathology following cholecystectomy. In this article, we provide a protocol for contrast-enhanced MR imaging of the biliary tree. We also review the classification and imaging manifestations of post-cholecystectomy bile duct injuries in addition to other complications such as bilomas, retained/dropped gallstones, and vascular injuries.

Role of magnetic resonance imaging in Bouveret's syndrome: A case report with review of the literature

Bouveret's syndrome is a rare form of gallstone ileus occurring due to obstructing gallstone into the proximal duodenum through a cholecystoduodenal fistula. We report the case of a 72-year-old female presenting with abdominal pain secondary to a large gallstone in the region of the duodenal bulb, causing the upstream gastric obstruction. Here we discuss the clinical features, imaging technologies, and surgical management of Bouveret's syndrome.

Treatment strategy for isolated bile leakage after hepatectomy: Literature review

Isolated bile leakage (IBL) after hepatectomy is intractable, and various treatment methods for it have been reported. This review aimed to clarify the treatment strategy for IBL by summarizing studies on IBL after hepatectomy without extrahepatic bile duct resection. Thirty-three cases of IBL were reported. The incidence of IBL is very low, accounting for 0.1%-1% of all hepatectomy cases. The risk factors for IBL are unclear; however, several reports mention that biliary anomaly is associated with a high risk of IBL, with preoperative and intraoperative confirmation of biliary tree anatomy being the most important preventive strategy. Treatment methods for IBL include liver resection, bilioenteric anastomosis, endoscopic treatment, bile duct ablation, percutaneous transhepatic portal vein embolization (PTPE), transcatheter arterial embolization, and use of fibrin glue. The therapeutic methods should be chosen depending on remnant liver function, amount of bile leakage, and the liver volume causing the bile leakage. When there is bile leakage from less than one segment, non-surgical treatment is recommended, whereas when there is bile leakage from one or more segments, surgical treatment can be recommended. Nevertheless, recently, non-surgical treatment such as PTPE, PTPE with bile duct ablation, and endoscopic methods have been considered as effective treatment approaches.

The role of gadoxetic acid-enhanced magnetic resonance cholangiography in the evaluation of postoperative bile duct injury: pictorial essay

Iatrogenic lesion of the bile ducts is a relatively common occurrence during liver surgery, increasing morbidity and mortality rates. T2-weighted magnetic resonance cholangiography and gadoxetic acid-enhanced functional magnetic resonance cholangiography (fMRC) with administration of hepatobiliary-specific contrast medium (gadoxetic acid) are fundamental to the diagnostic imaging approach in patients with such lesions. Here, we present a review of the literature and suggest an imaging approach to biliary tract injury, focusing on clinical cases in which fMRC had an impact on the decision-making process for the management of the affected patients.

Ultrasound-guided percutaneous irrigation of calcific tendinopathy: technical developments

Rotator cuff calcific tendinopathy (RCCT) is a common and painful shoulder disease characterised by deposition of calcium into the rotator cuff’s tendond. Different therapeutic options have been proposed, but the ultrasound-guided percutaneous irrigation (US-PICT) is been proved as an effective and safe first-line treatment. It can be performed with a single- of a double-needle tecnique, using warm saline solution to improve the dissolution of the calcific deposit. The procedure is ended with an intrabursal injection of local anaesthetics and slow-release steroids to improve the pain relief and to prevent complications. US-PICT leads to significative improvement in the shoulder funtion and pain relief in the short and long term, with a low complications rate. (www.actabiomedica.it)

Percutaneous needle biopsy of retroperitoneal lesions: technical developments

Percutaneous Needle Biopsy (PNB) is the insertion of a needle into a suspected lesion or an organ with the aim to obtain cells or tissue for diagnosis. It’s a relatively non-invasive procedure and is performed by radiologist under guidance of imaging techniques such as ultrasound (US), computed tomography (CT), fluoroscopy, magnetic resonance imaging (MRI), and positron emission tomography CT (PET-CT). The choice of imaging technique depends on the evaluation of the target lesion and patient compliance. PNB includes two categories: fine-needle aspiration biopsy (FNAB) that is the use of a thin needle (18-25 gauge) to extract cells for cytological evaluation; and core needle biopsy (CNB) that is the use of a larger needle (9-20 gauge) to extract a piece of tissue for histological evaluation. The indications for biopsy are the characterization of nature (benign or malignant) of a lesion, diagnosis and staging of tumor, and biological or immunohistochemical/genetic analisys on tissue. Success of PNB is the procurement of sufficient material to characterize lesions and to guide the patient outcome. Major complications are rare. PNB became a useful technique in diagnosis and study of retroperitoneal lesions, because of a more suitable access to specific intra-abdominal structures, lowering the risk of injury of interposed structures (such as bowel, great vessels). (www.actabiomedica.it)

Magnetic resonance enterography (MRE) and ultrasonography (US) in the study of the small bowel in Crohn's disease: state of the art and review of the literature

Crohn’s disease (CD) is a chronic idiopathic disease and its diagnosis is based on a combination of clinical symptoms, laboratory tests and imaging data. There isn’t a diagnostic gold standard: the ileocolonoscopy with mucosal biopsies represents the standard for luminal disease, while cross-sectional imaging such as Ultrasound (US), Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) can show transmural alterations and extraintestinal manifestations. CD is usually diagnosed in the young age and after baseline diagnosis, the patients have to undergo to variable follow-up depending on remission or active disease. The aim of our review is to compare Magnetic Resonance Enterography (MRE) to Ultrasonography (US) in the follow-up of CD. (www.actabiomedica.it)

Internal hernias: a difficult diagnostic challenge. Review of CT signs and clinical findings

Although internal hernias are uncommon, they must be beared in mind in the differential diagnosis in cases of intestinal obstruction, especially in patients with no history of previous surgery or trauma. Because of the high possibility of strangulation and ischemia of the affected loops, internal hernias represent a potentially life-threatening condition and surgical emergency that needs to be quickly recognized and managed promptly. Imaging plays a leading role in the diagnosis and in particular multidetector computed tomography (MDCT), with its thin-section and high-resolution multiplanar reformatted (MPR) images, represents the first line image technique in these patients. The purpose of the present paper is to illustrate the characteristic anatomic location, the clinical findings and the CT appearance associated with main types of internal hernia, including paraduodenal, foramen of Winslow, pericecal, sigmoid-mesocolon- and trans-mesenteric-related, transomental, supravesical and pelvic hernias. (www.actabiomedica.it)

Radiation-induced brain cavernomas in elderly: review of the literature and a rare case report

Radiation-induced brain cavernomas have been mainly reported in children who underwent radiotherapy for medulloblastoma, leukemia, or low-grade glioma. Otherwise, the “de novo” appearance of a cavernoma in an elderly long-survivor patient after resection and radiotherapy of a glioblastoma is a rare event. We report the case of a 62-year-old female patient who underwent surgical resection of a right temporal glioblastoma, followed by radiation therapy of the operative field and surrounding brain and concomitant adjuvant temozolomide. Four years after the operation, a follow-up Magnetic Resonance revealed a good tumor control and a small round lesion at the superior surface of the right cerebellar hemisphere, close to the margins of the previous irradiation field. The radiological items were consistent with a cavernous angioma. Because of the small size of the malformation and the absence of related symptoms, no treatment was performed. The patient died for tumor progression 86 months after the initial operation, with unchanged cerebellar cavernoma. The occurrence of a cavernous angioma in an elderly patient after radiotherapy for brain glioblastoma is an exceptional event; the distribution of radiotherapy-induced cavernous malformations reported in current literature is presented and the mechanism of their formation is discussed. (www.actabiomedica.it)

Diagnostic value/performance of radiological liver imaging during chemoterapy for gastrointestinal malignancy: a critical review

This article reviews the main toxic effect, complications and relative imaging findings of the liver that may appear during the oncologic follow up among patients affected by gastrointestinal malignancy. Awareness of the causative chemotherapeutic agent and regimens, pathophysiology and relative characteristic imaging findings of hepatic injuries is critical in order to obtain an accurate diagnosis especially when these parenchymal lesions are focal. An accurate synergic radiological diagnosis with Computed Tomography (CT) and Magnetic Resonance (MR) techniques may induce a potential termination of ineffective/toxic chemotherapy during early phases of treatment, changing the therapeutic plan in order to avoid first unnecessary liver biopsy and then invasive treatment as hepatic resection if not required.

Application of diffusion tensor imaging (DTI) and MR-tractography in the evaluation of peripheral nerve tumours: state of the art and review of the literature

Peripheral nerves can be affected by a variety of benign and malignant tumour and tumour-like lesions. Besides clinical evaluation and electrophysiologic studies, MRI is the imaging modality of choice for the assessment of these soft tissue tumours. Conventional MR sequences, however, can fail to assess the histologic features of the lesions. Moreover, the precise topographical relationship between the peripheral nerve and the tumor must be delineated preoperatively for complete tumour resection minimizing nerve damage. Using Diffusion tensor imaging (DTI) and tractography, it is possible to obtain functional information on tumour and nerve structures, allowing the assess anatomy, function and biological features. In this article, we review the technical aspects and clinical application of DTI for the evaluation of peripheral nerve tumours. (www.actabiomedica.it)

Imaging of long head biceps tendon. A multimodality pictorial essay

The aim of this is article is to provide an  imaging review of normal anatomy, most common anatomical variants and pathologies of the long head of the biceps tendon (LHB) encountered during the daily practice.

Misleading findings of liver-specific MR contrast agent for radiological diagnosis of cysto-biliary communication in hydatid cysts

OBJECTIVE

To investigate the effectiveness of gadoxetic acid-enhanced magnetic resonance cholangiopancreatography (CE-MRCP) and T2-weighted half-Fourier acquisition single-shot turbo spin-echo (T2W HASTE) sequences for diagnosis of cysto-biliary communication in hydatid cysts compared to surgical results.

METHODS

Preoperative abdominal magnetic resonance imaging examinations of patients who underwent surgery for hepatic hydatid cysts were reviewed by two radiologists retrospectively. A total of 45 patients with hydatid cysts were included. Of 45, 27 also had CE-MRCPs. T2W HASTE sequences and CE-MRCPs were investigated separately for cysto-biliary communication. The relationship between radiological and surgical results was analyzed. The interobserver agreement was evaluated.

RESULTS

Of 45 hydatid cysts, there were surgically proven 21 cysts without biliary communications and 24 cysts with biliary communications. All cysts with biliary communications were shown on T2W HASTE sequences. There was no leakage of gadoxetic acid into these cysts (n = 24). Sensitivity, specificity, negative predictive value, positive predictive value (PPV), and accuracy of diagnosis of cyst with biliary communication on T2W HASTE sequences was 100%, 63.64%, 100%, 66.67%, and 78.95%, respectively. Specificity (77.78%), PPV (87.50%), and accuracy (91.30%) were increased in ≥ 10 cm cysts. There was almost perfect interobserver agreement (K = 0.81-1.00).

CONCLUSION

Leakage of gadoxetic acid inside the cyst indicates biliary communication. However, the lack of leakage does not rule out cysto-biliary communication. When biliary communication is clearly shown on T2W HASTE sequences, it should be reported as cysto-biliary communication even if there is no leakage of gadoxetic acid into the cyst on CE-MRCP.

Pediatric Liver Transplant: Techniques and Complications

Liver transplant is considered to be the last-resort treatment approach for pediatric patients with end-stage liver disease. Despite the remarkable advance in survival rates, liver transplant remains an intricate surgery with significant morbidity and mortality. Early diagnosis of complications is crucial for patient survival but is challenging given the lack of specificity in clinical presentation. Knowledge of the liver and vascular anatomy of the donor and the recipient or recipients before surgery is also important to avoid complications. In this framework, radiologists play a pivotal role on the multidisciplinary team in both pre- and postoperative scenarios by providing a road map to guide the surgery and by assisting in diagnosis of complications. The most common complications after liver transplant are (a) vascular, including the hepatic artery, portal vein, hepatic veins, and inferior vena cava; (b) biliary; (c) parenchymal; (d) perihepatic; and (e) neoplastic. The authors review surgical techniques, the role of each imaging modality, normal posttransplant imaging features, types of complications after liver transplant, and information required in the radiology report that is critical to patient care. They present an algorithm for an imaging approach for pediatric patients after liver transplant and describe key points that should be included in radiologic reports in the pre- and postoperative settings. Online supplemental material is available for this article. ^©RSNA, 2017.

Imaging follow-up after liver transplantation

Liver transplantation (LT) represents the best treatment for end-stage chronic liver disease, acute liver failure and early stages of hepatocellular carcinoma. Radiologists should be aware of surgical techniques to distinguish a normal appearance from pathological findings. Imaging modalities, such as ultrasound, CT and MR, provide for rapid and reliable detection of vascular and biliary complications after LT. The role of imaging in the evaluation of rejection and primary graft dysfunction is less defined. This article illustrates the main surgical anastomoses during LT, the normal appearance and complications of the liver parenchyma and vascular and biliary structures.

The Impact of Gd-Eob-Dtpa-Enhanced MR Cholangiography in Biliary Diseases: Comparison with T2-Weighted MR Cholangiopancreatography

BACKGROUND

Contrast enhanced magnetic resonance cholangiography is a novel technique and promising method in demonstrating biliary tree anatomy and evaluating biliary disorders. However, to date, there are a limited number of studies that have focused on the impact of this technique.

AIMS

We aimed to evaluate the additional role of contrast enhanced MR cholangiography (MRC) and compare contrast enhanced MRC with T2-weighted (w) magnetic resonance cholangiopancreatography (MRCP) in the diagnosis of biliary disorders.

STUDY DESIGN

Diagnostic accuracy study.

METHODS

The T2w-MRCP and contrast enhanced MRC sequences of 31 patients whose gold standard test results were available were scored visually for the existence of pathological findings with regard to any of the biliary diseases. Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) was used as the contrast agent. The correlation values were determined according to the statistical analysis made from those scores and the sensitivity, specificity and accuracy values of each sequence were detected as well.

RESULTS

We detected that the correlation values with gold standard methods of contrast enhanced MRC sequences were significantly higher than the ones of T2w-MRCP sequences. The correlation ratios of T2w-MRCP sequences were between 26 and 34%, while those for contrast enhanced MRC sequences were between 81 and 83% for the first reader and the correlation ratios of T2w-MRCP sequences were between 10 and 61%, whereas those of contrast enhanced MRC were between 79 and 81% for the second reader The mean sensitivity, specificity and accuracy values of T2w-MRCP sequences were 14.3-42.5%, 85-89.2% and 59.3-72.5%, respectively, while the mean sensitivity, specificity and accuracy values of contrast enhanced MRC sequences were 100%, 86.7% and 93.2-93.3%, respectively.

CONCLUSION

We suggest that obtaining of contrast enhanced MRC sequences in addition to the T2w-MRCP can be useful in the diagnosis of many diseases in relation with biliary tree.

Imaging panorama in postoperative complications after liver transplantation

The liver is the second most-often transplanted solid organ after the kidney, so it is clear that liver disease is a common and serious problem around the globe. With the advancements in surgical, oncological and imaging techniques, orthotopic liver transplantation has become the first-line treatment for many patients with end-stage liver disease. Ultrasound, and Doppler are the most economical and cost-effective imaging modalities for evaluating postoperative fluid collections and vascular complications. Computed tomography (CT) is used to confirm the findings of ultrasound and look for pulmonary complications. Magnetic resonance imaging (MRI) is used for the diagnosis of biliary complications, bile leaks and neurological complications. This article illustrates the imaging options for diagnosing the various complications that can be encountered in the postoperative period after liver transplantation.

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 biliary complications, including anastomotic strictures, non-anastomotic strictures, leakage and stones.

Post-operative imaging in liver transplantation: State-of-the-art and future perspectives

Orthotopic liver transplantation (OLT) represents a major treatment for end-stage chronic liver disease, as well as selected cases of hepatocellular carcinoma and acute liver failure. The ever-increasing development of imaging modalities significantly contributed, over the last decades, to the management of recipients both in the pre-operative and post-operative period, thus impacting on graft and patients survival. When properly used, imaging modalities such as ultrasound, multidetector computed tomography, magnetic resonance imaging (MRI) and procedures of direct cholangiography are capable to provide rapid and reliable recognition and treatment of vascular and biliary complications occurring after OLT. Less defined is the role for imaging in assessing primary graft dysfunction (including rejection) or chronic allograft disease after OLT, e.g., hepatitis C virus (HCV) recurrence. This paper: (1) describes specific characteristic of the above imaging modalities and the rationale for their use in clinical practice; (2) illustrates main imaging findings related to post-OLT complications in adult patients; and (3) reviews future perspectives emerging in the surveillance of recipients with HCV recurrence, with special emphasis on MRI.

The role of organic anion transporters in diagnosing liver diseases by magnetic resonance imaging

The expression and transport functions of organic anion transporters are modified in liver diseases, and therefore the vascular clearances of endogenous and exogenous organic anions that are taken up by these transporters have been used to assess liver diseases in patients. More recently, liver imaging with hepatobiliary contrast agents, tracers, and dyes that cross hepatocytes through the organic anion transporting polypeptides (OATPs)-multidrug resistance-associated proteins (MRPs) pathway were developed to detect and characterize focal lesions and to assess the severity of diffuse liver diseases. This review focuses mainly on magnetic resonance imaging and highlights the growing interest in imaging the OATPs-MRP2 pathway to better understand liver diseases. Imaging provides noninvasive measurements of tissue concentrations that result from the interplay between influx and efflux membrane transport systems in normal or injured hepatocytes. Imaging with magnetic resonance hepatobiliary contrast agents improves the detection and the characterization of hepatic focal lesions. New developments of imaging to assess liver function and understand the hepatocellular concentrations of contrast agents are discussed.

Non-invasive detection of biliary leaks using Gd-EOB-DTPA-enhanced MR cholangiography: comparison with T2-weighted MR cholangiography

Objective

To evaluate the added role of T1-weighted (T1w) gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance cholangiography (MRC) compared with T2-weighted MRC (T2w-MRC) in the detection of biliary leaks.

Methods

Ninety-nine patients with suspected biliary complications underwent routine T2w-MRC and T1w contrast-enhanced (CE) MRC using Gd-EOB-DTPA to identify biliary leaks. Two observers reviewed the image sets separately and together. MRC findings were compared with those of surgery and percutaneous transhepatic cholangiopancreatography. The sensitivity, specificity and accuracy of the techniques in identifying biliary leaks were calculated.

Results

Accuracy of locating biliary leaks was superior with the combination of Gd-EOB-DTPA-enhanced MRC and T2w-MRC (P < 0.05).The mean sensitivities were 79 % vs 59 %, and the mean accuracy rates were 84 % vs 58 % for combined CE-MRC and T2w-MRC vs sole T2w-MRC. Nineteen out of 21 patients with biliary-cyst communication, 90.4 %, and 12/15 patients with post-traumatic biliary extravasations, 80 %, were detected by the combination of Gd-EOB-DTPA-enhanced MRC and T2w-MRC images, P < 0.05.

Conclusions

Gd-EOB-DTPA-enhanced MRC yields information that complements T2w-MRC findings and improves the identification and localisation of the bile extravasations (84 % accuracy, 100 % specificity, P < 0.05). We recommend Gd-EOB-DTPA-enhanced MRC in addition to T2w-MRC to increase the preoperative accuracy of identifying and locating extravasations of bile.

Key Points

• Magnetic resonance cholangiography (MRC) does not always detect bile leakage and cysto-biliary communications.

• Gd-EOB-DTPA-enhanced MRC helps by demonstrating extravasation of contrast material into fluid collections.

• Gd-EOB-DTPA-enhanced MRC also demonstrates the leakage site and bile duct injury type.

• Combined Gd-EOB-DTPA-enhanced and T2w-MRC can provide comprehensive information about biliary system.

• Gd-EOB-DTPA-enhanced MRC is non-invasive and does not use ionising radiation.

Modern imaging evaluation of the liver: emerging MR imaging techniques and indications

Modern MR imaging evaluation of the liver allows for a comprehensive morphologic and functional assessment of the liver parenchyma, hepatic vessels, and biliary tree, thus aiding in the diagnosis of both focal and diffuse liver diseases.