Imaging of hepatocellular carcinoma recurrence after liver transplantation.

Liver transplantation (LT) provides the highest survival benefit to patients with unresectable hepatocellular carcinoma (HCC). The Milan criteria have been developed for the selection of LT candidates with the goal of improving survival and maintaining an acceptable risk of HCC recurrence. Despite this, recurrence of HCC after LT occurs in up to 20% of cases and represents a major concern due to the poor prognosis of these patients. Furthermore, several extended criteria for the selection of LT candidates have been proposed to account for the growing demand for organs and the resultant increase in the risk of HCC recurrence. Radiologists should be aware that HCC can recur after LT with multiple organ involvement. Knowledge of the location and radiologic appearance of recurrent HCC is necessary to ensure the choice of the most appropriate therapy. This paper aims to comprehensively summarize the spectrum of HCC recurrence after LT and to examine and discuss the imaging features of these lesions. CRITICAL RELEVANCE STATEMENT: This paper aims to share a review of imaging findings of HCC recurrence after LT and to make radiologists familiar with the spectrum of this disease.

Transjugular intrahepatic portosystemic shunt (TIPS) complications: what diagnostic radiologists should know.

Transjugular intrahepatic portosystemic shunt (TIPS) is an effective therapy for portal hypertension complications and can successfully treat variceal bleeding and refractory ascites. Although TIPS is relatively safe, procedural- or shunt-related morbidity can reach 20%, and procedural complications have a fatality rate of 2%. Delayed recognition and treatment of TIPS complications can lead to life-threatening clinical scenarios. Complications can vary from stent migration or malpositioning to nontarget organ injury, TIPS dysfunction, encephalopathy, or liver failure. This review aims to outline the role of diagnostic radiology in assessing post-TIPS complications.

Bile duct anatomical variations: Relevance for liver division and preparing left split liver grafts for pediatric transplantation: Cohort study.

BACKGROUND: liver lateral section graft is the most common graft type used for transplantation in children worldwide. Compared to whole liver grafts, a higher rate of biliary complications has been described. Historically, 2 techniques have been described for transection of liver - trans-hilar or trans-umbilical parenchymal transection. Though these techniques allow dividing the biliary system at two distinct positions, the usual surgical strategies do not take advantage of this advantage. MATERIAL AND METHODS: A retrospective study was conducted on 40 candidates who volunteered for donation of their left lateral liver section for transplantation, between October 2017 and April 2019. Preoperative imaging was analyzed to depict the arterial and biliary anatomy of the liver and their variations, with a dedicated attention to the left liver (segments 2, 3 and 4). Anatomy of the biliary system was taken into account for defining the optimal surgical strategy - either through a trans-hilar or a trans-umbilical parenchymal transection. RESULTS: In 26/40 patients, arterial or biliary variations were much relevant for decision-making on the optimal plane of liver division (trans-umbilical (N = 14) and trans-hilar (N = 26)). This resulted in 23 grafts with a single artery and bile duct, 6 grafts with double arteries and a single bile duct, and 9 grafts with double bile ducts and a single artery; only two grafts had complex anatomy. There was no arterial complication and the overall incidence of biliary problems was 14.7%. All grafts are functioning well at a mean follow-up of 19.6 ± 8.5 months. CONCLUSIONS: Anatomical variations are frequent and their knowledge is relevant for procurement of lateral section liver graft. Knowledge of these variation, or -better- preoperative biliary imaging is helpful in guiding parenchymal transection at procurement and preparing optimal liver grafts.

Imaging of calcified hepatic lesions: spectrum of diseases.

Hepatic calcifications have been increasingly identified over the past decade due to the widespread use of high-resolution Computed Tomography (CT) imaging. Calcifications can be seen in a vast spectrum of common and uncommon diseases, from benign to malignant, including cystic lesions, solid neoplastic masses, and inflammatory focal lesions. The purpose of this paper is to present an updated review of CT imaging findings of a wide range of calcified hepatic focal lesions, which can help radiologists to narrow the differential diagnosis.

Resting-State Functional Connectome in Patients with Brain Tumors Before and After Surgical Resection.

PURPOSE: High-grade glioma surgery has evolved around the principal belief that a safe maximal tumor resection improves symptoms, quality of life, and survival. Mapping brain function has been recently improved by resting-state functional magnetic resonance imaging (rest-fMRI), a novel imaging technique that explores networks connectivity at "rest." METHODS: This prospective study analyzed 10 patients with high-grade glioma in whom rest-fMRI connectivity was assessed both in single-subject and in group analysis before and after surgery. Seed-based functional connectivity analysis was performed with CONN toolbox. Network identification focused on 8 major functional connectivity networks. A voxel-wise region of interest (ROI) to ROI correlation map to assess functional connectivity throughout the whole brain was computed from a priori seeds ROI in specific resting-state networks before and after surgical resection in each patient. RESULTS: Reliable topography of all 8 resting-state networks was successfully identified in each participant before surgical resection. Single-subject functional connectivity analysis showed functional disconnection for dorsal attention and salience networks, whereas the language network demonstrated functional connection either in the case of left temporal glioblastoma. Functional connectivity in group analysis showed wide variations of functional connectivity in the default mode, salience, and sensorimotor networks. However, salience and language networks, salience and default mode networks, and salience and sensorimotor networks showed a significant correlation (P uncorrected <0.0025; P false discovery rate <0.077) in comparison before and after surgery confirming non-disconnection of these networks. CONCLUSIONS: Resting-state fMRI can reliably detect common functional connectivity networks in patients with glioma and has the potential to anticipate network alterations after surgical resection.

Imaging of hepatic hemangioma: from A to Z.

The hemangioma is the most common solid lesion of the liver. Therefore, radiologists must know the typical and atypical imaging findings of this lesion in order to reach a correct diagnosis and avoid diagnostic errors. However, only few papers have comprehensively described the entire spectrum of atypical and uncommon imaging features. In this updated review, we provide the imaging features of hepatic hemangioma, in both typical and atypical forms, as well as its association with abnormalities in the adjacent hepatic parenchyma and other hepatic lesions, and its complications.

Budd-Chiari Syndrome and hepatic regenerative nodules: Magnetic resonance findings with emphasis of hepatobiliary phase.

Budd-Chiari syndrome (BCS) is a disorder with numerous causes that is a result of hepatic outflow obstruction, in the absence of right heart failure or constrictive pericarditis. Acute Budd-Chiari syndrome is uncommon and clinically characterized by ascites, hepatomegaly, and hepatic insufficiency. In the majority of cases, patients present with chronic BCS, showing a dysmorphic liver disease with variable fibrosis deposition. In chronic Budd-Chiari syndrome, hepatocellular carcinoma (HCC) and benign regenerative nodules (called large regenerative nodules or FNH-like lesions) have been described in the literature. Very few studies have reported magnetic resonance imaging (MRI) findings about these nodules, using hepatobiliary contrast medium. The aim of our review is to describe the magnetic resonance imaging findings of hepatic regenerative nodules in BCS, with emphasis on the hepatobiliary phase, and to compare the imaging features of benign nodules with those of HCC.

Magnetic resonance imaging of fibropolycystic liver disease: the spectrum of ductal plate malformations.

Fibropolycystic liver diseases, also known as ductal plate malformations, are a group of associated congenital disorders resulting from abnormal development of the biliary ductal system. These disorders include congenital hepatic fibrosis, biliary hamartomas, polycystic liver disease, choledochal cysts and Caroli disease. Recently, it has been thought to include biliary atresia in this group of diseases, because ductal plate malformations could be implicated in the pathogenesis of this disease. Concomitant associated renal anomalies can also be present, such as autosomal recessive polycystic kidney disease (ARPKD), medullary sponge kidney and nephronophthisis. These disorders can be clinically silent or can cause abnormalities such as cholangitis, portal hypertension, gastrointestinal bleeding and infections. The different types of ductal plate malformations show typical findings at magnetic resonance (MR) imaging. A clear knowledge of the embryology and pathogenesis of the ductal plate plays a pivotal role to understand the characteristic imaging appearances of these complex diseases. Awareness of these MR imaging findings is central to the detecting and differentiating between various fibropolycystic liver diseases and is important to direct appropriate clinical management and prevent misdiagnosis.

Multimodality imaging of the Meso-Rex bypass.

Extrahepatic portal vein obstruction (EHPVO) is the most common cause of upper gastrointestinal bleeding in children. It is defined as thrombosis of the extrahepatic portal vein with or without extension to the intrahepatic portal veins. The Meso-Rex shunt is the gold standard treatment in children with favorable anatomy since it restores physiological portal liver reperfusion. This is achieved by rerouting the splanchnic venous blood through an autologous graft from the superior mesenteric vein (SMV) into the Rex recess of the left portal vein, curing portal hypertension by doing so. General and hepatobiliary radiologists must be familiar with multimodality imaging appearances of EHPVO and with the role of imaging in identifying suitable candidates for Meso-Rex bypass surgery. Imaging might also detect complications of this procedure, some of which might be treated via interventional radiology.

Intrahepatic mass-forming cholangiocarcinoma: enhancement pattern on Gd-BOPTA-MRI with emphasis of hepatobiliary phase.

PURPOSE: To describe the Gd-BOPTA MRI findings of intrahepatic mass-forming type cholangiocarcinomas (IMCs), with emphasis on the hepatobiliary phase (HBP). METHODS: We reviewed retrospectively 29 IMC patients who underwent Gd-BOPTA-MRI between June, 2004 and June, 2014. Images were acquired prior to, and after, administration of 15-20 mL of Gd-BOPTA in the dynamic phase (arterial phase, portal venous phase, and 3-5 min phase), 10-15-min late phase, and 2-3 h HBP phase. RESULTS: In the dynamic phase, 27 (93%) lesions showed a peripheral rim-like enhancement in the arterial and portal venous phases, followed by progressive filling-in on the delayed images. In 14 (56%) cases, a hypointense peripheral rim was identified in the 10-15-min late phase, delineating a target pattern. In the HBP, the cholangiocarcinoma showed a diffuse, mainly central and inhomogeneous enhancement (cloud of enhancement) in 28 (96%) patients; in 23 (79%) cases, there was an association between cloud appearance and a hypointense peripheral rim, showing a target pattern. CONCLUSIONS: Gd-BOPTA MRI pattern of IMC on dynamic study is similar to that of conventional extracellular agents, that is peripheral enhancement with progressive and concentric filling of contrast material on delayed phases. At 10-15 min delayed phases, IMC shows often a peripheral hypointense rim consistent with a target appearance. In the HBP, due to progressive central enhancement (cloud) and peripheral hypointense rim, an higher number of tumors show a target appearance; this pattern is not specific and would also be expected to be seen in metastases from adenocarcinoma.

Multidisciplinary imaging of liver hydatidosis.

Liver hydatidosis is a parasitic endemic disease affecting extensive areas in our planet, a significant stigma within medicine to manage because of its incidence, possible complications, and diagnostic involvements. The diagnosis of liver hydatidosis should be as fast as possible because of the relevant complications that may arise with disease progression, involving multiple organs and neighboring structures causing disruption, migration, contamination. The aim of this essay is to illustrate the role of imaging as ultrasonography (US), multi detector row computed tomography, and magnetic resonance imaging (MRI) in the evaluation of liver hydatidosis: the diagnosis, the assessment of extension, the identification of possible complications and the monitoring the response to therapy. US is the screening method of choice. Computed tomography (CT) is indicated in cases in which US is inadequate and has high sensitivity and specificity for calcified hydatid cysts. Magnetic resonance is the best imaging procedure to demonstrate a cystic component and to show a biliary tree involvement. Diagnostic tests such as CT and MRI are mandatory in liver hydatidosis because they allow thorough knowledge regarding lesion size, location, and relations to intrahepatic vascular and biliary structures, providing useful information for effective treatment and decrease in post-operative morbidity. Hydatid disease is classified into four types on the basis of their radiologic appearance.

Multidetector CT-guided endovascular treatment of a splenic artery aneurysm in a child with split-liver transplant and surgically ligated splenic artery origin.

We report the case of a child who underwent left lateral split-liver transplantation for biliary atresia and surgical ligation of the origin of the splenic artery at the time of the transplantation. Post-transplant portal vein thrombosis was initially treated with a meso-rex shunt. This shunt subsequently thrombosed and was replaced by a splenorenal shunt. Three months after splenorenal shunt placement, US showed a 3.7-cm pseudoaneurysm at the hilum of the spleen. Multidetector CT with 3-D reconstruction allowed precise identification of the pseudoaneurysm feeding artery and therefore helped in planning the interventional radiology procedure, avoiding explorative selective catheterisation. The pseudoaneurysm was successfully treated with endovascular coil embolisation.

Thoracic complications following lung transplantation: 64-MDCT findings.

The aim of this review is to present the wide spectrum of common and uncommon thoracic complications that can affect the lung after transplantation. These complications were analyzed using 64 multi-detector row helical CT (MDCT). Sixty-four MDCT techniques and parameters are illustrated. Correlations of imaging findings and pathologic and histologic specimens obtained by transbronchial biopsy and broncoalveolar lavage are illustrated in representative cases.

Biliary cystadenoma with bile duct communication depicted on liver-specific contrast agent-enhanced MRI in a child.

Biliary cystadenoma is a benign, but potentially malignant, cystic neoplasm of the biliary ducts occurring most commonly in middle-aged females and very rarely in children. We present a 9-year-old boy with biliary cystadenoma, diagnosed by MRI using a new liver-specific contrast agent (gadoxetic acid) that is eliminated by the biliary system. The images clearly demonstrate the communication between the multiloculated cystic mass and the biliary tree, suggesting the possibility of biliary cystadenoma. Due to the malignant potential of a cystadenoma, the lesion was resected. The resection was complete and the postoperative course was uneventful.

Diffuse liver diseases in neonatal and pediatric liver transplant candidates: a pictorial essay.

A wide spectrum of common and uncommon diffuse liver diseases affecting neonatal and pediatric liver transplant candidates is presented and analyzed using 16 and 64 multi-detector row helical CT (MDCT) and 1.5 T MRI fast imaging. Correlation of imaging findings and explanted liver or histology is illustrated in representative cases. Associated uncommon congenital anomalies are shown. In conclusion, in pediatric liver transplant candidates, 16-MDCT and 1.5 T fast MRI are useful for diagnosis and staging of liver disease, as well as for the evaluation of associated congenital anomalies.

Multidetector-row computed tomography (MDCT) for the diagnosis of hepatocellular carcinoma in cirrhotic candidates for liver transplantation: prevalence of radiological vascular patterns and histological correlation with liver explants.

AIM: To define the prevalence of different multidetector-row computed tomography (MDCT) vascular patterns and their histopathological correlation with liver explants, and to evaluate the accuracy of MDCT for the diagnosis of hepatocellular carcinoma (HCC). METHODS: We retrospectively reviewed 125 cirrhotic patients imaged by MDCT before liver transplantation. Three main vascular patterns were identified: hypervascular lesion with washout (Hyper-L-Wo), hypervascular lesion without washout (Hyper-L) and non-hypervascular lesion (Hypo-L). Radiological findings were matched with histopathology of explants. RESULTS: Positive predictive value (PPV) and likelihood ratio (LR) were 95% and 18.66, respectively, for Hyper-L-Wo; 45% and 0.82 for Hyper-L; and 75% and 3 for Hypo-L of 20 mm or larger. Overall accuracy of MDCT for detection and characterisation of HCC was 89% and 43%, respectively. Sensitivity of MDCT for detection and characterisation was related to the lesion size, ranging from 78% (lesion smaller than 10 mm) to 98% (larger than 20 mm) and from 9% to 64%, respectively. MDCT established the accurate stage of disease in 46% of the patients, underestimated in 52% and overestimated in 2%. CONCLUSION: In cirrhotic patients, any Hyper-L-Wo detected by MDCT can be confidently considered to be HCC. Hyper-L larger than 10 mm and Hypo-L of 20 mm or larger are at high risk of HCC. However, even using MDCT and the newest imaging protocols, imaging underestimated the diagnosis of small HCC.

Focal liver diseases in neonatal and pediatric liver transplant candidates: a pictorial essay.

The aim of this review is to present the wide spectrum of common and uncommon focal liver diseases affecting neonatal and pediatric liver transplant candidates, analyzed using ultrasonography (US), 16- or 64-multidetector row helical CT (MDCT) and 1.5-T magnetic resonance (MR) fast imaging. Correlation of imaging findings and explanted liver or histology is illustrated in representative cases. Associated uncommon congenital anomalies are shown.