Molecular force-induced liberation of transforming growth factor-beta remodels the spleen for ectopic liver regeneration.

BACKGROUND & AIMS: Ectopic liver regeneration in the spleen is a promising alternative to organ transplantation for treating liver failure. To accommodate transplanted liver cells, the splenic tissue must undergo structural changes to increase extracellular matrix content, demanding a safe and efficient approach for tissue remodelling. METHODS: We synthesised sulphated hyaluronic acid (sHA) with an affinity for the latent complex of transforming growth factor-ß (TGF-ß) and cross-linked it into a gel network (sHA-X) via click chemistry. We injected this glycan into the spleens of mice to induce splenic tissue remodelling via supraphysiological activation of endogenous TGF-ß. RESULTS: sHA-X efficiently bound to the abundant latent TGF-ß in the spleen. It provided the molecular force to liberate the active TGF-ß dimers from their latent complex, mimicking the 'bind-and-pull' mechanism required for physiological activation of TGF-ß and reshaping the splenic tissue to support liver cell growth. Hepatocytes transplanted into the remodelled spleen developed into liver tissue with sufficient volume to rescue animals with a metabolic liver disorder (Fah-/- transgenic model) or following 90% hepatectomy, with no adverse effects observed and no additional drugs required. CONCLUSION: Our findings highlight the efficacy and translational potential of using sHA-X to remodel a specific organ by mechanically activating one single cytokine, representing a novel strategy for the design of biomaterials-based therapies for organ regeneration. IMPACT AND IMPLICATIONS: Cell transplantation may provide a lifeline to millions of patients with end-stage liver diseases, but their severely damaged livers being unable to accommodate the transplanted cells is a crucial hurdle. Herein, we report an approach to restore liver functions in another organ - the spleen - by activating one single growth factor in situ. This approach, based on a chemically designed polysaccharide that can mechanically liberate the active transforming growth factor-ß to an unusually high level, promotes the function of abundant allogenic liver cells in the spleen, rescuing animals from lethal models of liver diseases and showing a high potential for clinical translation.

ACG Clinical Guideline: Focal Liver Lesions.

Focal liver lesions (FLLs) have become an increasingly common finding on abdominal imaging, especially asymptomatic and incidental liver lesions. Gastroenterologists and hepatologists often see these patients in consultation and make recommendations for management of multiple types of liver lesions, including hepatocellular adenoma, focal nodular hyperplasia, hemangioma, and hepatic cystic lesions including polycystic liver disease. Malignancy is important to consider in the differential diagnosis of FLLs, and healthcare providers must be familiar with the diagnosis and management of FLLs. This American College of Gastroenterology practice guideline uses the best evidence available to make diagnosis and management recommendations for the most common FLLs.

Dorsal Approach Combined with In Situ Split for Laparoscopic Segment 7 Resection.

BACKGROUND: Laparoscopic segment 7 resection has been a technically challenging procedure (Li et al. in J Gastrointest Surg 23:1084-1085, 2019). We introduce a dorsal approach with in situ split for laparoscopic segment 7 resection. PATIENT AND METHODS: The patient was a 26-year-old male diagnosed with hepatic focal nodular hyperplasia located in segment 7. The lesion, measuring approximately 6.7 cm × 5.7 cm, was close to the right caudate lobe. Firstly, the segment 7 pedicle was exposed through the Rouviere's groove combined with caudate lobe-first approach, followed by clipping to confirm demarcation. Peripheral parenchymal transection at the dorsal side started and the intersegmental vein between segments 6 and 7 was found. Dissection of this vein towards its root proceeded preferentially at the dorsal side. Then the segment 7 pedicle was cut off, followed by parenchymal transection toward the cranial side to find the trunk of the compressed right hepatic vein (RHV). It was further dissociated from the trunk to periphery, exposing and cutting off its branches draining segment 7. The remaining parenchyma at the cranioventral side was subsequently separated along the exposed RHV. Finally, the resection of segment 7 was accomplished by dividing the right perihepatic ligaments. RESULTS: The operative time was 395 min with the estimated blood loss of 500 ml. The patient did not receive perioperative blood transfusion. The patient was discharged on tenth postoperative day following suture removal without experiencing any postoperative bleeding, hepatic failure, or other complications. CONCLUSION: Dorsal approach combined with in situ split for laparoscopic segment 7 resection is feasible and has certain advantages (Cao et al. in Surg Endosc 35:174-181, 2021; Liu et al. in Surg Oncol 38:101575, 2021; Yang et al. in Surg Endosc 37:1334-1341, 2023). Further investigations are required due to some limitations.

Association Between Gadoxetic Acid-Enhanced Magnetic Resonance Imaging, Organic Anion Transporters, and Farnesoid X Receptor in Benign Focal Liver Lesions.

The organic anion uptake and efflux transporters [organic anion-transporting polypeptide (OATP)1B1, OATP1B3 and multidrug resistance-associated protein (MRP)2 and MRP3] that mediate the transport of the hepatobiliary-specific contrast agent gadoxetate (Gd-EOB-DTPA) are direct or indirect targets of the farnesoid X receptor (FXR), a key regulator of bile acid and lipid homeostasis. In benign liver tumors, FXR expression and activation is not yet characterized. We investigated the expression and activation of FXR and its targets in hepatocellular adenoma (HCA) and focal nodular hyperplasia (FNH) and their correlation with Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI). Gd-EOB-DTPA MRI patterns were assessed by an expert radiologist. The intensity of the lesions on the hepatobiliary phase was correlated to mRNA expression levels of OATP1B1, OATP1B3, MRP2, MRP3, FXR, and small heterodimer partner (SHP) in fresh surgical specimens of patients with FNH or HCA subtypes. Normal and tumor sample pairs of 43 HCA and 14 FNH were included. All FNH (14/14) were hyperintense. Of the 34 HCA with available Gd-EOB-DTPA-enhanced MRI, 6 were hyperintense and 28 HCA were hypointense. OATP1B3 was downregulated in the hypointense tumors compared with normal surrounding liver tissue (2.77±3.59 vs. 12.9±15.6, P < 0.001). A significant positive correlation between FXR expression and activation and OATP1B3 expression level was found in the HCA cohort. SHP showed a trend toward downregulation in hypointense HCA. In conclusion, this study suggests that the MRI relative signal in HCA may reflect expression level and/or activity of SHP and FXR. Moreover, our data confirms the pivotal role of OATP1B3 in Gd-EOB-DTPA uptake in HCA. SIGNIFICANCE STATEMENT: FXR represents a valuable target for the treatment of liver disease and metabolic syndrome. Currently, two molecules, ursodeoxycholate and obeticholate, are approved for the treatment of primary biliary cirrhosis and cholestasis, with several compounds in clinical trials for the treatment of metabolic dysfunction-associated fatty liver disease. Because FXR expression and activation is associated with gadoxetate accumulation in HCA, an atypical gadoxetate-enhanced MRI pattern might arise in patients under FXR-targeted therapy, thereby complicating the differential diagnosis.

Congestive Hepatopathy: Pathophysiology, Workup, and Imaging Findings with Pathologic Correlation.

Liver congestion is increasingly encountered in clinical practice and presents diagnostic pitfalls of which radiologists must be aware. The complex altered hemodynamics associated with liver congestion leads to diffuse parenchymal changes and the development of benign and malignant nodules. Distinguishing commonly encountered benign hypervascular lesions, such as focal nodular hyperplasia (FNH)-like nodules, from hepatocellular carcinoma (HCC) can be challenging due to overlapping imaging features. FNH-like lesions enhance during the hepatic arterial phase and remain isoenhancing relative to the background liver parenchyma but infrequently appear to wash out at delayed phase imaging, similar to what might be seen with HCC. Heterogeneity, presence of an enhancing capsule, washout during the portal venous phase, intermediate signal intensity at T2-weighted imaging, restricted diffusion, and lack of uptake at hepatobiliary phase imaging point toward the diagnosis of HCC, although these features are not sensitive individually. It is important to emphasize that the Liver Imaging Reporting and Data System (LI-RADS) algorithm cannot be applied in congested livers since major LI-RADS features lack specificity in distinguishing HCC from benign hypervascular lesions in this population. Also, the morphologic changes and increased liver stiffness caused by congestion make the imaging diagnosis of cirrhosis difficult. The authors discuss the complex liver macro- and microhemodynamics underlying liver congestion; propose a more inclusive approach to and conceptualization of liver congestion; describe the pathophysiology of liver congestion, hepatocellular injury, and the development of benign and malignant nodules; review the imaging findings and mimics of liver congestion and hypervascular lesions; and present a diagnostic algorithm for approaching hypervascular liver lesions. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Membranoproliferative glomerulonephritis in a child with congenital portosystemic shunt.

Congenital portosystemic shunts (CPSS) are rare congenital vascular anomalies characterized by abnormal connections between the portal vein and systemic circulation, bypassing the liver. They can lead to complications such as recurrent encephalopathy, liver nodules, portopulmonary hypertension, and neurocognitive issues due to hyperammonemia and rarely kidney involvement. Hepatic hemodynamic changes can lead to liver nodules and hepatocellular carcinoma, particularly in extrahepatic shunts. We describe here an 11-year-old girl with type 1 intrahepatic portosystemic shunt with focal nodular hyperplasia in the liver, presenting with nephrotic syndrome that was diagnosed as membranoproliferative glomerulonephritis on kidney biopsy and that responded partially to therapy with immunosuppressants.

Superb Microvascular Imaging in Pediatric Focal Nodular Hyperplasia.

OBJECTIVE: To investigate superb microvascular imaging (SMI), a novel Doppler ultrasound technique that can visualize low-velocity microvascular flow, for assessing pediatric focal nodular hyperplasia (FNH). PATIENTS AND METHODS: Nine FNH lesions in 6 patients were enrolled. On SMI and color Doppler imaging (CDI), intralesional vascularity was assessed visually and categorized as typical spoke-wheel pattern (central vessel radiating from the center to the periphery), multifocal spoke-wheel pattern, and nonspecific pattern. We compared the vascular features of the lesions between SMI and CDI and evaluated vascular patterns according to lesion size. RESULTS: In terms of vascularity pattern, the typical spoke-wheel pattern of FNH was noted more frequently on SMI (67%) than on CDI (11%; P < 0.05). In addition, a multifocal spoke-wheel pattern was noted in all remaining lesions (33%) on SMI. On the contrary, a nonspecific vascular pattern was detected in the majority (78%) of CDI. Regarding the lesion size and vascularity on SMI, the typical spoke-wheel pattern was seen more frequently in the small FNH group than in the large FNH group. The intralesional vascular signal was detected more frequently on SMI (100%) than on CDI (89%). CONCLUSION: SMI is feasible in evaluating FNH in children and has a greater ability to demonstrate the spoke-wheel pattern than CDI.

Caudo-dorsal approach combined with the occlusion of right hepatic vein and Pringle maneuver in laparoscopic anatomical resection of segment 7.

BACKGROUND: Laparoscopic anatomical resection of segment 7 (LARS7) remains a technically challenging procedure due to the deep anatomical location and the potential risk of injury to the right hepatic vein (RHV). Herein, we initiated an innovative technique of caudo-dorsal approach combined with the occlusion of the RHV and Pringle maneuver for LARS7 and presented the outcomes of our initial series. METHOD: Since January 2021, the patients who underwent LARS7 by using this novel technique were enrolled in this study. The critical aspect of this technique was the interruption of communication between the RHV and the inferior vena cava. Meanwhile, the Pringle maneuver was adopted to control the hepatic inflow. RESULT: A total of 11 patients underwent LARS7 by using this novel technique, which included 8 hepatocellular carcinoma, 2 bile duct adenocarcinoma and one focal nodular hyperplasia. The median operative time was 199 min (range of 151-318 min) and the median blood loss was 150 ml (range of 50-200 ml). The main trunk of the RHV was fully exposed on the cutting surface in all cases and no patient received perioperative blood transfusion. No procedure was converted to open surgery. Of note, no indications of CO2 gas embolism were observed in these cases after the introduction of double occlusion. Only one patient suffered from postoperative complications and healed after treatment. The median postoperative stay was 5 days (range of 4-7 days). The 90-day mortality was nil. At a median follow-up period of 19 months, all of the patients were alive without any evidence of tumor recurrence. CONCLUSION: The caudo-dorsal approach combined with the occlusion of RHV and the Pringle maneuver may be a feasible and expected technique for safe exposure of RHV in LARS7. Further validation of the feasibility and efficacy of this technique is needed.

Gd-EOB-DTPA enhanced MRI nomogram model to differentiate hepatocellular carcinoma and focal nodular hyperplasia both showing iso- or hyperintensity in the hepatobiliary phase.

BACKGROUND: To develop and validate a nomogram model based on Gd-EOB-DTPA enhanced MRI for differentiation between hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH) showing iso- or hyperintensity in the hepatobiliary phase (HBP). METHODS: A total of 75 patients with 49 HCCs and 26 FNHs randomly divided into a training cohort (n = 52: 34 HCC; 18 FNH) and an internal validation cohort (n = 23: 15 HCC; 8 FNH). A total of 37 patients (n = 37: 25 HCC; 12 FNH) acted as an external test cohort. The clinical and imaging characteristics between HCC and FNH groups in the training cohort were compared. The statistically significant parameters were included into the FAE software, and a multivariate logistic regression classifier was used to identify independent predictors and establish a nomogram model. Receiver operating characteristic (ROC) curves were used to evaluate the prediction ability of the model, while the calibration and decision curves were used for model validation. Subanalysis was used to compare qualitative and quantitative characteristics of patients with chronic hepatitis and cirrhosis between the HCC and FNH groups. RESULTS: In the training cohort, gender, age, enhancement rate in the arterial phase (AP), focal defects in uptake were significant predictors for HCC showing iso- or hyperintensity in the HBP. In the training cohort, area under the curve (AUC), sensitivity and specificity of the nomogram model were 0.989(95%CI: 0.967-1.000), 97.1% and 94.4%. In the internal validation cohort, the above three indicators were 0.917(95%CI: 0.782-1.000), 93.3% and 87.5%. In the external test cohort, the above three indicators were 0.960(95%CI: 0.905-1.000), 84.0% and 100.0%. The results of subanalysis showed that age was the independent predictor in the patients with chronic hepatitis and cirrhosis between HCC and FNH groups. CONCLUSIONS: Gd-EOB-DTPA enhanced MRI nomogram model may be useful for discriminating HCC and FNH showing iso- or hyperintensity in the HBP before surgery.

Absent expansion of AXIN2+ hepatocytes and altered physiology in Axin2CreERT2 mice challenges the role of pericentral hepatocytes in homeostatic liver regeneration.

BACKGROUND & AIMS: Mouse models of lineage tracing have helped to describe the important subpopulations of hepatocytes responsible for liver regeneration. However, conflicting results have been obtained from different models. Herein, we aimed to reconcile these conflicting reports by repeating a key lineage-tracing study from pericentral hepatocytes and characterising this Axin2CreERT2 model in detail. METHODS: We performed detailed characterisation of the labelled population in the Axin2CreERT2 model. We lineage traced this cell population, quantifying the labelled population over 1 year and performed in-depth phenotypic comparisons, including transcriptomics, metabolomics and analysis of proteins through immunohistochemistry, of Axin2CreERT2 mice to WT counterparts. RESULTS: We found that after careful definition of a baseline population, there are marked differences in labelling between male and female mice. Upon induced lineage tracing there was no expansion of the labelled hepatocyte population in Axin2CreERT2 mice. We found substantial evidence of disrupted homeostasis in Axin2CreERT2 mice. Offspring are born with sub-Mendelian ratios and adult mice have perturbations of hepatic Wnt/ß-catenin signalling and related metabolomic disturbance. CONCLUSIONS: We find no evidence of predominant expansion of the pericentral hepatocyte population during liver homeostatic regeneration. Our data highlight the importance of detailed preclinical model characterisation and the pitfalls which may occur when comparing across sexes and backgrounds of mice and the effects of genetic insertion into native loci. IMPACT AND IMPLICATIONS: Understanding the source of cells which regenerate the liver is crucial to harness their potential to regrow injured livers. Herein, we show that cells which were previously thought to repopulate the liver play only a limited role in physiological regeneration. Our data helps to reconcile differing conclusions drawn from results from a number of prior studies and highlights methodological challenges which are relevant to preclinical models more generally.

Human duodenal submucosal glands contain a defined stem/progenitor subpopulation with liver-specific regenerative potential.

BACKGROUND & AIMS: Common precursors for the liver, biliary tree, and pancreas exist at an early stage of development in the definitive endoderm forming the foregut. We have identified and characterised endodermal stem/progenitor cells with regenerative potential persisting in the adult human duodenum. METHODS: Human duodena were obtained from organ donors, and duodenal submucosal gland cells were isolated after removal of the mucosa layer. Cells were cultured on plastic or as organoids and were transplanted into severe combined immunodeficient (SCID) mouse livers. RESULTS: In situ studies of submucosal glands in the human duodenum revealed cells expressing stem/progenitor cell markers that had unique phenotypic traits distinguishable from intestinal crypt cells. Genetic signature studies indicated that the cells are closer to biliary tree stem cells and to definitive endodermal cells than to adult hepatocytes, supporting the interpretation that they are endodermal stem/progenitor cells. In vitro, human duodenal submucosal gland cells demonstrated clonal growth, capability to form organoids, and ability to acquire functional hepatocyte traits. In vivo, transplanted cells engrafted into the livers of immunocompromised mice and differentiated to mature liver cells. In an experimental model of fatty liver, human duodenal submucosal gland cells were able to rescue hosts from liver damage by supporting repopulation and regeneration of the liver. CONCLUSIONS: A cell population with clonal growth and organoid formation capability, which has liver differentiation potency in vitro and in vivo in murine experimental models, is present within adult duodenal submucosal glands. These cells can be isolated, do not require reprogramming, and thus could potentially represent a novel cell source for regenerative medicine of the liver. IMPACT AND IMPLICATIONS: Cell therapies for liver disease could represent an option to support liver function, but the identification of sustainable and viable cell sources is critical. Here, we describe a cell population with organoid formation capability and liver-specific regenerative potential in submucosal glands of the human duodenum. Duodenal submucosal gland cells are isolated from adult organs, do not require reprogramming, and could rescue hepatocellular damage in preclinical models of chronic, but not acute, liver injury. Duodenal submucosal gland cells could represent a potential candidate cell source for regenerative medicine of the liver, but the determination of cell dose and toxicity is needed before clinical testing in humans.

Deep Learning-Based Classification of Hepatocellular Nodular Lesions on Whole-Slide Histopathologic Images.

BACKGROUND & AIMS: Hepatocellular nodular lesions (HNLs) constitute a heterogeneous group of disorders. Differential diagnosis among these lesions, especially high-grade dysplastic nodules (HGDNs) and well-differentiated hepatocellular carcinoma (WD-HCC), can be challenging, let alone biopsy specimens. We aimed to develop a deep learning system to solve these puzzles, improving the histopathologic diagnosis of HNLs (WD-HCC, HGDN, low-grade DN, focal nodular hyperplasia, hepatocellular adenoma), and background tissues (nodular cirrhosis, normal liver tissue). METHODS: The samples consisting of surgical and biopsy specimens were collected from 6 hospitals. Each specimen was reviewed by 2 to 3 subspecialists. Four deep neural networks (ResNet50, InceptionV3, Xception, and the Ensemble) were used. Their performances were evaluated by confusion matrix, receiver operating characteristic curve, classification map, and heat map. The predictive efficiency of the optimal model was further verified by comparing with that of 9 pathologists. RESULTS: We obtained 213,280 patches from 1115 whole-slide images of 738 patients. An optimal model was finally chosen based on F1 score and area under the curve value, named hepatocellular-nodular artificial intelligence model (HnAIM), with the overall 7-category area under the curve of 0.935 in the independent external validation cohort. For biopsy specimens, the agreement rate with subspecialists' majority opinion was higher for HnAIM than 9 pathologists on both patch level and whole-slide images level. CONCLUSIONS: We first developed a deep learning diagnostic model for HNLs, which performed well and contributed to enhancing the diagnosis rate of early HCC and risk stratification of patients with HNLs. Furthermore, HnAIM had significant advantages in patch-level recognition, with important diagnostic implications for fragmentary or scarce biopsy specimens.

The Early-Enhancing Hepatic Vein: Differentiating Focal Nodular Hyperplasia and Hepatic Adenoma With Pathologic Validation in MRI.

BACKGROUND: Focal nodular hyperplasia (FNH) and hepatic adenoma (HA) are two common benign liver lesions with different management options. In particular, resection is considered for large HA lesions to avoid possible bleeding complications or rarely malignant degeneration. PURPOSE: To determine whether early enhancement of a draining hepatic vein (EDHV) and absence of perilesional enhancement (PLE) on arterial phase MR images are useful for distinguishing FNH from HA. STUDY TYPE: Retrospective. POPULATION: A total of 34 patients: 16 with FNH and 18 with HA lesions. FIELD STRENGTH/SEQUENCE: A1.5 T, axial T1 fat-suppressed arterial postcontrast. ASSESMENT: Four abdominal radiologists blinded to pathologic diagnosis assessed for the presence or absence of EDHV in association with the lesion, definitively characterized by pathology. This was considered present if contrast could be identified in a hepatic vein contiguous with the lesion in question. Secondarily, PLE was evaluated. STATISTICAL TESTS: Fleiss's multirater kappa statistic, Chi-squared statistic, Phi-coefficient. Significance level P < 0.05. RESULTS: Considering all observations obtained from the four readers, an EDHV was identified with FNH 48.5% of the time. EDHV was seen with HA in 8.8% of cases. PLE was seen with significantly greater frequency in HA. The presence of an EDHV was associated with the absence of PLE. DATA CONCLUSION: In a lesion that may be either an FNH or HA, confident identification on arterial phase images of an EDHV should lead the reader to favor FNH, while the presence PLE should dissuade the reader from FNH. EVIDENCE LEVEL: 4. TECHNICAL EFFICACY: Stage 2.

Lack of endothelial autophagy does not impair liver regeneration after partial hepatectomy in mice.

Liver sinusoidal endothelial cells (LSEC) are key elements in regulating the liver response to injury and regeneration. While endothelial autophagy is essential to protect endothelial cells from injury-induced oxidative stress and fibrosis, its role in liver regeneration has not been elucidated. This study was intended to investigate the role of endothelial autophagy in liver regeneration in the context of partial hepatectomy (PHx). Analysis of autophagy levels in rat LSEC after PHx indicated a tendency to decrease activity the first 2 days after surgery. PHx performed in mice with impaired endothelial autophagy (Atg7flox/flox ;VE-Cadherin-Cre+ ) and their littermate controls showed no differences neither in liver-to-body weight ratio, histological analysis, hepatocyte proliferation nor vascular integrity during the first 7 days after PH and liver regeneration was completely achieved. Our results indicate that endothelial autophagy does not play an essential role in the coordination of the liver regeneration process after PHx.

Endothelial autophagy is not required for liver regeneration after partial hepatectomy in mice with fatty liver.

BACKGROUND & AIMS: Patients with non-alcoholic fatty liver disease (NAFLD) have impaired liver regeneration. Liver endothelial cells play a key role in liver regeneration. In non-alcoholic steatohepatitis (NASH), liver endothelial cells display a defect in autophagy, contributing to NASH progression. We aimed to determine the role of endothelial autophagy in liver regeneration following liver resection in NAFLD. METHODS: First, we assessed autophagy in primary endothelial cells from wild type mice fed a high fat diet and subjected to partial hepatectomy. Then, we assessed liver regeneration after partial hepatectomy in mice deficient (Atg5lox/lox ;VE-cadherin-Cre+ ) or not (Atg5lox/lox ) in endothelial autophagy and fed a high fat diet. The role of endothelial autophagy in liver regeneration was also assessed in ApoE-/- hypercholesterolemic mice and in mice with NASH induced by methionine- and choline-deficient diet. RESULTS: First, autophagy (LC3II/protein) was strongly increased in liver endothelial cells following hepatectomy. Then, we observed at 40 and 48 h and at 7 days after partial hepatectomy, that Atg5lox/lox ;VE-cadherin-Cre+ mice fed a high fat diet had similar liver weight, plasma AST, ALT and albumin concentration, and liver protein expression of proliferation (PCNA), cell-cycle (Cyclin D1, BrdU incorporation, phospho-Histone H3) and apoptosis markers (cleaved Caspase-3) as Atg5lox/lox mice fed a high fat diet. Same results were obtained in ApoE-/- and methionine- and choline-deficient diet fed mice, 40 h after hepatectomy. CONCLUSION: These results demonstrate that the defect in endothelial autophagy occurring in NASH does not account for the impaired liver regeneration occurring in this setting.

Intravoxel incoherent motion diffusion weighted imaging for preoperative evaluation of liver regeneration after hepatectomy in hepatocellular carcinoma.

OBJECTIVES: To explore whether intravoxel incoherent motion (IVIM) parameters could evaluate liver regeneration preoperatively. METHODS: A total of 175 HCC patients were initially recruited. The apparent diffusion coefficient, true diffusion coefficient (D), pseudodiffusion coefficient (D*), pseudodiffusion fraction (f), diffusion distribution coefficient, and diffusion heterogeneity index (Alpha) were measured by two independent radiologists. Spearman's correlation test was used to assess correlations between IVIM parameters and the regeneration index (RI), calculated as 100% × (the volume of the postoperative remnant liver - the volume of the preoperative remnant liver) / the volume of the preoperative remnant liver. Multivariate linear regression analyses were used to identify the factors for RI. RESULTS: Finally, 54 HCC patients (45 men and 9 women, mean age 51.26 ± 10.41 years) were retrospectively analyzed. The intraclass correlation coefficient ranged from 0.842 to 0.918. In all patients, fibrosis stage was reclassified as F0-1 (n = 10), F2-3 (n = 26), and F4 (n = 18) using the METAVIR system. Spearman correlation test showed D* (r = 0.303, p = 0.026) was associated with RI; however, multivariate analysis showed that only D value was a significant predictor (p < 0.05) of RI. D and D*showed moderate correlations with fibrosis stage (r = -0.361, p = 0.007; r = -0.457, p = 0.001). Fibrosis stage showed a negative correlation with RI (r = -0.263, p = 0.015). In the 29 patients who underwent minor hepatectomy, only the D value showed a positive association (p < 0.05) with RI, and a negative correlation with fibrosis stage (r = -0.360, p = 0.018). However, in the 25 patients who underwent major hepatectomy, no IVIM parameters were associated with RI (p > 0.05). CONCLUSIONS: The D and D* values, especially the D value, may be reliable preoperative predictors of liver regeneration. KEY POINTS: • The D and D* values, especially the D value, derived from IVIM diffusion-weighted imaging may be useful markers for the preoperative prediction of liver regeneration in patients with HCC. • The D and D* values derived from IVIM diffusion-weighted imaging show significant negative correlations with fibrosis, an important predictor of liver regeneration. • No IVIM parameters were associated with liver regeneration in patients who underwent major hepatectomy, but the D value was a significant predictor of liver regeneration in patients who underwent minor hepatectomy.

Hepatic Adenoma Subtypes on Hepatobiliary Phase of Gadoxetic Acid-Enhanced MRI: Systematic Review and Meta-Analysis.

BACKGROUND. Accumulating evidence indicates that hepatocellular adenoma (HCA) may have a higher frequency of hepatobiliary phase (HBP) iso- or hyperintensity than previously reported. OBJECTIVE. The purpose of this study was to evaluate the proportion of HCA that shows iso- or hyperintensity in the HBP of gadoxetic acid-enhanced MRI, stratified by HCA subtype (HNF1a-inactivated [H-HCA], inflammatory [I-HCA], ß-catenin-activated [B-HCA], and unclassified [U-HCA] HCA), and to assess the diagnostic performance of HBP iso- or hyperintensity for differentiating focal nodular hyperplasia (FNH) from HCA. EVIDENCE ACQUISITION. PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched through February 14, 2022, for articles reporting HBP signal intensity on gadoxetic acid-enhanced MRI among pathologically proven HCAs, stratified by subtype. The pooled proportion of HBP iso- or hyperintensity was determined for each subtype and compared using metaregression. Diagnostic performance of HBP iso- or hyperintensity for differentiating FNH from all HCA subtypes combined and from B-HCA and U-HCA combined was assessed using bivariate modeling. EVIDENCE SYNTHESIS. Twenty-eight studies (12 original investigations, 16 case reports or case series) were included, yielding 364 patients with 410 HCAs (112 H-HCAs, 203 I-HCAs, 33 B-HCAs, 62 U-HCAs). Pooled proportion of HBP iso- or hyperintensity was 14% (95% CI, 4-26%) among all HCAs, 0% (95% CI, 0-2%) among H-HCAs, 11% (95% CI, 0-29%) among U-HCAs, 14% (95% CI, 2-31%) among I-HCAs, and 59% (95% CI, 26-88%) among B-HCAs; metaregression showed significant difference among subtypes (p < .001). In four studies reporting diagnostic performance information, HBP iso- or hyperintensity had sensitivity of 99% (95% CI, 57-100%) and specificity of 89% (95% CI, 82-94%) for differentiating FNH from all HCA subtypes and sensitivity of 99% (95% CI, 53-100%) and specificity of 65% (95% CI, 44-80%) for differentiating FNH from B-HCA or U-HCA. CONCLUSION. HCA subtypes other than H-HCA show proportions of HBP iso- or hyperintensity ranging from 11% (U-HCA) to 59% (B-HCA). Low prevalence of B-HCA has contributed to prior reports of high diagnostic performance of HBP iso- or hyperintensity for differentiating FNH from HCA. CLINICAL IMPACT. Radiologists should recognize the low specificity of HBP iso- or hyperintensity on gadoxetic acid-enhanced MRI for differentiating FNH from certain HCA subtypes.

Focal Nodular Hyperplasia-Like Lesions With Glypican-3 Positivity in Infancy.

PURPOSE AND CONTEXT: Glypican-3 is often used to discriminate between neoplastic and nonneoplastic liver. In focal lesions, positivity may be considered suggestive of a malignancy such as hepatoblastoma. However, glypican-3 is also normally expressed in the immature liver. We present a series of 5 cases of focal nodular hyperplasia (FNH)-like lesions arising in very young patients with glypican-3 expression and highlight the challenges these lesions present in the differential diagnosis of hepatoblastoma. METHODS: Cases were obtained from the files of 3 tertiary pediatric hospitals. Clinical data were obtained from the electronic medical record and histopathologic material including immunohistochemical stains were reviewed. KEY RESULTS: Patients were aged 2 weeks to 6 months with peak AFP levels ranging from 88.6 to 204,696 ng/mL. Microscopically, all were variably demarcated hepatocellular lesions with cords of hepatocytes, marked sinusoidal dilatation, and occasional fibrous bands and areas reminiscent of central scar with bile ducts. No significant cytologic atypia or increased mitotic activity were present. All showed glypican-3 expression and were negative for nuclear beta-catenin with intact reticulin framework. CONCLUSIONS: Our study highlights the pitfalls of evaluating focal liver lesions in infants when high AFP levels and glypican-3 expression may reflect immaturity rather than neoplasia.

Focal Nodular Hyperplasia in the Pediatric Population: A Multicenter Experience.

BACKGROUND: Focal nodular hyperplasia (FNH) is a benign liver lesion classically presenting in young females. In children, FNH is rare and its detailed clinicopathologic characteristics remain largely unknown. Furthermore, there are no studies comparing pediatric FNH features to those presenting in adults. METHODS: In this study, we analyzed a total of 47 FNH cases in pediatric patients (age range: 23 days to 18 years) from 3 centers and compared them to a cohort of 31 FNH cases in adult patients (age range: 20-64 years). RESULTS: Of the pediatric cases, 13 cases (28%) had a history of a prior malignancy of which 4 were treated with chemoradiation and stem cell transplantation (SCT), 5 with chemoradiation alone and 3 with chemotherapy and SCT. In the pediatric cases 41 (87%) had a central scar and 46 (98%) had fibrous septa. Both pediatric and adult FNH were more common in female patients. Cases in pediatric patients were also significantly associated with larger size (P = .047), absence of dystrophic vessels (P = .001), absence of sinusoidal dilatation (P = .029), pseudoacini formation (P = .013), and steatosis (P = .029). CONCLUSION: In our experience although most cases of pediatric FNH show the classic histologic features seen in adults, some significant differences exist, and awareness of these findings could aid in the evaluation of these rare cases.

Hepatocellular carcinoma and focal nodular hyperplasia in patients with Fontan-associated liver disease: characterisation using dynamic gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced MRI.

AIM: To identify the characteristic diagnostic features of hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH) in Fontan-associated liver disease (FALD) patients using dynamic gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI). MATERIALS AND METHODS: Thirty-one FALD patients (mean age, 28.3 ± 7.2 years) with liver nodules who underwent dynamic Gd-EOB-DTPA-enhanced MRI were enrolled prospectively. Twenty-five patients (mean age, 72.8 ± 11.4 years) with hepatitis C virus (HCV)-related HCC constituted the control group. The tumour-to-liver signal intensity (SI) ratio was measured at 30, 60, 100, 180 seconds and 15 minutes, and the SI ratio was compared among FALD-HCC, FALD-FNH, and HCV-HCC. RESULTS: FALD-HCC exhibited weak early enhancement with mild washout in late phases. FALD-FNH exhibited marked early enhancement that continued until the late phases. The SI ratio was significantly lower for FALD-HCC than for FALD-FNH in all phases. The SI ratio was significantly lower for FALD-HCC than for HCV-HCC only at 30 seconds (p<0.05), whereas poorer washout was seen in FALD-HCC than HCV-HCC in other phases. In 15 minutes, FALD-HCC had a significantly lower SI ratio compared to FALD-FNH (p<0.001). CONCLUSIONS: The time course of Gd-EOB-DTPA-enhanced MRI signal intensity in FALD-HCC was different from that in FALD-FNH or HCV-HCC. This imaging finding may be useful adjunctive information to distinguish FALD-HCC from FALD-FNH.