A New Reporting System for Diagnosis of Hepatocellular Carcinoma in Chronic Hepatitis B With Clinical and Gadoxetic Acid-Enhanced MRI Features.

BACKGROUND: Current major guidelines for diagnosis of hepatocellular carcinoma (HCC) based on imaging findings are different from each other and do not include clinical risk factors as a diagnostic criteria. PURPOSE: To developed and validated a new diagnostic score system using MRI and clinical features as applied in chronic hepatitis B patients. STUDY TYPE: Retrospective observational study. SUBJECT: A total of 418 treatment-naïve patients (out of 902 patients) with chronic hepatitis B having 556 lesions suspected for HCC which were eligible for curative treatment. FIELD STRENGTH/SEQUENCE: T1W GRE in- and opposed-phase, T2W FSE, DWI, and T1W 3D-GRE dynamic contrast-enhanced sequences at 1.5  T and 3  T. ASSESSMENT: Six radiologists with 7-22 years of experience independently evaluated MR images based on Liver Imaging Reporting and Data System (LI-RADS) version 2018. STATISTICAL TESTS: Based on logistic regression analysis of MRI features and clinical factors, a risk score system was devised in derivation cohorts (268 patients, 352 lesions) and externally validated (150 patients, 204 lesions). The performance of the new score system was assessed by Harell's c-index. Using cutoff value of 12, maintaining positive predictive value ≥95%, the diagnostic performances of the score system were compared with those of LR-5. RESULTS: The 15-point diagnostic scoring system used MRI features (lesion size, nonrim arterial phase hyperenhancement, portal venous phase hypointensity, hepatobiliary phase hypointensity, and diffusion restriction) and clinical factors (alpha-fetoprotein and platelet). It showed good discrimination in the derivation (c-index, 0.946) and validation cohorts (c-index, 0.907). Using a risk score of 12 as a cut-off, this system yielded higher sensitivity than LR-5 (derivation cohort, 76.8% vs. 52.1%; validation cohort, 73.4% vs. 49.5%) without significant decrease in specificity (derivation cohort, 93.1% vs. 97.2%, P = 0.074; validation cohort, 91.7% vs. 96.1%, P = 0.299). DATA CONCLUSION: A new score system showed improved sensitivity in chronic hepatitis B patients compared to LI-RADS without significant compromise in specificity. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

Preoperative magnetic resonance imaging-based prognostic model for mass-forming intrahepatic cholangiocarcinoma.

BACKGROUND & AIMS: As most staging systems for intrahepatic cholangiocarcinoma (iCCA) are based on pathological results, preoperative prognostic prediction is limited. This study aimed to develop and validate a prognostic model for the overall survival of patients with mass-forming iCCA (MF-iCCA) using preoperative magnetic resonance imaging (MRI) and clinical findings. METHODS: We enrolled a total of 316 patients who underwent preoperative MRI and surgical resection for treatment-naive MF-iCCA from six institutions, between January 2009 and December 2015. The subjects were randomly assigned to a training set (n = 208) or validation set (n = 108). The MRIs were independently reviewed by three abdominal radiologists. Using MRI and clinical findings, an MRI prognostic score was established. We compared the discrimination performance of MRI prognostic scores with those of conventional pathological staging systems. RESULTS: We developed an MRI prognostic score consisting of serum CA19-9 and three MRI findings (tumour multiplicity, lymph node metastasis and bile duct invasion). The MRI prognostic score demonstrated good discrimination performance in both the training set (C-index, 0.738; 95% confidence interval [CI], 0.698-0.780) and validation set (C-index, 0.605; 95% CI, 0.526-0.680). In the validation set, MRI prognostic score showed no significant difference with AJCC 8th TNM stage, MEGNA score and Nathan's stage. CONCLUSIONS: Our MRI prognostic score for overall survival of MF-iCCA showed comparable discriminatory performance with pathological staging systems and might be used to determine an optimal treatment strategy.

Comparison of the current guidelines for diagnosing hepatocellular carcinoma using gadoxetic acid-enhanced magnetic resonance imaging.

OBJECTIVES: To compare the performance of current guidelines applicable to the diagnosis of hepatocellular carcinomas (HCCs) using gadoxetic acid-enhanced magnetic resonance imaging (MRI). METHODS: Two hundred and forty-one hepatic lesions (149 HCCs, six other malignancies, 86 benign lesions) in 177 patients at risk of HCC without a history of previous treatment for hepatic malignancy in a tertiary center were retrospectively reviewed. Either histopathology results or long-term (> 24 months) follow-up images were used as a standard of reference. All lesions were categorized according to the Liver Imaging Reporting and Data System (LI-RADS), European Association for the Study of the Liver (EASL), Asian Pacific Association for the Study of the Liver (APASL), and Korean Liver Cancer Study Group-National Cancer Center (KLCSG-NCC) guidelines. The sensitivity and specificity thereof were assessed using a generalized estimation equation. RESULTS: For gadoxetic acid-enhanced MRI, LI-RADS (95%, 95% confidence interval [CI] 88-98) and EASL (94%, 95% CI 86-97) yielded the highest specificity, while EASL yielded the lowest sensitivity (54% [95% CI 46-62]). APASL yielded the highest sensitivity (91% [95% CI 86-95]) with the lowest specificity (78% [95% CI 69-86]). KLCSG-NCC showed balanced sensitivity (85% [79-90]) and specificity (88% [95% CI 80-93]). Differences were more prominent in small nodules between 1 and 2 cm. CONCLUSION: The diagnostic performance of current guidelines for HCC on gadoxetic acid-enhanced MRI was significantly different, and a potential inverse association between sensitivity and specificity was observed. KEY POINTS: • EASL and LI-RADS yielded the highest specificity with the lowest sensitivity, whereas APASL yielded the highest sensitivity with the lowest specificity. • Differences in the diagnostic performances of guidelines were prominent in small nodules between 1 and 2 cm. • Additional evaluation of CT findings improved the diagnostic sensitivity and accuracy of EASL and LI-RADS. Although doing so decreased specificity, it remained above 89-90%.

Subcentimeter hepatocellular carcinoma in treatment-naïve patients: noninvasive diagnostic criteria and tumor staging on gadoxetic acid-enhanced MRI.

OBJECTIVE: It is controversial to adopt non-invasive diagnostic criteria of hepatocellular carcinoma (HCC) in subcentimeter lesions. This study was aimed to define the optimal noninvasive diagnostic criteria of subcentimeter HCC and to evaluate the effect on tumor staging. METHODS: We included 110 treatment-naïve patients at risk of HCC and eligible for curative treatment who had subcentimeter lesions (n = 136) on gadoxetic acid-enhanced magnetic resonance imaging (MRI) performed between January 2013 and December 2013. Modified diagnostic criteria for subcentimeter HCC were developed using logistic regression analysis. Accuracies of MR staging with and without using the modified criteria were compared by generalized estimating equation test using pathologic staging as reference standards. Subgroup analysis was performed for patients with co-existing HCC ≥ 1 cm (co-HCC). RESULTS: The modified criteria (presence of co-HCC, arterial phase hyperenhancement, and hypointensity on transitional phase [TP]) showed 61.5% (95% CI, 41.6-78.2) of sensitivity and 98.2% (95% CI, 93.0-99.5) of specificity. Including subcentimeter HCCs improved the accuracy of MR staging from 84.5 to 94.5% (p = 0.001). Fifty percent of subcentimeter lesions found in patients with co-HCCs were HCC, whereas 5.9% of them without co-HCCs were HCC (p = 0.001). In the subgroup with co-HCCs, the accuracy of MR staging with subcentimeter HCCs was improved from 69.0% to 92.8% (p = 0.001). CONCLUSIONS: Including subcentimeter HCCs based on the modified diagnostic criteria (co-existing HCC ≥ 1 cm, arterial phase hyperenhancement, and hypointensity on TP) improved MR staging accuracy. KEY POINTS: • Fifty percent of non-benign appearing subcentimeter lesions found in patients with co-HCCs were HCC, whereas 5.9% of them without co-HCCs were HCC (p = 0.001). • Including subcentimeter HCCs improved the accuracy of MR staging from 84.5 to 94.5% (p = 0.001).

Preoperative prediction of postsurgical outcomes in mass-forming intrahepatic cholangiocarcinoma based on clinical, radiologic, and radiomics features.

OBJECTIVES: Current prognostic systems for intrahepatic cholangiocarcinoma (IHCC) rely on surgical pathology data and are not applicable to a preoperative setting. We aimed to develop and validate preoperative models to predict postsurgical outcomes in mass-forming IHCC patients based on clinical, radiologic, and radiomics features. METHODS: This multicenter retrospective cohort study included patients who underwent curative-intent resection for mass-forming IHCC. In the development cohort (single institution data), three preoperative multivariable Cox models for predicting recurrence-free survival (RFS) were constructed, including the clinical-radiologic, radiomics, and clinical-radiologic-radiomics (CRR) models based on clinical and CT findings, CT-radiomics features, and a combination of both, respectively. Model performance was evaluated in the test cohort (data from five institutions) using Harrell's C-index and compared with postoperative prognostic systems. RESULTS: A total of 345 patients (233, development cohort; 112, test cohort) were evaluated. The clinical-radiologic model included five independent CT predictors (infiltrative contour, multiplicity, periductal infiltration, extrahepatic organ invasion, and suspicious metastatic lymph node) and showed similar performance in predicting RFS to the radiomics model (C-index, 0.65 vs. 0.68; p = 0.43 in the test cohort). The CRR model showed significantly improved performance (C-index, 0.71; p = 0.01) than the clinical-radiologic model and demonstrated similar performance to the postoperative prognostic systems in predicting RFS (C-index, 0.71-0.73 vs. 0.70-0.73; p ≥ 0.40) and overall survival (C-index, 0.68-0.71 vs. 0.64-0.74; p ≥ 0.27) in the test cohort. CONCLUSIONS: A model integrating clinical, CT, and radiomics information may be useful for the preoperative assessment of postsurgical outcomes in patients with mass-forming IHCC. KEY POINTS: • The radiomics analysis had incremental value in predicting recurrence-free survival of patients with intrahepatic mass-forming cholangiocarcinoma. • The clinical-radiologic-radiomics model demonstrated similar performance to the postoperatively available prognostic systems (including 8th AJCC system) in predicting recurrence-free survival and overall survival. • The clinical-radiologic-radiomics model may be useful for the preoperative assessment of postsurgical outcomes in patients with mass-forming intrahepatic cholangiocarcinoma.

Management of subcentimetre arterially enhancing and hepatobiliary hypointense lesions on gadoxetic acid-enhanced MRI in patients at risk for HCC.

OBJECTIVES: To investigate the significance of subcentimetre (≤1 cm) arterially enhancing and hepatobiliary hypointense lesions (SAELs) observed on gadoxetic acid-enhanced magnetic resonance imaging (MRI) of patients at risk of hepatocellular carcinoma (HCC). METHODS: A SAEL was defined as a subcentimetre hypervascular nodule exhibiting a hepatobiliary phase defect on gadoxetic acid-enhanced MRI. We included 52 SAELs from 46 patients in a HCC surveillance population. The HCC reference standard was pathologic confirmation or a nodule >1 cm with typical imaging features of HCC at follow-up imaging. The malignancy rate and HCC-favourable imaging findings of SAELs were evaluated. RESULTS: The malignancy rate among SAELs was 57.7% (30/52). At diagnosis, all SAELs that progressed to overt HCC were treatable with curative intention. Venous or late dynamic phase washout was more frequently observed with malignant SAELs than with benign SAELs (57.7% vs. 30.6%; P = 0.01). If SAELs exhibiting washout were considered as HCC, sensitivity, specificity, and positive predictive value was 83.3%, 50%, and 69.4%, respectively. CONCLUSION: Among patients at risk of HCC, SAELs on gadoxetic acid-enhanced MRI exhibited high malignant potential. However, close observation may be an appropriate strategy for isolated SAELs. A washout appearance may be helpful for predicting malignancy. KEY POINTS: • Gadoxetic acid-enhanced MRI provides hepatobiliary phase (HBP) images. • Screening frequently detects subcentimetre arterially enhancing and hepatobiliary hypointense lesions (SAELs). • A majority of SAELs progressed to overt HCC within 2 years. • A venous-phase washout appearance correlated significantly with malignancy in SAELs.

Efficacy and safety of ipragliflozin as an add-on therapy to sitagliptin and metformin in Korean patients with inadequately controlled type 2 diabetes mellitus: A randomized controlled trial.

AIM: To evaluate the efficacy and safety of ipragliflozin vs placebo as add-on therapy to metformin and sitagliptin in Korean patients with type 2 diabetes mellitus (T2DM). METHODS: This double-blind, placebo-controlled, multi-centre, phase III study was conducted in Korea in 2015 to 2017. Patients were randomized to receive either ipragliflozin 50 mg/day or placebo once daily for 24 weeks in addition to metformin and sitagliptin. The primary endpoint was the change in glycated haemoglobin (HbA1c) from baseline to end of treatment (EOT). RESULTS: In total, 143 patients were randomized and 139 were included in efficacy analyses (ipragliflozin: 73, placebo: 66). Baseline mean (SD) HbA1c levels were 7.90 (0.69)% for ipragliflozin add-on and 7.92 (0.79)% for placebo. The corresponding mean (SD) changes from baseline to EOT were -0.79 (0.59)% and 0.03 (0.84)%, respectively, in favour of ipragliflozin (adjusted mean difference -0.83% [95% CI -1.07 to -0.59]; P < .0001). More ipragliflozin-treated patients than placebo-treated patients achieved HbA1c target levels of <7.0% (44.4% vs 12.1%) and < 6.5% (12.5% vs 1.5%) at EOT (P < .05 for both). Fasting plasma glucose, fasting serum insulin, body weight and homeostatic model assessment of insulin resistance decreased significantly at EOT, in favour of ipragliflozin (adjusted mean difference -1.64 mmol/L, -1.50 µU/mL, -1.72 kg, and -0.99, respectively; P < .05 for all). Adverse event rates were similar between groups (ipragliflozin: 51.4%; placebo: 50.0%). No previously unreported safety concerns were noted. CONCLUSIONS: Ipragliflozin as add-on to metformin and sitagliptin significantly improved glycaemic variables and demonstrated a good safety profile in Korean patients with inadequately controlled T2DM.

Use of Imaging to Predict Complete Response of Colorectal Liver Metastases after Chemotherapy: MR Imaging versus CT Imaging.

Purpose To compare the diagnostic performances of contrast agent-enhanced computed tomography (CT) and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced liver magnetic resonance (MR) imaging (referred to as EOB MR imaging) in the evaluation of disappearing colorectal liver metastases (CRLMs) after chemotherapy. Materials and Methods The eight institutional review boards approved this retrospective study and waived the requirement for informed consent. On the basis of retrospective searches in eight hospitals, 87 patients with 393 CRLMs, each patient with one or more CRLM that later disappeared on contrast-enhanced CT scans after chemotherapy, and subsequently underwent surgery for the CRLMs, were enrolled. The anonymized imaging data and case report forms were sent to the central review system and independently reviewed by four radiologists. All anonymized data were randomly allocated into two groups (groups A and B), which were read by two independent readers. True absence of tumor was defined as pathologic absence of tumor for resected lesions and no in situ recurrence within 1 year after surgery for lesions left unresected at each 3-month follow-up contrast-enhanced CT. Positive predictive values for absence of tumor and for residual tumor on contrast-enhanced CT and EOB MR images were compared by using a generalized estimating equation. Results Among 393 CRLMs, the positive predictive value for absence of tumor on EOB MR images (78.0%; 95% confidence interval [CI]: 63.68%, 87.74%) was significantly higher than that on contrast-enhanced CT scans (35.2%; 95% CI: 25.11%, 46.79%; P < .001). The positive predictive value for residual tumor on CT scans (86.0%; 95% CI: 78.61%, 91.16%) was higher than that on EOB MR images (83.8%; 95% CI: 77.50%, 88.67%) without statistical significance (P = .330). Conclusion EOB MR imaging was superior to contrast-enhanced CT imaging for assessment of disappearing CRLMs after chemotherapy. © RSNA, 2017 Online supplemental material is available for this article.

Added value of smooth hypointense rim in the hepatobiliary phase of gadoxetic acid-enhanced MRI in identifying tumour capsule and diagnosing hepatocellular carcinoma.

OBJECTIVES: To examine the added value of considering smooth hypointense rim in the hepatobiliary phase (HBP) of gadoxetic acid-enhanced MRI as capsule appearance for diagnosing tumour capsules and hepatocellular carcinoma (HCC). METHODS: A total of 377 hepatic lesions (330 HCCs, 35 non-HCC malignancies and 12 benign) were included from 345 patients who underwent resection after MRI between January 2008 and December 2011. Two radiologists assessed the presence or absence of conventional capsule appearance and smooth hypointense rim in the HBP, and categorized each hepatic lesion according to the Liver Imaging Reporting and Data System. Difference in diagnostic performance was evaluated using the generalized estimating equation method. RESULTS: For identifying capsule, the sensitivity and accuracy of HBP hypointense rim were significantly higher than those of conventional capsule appearance (81.5 % vs. 57.8 % and 76.1 % vs. 59.4 %, respectively; P < 0.001). For diagnosing HCC, the sensitivity and accuracy of LR-5 or LR-5 V were significantly higher when the HBP hypointense rim was also considered capsule appearance (83 % vs. 72.7 % and 84.1 % vs. 75.1 %, respectively; P < 0.001), with the same specificity (91.5 %). CONCLUSIONS: Regarding smooth hypointense rim in the HBP as capsule appearance could improve the detection of tumour capsule and the diagnosis of HCC. KEY POINTS: • Identifying tumour capsule is important for diagnosis of hepatocellular carcinoma (HCC). • Gadoxetic acid-enhanced MRI provides hepatobiliary phase (HBP) images. • Smooth hypointense rim seen in HBP may represent tumour capsule. • Regarding smooth hypointense rim as capsule appearance may improve HCC diagnosis.

Curative Resection of Single Primary Hepatic Malignancy: Liver Imaging Reporting and Data System Category LR-M Portends a Worse Prognosis.

OBJECTIVE: The purpose of this study was to examine the associations between preoperative Liver Imaging Reporting and Data System (LI-RADS) categories and prognosis after curative resection of single hepatic malignancies in patients with chronic liver disease. MATERIALS AND METHODS: Between January 2008 and December 2010, 225 patients with chronic liver disease underwent resection of single hepatic malignant tumors (218 hepatocellular carcinomas, three cholangiocarcinomas, four biphenotypic carcinomas) after undergoing gadoxetic acid-enhanced MRI. Two radiologists retrospectively categorized the tumors into LI-RADS categories. Differences in disease-free survival duration between categories were analyzed by the Kaplan-Meier method with the log-rank test. RESULTS: Reviewer 1 categorized two (0.9%) patients as having LR-3, 53 (23.6%) LR-4, 159 (70.7%) LR-5, and 11 (4.9%) LR-M lesions. The corresponding numbers for reviewer 2 were six (2.7%) LR-3, 30 (13.3%) LR-4, 178 (79.1%) LR-5, and 11 (4.9%) LR-M. The 2-year cumulative recurrence or death rates were 15.1% for lesions categorized LR-3 or LR-4 by reviewer 1, 31.7% for LR-5, and 60% for LR-M. For lesions categorized by reviewer 2 the corresponding rates were 20.6% for LR-3 or LR-4, 29% for LR-5, and 54.5% for LR-M. Disease-free survival was significantly worse among patients with lesions categorized as LR-M than for lesions categorized as LR-3 or LR-4 or as LR-5 (p < 0.01 for both reviewers). Disease-free survival did not significantly differ between patients with LR-3 or LR-4 and those with LR-5 lesions (reviewer 1, p = 0.301; reviewer 2, p = 0.291). CONCLUSION: Patients with tumors preoperatively categorized as LR-M may have a worse prognosis than those with tumors categorized LR-3, LR-4, or LR-5 after curative resection of single hepatic malignancy.

Ligand binding pocket formed by evolutionarily conserved residues in the glucagon-like peptide-1 (GLP-1) receptor core domain.

Glucagon-like peptide-1 (GLP-1) plays a pivotal role in glucose homeostasis through its receptor GLP1R. Due to its multiple beneficial effects, GLP-1 has gained great attention for treatment of type 2 diabetes and obesity. However, little is known about the molecular mechanism underlying the interaction of GLP-1 with the heptahelical core domain of GLP1R conferring high affinity ligand binding and ligand-induced receptor activation. Here, using chimeric and point-mutated GLP1R, we determined that the evolutionarily conserved amino acid residue Arg(380) flanked by hydrophobic Leu(379) and Phe(381) in extracellular loop 3 (ECL3) may have an interaction with Asp(9) and Gly(4) of the GLP-1 peptide. The molecular modeling study showed that Ile(196) at transmembrane helix 2, Met(233) at ECL1, and Asn(302) at ECL2 of GLP1R have contacts with His(1) and Thr(7) of GLP-1. This study may shed light on the mechanism underlying high affinity interaction between the ligand and the binding pocket that is formed by these conserved residues in the GLP1R core domain.

Prevertebrate Local Gene Duplication Facilitated Expansion of the Neuropeptide GPCR Superfamily.

In humans, numerous genes encode neuropeptides that comprise a superfamily of more than 70 genes in approximately 30 families and act mainly through rhodopsin-like G protein-coupled receptors (GPCRs). Two rounds of whole-genome duplication (2R WGD) during early vertebrate evolution greatly contributed to proliferation within gene families; however, the mechanisms underlying the initial emergence and diversification of these gene families before 2R WGD are largely unknown. In this study, we analyzed 25 vertebrate rhodopsin-like neuropeptide GPCR families and their cognate peptides using phylogeny, synteny, and localization of these genes on reconstructed vertebrate ancestral chromosomes (VACs). Based on phylogeny, these GPCR families can be divided into five distinct clades, and members of each clade tend to be located on the same VACs. Similarly, their neuropeptide gene families also tend to reside on distinct VACs. Comparison of these GPCR genes with those of invertebrates including Drosophila melanogaster, Caenorhabditis elegans, Branchiostoma floridae, and Ciona intestinalis indicates that these GPCR families emerged through tandem local duplication during metazoan evolution prior to 2R WGD. Our study describes a presumptive evolutionary mechanism and development pathway of the vertebrate rhodopsin-like GPCR and cognate neuropeptide families from the urbilaterian ancestor to modern vertebrates.

Expansion of secretin-like G protein-coupled receptors and their peptide ligands via local duplications before and after two rounds of whole-genome duplication.

In humans, the secretin-like G protein-coupled receptor (GPCR) family comprises 15 members with 18 corresponding peptide ligand genes. Although members have been identified in a large variety of vertebrate and nonvertebrate species, the origin and relationship of these proteins remain unresolved. To address this issue, we employed large-scale genome comparisons to identify genome fragments with conserved synteny and matched these fragments to linkage groups in reconstructed early gnathostome ancestral chromosomes (GAC). This genome comparison revealed that most receptor and peptide genes were clustered in three GAC linkage groups and suggested that the ancestral forms of five peptide subfamilies (corticotropin-releasing hormone-like, calcitonin-like, parathyroid hormone-like, glucagon-like, and growth hormone-releasing hormone-like) and their cognate receptor families emerged through tandem local gene duplications before two rounds (2R) of whole-genome duplication. These subfamily genes have, then, been amplified by 2R whole-genome duplication, followed by additional local duplications and gene loss prior to the divergence of land vertebrates and teleosts. This study delineates a possible evolutionary scenario for whole secretin-like peptide and receptor family members and may shed light on evolutionary mechanisms for expansion of a gene family with a large number of paralogs.

CT Evaluation of Long-Term Changes in Common Bile Duct Diameter after Cholecystectomy.

Purpose: The present study aimed to investigate the frequency and extent of compensatory common bile duct (CBD) dilatation after cholecystectomy, assess the time between cholecystectomy and CBD dilatation, and identify potentially useful CT findings suggestive of obstructive CBD dilatation. Materials and Methods: This retrospective study included 121 patients without biliary obstruction who underwent multiple CT scans before and after cholecystectomy at a single center between 2009 and 2011. The maximum short-axis diameters of the CBD and intrahepatic duct (IHD) were measured on each CT scan. In addition, the clinical and CT findings of 11 patients who were initially excluded from the study because of CBD stones or periampullary tumors were examined to identify distinguishing features between obstructive and non-obstructive CBD dilatation after cholecystectomy. Results: The mean (standard deviation) short-axis maximum CBD diameter of 121 patients was 5.6 (± 1.9) mm in the axial plane before cholecystectomy but increased to 7.9 (± 2.6) mm after cholecystectomy (p < 0.001). Of the 106 patients with a pre-cholecystectomy axial CBD diameter of < 8 mm, 39 (36.8%) showed CBD dilatation of ≥ 8 mm after cholecystectomy. Six of the 17 patients with longterm (> 2 years) serial follow-up CT scans (35.3%) eventually showed a significant (> 1.5-fold) increase in the axial CBD diameter, all within two years after cholecystectomy. Of the 121 patients without obstruction or related symptoms, only one patient (0.1%) showed IHD dilatation > 3 mm after cholecystectomy. In contrast, all 11 patients with CBD obstruction had abdominal pain and abnormal laboratory indices, and 81.8% (9/11) had significant dilatation of the IHD and CBD. Conclusion: Compensatory non-obstructive CBD dilatation commonly occurs after cholecystectomy to a similar extent as obstructive dilatation. However, the presence of relevant symptoms, significant IHD dilatation, or further CBD dilatation 2-3 years after cholecystectomy should raise suspicion of CBD obstruction.

Evolutionarily conserved residues at glucagon-like peptide-1 (GLP-1) receptor core confer ligand-induced receptor activation.

Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) play important roles in insulin secretion through their receptors, GLP1R and GIPR. Although GLP-1 and GIP are attractive candidates for treatment of type 2 diabetes and obesity, little is known regarding the molecular interaction of these peptides with the heptahelical core domain of their receptors. These core domains are important not only for specific ligand binding but also for ligand-induced receptor activation. Here, using chimeric and point-mutated GLP1R/GIPR, we determined that evolutionarily conserved amino acid residues such as Ile(196) at transmembrane helix 2, Leu(232) and Met(233) at extracellular loop 1, and Asn(302) at extracellular loop 2 of GLP1R are responsible for interaction with ligand and receptor activation. Application of chimeric GLP-1/GIP peptides together with molecular modeling suggests that His(1) of GLP-1 interacts with Asn(302) of GLP1R and that Thr(7) of GLP-1 has close contact with a binding pocket formed by Ile(196), Leu(232), and Met(233) of GLP1R. This study may provide critical clues for the development of peptide and/or nonpeptide agonists acting at GLP1R.

Usefulness of the tensile gallbladder fundus sign in the diagnosis of early acute cholecystitis.

OBJECTIVE: The purpose of this article is to evaluate the usefulness of the tensile gallbladder fundus sign on CT in diagnosing early acute cholecystitis. MATERIALS AND METHODS: The tensile gallbladder fundus sign on CT is defined as the absence of gallbladder fundus flattening by the anterior abdominal wall due to increased gallbladder pressures. Between October 2010 and March 2012, 222 patients with confirmed diagnoses of acute cholecystitis by surgery or follow-up imaging studies underwent CT scans in the emergency department because of right upper quadrant pain. Two radiologists retrospectively reviewed all CT images to determine the presence of the tensile gallbladder fundus sign and other CT findings previously reported to be suggestive of acute cholecystitis. Diagnostic performances were calculated and analyzed using pairwise comparisons of receiver operating characteristic curves. The kappa statistic was calculated to evaluate the interobserver agreement. RESULTS: Using the diagnostic criteria in which acute cholecystitis is defined as the presence of three or more classic CT findings, the addition of the tensile gallbladder fundus sign increased the area under the receiver operating characteristic curve (Az) value from 0.693 to 0.739 (p = 0.003). In the subgroup of 91 patients with no other CT features suggestive of acute cholecystitis, the sensitivity, specificity, and Az value of the tensile gallbladder fundus sign for acute cholecystitis were 74.1%, 96.9%, and 0.855, respectively. Interobserver agreement was good with the tensile gallbladder fundus sign (κ = 0.721). CONCLUSION: The tensile gallbladder fundus sign may be useful for diagnosing acute cholecystitis, especially in the early stage when other CT findings are absent.

Primary hepatic mucosa-associated lymphoid tissue lymphoma mimicking hepatocellular carcinoma in a patient with chronic hepatitis B: a case report.

Primary hepatic lymphoma is a rare disease, and primary hepatic mucosa-associated lymphoid tissue (MALT) lymphoma accounts for only 0.3% of all primary hepatic lymphomas. Herein, we report a case of primary hepatic MALT lymphoma in a male patient in his mid-40 s with chronic hepatitis B infection. The patient visited our department for further examination of a hepatic nodule initially visualized through abdominal pelvic computed tomography (CT). Based on imaging studies and elevated levels of tumor markers, the tumor was suspected to be hepatocellular carcinoma. A laparoscopic inferior sectionectomy (segment 5 and 6) was performed, and immunohistochemical staining revealed that the tumor was positive for CD20, B-cell lymphoma 2, pan-cytokeratin (CK), and CK19 markers. Pathological findings revealed it to be a primary hepatic MALT lymphoma. After surgery, bone marrow biopsies and fluorodeoxyglucose-positron emission tomography integrated with CT scanning confirmed that there was no other involvement. The patient did not receive chemotherapy, and there was no recurrence during the 24-month follow-up period. Hepatocellular carcinoma is the most common malignancy in patients with chronic hepatitis B, but rare tumors such as primary MALT lymphoma can also occur, so a careful approach is required for their differentiation.

Suspicious findings observed retrospectively on CT imaging performed before the diagnosis of pancreatic cancer.

Background: Few studies have focused on computed tomography findings before a pancreatic cancer diagnosis. We aimed to investigate the prediagnostic computed tomography findings of patients who had undergone computed tomography within the prediagnostic period of their pancreatic cancer diagnosis. Methods: Between January 2008 and December 2019, 27 patients who underwent contrast-enhanced abdominal or chest computed tomography including the pancreas within 1 year of a pancreatic cancer diagnosis were enrolled in this retrospective study. The prediagnostic computed tomography imaging findings were divided into pancreatic parenchyma and pancreatic duct findings. Results: All patients underwent computed tomography for reasons unrelated to pancreatic cancer. The pancreatic parenchyma and ducts showed normal findings in seven patients and abnormal findings in 20 patients. Hypoattenuating mass-like lesions were detected in nine patients with a median size of 1.2 cm. Six patients had focal pancreatic duct dilatations, and two patients had distal parenchymal atrophy. In three patients, two of these findings were found simultaneously. Taken together, 14 (51.9%) of 27 patients had findings suggestive of pancreatic cancer in prediagnostic computed tomography. Conclusions: In contrast-enhanced computed tomography performed for other purposes, attention should be paid to the presence of a hypoattenuating mass, focal pancreatic duct dilatation, or distal parenchymal atrophy of the pancreas. These features may be clues for an early diagnosis of pancreatic cancer.

A preoperative scoring system to predict lymph node metastasis in intrahepatic cholangiocarcinoma.

BACKGROUND: The abnormality of imaging finding of lymph node (LN) has demonstrated unsatisfactory diagnostic accuracy for pathologic lymph node metastasis (LNM). We aimed to develop and validate a simple scoring system predicting LNM in patients with intrahepatic cholangiocarcinoma (iCCA) prior to surgery based on MRI and clinical findings. METHODS: We retrospectively enrolled consecutive patients who underwent surgical resection for treatment-naïve iCCA from six institutions between January 2009 and December 2015. Patients who underwent lymph node dissection (LND) were randomly assigned to the training and validation cohorts at a 2:1 ratio, an¹ìd pathologic LN status was evaluated. Patients who did not undergo LND were assigned to the test cohort, and clinical LN status was evaluated. Using MRI and clinical findings, a preoperative LNM score was developed in the training cohort and validated in the validation and test cohorts. RESULTS: The training, validation, and test cohorts included 102, 53, and 118 patients, respectively. The preoperative LNM score consisted of serum carcinoembryonic antigen and two MRI findings (suspicious LN and bile duct invasion). The preoperative LNM score was associated with pathologic LNM in training (p < 0.001) and validation (p = 0.010) cohorts and clinical LNM in test cohort (p < 0.001). The preoperative LNM score outperformed MRI-suspicious LN alone in predicting pathologic LNM (area under the curve, 0.703 vs. 0.604, p = 0.004). The preoperative LNM score was also associated with overall survival in all cohorts (p < 0.001). CONCLUSIONS: Our preoperative LNM score was significantly associated with pathologic or clinical LNM and outperformed MRI-suspicious LN alone.

Revisiting the evolution of gonadotropin-releasing hormones and their receptors in vertebrates: secrets hidden in genomes.

Gonadotropin-releasing hormone (GnRH) and its G protein-coupled receptor, GnRHR, play a pivotal role in the control of reproduction in vertebrates. To date, many GnRH and GnRHR genes have been identified in a large variety of vertebrate species using conventional biochemical and molecular biological tools in combination with bioinformatic tools. Phylogenetic approaches, primarily based on amino acid sequence identity, make it possible to classify these multiple GnRHs and GnRHRs into several lineages. Four vertebrate GnRH lineages GnRH1, GnRH2, GnRH3, and GnRH4 (for lamprey) are well established. Four vertebrate GnRHR lineages have also been proposed-three for nonmammalian GnRHRs and mammalian GnRHR2 as well as one for mammalian GnRHR1. However, these phylogenetic analyses cannot fully explain the evolutionary origins of each lineage and the relationships among the lineages. Rapid and vast accumulation of genome sequence information for many vertebrate species, together with advances in bioinformatic tools, has allowed large-scale genome comparison to explore the origin and relationship of gene families of interest. The present review discusses the evolutionary mechanism of vertebrate GnRHs and GnRHRs based on extensive genome comparison. In this article, we focus only on vertebrate genomes because of the difficulty in comparing invertebrate and vertebrate genomes due to their marked divergence.