Development and validation of MRI PDFF Cut-offs for living liver donor eligibility assessment.

Hepatic steatosis (HS) criteria for living donor liver transplantation (LDLT) donor eligibility should be based on large droplet fat as per Banff consensus recommendations. We aimed to establish MRI PDFF cut-offs for HS assessment in potential LDLT donors. This retrospective study included consecutive potential LDLT donors who underwent MRI and liver biopsy between 2013 and 2023 at two tertiary institutions, each as development (n=3062; 2015 men; median [interquartile range] age of 32 [25-38] years) and external validation (n=472; 287 men; 35 [26-44] years) datasets. PDFF was measured using dedicated MRI sequences. Histologic HS defined as large droplet fat fraction was used as the reference standard. Dual PDFF cut-offs aimed at 95% sensitivity or 95% specificity, for diagnosing histologic HS of ≥10%, ≥20%, ≥30%, and ≥40%, were determined in the development dataset using ten-fold cross validation. The cut-offs were then validated in the external validation dataset. Equation for estimating histologic HS from PDFF was also derived using linear regression. The PDFF cut-offs for histologic HS of ≥10%, ≥20%, ≥30%, and ≥40%, targeting 95% sensitivity, were 3.7%, 5.5%, 8.0%, and 10.0%, respectively. External validation demonstrated high sensitivities ≥ 97.9% with specificities ranging from 60.9% to 95.1%. The PDFF cut-offs targeting 95% specificity were 6.3%, 8.0%, 9.1%, and 10.1%, respectively. External validation rendered high specificities ranging from 88.5% to 95.3% with sensitivities ranging from 76.6% to 100%. For diagnosing histologic HS ≥30%, which is the most prevalently used threshold for LDLT donor eligibility assessment, the PDFF cut-offs achieved sensitivities and specificities of both over 90%. The equation of (Histologic HS=-2.95 + 1.93 * PDFF) was derived.

Comparison of clinical and MRI features of hepatic angiosarcoma and epithelioid hemangioendothelioma.

OBJECTIVE: Differentiating hepatic epithelioid hemangioendothelioma (EHE) and angiosarcoma (AS), the two most common vascular tumors in the liver, is important due to disparities in their prognosis and treatment. We aimed to compare clinical and MRI features of the two tumors. METHODS: This retrospective study included patients with pathologically-confirmed AS or EHE who underwent MRI using gadoxetate disodium between 2008 and 2023. Two radiologists independently reviewed MR images. Wilcoxon rank sum and Fisher's exact tests were used to compare clinical and imaging features. Overall survival was compared using restricted mean survival time at 3 years. RESULTS: 32 patients with AS (18 women [56.3%]; median age, 68 years) and 38 with EHE (24 women [63.2%]; 51 years) were included. Patients with AS were generally older (81.3% ≥ 60 years; P < 0.001), had more frequent laboratory abnormalities (P ≤ 0.018), and poorer overall survival (11.2 vs. 31.8 months; P < 0.001) than those with EHE. On MRI, a large dominant mass accompanied by smaller nodules (14/32, 43.8%), often with ill-defined margins (15/32, 46.9%) was prevalent in AS; compared with nodules of similar sizes (24/38, 63.2%; P = 0.015) with well-defined margin (30/38, 78.9%; P = 0.002) in EHE. Cirrhotic appearance of the liver was more frequent in AS (62.5%, P < 0.001), along with decreased parenchymal enhancement on hepatobiliary phase (31.3%, P < 0.001) and ascites (37.5%, P = 0.010). AS frequently presented with avid enhancement of bizarrely-shaped foci, with a centrifugal enhancement pattern. In comparison, targetoid appearance was characteristic of EHE (78.9% on T2-weighted, 54.1% on diffusion-weighted, 65.8% on multiphase images) (P ≤ 0.002), with enhancement degree typically lower than that of the aorta. On hepatobiliary phase, all the AS exhibited hypointensity, while 39.5% of EHE showed targetoid appearance (P < 0.001). CONCLUSION: Patients aged ≥ 60 years presenting with laboratory abnormalities, typically with a large dominant mass accompanied by smaller nodules, exhibiting avid, bizarre, and centrifugal enhancement-particularly in the cirrhotic-appearing liver-suggests the likelihood of AS over EHE.

Prognostic effect of microscopically negative but close resection margin in gastric cancer.

INTRODUCTION: Microscopically positive resection margin (RM) following curative surgery has been linked to disease recurrence in gastric cancer (GC), but the impact of microscopically negative but close RM (CRM) remains unclear. This study aimed to evaluate the prognostic implications of a CRM of ≤0.5 cm in GC patients. METHODS: A retrospective review of the institutional GC database identified 1958 patients who underwent curative gastrectomy for pathologically proven GC between January 2011 and December 2015. The patients were categorized into CRM (RM ≤0.5 cm) and sufficient RM (SRM, RM >0.5 cm) groups. The impact of CRM on recurrence-free survival (RFS) and overall survival (OS) was analyzed compared to the SRM group. RESULTS: The cohort comprised 1264 patients with early GC (EGC, 64.6%) and 694 with advanced GC (AGC, 35.4%). Forty-four patients (2.2%) had RM of ≤0.5 cm. CRM was associated with worse RFS in AGC (5-year RFS in the CRM vs. SRM groups; 41.6% vs. 68.7%, p = 0.011); however, the effect on OS was not significant (p = 0.159). Multivariate analysis revealed that CRM was an independent prognostic factor for RFS (hazard ratio [HR] 2.035, 95% confidence interval [CI] 1.097-3.776). In AGC, the locoregional recurrence rate was significantly higher in the CRM group than in the SRM group (15.4% vs. 4.9%, p = 0.044). CONCLUSION: CRM of ≤0.5 cm was a significant prognostic factor for RFS in GC patients and was associated with a significant increase in locoregional recurrence in AGC.

Korean Consensus Criteria for the Severity Classification of Alopecia Areata.

BACKGROUND: A set of criteria for severity classification is essential in alopecia areata (AA). Currently, no guidelines are universally accepted for defining AA severity. OBJECTIVE: This study aimed to establish a set of consensus criteria for classifying the severity of and identifying treatment refractoriness in AA. METHODS: A preliminary draft of the definition for moderate-to-severe AA was crafted based on available evidence, and members of the Korean Hair Research Society (KHRS) subsequently endorsed the recommendation through an online survey. RESULTS: In the first Delphi round, consensus was attained on 15 questions. After refining certain items in the second round, consensus was achieved on 23 out of 26 questions. The KHRS first defined AA severity using the severity of alopecia tool (SALT). SALT ≥50 was defined as severe, 20≤ SALT <50 as moderate, and SALT <20 as mild. Moderate AA was considered severe if it meets one or more of the following criteria: dermatology life quality index >10, presence of accompanying eyebrow or eyelash loss, positive hair loss activity, or treatment-refractory AA. CONCLUSION: These consensus criteria can help clinicians accurately diagnose AA, provide appropriate treatment, and monitor its progression.

Predicting Recurrence-Free Survival After Upfront Surgery in Resectable Pancreatic Ductal Adenocarcinoma: A Preoperative Risk Score Based on CA 19-9, CT, and 18F-FDG PET/CT.

OBJECTIVE: To develop and validate a preoperative risk score incorporating carbohydrate antigen (CA) 19-9, CT, and fluorine-18-fluorodeoxyglucose (18F-FDG) PET/CT variables to predict recurrence-free survival (RFS) after upfront surgery in patients with resectable pancreatic ductal adenocarcinoma (PDAC). MATERIALS AND METHODS: Patients with resectable PDAC who underwent upfront surgery between 2014 and 2017 (development set) or between 2018 and 2019 (test set) were retrospectively evaluated. In the development set, a risk-scoring system was developed using the multivariable Cox proportional hazards model, including variables associated with RFS. In the test set, the performance of the risk score was evaluated using the Harrell C-index and compared with that of the postoperative pathological tumor stage. RESULTS: A total of 529 patients, including 335 (198 male; mean age ± standard deviation, 64 ± 9 years) and 194 (103 male; mean age, 66 ± 9 years) patients in the development and test sets, respectively, were evaluated. The risk score included five variables predicting RFS: tumor size (hazard ratio [HR], 1.29 per 1 cm increment; P < 0.001), maximal standardized uptake values of tumor ≥ 5.2 (HR, 1.29; P = 0.06), suspicious regional lymph nodes (HR, 1.43; P = 0.02), possible distant metastasis on 18F-FDG PET/CT (HR, 2.32; P = 0.03), and CA 19-9 (HR, 1.02 per 100 U/mL increment; P = 0.002). In the test set, the risk score showed good performance in predicting RFS (C-index, 0.61), similar to that of the pathologic tumor stage (C-index, 0.64; P = 0.17). CONCLUSION: The proposed risk score based on preoperative CA 19-9, CT, and 18F-FDG PET/CT variables may have clinical utility in selecting high-risk patients with resectable PDAC.

Food passage following proximal gastrectomy with double-tract reconstruction and its effect on nutritional status in early gastric cancer: a prospective single-center cohort study.

Purpose: Laparoscopic proximal gastrectomy with double-tract reconstruction (LPG-DTR) expectedly results in improved nutritional status and less body weight loss than conventional total gastrectomy in upper-third gastric cancer. This study aimed to investigate the food passage patterns following LPG-DTR and its effect on nutritional outcomes up to 1 year after surgery. Methods: This prospective cohort study recruited 10 patients with early gastric cancer scheduled for LPG-DTR. Nutritional indices and body composition were assessed every 3 months up to 12 months. Liquid and solid food transits were evaluated with fluoroscopic upper gastrointestinal study and radionuclide scintigraphy, respectively. Results: At 12 months, patients exhibited a body weight loss of 14.5% ± 3.6%. The main passage routes for liquid and solid foods differed, primarily via the interposed jejunum for liquids, whereas via both tracts for solids. The median half-life of solid food emptying from the remnant distal stomach was 105.1 minutes (range, 50.8-2,194.2 minutes), and duodenal passage of solid food was noted in 9 of 10 patients. Those with gastric half-emptying time >3 hours demonstrated greater weight loss (19.5% ± 1.4% vs. 12.5% ± 1.1%, P = 0.024) and more pronounced reduction in serum albumin levels (-0.5 ± 0.3 g/dL vs. 0.0 ± 0.2 g/dL, P = 0.024) after 12 months. Conclusion: LPG-DTR demonstrated varying food passage patterns depending on the food contents and delayed solid food emptying from the remnant stomach was associated with more substantial weight loss.

Clinical and Radiologic Predictors of Response to Atezolizumab-Bevacizumab in Advanced Hepatocellular Carcinoma.

Purpose: This study aimed to identify clinical and radiologic characteristics that could predict response to atezolizumab-bevacizumab combination therapy in patients with advanced hepatocellular carcinoma (HCC). Materials and Methods: This single-center retrospective study included 108 advanced HCC patients with intrahepatic lesions who were treated with atezolizumab-bevacizumab. Two radiologists independently analyzed Imaging characteristics of the index tumor on pretreatment computed tomography. Predictive factors associated with progressive disease (PD) at the best response based on Response Evaluation Criteria in Solid Tumors, Version 1.1 were evaluated using logistic regression analysis. Progression-free survival (PFS) was estimated by the Kaplan-Meier method and compared with the log-rank test. Results: Of 108 patients with a median PFS of 15 weeks, 40 (37.0%) had PD during treatment. Factors associated with PD included the presence of extrahepatic metastases (adjusted odds ratio [aOR], 4.13; 95% confidence interval [CI], 1.19-14.35; p=0.03), the infiltrative appearance of the tumor (aOR, 3.07; 95% CI, 1.05-8.93; p=0.04), and the absence of arterial phase hyperenhancement (APHE) (aOR, 6.34; 95% CI, 2.18-18.47; p<0.001). Patients with two or more of these factors had a PD of 66.7% and a median PFS of 8 weeks, indicating a significantly worse outcome compared to the patients with one or no of these factors. Conclusion: In patients with advanced HCC treated with atezolizumab-bevacizumab treatment, the absence of APHE, infiltrative appearance of the intrahepatic tumor, and presence of extrahepatic metastases were associated with poor response and survival. Evaluation of early response may be necessary in patients with these factors.

Prognostication of Hepatocellular Carcinoma Using Artificial Intelligence.

Hepatocellular carcinoma (HCC) is a biologically heterogeneous tumor characterized by varying degrees of aggressiveness. The current treatment strategy for HCC is predominantly determined by the overall tumor burden, and does not address the diverse prognoses of patients with HCC owing to its heterogeneity. Therefore, the prognostication of HCC using imaging data is crucial for optimizing patient management. Although some radiologic features have been demonstrated to be indicative of the biologic behavior of HCC, traditional radiologic methods for HCC prognostication are based on visually-assessed prognostic findings, and are limited by subjectivity and inter-observer variability. Consequently, artificial intelligence has emerged as a promising method for image-based prognostication of HCC. Unlike traditional radiologic image analysis, artificial intelligence based on radiomics or deep learning utilizes numerous image-derived quantitative features, potentially offering an objective, detailed, and comprehensive analysis of the tumor phenotypes. Artificial intelligence, particularly radiomics has displayed potential in a variety of applications, including the prediction of microvascular invasion, recurrence risk after locoregional treatment, and response to systemic therapy. This review highlights the potential value of artificial intelligence in the prognostication of HCC as well as its limitations and future prospects.

Fewer Feedback Opportunities and Health Perception of Gastric Cancer Survivors: Opportunities for Patient Education.

This study aimed to estimate the impact of having fewer opportunities for patient education on health perception of gastric cancer survivors by examining quality-of-life (QoL) responses from patients who had been away for chemotherapy for a year. The full-surveillance (FullSV) group was comprised of gastric cancer survivors with stage I cancer who completed preoperative and postoperative 3-, 6-, 9-, and 12-month surveillances. The returning (RTN) group was comprised of 1-year survivors of stage II cancer who had been away for chemotherapy for a year. Surveillance periods were utilized to provide patient education about expected postoperative weight changes. The European Organisation for Research and Treatment of Cancer QoL questionnaires were used to assess QoL. The study included a total of 278 patients (243 in the FullSV group and 35 in the RTN group). The baseline QoL was not significantly different between the groups. Significant differences in postoperative QoL were revealed by some scales (global health status/QoL, physical functioning, fatigue, financial difficulties, anxiety, dry mouth, and body image), all in favor of the FullSV group. Despite no significant difference in their actual weight changes, stronger weight dissatisfaction was revealed among the RTN group. Patients with fewer educational inputs for postoperative adjustment of weight perception were the ones with stronger dissatisfaction about current weight. The health perception of cancer survivors is under the constant influence of clinician feedback during patient education. For the best cancer survivorship care, sufficient opportunities for adjustment of health perception through patient education need to be ensured.

Comparison of the different versions of NCCN guidelines for predicting margin-negative resection of pancreatic cancer in patients undergoing upfront surgery.

OBJECTIVES: The purpose of this study was to compare the different versions of the National Comprehensive Cancer Network (NCCN) guidelines for defining resectability of pancreatic ductal adenocarcinoma (PDAC) in predicting margin-negative (R0) resection, and to assess inter-reader agreement. METHODS: This retrospective study included 283 patients (mean age, 65.1 years ± 9.4 [SD]; 155 men) who underwent upfront pancreatectomy for PDAC between 2017 and 2019. Two radiologists independently determined the resectability on preoperative CT according to the 2017, 2019, and 2020 NCCN guidelines. The sensitivity and specificity for R0 resection were analyzed using a multivariable logistic regression analysis with generalized estimating equations. Inter-reader agreement was assessed using kappa statistics. RESULTS: R0 resection was accomplished in 239 patients (84.5%). The sensitivity and specificity averaged across two readers were, respectively, 76.6% and 29.5% for the 2020 guidelines, 74.1% and 32.9% for the 2019 guidelines, and 72.6% and 34.1% for the 2017 guidelines. Compared with the 2020 guidelines, both 2019 and 2017 guidelines showed significantly lower sensitivity for R0 resection (p ≤ .009). Specificity was significantly higher with the 2017 guidelines (p = .043) than with the 2020 guidelines. Inter-reader agreements for determining the resectability of PDCA were strong (k ≥ 0.83) with all guidelines, being highest with the 2020 guidelines (k = 0.91). CONCLUSION: The 2020 NCCN guidelines showed significantly higher sensitivity for prediction of R0 resection than the 2017 and 2019 guidelines.

Retrograde jejunoduodenogastric intussusception associated with fully functioning nonballoon nasojejunal feeding catheter: A case report.

RATIONALE: Retrograde jejunoduodenogastric intussusception refers to invagination of distal small intestine into the stomach. It is extremely rare. It is often associated with displaced feeding catheter in which its balloon tip migrates past the gastric pylorus. The intussusception is triggered by retraction of migrated catheter. It is often accompanied by feeding intolerance or catheter malfunction. This report describes a distinctive case of retrograde jejunoduodenogastric intussusception associated with a fully functioning nonballoon nasojejunal tube. PATIENT CONCERN: A 19-year-old female was presented with repeated vomiting and abdominal distension for 5 days. DIAGNOSIS: An abdominal computerized tomography revealed retrograde jejunoduodenogastric intussusception causing air/fluid-filled gastric distension. Immediate endoscopic examination revealed a loop of small intestine, protruding through the pylorus. Progressed ischemia of the migrated small bowel loop was confirmed. INTERVENTIONS: At laparotomy, a jejunal loop migrating into the duodenum and stomach at the level of the ligament of Treitz was noticed. After manual reduction of migrated bowel, 2 segmental resections of necrotic segment were performed. A feeding jejunostomy was constructed in the proximal jejunum. OUTCOMES: Enteral feeding through the surgically constructed feeding jejunostomy was started on the 5th operative day and the patient was discharged on the 16th postoperative day. LESSONS: When a patient under tube feeding exhibits abrupt intractable gastroesophageal reflux with a sign of catheter migration, we must consider the possibility of catheter-related intussusception. Having a fully functioning feeding catheter with nonballoon tip does not preclude retrograde jejunoduodenogastric intussusception.

Utilizing 3D Point Cloud Technology with Deep Learning for Automated Measurement and Analysis of Dairy Cows.

This paper introduces an approach to the automated measurement and analysis of dairy cows using 3D point cloud technology. The integration of advanced sensing techniques enables the collection of non-intrusive, precise data, facilitating comprehensive monitoring of key parameters related to the health, well-being, and productivity of dairy cows. The proposed system employs 3D imaging sensors to capture detailed information about various parts of dairy cows, generating accurate, high-resolution point clouds. A robust automated algorithm has been developed to process these point clouds and extract relevant metrics such as dairy cow stature height, rump width, rump angle, and front teat length. Based on the measured data combined with expert assessments of dairy cows, the quality indices of dairy cows are automatically evaluated and extracted. By leveraging this technology, dairy farmers can gain real-time insights into the health status of individual cows and the overall herd. Additionally, the automated analysis facilitates efficient management practices and optimizes feeding strategies and resource allocation. The results of field trials and validation studies demonstrate the effectiveness and reliability of the automated 3D point cloud approach in dairy farm environments. The errors between manually measured values of dairy cow height, rump angle, and front teat length, and those calculated by the auto-measurement algorithm were within 0.7 cm, with no observed exceedance of errors in comparison to manual measurements. This research contributes to the burgeoning field of precision livestock farming, offering a technological solution that not only enhances productivity but also aligns with contemporary standards for sustainable and ethical animal husbandry practices.

Multiplexable and Scalable Aqueous Synthesis Platform for Oleate-Based, Bilayer-Coated Gold Nanoparticles.

Despite gold-based nanomaterials having a unique role in nanomedicine, among other fields, synthesis limitations relating to reaction scale-up and control result in prohibitively high gold nanoparticle costs. In this work, a new preparation procedure for lipid bilayer-coated gold nanoparticles in water is presented, using sodium oleate as reductant and capping agent. The seed-free synthesis not only allows for size precision (8-30 nm) but also remarkable particle concentration (10 mm Au). These reaction efficiencies allow for multiplexing and reaction standardization in 96-well plates using conventional thermocyclers, in addition to simple particle purification via microcentrifugation. Such a multiplexing approach also enables detailed spectroscopic investigation of the nonlinear growth process and dynamic sodium oleate/oleic acid self-assembly. In addition to scalability (at gram-level), resulting gold nanoparticles are stable at physiological pH, in common cell culture media, and are autoclavable. To demonstrate the versatility and applicability of the reported method, a robust ligand exchange with thiolated polyethylene glycol analogues is also presented.

All lactose-oxidizing enzymes of Pseudomonas taetrolens, a highly efficient lactobionic acid-producing microorganism, are pyrroloquinoline quinone-dependent enzymes.

In previous and present studies, four enzymes (GCD1, GCD3, GCD4, and MQO1) have been found to act as lactose-oxidizing enzymes of Pseudomonas taetrolens. To investigate whether the four enzymes were the only lactose-oxidizing enzymes of P. taetrolens, we performed the inactivation of gcd1, gcd3, gcd4, and mqo1 genes in P. taetrolens. Compared to the wild-type strain, the lactobionic acid (LBA)-producing ability of P. taetrolens ∆gcd1 ∆gcd3 ∆gcd4 ∆mqo1 was only slightly decreased, implying that P. taetrolens possesses more lactose-oxidizing enzymes. Interestingly, the four lactose-oxidizing enzymes were all pyrroloquinoline quinone (PQQ)-dependent. To identify other unidentified lactose-oxidizing enzymes of P. taetrolens, we prevented the synthesis of PQQ in P. taetrolens by inactivating the genes related to PQQ synthesis such as pqqC, pqqD, and pqqE. Surprisingly, all three knocked-out strains were unable to convert lactose to LBA, indicating that all lactose-oxidizing enzymes in P. taetrolens were inactivated by eliminating PQQ synthesis. In addition, external PQQ supplementation restored the LBA production ability of P. taetrolens ∆pqqC, comparable to the wild-type strain. These results indicate that all lactose-oxidizing enzymes in P. taetrolens are PQQ-dependent.

Korean Cattle 3D Reconstruction from Multi-View 3D-Camera System in Real Environment.

The rapid evolution of 3D technology in recent years has brought about significant change in the field of agriculture, including precision livestock management. From 3D geometry information, the weight and characteristics of body parts of Korean cattle can be analyzed to improve cow growth. In this paper, a system of cameras is built to synchronously capture 3D data and then reconstruct a 3D mesh representation. In general, to reconstruct non-rigid objects, a system of cameras is synchronized and calibrated, and then the data of each camera are transformed to global coordinates. However, when reconstructing cattle in a real environment, difficulties including fences and the vibration of cameras can lead to the failure of the process of reconstruction. A new scheme is proposed that automatically removes environmental fences and noise. An optimization method is proposed that interweaves camera pose updates, and the distances between the camera pose and the initial camera position are added as part of the objective function. The difference between the camera's point clouds to the mesh output is reduced from 7.5 mm to 5.5 mm. The experimental results showed that our scheme can automatically generate a high-quality mesh in a real environment. This scheme provides data that can be used for other research on Korean cattle.

Harnessing the potential of in-situ, electrically generated microbubbles via nickel foam for enhanced, low energy membrane fouling control.

For membrane-based, water treatment technologies, fouling remains a significant challenge for pressure-driven processes. While many antifouling strategies have been proposed, there remains significant room for improved efficiency. Direct application of microbubbles (MBs) at a membrane surface offers a promising approach for managing interfacial fouling through continuous physical interaction(s). Despite such potential, to date, integration and optimization of in-situ generated MBs at the membrane interface that are both highly antifouling with minimal energy inputs and unwanted side reactions remains mostly outstanding. Here we demonstrate the application of conductive, porous nickel foam for electrolysis-based generation of hydrogen microbubbles at an ultra-filtration (UF) membrane interface, which significantly mitigates membrane fouling for a range of model foulants. System characterization and optimization includes comparison of metal foams (Ni, Cu, Ti), faradic efficiencies, hydrogen evolution reaction (HER) curves, cyclic voltammetry, and quantification of hydrogen gas flux and bubble size, as a function of applied current. When optimized, we report rapid (<5 min) and near complete (∼99 %) flux recovery for three classes of foulants, including calcium alginate, humic acid (HA), and SiO2 particles. For all, the described MB-based approach is orders of magnitude more energy efficient when compared to conventional cleaning strategies. Finally, we demonstrate the MB-based regeneration/cleaning process is stable and repeatable for ten cycles and also highly effective for a challenge water (as a model oilfield brine). Taken together, this work presents a novel and efficient approach for the application of in-situ electrically generated MBs to support sustainable pressure-driven membrane processes.

Pancreas CT assessment for pancreatic ductal adenocarcinoma resectability: effect of tube voltage and slice thickness on image quality and diagnostic performance.

OBJECTIVES: To assess the resectability of pancreatic ductal adenocarcinoma (PDAC), the evaluation of tumor vascular contact holds paramount significance. This study aimed to compare the image quality and diagnostic performance of high-resolution (HR) pancreas computed tomography (CT) using an 80 kVp tube voltage and a thin slice (1 mm) for assessing PDAC resectability, in comparison with the standard protocol CT using 120 kVp. METHODS: This research constitutes a secondary analysis originating from a multicenter prospective study. All participants underwent both the standard protocol pancreas CT using 120 kVp with 3 mm slice thickness (ST) and HR-CT utilizing an 80 kVp tube voltage and 1 mm ST. The contrast-to-noise ratio (CNR) between parenchyma and tumor, along with the degree of enhancement of the abdominal aorta and main portal vein (MPV), were measured and subsequently compared. Additionally, the likelihood of margin-negative resection (R0) was evaluated using a five-point scale. The diagnostic performance of both CT protocols in predicting R0 resection was assessed through the area under the receiver operating characteristic curve (AUC). RESULTS: A total of 69 patients (37 males and 32 females; median age, 66.5 years) were included in the study. The median CNR of PDAC was 10.4 in HR-CT, which was significantly higher than the 7.1 in the standard CT (P=0.006). Furthermore, HR-CT demonstrated notably higher median attenuation values for both the abdominal aorta (579.5 HU vs. 327.2 HU; P=0.002) and the MPV (263.0 HU vs. 175.6 HU; P=0.004) in comparison with standard CT. Following surgery, R0 resection was achieved in 51 patients. The pooled AUC for HR-CT in predicting R0 resection was 0.727, slightly exceeding the 0.699 of standard CT, albeit lacking a significant statistical distinction (P=0.128). CONCLUSION: While HR pancreas CT using 80 kVp offered a notably greater degree of contrast enhancement in vessels and a higher CNR for PDAC compared to standard CT, its diagnostic performance in predicting R0 resection remained statistically comparable.

Large Duct Pancreatic Ductal Adenocarcinoma: A Morphological Variant of Pancreatic Ductal Adenocarcinoma With Distinct CT and MRI Characteristics.

OBJECTIVE: To investigate the imaging characteristics of large duct pancreatic ductal adenocarcinoma (LD-PDAC) on computed tomography (CT) and magnetic resonance imaging (MRI). MATERIALS AND METHODS: Thirty-five patients with LD-PDAC (63.2 ± 9.7 years) were retrospectively evaluated. Tumor morphology on CT and MRI (predominantly solid mass vs. solid mass with prominent cysts vs. predominantly cystic mass) was evaluated. Additionally, the visibility, quantity, shape (oval vs. branching vs. irregular), and MRI signal intensity of neoplastic cysts within the LD-PDAC were investigated. The radiological diagnoses rendered for LD-PDAC in radiology reports were reviewed. RESULTS: LD-PDAC was more commonly observed as a solid mass with prominent cysts (45.7% [16/35] on CT and 37.1% [13/35] on MRI) or a predominantly cystic mass (20.0% [7/35] on CT and 40.0% [14/35] on MRI) and less commonly as a predominantly solid mass on CT (34.3% [12/35]) and MRI (22.9% [8/35]). The tumor morphology on imaging was significantly associated with the size of the cancer gland on histopathological examination (P = 0.020 [CT] and 0.013 [MRI]). Neoplastic cysts were visible in 88.6% (31/35) and 91.4% (32/35) of the LD-PDAC cases on CT and MRI, respectively. The cysts appeared as branching (51.6% [16/35] on CT and 59.4% [19/35] on MRI) or oval shapes (45.2% [14/35] on CT and 31.2% [10/35] on MRI) with fluid-like MRI signal intensity. In the radiology reports, 10 LD-PDAC cases (28.6%) were misinterpreted as diseases other than typical PDAC, particularly intraductal papillary mucinous neoplasms. CONCLUSION: LD-PDAC frequently appears as a solid mass with prominent cysts or as a predominantly cystic mass on CT and MRI. Radiologists should be familiar with the imaging features of LD-PDAC to avoid misdiagnosis.

CT Rule-in and Rule-out Criteria for Clinically Significant Portal Hypertension in Chronic Liver Disease.

Background The value of CT in assessment of clinically significant portal hypertension (CSPH) has not been well determined. Purpose To evaluate the performance of CT features that have been associated with portal hypertension for diagnosing CSPH in patients with chronic liver disease (CLD). Materials and Methods This retrospective study included patients with CLD who underwent contrast-enhanced CT and subsequent hepatic venous pressure gradient (HVPG) measurement within 3 months at two tertiary institutions from January 2001 to December 2019. Two readers independently evaluated the presence of gastroesophageal varix, spontaneous portosystemic shunt (SPSS), and ascites on CT images. Splenomegaly at CT was determined using three methods, as follows: personalized or fixed volume criteria, based on spleen volume as measured by a deep learning algorithm, or manually measured spleen diameter. The diagnostic performance of these findings alone or in combination for detecting CSPH (HVPG ≥10 mm Hg) was evaluated. Results A total of 235 patients (mean age, 53.2 years ± 13.0 [SD]; 155 male patients), including 110 (46.8%) with CSPH, were included. Detection of CSPH according to the presence of both splenomegaly and at least one other CT feature (ie, gastroesophageal varix, SPSS, and ascites) achieved specificities of 94.4%-97.6%, whereas detection of CSPH according to the presence of any feature (ie, splenomegaly, gastroesophageal varix, SPSS, or ascites) achieved sensitivities of 94.5%-98.2%. When employing the former as rule-in criteria with the absence of splenomegaly, gastroesophageal varix, SPSS, and ascites as rule-out criteria for CSPH, 171-185 (range, 72.8%-78.7%) of 235 patients were correctly classified as either having CSPH or not, seven to 13 (range, 3%-5.5%) of 235 patients were incorrectly classified, and 42-54 (range, 17.9%-23%) of 235 patients were unclassified. Conclusion The presence or absence of splenomegaly, gastroesophageal varix, SPSS, and/or ascites on CT images may be useful for ruling in and ruling out CSPH in patients with CLD. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Fraum in this issue.