Abdominal MRI Research Articles

Diagnostic performance of quantitative ultrasonography for hepatic steatosis in a health screening program: a prospective single-center study.

This study compared the diagnostic performance of quantitative ultrasonography (QUS) with that of conventional ultrasonography (US) in assessing hepatic steatosis among individuals undergoing health screening using magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) as the reference standard. This single-center prospective study enrolled 427 participants who underwent abdominal MRI and US. Measurements included the attenuation coefficient in tissue attenuation imaging (TAI) and the scatter-distribution coefficient in tissue scatter-distribution imaging (TSI). The correlation between QUS and MRI-PDFF was evaluated. The diagnostic capabilities of QUS, conventional B-mode US, and their combined models for detecting hepatic fat content of ≥5% (MRI-PDFF ≥5%) and ≥10% (MRI-PDFF ≥10%) were compared by analyzing the areas under the receiver operating characteristic curves. Additionally, clinical risk factors influencing the diagnostic performance of QUS were identified using multivariate linear regression analyses. TAI and TSI were strongly correlated with MRI-PDFF (r=0.759 and r=0.802, respectively; both P<0.001) and demonstrated good diagnostic performance in detecting and grading hepatic steatosis. The combination of QUS and B-mode US resulted in the highest areas under the ROC curve (AUCs) (0.947 and 0.975 for detecting hepatic fat content of ≥5% and ≥10%, respectively; both P<0.05), compared to TAI, TSI, or B-mode US alone (AUCs: 0.887, 0.910, 0.878 for ≥5% and 0.951, 0.922, 0.875 for ≥10%, respectively). The independent determinants of QUS included skinliver capsule distance (β=7.134), hepatic fibrosis (β=4.808), alanine aminotransferase (β=0.202), triglyceride levels (β=0.027), and diabetes mellitus (β=3.710). QUS is a useful and effective screening tool for detecting and grading hepatic steatosis during health checkups.

A Prospective Study of the Diagnostic Performance of Photon-Counting CT Compared With MRI in the Characterization of Renal Masses.

The aim of this study was to assess the interreader reliability and per-RCC sensitivity of high-resolution photon-counting computed tomography (PCCT) in the detection and characterization of renal masses in comparison to MRI. This prospective study included 24 adult patients (mean age, 52 ± 14 years; 14 females) who underwent PCCT (using an investigational whole-body CT scanner) and abdominal MRI within a 3-month time interval and underwent surgical resection (partial or radical nephrectomy) with histopathology (n = 70 lesions). Of the 24 patients, 17 had a germline mutation and the remainder were sporadic cases. Two radiologists (R1 and R2) assessed the PCCT and corresponding MRI studies with a 3-week washout period between reviews. Readers recorded the number of lesions in each patient and graded each targeted lesion's characteristic features, dimensions, and location. Data were analyzed using a 2-sample t test, Fisher exact test, and weighted kappa. In patients with von Hippel-Lindau mutation, R1 identified a similar number of lesions suspicious for neoplasm on both modalities (51 vs 50, P = 0.94), whereas R2 identified more suspicious lesions on PCCT scans as compared with MRI studies (80 vs 56, P = 0.12). R1 and R2 characterized more lesions as predominantly solid in MRIs (R1: 58/70 in MRI vs 52/70 in PCCT, P < 0.001; R2: 60/70 in MRI vs 55/70 in PCCT, P < 0.001). R1 and R2 performed similarly in detecting neoplastic lesions on PCCT and MRI studies (R1: 94% vs 90%, P = 0.5; R2: 73% vs 79%, P = 0.13). The interreader reliability and per-RCC sensitivity of PCCT scans acquired on an investigational whole-body PCCT were comparable to MRI scans in detecting and characterizing renal masses. PCCT scans have comparable performance to MRI studies while allowing for improved characterization of the internal composition of lesions due to material decomposition analysis. Future generations of this imaging modality may reveal additional advantages of PCCT over MRI.

Self-support matching networks with multiscale attention for few-shot semantic segmentation

Recent advancements in Few-shot segmentation (FSS) have displayed remarkable capabilities in predicting segmentation masks for unseen class images, using only a limited number of annotated images. However, existing methods have overlooked the influence of contextual information on segmentation and primarily rely on supporting prototypes, with limited research on query prototyping. Effectively utilizing multi-scale features and query information poses a challenging problem in this domain. To address these challenges, this paper proposes a novel approach called the multi-scale and attention-based self-support prototype few-shot semantic segmentation network (MASNet). First, a multi-scale feature enhancement module is designed to obtain features at different scales to enrich global context information. Then, simple and efficient channel attention is utilized to guide the query features related to the target class. Finally, the query prototype is matched with the query features using a self-supporting matching module. This strategy efficiently captures class-based features and addresses the issue of intra-class variance in few-shot segmentation. The experimental results on Pascal-5i, COCO-20i and Abdominal MRI datasets demonstrate that the proposed method achieves remarkable robustness and improved accuracy performance.

A case of Osler-Weber-Rendu syndrome, diagnosed at geriatric age, presenting with gastrointestinal bleeding, telangiectasias, and asymptomatic liver and lung angiodysplasia

Abstract Background Osler-Weber-Rendu syndrome (OWRS) is an autosomal dominant disease with recurrent epistaxis, mucocutaneous telangiectasias, and arteriovenous malformations. Its clinical presentation ranges from simple skin lesions to life-threatening complications. When the diagnosis of the disease is delayed, it can be mortal and have high morbidity. This case is presented because OWRS is rare, and although she has all the features of the disease, she was diagnosed in the geriatric age group. Case presentation A 72-year-old female patient who applied to the emergency department with the complaint of melena was diagnosed with upper gastrointestinal system bleeding. Gastroscopy revealed angiodysplasia in the bulb. Colonoscopy was normal. She had telangiectasias on her face, maxilla, nose, tongue and lips. She also had recurrent epistaxis and a family history. Thorax CT showed aneurysmatic vascular malformations in the lung. Abdominal MRI revealed vascular malformations in the liver. Brain MRI was normal. The patient was diagnosed with OWRS according to the Curaçao diagnostic criteria because of telangiectasia in the mouth, nose, and face, angiodysplasia in the gastric bulb, aneurysmatic vascular dilatation in the lung, vascular pathologies in the liver, and a history of epistaxis and telangiectasia in the patient’s family members. Conclusion This patient is presented because OWRS is rare, and although she has all the features of the disease, she was diagnosed in the geriatric age group. Clinicians should be aware of this rare disease. Especially in the elderly, when angiodysplasia causing gastrointestinal bleeding is detected, it should be considered in the differential diagnosis that this may be an OWSR case.

Unsupervised Multi-parametric MRI Registration Using Neural Optimal Transport.

Precise deformable image registration of multi-parametric MRI sequences is necessary for radiologists in order to identify abnormalities and diagnose diseases, such as prostate cancer and lymphoma. Despite recent advances in unsupervised learning-based registration, volumetric medical image registration that requires considering the variety of data distributions is still challenging. To address the problem of multi-parametric MRI sequence data registration, we propose an unsupervised domain-transported registration method, called OTMorph by employing neural optimal transport that learns an optimal transport plan to map different data distributions. We have designed a novel framework composed of a transport module and a registration module: the former transports data distribution from the moving source domain to the fixed target domain, and the latter takes the transported data and provides the deformed moving volume that is aligned with the fixed volume. Through end-to-end learning, our proposed method can effectively learn deformable registration for the volumes in different distributions. Experimental results with abdominal multi-parametric MRI sequence data show that our method has superior performance over around 67-85% in deforming the MRI volumes compared to the existing learning-based methods. Our method is generic in nature and can be used to register inter-/intra-modality images by mapping the different data distributions in network training.

Magnetic Resonance Imaging in Objective Response Evaluation in Klatskin Tumor Patients after Endobiliary Photodynamic Therapy

Purpose: Visualization of periductal infiltrative hilar cholangiocarcinomas in general and their changes in response to endobiliary photodynamic therapy (PDT) in particular is not an easy diagnostic task because of their small size, infiltrative growth pattern, and absence of clearly circumscribed margins with adjacent tissue. This caused most researchers to give up the study of criteria for objective response to locoregional treatment, and to use only the survival rate as performance criteria. The aim of this study is to determine the criteria of objective response in Klatskin tumor after PDT based on the analysis of preand postoperative MRI.Material and methods: The study covered 42 patients (26 male (62 %) and 16 female (38 %)) with morphologically verified Klatskin tumor aged 21-76 (median 55) after 104 sessions (from 1 to 10, median 2) of percutaneous endobiliary PDT over the period of 2007-2020. All patients had percutaneous transhepatic or intraoperative drainage of bile ducts from 1 week to 2 years before PDT. Chlorine photosensitizers were used for PDT. The LAHTA-MILON programmable laser unit with 662 nm wavelength was used for photo-irradiation. The specific dose varied from 4.6 to 232,2 J/cm2 (median 29) and the total dose was 64.6-3890 J (median 950), depending on the extent of lesion and the patient’s tolerance to interventions. 220 abdominal MRI were done at various times before and after PDT. Preoperative MRI were completed 1-101 days (median 13.5 days) before the intervention. Postoperative MRI scans were split into groups based on the time following the intervention: 1) after 1–5 days, 2) after 2 months, 3) after 3 months, and 4) after 4 months. Examinations were carried out with the Siemens Magnetom Avanto/Espree 1.5 Tesla MRI scanner. To compare the indicators at different times, the Kruskal–Wallis test was used, p &lt; 0.05 were considered significant.Results: As a result of the analysis, the following statistically significant changes in the Klatskin tumor after PDT were obtained at various times: the largest transverse size of the tumor infiltrate decrease at the proximal hepaticocholedochus level 1 month after PDT; the infiltrate longitudinal size increase at the bile ducts confluence level 4 month after PDT; T2-WI signal intensity increase at the photodynamic area in 1–5 days after PDT; T1-WI signal intensity decrease in various contrasting phases at the photodynamic area in 1–5 days after PDT; ADC signal intensity increase at the photodynamic and conditionally healthy tissues areas 1 month after PDT; T1-WI signal intensity increase in venous and delayed contrasting phases at the photodynamic area 1 month after PDT; T1-WI signal intensity decrease in porto-venous and delayed contrasting phases at the photodynamic area 2 month after PDT; ADC signal intensity decrease at conditionally healthy tissues 4 month after PDT.Conclusion: Changes in MR signal intensity after endobiliary PDT with different pulse sequences (DWI + ADC, T2-WI with and without suppression of signal from adipose tissue, T1-WI before and after intravenous injection of contrast agent in 4 phases of contrasting) in pathological and conditionally healthy intraand periductal tissues and the tumor dimensions (largest crosssectional dimensions and thickness measured in axial and coronal projections in T2-WI) may be used as the criteria of objective response. Determination in the early postoperative period of periductal segments in the area of photodynamic treatment that do not accumulate contrast agent is the most informative, displayable and convenient for practical use criterion of objective response indicating the ischemia of tumor tissue.

The Impact of Body Fat Distribution on COVID-19 Vaccine Response: An MRI-Based Study

Objective: Subcutaneous and visceral adipose tissue have distinct physiological roles. The correlation between the amount of visceral tissue and the immunity response following vaccination remains unclear, despite its known effects on immunity. The purpose of this study is to examine the relationship between SARS-CoV-2 IgG antibody levels after vaccination and body fat tissue values measured using a specialized software on specific magnetic resonance imaging sequences.&#x0D; Methods: After ethics committee approval, prospectively 60 volunteers (27 males, 33 females; median age of 33 years) were vaccinated with inactivated SARS-CoV-2 vaccine and tested for IgG levels. Abdominal MRI was performed to measure subcutaneous and visceral fat tissue areas using a semiautomatic application.&#x0D; Results: The median value of IgG antibody titers after vaccination was 1039 (113 – 6613). Median subcutaneous adipose tissue(cm2), visceral adipose tissue (cm2), SAT index (SATI) (cm2/m2), VAT index (VATI) (cm2/m2), total fat area (TFA) (cm2), and SAT/VAT (cm2) were 178.5 (38.1-552.5), 51.5 (7.1-273.2), 61.4 (14.3-213.1), 19.1 (2.7-90.6), 251.3 (45.3-683.2), and 3.3 (0.4-12.3) respectively. There was no significant&#x0D; correlation between the adipose tissue measurements and antibody titers (p&gt;.05).&#x0D; Conclusion: This study demonstrated that automated software can efficiently and accurately evaluate body fat distribution using MRI. However, the results showed no significant association between fat distribution and the immunization response to the SARS-CoV-2 vaccine.

Endoscopic loco-regional treatment in controlling pancreatic neuroendocrine tumors (PNETs) behavior: a case series and literature review.

Pancreatic neuroendocrine tumors (PNETs) are considered rare pancreatic neoplasms, and it is a challenging disease entity due to its indolent behavior and is difficult to manage. Diagnostic challenge is usually found in the imaging-based approach, such as transabdominal ultrasound, abdominal CT scan, and abdominal MRI. Surgery is still the main key player in controlling the disease. The main problems in clinical practice are the early detection of small PNETs lesion and non-functional PNET (NF-PNET) cases. Most cases usually come with large tumor size or metastatic disease. Endoscopic ultrasound (EUS) has been well-known as the most sensitive tool for early detection of pancreatic malignancy. It has now also been developed for managing pancreatic cancer, such as tumor ablation therapy. We presented four variety of PNETs cases (one patient with non-functioning PNETs and three patients with functioning PNETs) who have been successfully treated with EUS-guided radiofrequency ablation (RFA) with good control of tumor growth during follow-up. One patient with a large-size insulinoma could have the tumor controlled gradually after several EUS-RFA sessions. No adverse events or major complications were observed during and after the EUS-RFA procedure. EUS has been shown as a promising tool not only for more accurate diagnosis but also for tumor growth control. However, it would need further comparison studies between EUS and surgical approaches to make a better treatment strategy.

Investigating the associations between lumbar paraspinal muscle health and age, BMI, sex, physical activity, and back pain using an automated computer-vision model: a UK Biobank study

Background contextThe role of lumbar paraspinal muscle health in back pain (BP) is not straightforward. Challenges in this field have included the lack of tools and large, heterogenous datasets to interrogate the association between muscle health and BP. Computer-vision models have been transformative in this space, enabling the automated quantification of muscle health and the processing of large datasets. PurposeTo investigate the associations between lumbar paraspinal muscle health and age, sex, BMI, physical activity, and BP in a large, heterogenous dataset using an automated computer-vision model. DesignCross-sectional study. Patient sampleParticipants from the UK Biobank with abdominal Dixon fat-water MRI (N=9,564) were included (41.8% women, mean [SD] age: 63.5 [7.6] years, BMI: 26.4 [4.1] kg/m2) of whom 6,953 reported no pain, 930 acute BP, and 1,681 chronic BP. Outcome measuresIntramuscular fat (IMF) and average cross-sectional area (aCSA) were automatically derived using a computer-vision model for the left and right lumbar multifidus (LM), erector spinae (ES), and psoas major (PM) from the L1 to L5 vertebral levels. MethodsTwo-tailed partial Pearson correlations were generated for each muscle to assess the relationships between the muscle measures (IMF and aCSA) and age (controlling for BMI, sex, and physical activity), BMI (controlling for age, sex, and physical activity), and physical activity (controlling for age, sex, and BMI). One-way ANCOVA was used to identify sex differences in IMF and aCSA for each muscle while controlling for age, BMI, and physical activity. Similarly, one-way ANCOVA was used to identify between-group differences (no pain, acute BP, and chronic BP) for each muscle and along the superior-inferior expanse of the lumbar spine while controlling for age, BMI, sex, and physical activity (α=0.05). ResultsFemales had higher IMF (LM mean difference [MD]=11.1%, ES MD=10.2%, PM MD=0.3%, p<.001) and lower aCSA (LM MD=47.6 mm2, ES MD=350.0 mm2, PM MD=321.5 mm2, p<.001) for all muscles. Higher age was associated with higher IMF and lower aCSA for all muscles (r≥0.232, p<.001) except for LM and aCSA (r≤0.013, p≥.267). Higher BMI was associated with higher IMF and aCSA for all muscles (r≥0.174, p<.001). Higher physical activity was associated with lower IMF and higher aCSA for all muscles (r≥0.036, p≤.002) except for LM and aCSA (r≤0.010, p≥.405). People with chronic BP had higher IMF and lower aCSA than people with no pain (IMF MD≤1.6%, aCSA MD≤27.4 mm2, p<.001) and higher IMF compared to acute BP (IMF MD≤1.1%, p≤.044). The differences between people with BP and people with no pain were not spatially localized to the inferior lumbar levels but broadly distributed across the lumbar spine. ConclusionsParaspinal muscle health is associated with age, BMI, sex, and physical activity with the exception of the association between LM aCSA and age and physical activity. People with BP (chronic>acute) have higher IMF and lower aCSA than people reporting no pain. The differences were not localized but broadly distributed across the lumbar spine. When interpreting measures of paraspinal muscle health in the research or clinical setting, the associations with age, BMI, sex, and physical activity should be considered.

Bidirectional two-sample mendelian randomization analysis identifies causal associations of MRI-based cortical thickness and surface area relation to NAFLD

BackgroundNon-alcoholic fatty liver disease (NAFLD) patients have exhibited extra-hepatic neurological changes, but the causes and mechanisms remain unclear. This study investigates the causal effect of NAFLD on cortical structure through bidirectional two-sample Mendelian randomization analysis.MethodsGenetic data from 778,614 European individuals across four NAFLD studies were used to determine genetically predicted NAFLD. Abdominal MRI scans from 32,860 UK Biobank participants were utilized to evaluate genetically predicted liver fat and volume. Data from the ENIGMA Consortium, comprising 51,665 patients, were used to evaluate the associations between genetic susceptibility, NAFLD risk, liver fat, liver volume, and alterations in cortical thickness (TH) and surface area (SA). Inverse-variance weighted (IVW) estimation, Cochran Q, and MR-Egger were employed to assess heterogeneity and pleiotropy.ResultsOverall, NAFLD did not significantly affect cortical SA or TH. However, potential associations were noted under global weighting, relating heightened NAFLD risk to reduced parahippocampal SA and decreased cortical TH in the caudal middle frontal, cuneus, lingual, and parstriangularis regions. Liver fat and volume also influenced the cortical structure of certain regions, although no Bonferroni-adjusted p-values reached significance. Two-step MR analysis revealed that liver fat, AST, and LDL levels mediated the impact of NAFLD on cortical structure. Multivariable MR analysis suggested that the impact of NAFLD on the cortical TH of lingual and parstriangularis was independent of BMI, obesity, hyperlipidemia, and diabetes.ConclusionThis study provides evidence that NAFLD causally influences the cortical structure of the brain, suggesting the existence of a liver-brain axis in the development of NAFLD.

Fast MRI Techniques for Abdominal Imaging Simplified: Part 1—Making Sense of It All

Motion is a major limiting factor in abdominal MRI. Scan time is related to MR signal acquisition and k-space filling. K-space is the raw data matrix that stores digitized MR signal, which is Fourier transformed into an image. So rapid signal acquisition, reduced k-space filling, and partial Fourier techniques can reduce scan time. This article aims to provide a simplified explanation of the physics behind various techniques for fast abdominal MRI.

Hemorrhagic Hepatic Cyst Mimicking a Cystic Neoplasm: Case Report

Background: Intracystic hemorrhage is an extremely rare complication of simple hepatic cysts. Clinical symptomatology is non-specific, and imaging frequently mimics a biliary cystadenoma or cystadenocarcinoma, which makes it challenging from a diagnostic point of view to an appropriate therapeutic approach. In this report, we present a case of a simple hemorrhagic hepatic cyst mimicking a cystic neoplasm. Case Report: 48-year-old men was referred to our hospital for periumbilical abdominal pain with asthenia and 11 kg weight loss. His physical examination and laboratory findings were unremarkable. Carcinoembryonic antigen concentration was three times higher than normal. Abdominal ultrasonography demonstrated an impure cystic mass measuring 120 x 96 x 108 mm on hepatic segments VI and VII. Abdominal CT showed a cystic mass at the liver possibly related to a cystadenocarcinoma. Abdominal MRI revealed a cystic mass with lobulated contours, located in segments VII, VIII and part of VI, measuring 11.8 x11.4 cm long axis, heterogeneous signal with intense fluid towards the top in T1 and T2 and intense fluid towards the decline in T2 and T1, with the appearance of a small inferior septum slightly enhanced after injection. These findings did not exclude the possibility of malignant cystic tumor, such as biliary cystadenocarcinoma. Therefore, endoscopic ultrasound showed a cystic lesion developing in the liver, with a thickened wall in places, mainly adjacent to an intracystic nodule of 25 mm, this nodule continued with the wall. Biopsy performed using a 22G ultrasound. Aspiration of liquid: string test negative. Pathological examination confirmed a hemorrhagic biliary cyst and there was no tumor tissue. We observed a significant improvement in symptoms and reduction in cyst size after needle aspiration and we decided to adopt a conservative approach. The patient was followed and one year later, the patient remained in good condition without any complaints. ................

Comparison of the accuracy of commercial two-point and multi-echo Dixon MRI for quantification of fat in liver, paravertebral muscles, and vertebral bone marrow

PurposeExcess fat accumulation contributes significantly to metabolic dysfunction and diseases. This study aims to systematically compare the accuracy of commercially available Dixon techniques for quantification of fat fraction in liver, skeletal musculature, and vertebral bone marrow (BM) of healthy individuals, investigating biases and sex-specific influences. Method100 healthy White individuals (50 women) underwent abdominal MRI using two-point and multi-echo Dixon sequences. Fat fraction (FF), proton density fat fraction (PDFF) and T2* values were calculated for liver, paravertebral muscles (PVM) and vertebral BM (Th8–L5). Agreement and systematic deviations were assessed using linear correlation and Bland-Altman plots. ResultsHigh correlations between FF and PDFF were observed in liver (r = 0.98 for women; r = 0.96 for men), PVM (r = 0.92 for women; r = 0.93 for men) and BM (r = 0.97 for women; r = 0.95 for men). Relative deviations between FF and PDFF in liver (18.92 % for women; 13.32 % for men) and PVM (1.96 % for women; 11.62 % for men) were not significant. Relative deviations in BM were significant (38.13 % for women; 27.62 % for men). Bias correction using linear models reduced discrepancies. T2* times were significantly shorter in BM (8.72 ms for women; 7.26 ms for men) compared to PVM (13.45 ms for women; 13.62 ms for men) and liver (29.47 ms for women; 26.35 ms for men). ConclusionWhile no significant differences were observed for liver and PVM, systematic errors in BM FF estimation using two-point Dixon imaging were observed. These discrepancies – mainly resulting from organ-specific T2* times – have to be considered when applying two-point Dixon approaches for assessment of fat content. As suitable correction tools, linear models could provide added value in large-scale epidemiological cohort studies. Sex-specific differences in T2* should be considered.

Leisure time physical activity is associated with improved diastolic heart function and is partly mediated by unsupervised quantified metabolic health

ObjectivesTo investigate the association between leisure time physical activity (LTPA) and MRI-based diastolic function and the mediating role of metabolic health.MethodsThis cross-sectional analysis comprised 901 participants (46% women, mean age...

Robust Deformable Image Registration Using Cycle-Consistent Implicit Representations.

Recent works in medical image registration have proposed the use of Implicit Neural Representations, demonstrating performance that rivals state-of-the-art learning-based methods. However, these implicit representations need to be optimized for each new image pair, which is a stochastic process that may fail to converge to a global minimum. To improve robustness, we propose a deformable registration method using pairs of cycle-consistent Implicit Neural Representations: each implicit representation is linked to a second implicit representation that estimates the opposite transformation, causing each network to act as a regularizer for its paired opposite. During inference, we generate multiple deformation estimates by numerically inverting the paired backward transformation and evaluating the consensus of the optimized pair. This consensus improves registration accuracy over using a single representation and results in a robust uncertainty metric that can be used for automatic quality control. We evaluate our method with a 4D lung CT dataset. The proposed cycle-consistent optimization method reduces the optimization failure rate from 2.4% to 0.0% compared to the current state-of-the-art. The proposed inference method improves landmark accuracy by 4.5% and the proposed uncertainty metric detects all instances where the registration method fails to converge to a correct solution. We verify the generalizability of these results to other data using a centerline propagation task in abdominal 4D MRI, where our method achieves a 46% improvement in propagation consistency compared with single-INR registration and demonstrates a strong correlation between the proposed uncertainty metric and registration accuracy.

Association between type 2 diabetes mellitus and body composition based on MRI fat fraction mapping.

To explore the association between type 2 diabetes mellitus (T2DM) and body composition based on magnetic resonance fat fraction (FF) mapping. A total of 341 subjects, who underwent abdominal MRI examination with FF mapping were enrolled in this study, including 68 T2DM patients and 273 non-T2DM patients. The FFs and areas of visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and abdominal muscle (AM) were measured at the level of the L1-L2 vertebral. The FF of bone marrow adipose tissue (BMAT) was determined by the averaged FF values measured at the level of T12 and L1 vertebral, respectively. The whole hepatic fat fraction (HFF) and pancreatic fat fraction (PFF) were measured based on 3D semi-automatic segmentation on the FF mapping. All data were analyzed by GraphPad Prism and MedCalc. VAT area, VAT FF, HFF, PFF of T2DM group were higher than those of non-T2DM group after adjusting for age and sex (P < 0.05). However, there was no differences in SAT area, SAT FF, BMAT FF, AM area and AM FF between the two groups (P > 0.05). VAT area and PFF were independent risk factors of T2DM (all P < 0.05). The area under the curve (AUC) of the receiver operating characteristic (ROC) for VAT area and PFF in differentiating between T2DM and non-T2DM were 0.685 and 0.787, respectively, and the AUC of PFF was higher than VAT area (P < 0.05). Additionally, in seemingly healthy individuals, the SAT area, VAT area, and AM area were found to be significantly associated with being overweight and/or obese (BMI ≥ 25) (all P < 0.05). In this study, it was found that there were significant associations between T2DM and VAT area, VAT FF, HFF and PFF. In addition, VAT area and PFF were the independent risk factors of T2DM. Especially, PFF showed a high diagnostic performance in discrimination between T2DM and non-T2DM. These findings may highlight the crucial role of PFF in the pathophysiology of T2DM, and it might be served as a potential imaging biomarker of the prevention and treatment of T2DM. Additionally, in individuals without diabetes, focusing on SAT area, VAT area and AM area may help identify potential health risks and provide a basis for targeted weight management and prevention measures.

Radiological characteristics and diagnostic clues for persistent descending mesocolon in patients with rectal cancer.

Persistent descending mesocolon (PDM) increases the difficulty and colonic ischemia in the surgery of colorectal cancer, but the preoperative diagnostic criteria have not yet been clearly demonstrated. This study explored the MR imaging features and diagnostic criteria of PDM to improve the preoperative diagnostic rate. The clinical data of 54 patients with PDM and 270 patients without PDM who underwent rectal surgery at the Department of Colorectal Surgery, Fujian Medical University Union Hospital, from March 2018 to December 2022 were analyzed, retrospectively. The radiological parameters of PDM from MRI were analyzed. On MRI T2WI axial image, the left edge of the abdominal aorta was defined as the reference line. The shortest vertical distance between the right edge of the descending colon and this line (dN) and the maximum transverse diameter of the peritoneal cavity (dA) at the same level and the maximum vertical distance between the right edge of the descending colon and this line (dW) were measured. There were significant statistical differences in dN, dW, dN/dW, and dN/dA between the PDM group and the non-PDM group. dN, dN/dW, and dN/dA have high diagnostic performance for the PDM. dN < 4.16cm, dN/dW < 0.52, and dN/dA < 0.15 can all be used as clues to diagnose PDM. We propose a feasible set of diagnostic criteria for PDM based on abdominal MRI, which can quickly and accurately diagnose PDM, and provide some reference for preoperative planning and surgical decision-making.

Staging liver fibrosis: comparison of radiomics model and fusion model based on multiparametric MRI in patients with chronic liver disease.

To develop and compare radiomics model and fusion model based on multiple MR parameters for staging liver fibrosis in patients with chronic liver disease. Patients with chronic liver disease who underwent multiparametric abdominal MRI were included in this retrospective study. Multiparametric MR images were imported into 3D-Slicer software for drawing bounding boxes on MR images. By using a 3D-Slicer extension of SlicerRadiomics, radiomics features were extracted from these MR images. The z-score normalization method was used for post-processing radiomics features. The least absolute shrinkage and selection operator method (LASSO) was performed for selecting significant radiomics features. The logistic regression analysis was used for building the radiomics model. A fusion model was built by integrating serum fibrosis biomarkers of aspartate transaminase-to-platelet ratio index (APRI) and the fibrosis-4 index (FIB-4) with radiomics signatures. In the training cohort, AUCs of radiomics and fusion model were 0.707-0.842 and 0.718-0.854 for differentiating different groups. In the testing cohort, AUCs were 0.514-0.724 and 0.609-0.728. For the training cohort, there was no significantdifference of AUCs between radiomics and fusion model (p > 0.05). For the testing cohort, AUCs of fusion model were higher than those of radiomics model in differentiating F1-3 vs. F4 and F1-2 vs. F4 (p = 0.011 & 0.042). Radiomics model and fusion model based on multiparametric MRI exhibited the feasibility for staging liver fibrosis in patients with CLD, and APRI and FIB-4 could improve the diagnostic performance of radiomics model in differentiatingF1-3 vs. F4 and F1-2 vs. F4.

O-05 A novel mutation of MEN1 gene in familial Multiple Endocrine Neoplasia Type 1 (MEN1): A report of two cases

Abstract Introduction Multiple Endocrine Neoplasia Type 1 (MEN1) is a rare (1-9/100000) autosomal dominant disease. It is characterized by primary hyperparathyroidism (90%), enteropancreatic tumor (60-70%), non-functional adrenal adenomas (30%) and pituitary tumors (10-20%). Herein, we present two cases in the same family with MEN1 syndrome caused by a novel mutation. Clinical Case 1: 49-year-old male presented to our clinic with fasting hypoglycemia. Fasting serum glucose (FSG) was 51 mg/dl and serum cortisol was 18 ug/dl. During the hypoglycemia in prolonged fasting test, the serum levels of glucose, insulin and C-peptide were 37 mg/dl, 17.3 mu/l, 7.75 ng/ml respectively (Table 1). Abdominal MRI revealed mass lesions in the pancreas (Figure 1). Ultrasonography of the neck and MIBI scintigraphy performed because of the high levels of calcium and parathyroid hormone (PTH), were consistent with parathyroid adenoma (Table 2). Pituitary MRI showed a 12 mm macroadenoma. He underwent parathyroidectomy and distal pancreatectomy simultaneously. The resected specimens revealed a well-differentiated neuroendocrine tumor (NET) of the pancreas and parathyroid adenoma. The patient had no new hypoglycemic episodes after surgery and serum calcium remained within the normal range (Table 2). Central hypothyroidism and hypogonadotropic hypogonadism which was resulted from the pressure of the adenoma was managed medically. Genetic testing revealed a heterozygous mutation in NM_001370251.1:c.949del(HET). First degree relatives of the patient were screened for MEN. Clinical Case 2: The son of case 1, an 18-year-old male, presented with fasting hypoglycemia. He had a BMI of 37 kg/m2 and underwent gastric botox 3 months prior to his presentation. FPG was 52 mg/dl and serum cortisol was 20 ug/dl. Prolonged fasting test confirmed the diagnosis of insulinoma (Table 1). Abdominal MRI showed a pancreatic tail mass 37×22 mm in size. Gallium 68 PET/CT DOTATATE revealed increased uptake in multiple lesions in the pancreas. Ultrasonography and MIBI scintigraphy showed a parathyroid adenoma. A nonfunctional microadenoma was detected in pituitary MRI. The patient underwent distal pancreatectomy. Following pancreatectomy, right superior and left inferior parathyroidectomies were performed. Since his serum calcium levels started to increase in 48 hours after the operation, the patient has had second operation for left superior parathyroidectomy. After the operation, the serum calcium and parathyroid hormone levels were 9.2 mg/dl, 58 pg/ml respectively. Specimens revealed well-differentiated NET and atypical parathyroid adenoma. The patient was found to have the same genetic mutation with his father and during the follow up the serum glucose and calcium levels remained within the normal range (Table 2). Conclusion In the genetic examination the heterozygous mutation NM_001370251.1:c.949del(HET) in exon 7/11 of the MEN1 gene found in our patients represents a novel mutation.Figure 1.MRI showing pancreatic masses Table 1.Laboratory findings Table 2.Prolonged fasting test

P-43 Pancreatic insulinoma with delayed challenging diagnosis by 68Ga-DOTATATE PET/CT scan: Case report

Abstract Introduction Insulinoma (I) is most common neuroendocrine pancreatic tumor with an incidence of 0.1-0.3/100000(1). It is faintly more in females and can develop at any age(2). Usually benign, sporadic, less than 2 cm, solitary and in 10% of cases is multiple and happens as a component of multiple endocrine neoplasia syndrome type I (MEN–I)(3). Nonspecific symptoms may lead to delayed or misdiagnosis. Improper insulin secretion causes clinical features of hypoglycemia(2). Laboratory verification, localization followed by surgical removal are the main steps management. Localization may be difficult and delayed as here. Clinical Case A female of 58 years old with episodes of sweating, palpitation and tremor improved by drinking sweets, weight gain and denied any drugs intake. No personal or family history of diabetes or antidiabetic drugs. Body weight was 87 kg. Investigations during the attack showed low plasma glucose of 36 mg/dL, high serum insulin of 94.8 mIU/L (1.7 - 31), elevated C-peptide of 10.6 ng/mL (0.9-4). Cortisol and thyroid function are normal. Abdominal ultrasound (US), CT scan and MRI are normal. Due to failure of localization of Insulinoma, treatment by diazoxide started with no response. Octreotide long-acting repeatable (Octreotide LAR) 20 mg monthly injection was initiated and increased to 30 mg monthly with good improvement and less attacks. After three years, the patient developed abdominal pain and abdominal US showed multiple gall stones. The patient was advised to do 68Ga-DOTATATE PET/CT Scan, which revealed distal pancreatic mass of 26 mm (Figure1A and B). Distal pancreatectomy and cholecystectomy had been done with smooth postoperative period normal normal plasma glucose, insulin and c-peptide with no further hypoglycemia, histopathological examination confirmed Insulinoma (Figure 2A and B). Hypoglycemic symptoms of I, whether neuroglycopenic or sympathoadrenal are precipitated by fasting or exercise and could precede diagnosis by months and even years(3). Insulinoma, should be suggested when patient has typical Whipple's triad, high insulin, c-peptide and proinsulin during the attack(3). Weight gain noted in about 18% of cases(4). Modalities used to localize Insulinoma include trans-abdominal US, CT scan, MRI, EUS (endoscopic ultrasound), intraoperative US, intraoperative palpation and arteriography. An American study considered 68Ga-DOTATATE PET/CT as an adjuvant tool for diagnosis with 90% detection rate (5). A 90-95% of cases are benign, patients have high survival with complete resolution of symptoms after excision with only 5.4% recurrences(6). Malignant I limited to pancreas and responsive to chemotherapy has 5 years survival rate after resection and 19 months for recurrent tumors(6). Conclusion Insulinoma should be considered in patients with typical clinical and laboratory finding. Follow up, assessment and different imaging techniques are main steps in management with teamwork.Figure 1.68Ga-DOTATATE PET/CT Scan68Ga-DOTATATE PET/CT Scan revealed distal pancreatic mass of 26 mm