Delayed Perforation After Endoscopic Resection of Upper Gastrointestinal Tumors: CT Findings to Identify Patients Requiring Surgery.

PURPOSE: To determine the clinical and imaging factors associated with surgical treatment in patients with delayed perforation after endoscopic resection of upper gastrointestinal tumors. METHODS: We retrospectively included patients with delayed perforation after endoscopic tumor resection for gastric or duodenal tumors between January 2007 and December 2021 in a tertiary hospital. We compared the clinical, endoscopic, and CT findings of the surgical and conservative treatment groups. Univariable and multivariable analyses were performed to identify significant factors associated with surgery. RESULTS: Among 10,423 patients who had undergone endoscopic tumor resection, 52 (0.50%) experienced delayed perforation, with 20 patients (35.5%) treated surgically and 32 patients (64.5%) treated conservatively. The CT findings of gross perforation (adjusted odds ratio [OR]=6.75, 95% confidence interval [CI], 1.04-43.89; P=0.045) and presence of peritonitis (OR=34.26, 95% CI, 5.52-212.50; P<0.001) were significantly associated with surgical treatment. Other clinical factors as well as CT-measured amount of pneumoperitoneum were not significant factors. CONCLUSIONS: CT findings of gross perforation and peritonitis are significant factors associated with surgery in delayed perforation after endoscopic tumor resection. These factors can aid in guiding the patients towards an appropriate treatment plan.

A Deep Residual U-Net Algorithm for Automatic Detection and Quantification of Ascites on Abdominopelvic Computed Tomography Images Acquired in the Emergency Department: Model Development and Validation.

BACKGROUND: Detection and quantification of intra-abdominal free fluid (ie, ascites) on computed tomography (CT) images are essential processes for finding emergent or urgent conditions in patients. In an emergency department, automatic detection and quantification of ascites will be beneficial. OBJECTIVE: We aimed to develop an artificial intelligence (AI) algorithm for the automatic detection and quantification of ascites simultaneously using a single deep learning model (DLM). METHODS: We developed 2D DLMs based on deep residual U-Net, U-Net, bidirectional U-Net, and recurrent residual U-Net (R2U-Net) algorithms to segment areas of ascites on abdominopelvic CT images. Based on segmentation results, the DLMs detected ascites by classifying CT images into ascites images and nonascites images. The AI algorithms were trained using 6337 CT images from 160 subjects (80 with ascites and 80 without ascites) and tested using 1635 CT images from 40 subjects (20 with ascites and 20 without ascites). The performance of the AI algorithms was evaluated for diagnostic accuracy of ascites detection and for segmentation accuracy of ascites areas. Of these DLMs, we proposed an AI algorithm with the best performance. RESULTS: The segmentation accuracy was the highest for the deep residual U-Net model with a mean intersection over union (mIoU) value of 0.87, followed by U-Net, bidirectional U-Net, and R2U-Net models (mIoU values of 0.80, 0.77, and 0.67, respectively). The detection accuracy was the highest for the deep residual U-Net model (0.96), followed by U-Net, bidirectional U-Net, and R2U-Net models (0.90, 0.88, and 0.82, respectively). The deep residual U-Net model also achieved high sensitivity (0.96) and high specificity (0.96). CONCLUSIONS: We propose a deep residual U-Net-based AI algorithm for automatic detection and quantification of ascites on abdominopelvic CT scans, which provides excellent performance.

A reliable and robust method for the upper thigh muscle quantification on computed tomography: toward a quantitative biomarker for sarcopenia.

BACKGROUND: We aimed to evaluate the feasibility of the upper thigh level as a landmark to measure muscle area for sarcopenia assessment on computed tomography (CT). METHODS: In the 116 healthy subjects who performed CT scans covering from mid-abdomen to feet, the skeletal muscle area in the upper thigh level at the inferior tip of ischial tuberosity (SMAUT), the mid-thigh level (SMAMT), and L3 inferior endplate level (SMAL3) were measured by two independent readers. Pearson correlation coefficients between SMAUT, SMAMT, and SMAL3 were calculated. Inter-reader agreement between the two readers were evaluated using intraclass correlation coefficient (ICC) and Bland-Altman plots with 95% limit of agreement (LOA). RESULTS: In readers 1 and 2, very high positive correlations were observed between SMAUT and SMAMT (r = 0.91 and 0.92, respectively) and between SMAUT and SMAL3 (r = 0.90 and 0.91, respectively), while high positive correlation were observed between SMAMT and SMAL3 (r = 0.87 and 0.87, respectively). Based on ICC values, the inter-reader agreement was the best in the SMAUT (0.999), followed by the SMAL3 (0.990) and SMAMT (0.956). The 95% LOAs in the Bland-Altman plots indicated that the inter-reader agreement of the SMAUT (- 0.462 to 1.513) was the best, followed by the SMAL3 (- 9.949 to 7.636) and SMAMT (- 12.105 to 14.605). CONCLUSION: Muscle area measurement at the upper thigh level correlates well with those with the mid-thigh and L3 inferior endpoint level and shows the highest inter-reader agreement. Thus, the upper thigh level might be an excellent landmark enabling SMAUT as a reliable and robust biomarker for muscle area measurement for sarcopenia assessment.

Risk Prediction Model Based on Magnetic Resonance Elastography-Assessed Liver Stiffness for Predicting Posthepatectomy Liver Failure in Patients with Hepatocellular Carcinoma.

BACKGROUND/AIMS: Posthepatectomy liver failure (PHLF) is a major complication that increases mortality in patients with hepatocellular carcinoma after surgical resection. The aim of this retrospective study was to evaluate the utility of magnetic resonance elastography-assessed liver stiffness (MRE-LS) for the prediction of PHLF and to develop an MRE-LS-based risk prediction model. METHODS: A total of 160 hepatocellular carcinoma patients who underwent surgical resection with available preoperative MRE-LS data were enrolled. Clinical and laboratory parameters were collected from medical records. Logistic regression analyses were conducted to identify the risk factors for PHLF and develop a risk prediction model. RESULTS: PHLF was present in 24 patients (15%). In the multivariate logistic analysis, high MRE-LS (kPa; odds ratio [OR] 1.49, 95% confidence interval [CI] 1.12 to 1.98, p=0.006), low serum albumin (≤3.8 g/dL; OR 15.89, 95% CI 2.41 to 104.82, p=0.004), major hepatic resection (OR 4.16, 95% CI 1.40 to 12.38, p=0.014), higher albumin-bilirubin score (>-0.55; OR 3.72, 95% CI 1.15 to 12.04, p=0.028), and higher serum α-fetoprotein (>100 ng/mL; OR 3.53, 95% CI 1.20 to 10.40, p=0.022) were identified as independent risk factors for PHLF. A risk prediction model for PHLF was established using the multivariate logistic regression equation. The area under the receiver operating characteristic curve (AUC) of the risk prediction model was 0.877 for predicting PHLF and 0.923 for predicting grade B and C PHLF. In leave-one-out cross-validation, the risk model showed good performance, with AUCs of 0.807 for all-grade PHLF and 0. 871 for grade B and C PHLF. CONCLUSIONS: Our novel MRE-LS-based risk model had excellent performance in predicting PHLF, especially grade B and C PHLF.

Combining hepatic surface nodularity and serum tests better predicts hepatic fibrosis stages in chronic liver disease.

PURPOSE: Hepatic surface nodularity quantified on CT images has shown promising results in staging hepatic fibrosis in chronic hepatitis C. The aim of this study was to evaluate hepatic surface nodularity, serum fibrosis indices, and a linear combination of them for staging fibrosis in chronic liver disease, mainly chronic hepatitis B. METHODS: We developed a semiautomated software quantifying hepatic surface nodularity on CT images. Hepatic surface nodularity and serum fibrosis indices were assessed in the development group of 125 patients to generate 3 linear models combining hepatic surface nodularity with the aspartate aminotransferase to platelet ratio index, fibrosis-4 index, or platelet count in reference to the METAVIR scoring system. The models were validated in 183 patients. RESULTS: Hepatic surface nodularity and serum fibrosis indices all significantly correlated with fibrosis stages. For binary classifications into cirrhosis (F4), advanced fibrosis (≥ F3), and significant fibrosis (≥ F2), hepatic surface nodularity was significantly different across categories. The areas under the curve (AUCs) of the best model were 0.901, 0.872, and 0.794 for cirrhosis, advanced fibrosis, and significant fibrosis, respectively, higher than serum fibrosis indices alone (0.797-0.802, 0.799-0.818, and 0.761-0.773). In the validation group, the same model likewise showed higher AUCs (0.872, 0.831, and 0.850) compared to serum fibrosis indices (0.722-0.776, 0.692-0.768, and 0.695-0.769; p < 0.001 for F4). CONCLUSION: Hepatic surface nodularity combined with serum blood test could be a practical method to predict cirrhosis, advanced fibrosis, and significant fibrosis in chronic liver disease patients, providing higher accuracy than using serum fibrosis indices alone.

Hepatic Arterial Infusion Chemotherapy for Advanced Hepatocellular Carcinoma: Radiologic and Clinical Factors Predictive of Survival.

OBJECTIVE. The goal of this study was to evaluate radiologic and clinical factors associated with overall survival of advanced hepatocellular carcinoma treated with hepatic arterial infusion chemotherapy (HAIC). MATERIALS AND METHODS. This single-center retrospective study included 180 patients with advanced hepatocellular carcinoma who underwent HAIC with a 5-fluorouracil (250-500 mg/m2 for 5 hours) plus cisplatin (10-20 mg/m2 for 1-2 hours) regimen via an implantable port system. Survival curves were generated by the Kaplan-Meier method and compared by log-rank tests. Factors associated with overall survival were evaluated with Cox proportional hazard models. RESULTS. The median overall survival time was 7.6 months (95% CI, 6.1-9.1), and the objective response rate was 15%. In multivariate analysis, infiltrative tumor growth (hazard ratio [HR], 1.002; p = .03) and rimlike arterial enhancement (HR, 3.040; p < .001) were pretreatment radiologic factors associated with reduced overall survival. No early response to treatment (HR, 2.064-6.491) and higher Child-Pugh class (HR, 2.010-2.815) were strong prognostic factors of poor outcome. Treatment with three or more HAIC cycles (HR, 0.371; p = .001) and high-dose HAIC (HR, 0.447; p < .001) were favorable for increased overall survival. CONCLUSION. Infiltrative tumor growth and rimlike arterial enhancement in pre-treatment imaging studies were associated with poor prognosis, and better early radiologic response and preserved liver function reserve were strong indicators of prolonged survival. Recognizing these radiologic and clinical predictors may help optimize care of patients with hepatocellular carcinoma.

Added Value of CT Arterial Subtraction Images in Liver Imaging Reporting and Data System Treatment Response Categorization for Transcatheter Arterial Chemoembolization-Treated Hepatocellular Carcinoma.

OBJECTIVES: The aim of this study was to assess the benefit of adding arterial subtraction images from computed tomography (CT) to the Liver Imaging Reporting and Data System (LI-RADS) v2018 treatment response (LR-TR) categorization in patients treated with transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This retrospective study included 115 patients with 151 HCCs treated by TACE using an emulsion of doxorubicin and iodized oil who underwent multiphasic CT protocol that additionally generated arterial subtraction images based on nonrigid anatomic correction algorithm. Of 151 HCCs, 67 (44.4%) were viable and 84 (55.6%) were nonviable. Two independent readers assessed the per-lesion LR-TR categories in set 1 of multiphasic CT images alone and set 2 including both set 1 and CT arterial subtraction images, besides diagnostic confidence, and the quality of subtraction images. The sensitivity and specificity of LR-TR viable category between the sets were compared using the generalized estimating equation. Interobserver agreements of LR-TR categorization in each set and the quality of subtraction images were assessed by Cohen κ. RESULTS: The quality of subtraction images was mostly good to perfect (98.7%) with good interobserver agreement (κ = 0.71), and none were nondiagnostic. For detecting viable HCC, LR-TR viable category showed sensitivity of 53.7% to 56.7% and specificity of 96.4% to 98.8% in set 1. In comparison, set 2 showed significantly higher sensitivity of 88.1% to 89.6% (P < 0.002) and equivalent specificity of 94% to 95.2% (P > 0.13) for the same category. In sets 1 and 2, 31.3% to 34.3% and 9% to 10.4% of viable HCC were miscategorized as LR-TR nonviable, respectively. LR-TR equivocal category was less assigned in set 2 (1.3%) than in set 1 (6.6%-7.9%). Set 2 showed slightly higher level of confidence for LR-TR categorization compared with set 1 (3.4 ± 0.8 vs 3.8 ± 0.5). Interobserver agreement was excellent in both sets (κ = 0.85 in set 1 and 0.97 in set 2). CONCLUSIONS: The LR-TR viable category is highly specific but inadequately sensitive for detecting viable tumor in TACE-treated HCC on conventional multiphasic CT. Adding arterial subtraction images to the conventional CT images significantly increases sensitivity without compromising the specificity and improves the diagnostic confidence of LR-TR viable category.

Liver stiffness in magnetic resonance elastography is prognostic for sorafenib-treated advanced hepatocellular carcinoma.

OBJECTIVE: We investigated whether liver stiffness (LS) quantified using magnetic resonance elastography (MRE) could predict the prognosis of advanced hepatocellular carcinoma (HCC) patients treated with sorafenib. METHODS: We selected 50 sorafenib-treated advanced HCC patients who underwent MRE within 3 months before drug administration from a prospectively maintained cohort of chronic liver disease patients, according to the inclusion and exclusion criteria. Univariate and multivariate analyses were performed to evaluate the prognostic role of laboratory data, tumor characteristics, and MRE-assessed LS for overall survival (OS), progression-free survival (PFS), and significant liver injury (grade ≥ 3) after sorafenib administration. RESULTS: High MRE-assessed LS either as continuous (per kPa, hazard ratio (HR) 1.54; 95% confidence interval (CI) 1.23-1.92, p < 0.001) or categorical (> 7.5 kPa, HR 4.06, 95% CI 1.40-11.79, p < 0.01) variable was significantly associated with poor OS along with higher serum alpha-fetoprotein (AFP, ≥ 400 ng/mL) and advanced tumor stage (modified Union for International Cancer Control (mUICC) IVb). Higher MRE-assessed LS was also significantly associated with the development of significant liver injury after sorafenib administration (per kPa, HR 1.62, 95% CI 1.21-2.17, p = 0.001; > 7.5 kPa, HR 10.11, 95% CI 2.41-42.46, p = 0.002). PFS analysis identified higher serum AFP (≥ 400 ng/mL) and advanced tumor stage (mUICC IVb) as significant risk factors for early disease progression, whereas LS was not associated with PFS CONCLUSION: Higher MRE-assessed LS is a potential biomarker for predicting poor OS and significant liver injury in advanced HCC patients treated with sorafenib. KEY POINTS: • Higher pretreatment LS by MRE (> 7.5 kPa), higher AFP (≥ 400 ng/mL), and advanced tumor stage (mUICC IVb) were associated with poor OS in advanced HCC patients treated with sorafenib. • Higher pretreatment LS by MRE was associated with developing significant (grade ≥ 3) liver injury during sorafenib treatment, which required termination of the therapy. • Patients with high pretreatment LS by MRE should be monitored carefully for potential liver injury during sorafenib treatment.

Liver stiffness measured by MR elastography is a predictor of early HCC recurrence after treatment.

OBJECTIVES: Magnetic resonance elastography (MRE) is a non-invasive tool for measuring liver stiffness (LS) with high diagnostic accuracy. This study investigated whether quantified LS by MRE could predict early recurrence of patients with hepatocellular carcinoma (HCC) within the Milan criteria. METHODS: A prospectively collected cohort, which included the HCC patients who underwent MRE before treatment (an HCC-MRE cohort), was analyzed. In the HCC-MRE cohort, only patients under the Milan criteria, who underwent hepatic resection, radiofrequency ablation (RFA), or transarterial chemoembolization (TACE), were reviewed. We investigated whether LS assessed by MRE was an independent predictor of early recurrence using Cox regressions and Kaplan-Meier analyses. RESULTS: A total of 192 HCC patients under the Milan criteria who underwent hepatic resection (n = 96), RFA (n = 23), or TACE (n = 73) were included. Higher LS ratings (kPa; hazard ratio [HR] = 1.12; 95% confidence interval [CI] = 1.01-1.25; p = 0.040) emerged as an independent risk factor for early tumor recurrence. In the subgroup analysis, higher LS ratings were associated with higher risks of early HCC recurrence in both the resection/RFA group (> 4.5 kPa; HR = 2.95; 95% CI = 1.26-6.94; p = 0.013) and the TACE group (> 6 kPa; HR = 2.94; 95% CI = 1.27-6.83; p = 0.012). CONCLUSION: LS assessed by MRE was an independent predictor of early recurrence among HCC patients under the Milan criteria after achieving a complete response. KEY POINTS: • Liver parenchymal stiffness measured by MRE predicts early recurrence of treated HCC under Milan criteria. • A liver stiffness > 5.5 kPa was associated with worse recurrence-free survival. • Patients with high pre-treatment LS may benefit from stringent follow-up.

Reproducibility of hepatic MR elastography across field strengths, pulse sequences, scan intervals, and readers.

PURPOSE: To evaluate the reproducibility of hepatic MRE under various combinations of settings of field strength, pulse sequence, scan interval, and reader in non-alcoholic fatty liver disease (NAFLD) patients. METHODS: Adult NAFLD patients were prospectively enrolled for serial hepatic MRE with 1.5 T using 2D GRE sequence and 3.0 T using 2D SE-EPI sequence on the same day and after 2 weeks, resulting a total of four MRE examinations per patient. Three readers with various levels of background knowledge in MRE technique and liver anatomy measured liver stiffness after a training session. Linear regression, Bland-Altman analysis, within-subject coefficient of variation, and reproducibility coefficient (RDC) were used to determine reproducibility of hepatic MRE measurement. RESULTS: Twenty patients completed the MRE sessions. Liver stiffness through MRE showed pooled RDC of 26% (upper 95% CI 30.6%) and corresponding limits of agreement (LOA) within 0.55 kPa across field strengths, MRE sequences, and 2-week interscan interval in three readers. Small mean biases and narrow LOA were observed among readers (0.05-0.19 kPa ± 0.53). CONCLUSION: The magnitude of change across combinations of scan parameters is within acceptable clinical range, rendering liver stiffness through MRE a reproducible quantitative imaging biomarker. A lower reproducibility was observed for measurements under different field strengths/MRE sequences at a longer (2 weeks) interscan interval. Operators should be trained to acquire region of interest consistently in repeat examinations.

Multimodality imaging studies of intraductal tubulopapillary neoplasms of the pancreas.

PURPOSE: We aimed to investigate multimodality imaging findings of intraductal tubulopapillary neoplasms (ITPN) of the pancreas. METHODS: This study was approved by the institutional review board with waived informed consent. A total of eight patients were histopathologically diagnosed with pancreatic ITPN in a single institution over a 6-year period. The imaging findings of dynamic contrast-enhanced computed tomography (CT), magnetic resonance cholangiopancreatography (MRCP), endoscopic ultrasonography (EUS), and positron emission tomography-computed tomography (PET-CT) were reviewed and correlated with clinicopathologic findings. RESULTS: Histopathologically, an invasive carcinoma component was found in 5 of 8 patients (62.5%). The median diameter of the lesions and the main pancreatic ducts were larger in ITPN with invasive carcinoma (19 mm, 13.3-98.0 mm and 13 mm, 5.9-16.3 mm, respectively) than in ITPN without invasive carcinoma (13 mm, 12.7-18.5 mm and 6 mm, 5.6-6.1 mm, respectively), but not significantly (lesions, P = 0.229 and main pancreatic ducts, P = 0.143). Pancreatolithiasis accompanied invasive carcinoma in 3 of 5 patients (60%). Intraductal solid tumors were demonstrated on CT (5/8, 62.5%), MRCP (5/7, 71.4%), and EUS (7/7, 100%). In addition, various imaging findings mimicking chronic autoimmune pancreatitis or pancreatic ductal adenocarcinoma were found in 3 patients (37.5%) on multimodality imaging. The lesion multiplicity and synchronous or metachronous biliary cancer occurred in 3 patients (37.5%), respectively. CONCLUSION: Patients with associated invasive carcinoma from pancreatic ITPN may have presented a trend toward larger tumor size and dilated pancreatic duct with pancreatoliths, but the difference was not statistically significant. Further studies with a larger number of patients are needed to provide better insight into these findings. Pancreatic ITPN can show various atypical imaging findings as well as typical intraductal solid tumor on multimodality imaging. The presence of lesion multiplicity and synchronous or metachronous biliary cancer can be helpful for assisting with the diagnosis of pancreatic ITPN.

Sigmoid volvulus: identifying patients requiring emergency surgery with the dark torsion knot sign.

OBJECTIVES: To determine which clinical or CT imaging factors can help accurately identify complicated sigmoid volvulus (SV), defined as irreversible bowel ischaemia or necrosis requiring emergent surgery in patients with SV. METHODS: We performed a retrospective study of 51 patients admitted consecutively to the emergency department for SV. All patients attempted endoscopic detorsion as the first treatment. Clinical and contrast-enhanced CT factors were analysed. A newly described dark torsion knot sign (sudden loss of mucosal enhancement in the volvulus torsion knot) was included as a CT factor. Patients were diagnosed with complicated versus simple SV based on either surgery or follow-up endoscopic findings. Univariate and multivariate analyses were used to identify predictors of complicated SV. RESULTS: Of 51 study patients, 9 patients (17.6%) had complicated SV. Univariate analysis revealed that three clinical factors (sepsis, elevated C-reactive protein, and elevated lactic acid levels) and four CT factors (reduced bowel wall enhancement, increased bowel wall thickness, dark torsion knot sign, and diffuse omental infiltration) were significantly associated with complicated SV. Multivariate analysis identified only dark torsion knot sign (odds ratio = 104.40; p = 0.002) and sepsis (odds ratio = 16.85; p = 0.043) as independent predictive factors of complicated SV. CONCLUSION: A newly defined CT imaging factor of dark torsion knot sign and a clinical factor of sepsis can predict complicated SV necessitating emergent surgery instead of colonoscopic detorsion as a primary treatment of choice. KEY POINTS: • A newly defined CT imaging factor of dark torsion knot sign and a clinical factor of sepsis can be helpful for predicting complicated SV necessitating emergent surgery instead of endoscopic detorsion.

Accuracy and precision of proton density fat fraction measurement across field strengths and scan intervals: A phantom and human study.

BACKGROUND: Complex-based chemical shift imaging-based magnetic resonance imaging (CSE-MRI) is emerging as a preferred method for noninvasively quantifying proton density fat fraction (PDFF), a promising quantitative imaging biomarker (QIB) for longitudinal hepatic steatosis measurement. PURPOSE: To determine linearity, bias, repeatability, and reproducibility of the PDFF measurement using CSE-MRI (CSE-PDFF) across scan intervals, MR field strengths, and readers in phantom and nonalcoholic fatty liver disease (NAFLD) patients. STUDY TYPE: Institutional Review Board (IRB)-approved prospective. SUBJECTS: Fat-water phantom and 20 adult patients. FIELD STRENGTH/SEQUENCE: 1.5 T and 3.0 T MR systems and a commercially available CSE-MRI sequence (IDEAL-IQ). ASSESSMENT: Two independent readers measured CSE-PDFF of fat-water phantom and NAFLD patients across two field strengths and scan intervals (same-day and 2-week) each and in a combination of both. MR spectroscopy-based PDFF (MRS-PDFF) was used as the reference standard for phantom PDFF. STATISTICAL TESTS: Linearity and bias of measurement were evaluated by linear regression analysis and Bland-Altman plots, respectively. Repeatability and reproducibility were assessed by coefficient of variance and repeatability / reproducibility coefficients (RC). The intraclass correlation coefficient was used to validate intra- and interobserver agreements. RESULTS: CSE-PDFF showed high linearity and small bias (-0.6-0.4 PDFF%) with 95% limits of agreement within ±2.9 PDFF% across field strengths, 2-week interscan period, and readers in the clinical scans. CSE-PDFF was highly repeatable and reproducible both in phantom and clinical scans, with the largest observed RC across field strengths and 2-week interscan period being 3 PDFF%. DATA CONCLUSION: CSE-PDFF is a robust QIB with high linearity, small bias, and excellent repeatability/reproducibility. A change of more than 3 PDFF% across field strengths within 2 weeks of scan interval likely reflects a true change, which is well within the clinically acceptable range. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:305-314.

Three cases of pancreatic pseudocysts associated with dorsal pancreatic agenesis.

Agenesis of the dorsal pancreas (ADP) is an extremely rare congenital anomaly. Human pancreas is formed by ventral and dorsal endodermal buds of the foregut endoderm. The dorsal bud forms the upper part of the head, neck, body, and tail of the pancreas and the ventral bud generates most of the head and uncinate process. ADP is derived from the embryologic failure of the dorsal pancreatic bud to form the pancreatic body and tail. ADP can be related to some diseases and conditions such as pancreatitis, hypoglycemia, and rarely pancreatic tumors. The association between cystic lesions with ADP has previously been reported. Three cases of cystic lesions of the pancreas with ADP were diagnosed clinically based on the imaging features and without any past history of pancreatitis. However, the pathologic diagnosis of resected lesions confirmed pseudocysts without pathologic evidence of tumor. We report 3 cases of pancreatic pseudocysts associated with ADP.

Radiological patterns of secondary sclerosing cholangitis in patients after lung transplantation.

PURPOSE: The purpose of this study was to investigate the radiological patterns of secondary sclerosing cholangitis (SSC) following lung transplantation. METHODS: Fifty-five patients underwent abdominopelvic CT before and after lung transplantation for end stage pulmonary disease. Nine patients underwent MR cholangiopancreatography (MRCP). The radiological patterns of biliary abnormalities (location, bile duct dilatation with stricture, beaded appearance, and biliary casts/sludge), laboratory data (serum total bilirubin and alkaline phosphatase), and patient survival rates were evaluated. SSC was diagnosed when there were newly developed biliary abnormalities with cholestasis after lung transplantation. Potential perioperative risk factors pertaining to SSC were analyzed. Patient survival rates with or without SSC were compared. RESULTS: Six of the 55 patients showed imaging and laboratory findings of SSC after lung transplantation. Multifocal dilatation and stricture involved the intrahepatic (6 of 6, 100%), hilar (4 of 6, 66.7%), and extrahepatic bile duct (1 of 6, 16.7%). On CT, the lesions presented as multifocal small cyst-like lesions along the bile duct course. On MRCP, the lesions showed beaded appearance with mild duct dilatation. Preoperative mechanical ventilation and bilateral lung transplantation were associated with SSC (p < 0.05). The median survival of patients with SSC was 4.6 months. CONCLUSION: Lung transplantation can induce SSC similar to SSC in critically ill patients, and result in worse clinical outcomes than in patients without SSC. Multifocal small cyst-like lesions along the intrahepatic bile duct on CT and beaded appearance on MRCP are suggestive findings of SSC in patients with cholestasis after lung transplantation.

Clinical impact of collateral circulation in patients with median arcuate ligament syndrome.

PURPOSE: We aimed to analyze computed tomography (CT) findings and medical records of patients diagnosed with median arcuate ligament syndrome (MALS) and evaluate possible risk factors associated with vascular complications that develop in patients with MALS. METHODS: This retrospective study was approved by the institutional review board, and the requirement to obtain informed consent was waived. A total of 37 consecutive patients were diagnosed with MALS using both axial and sagittal CT reconstruction imaging at a single institution over a 7-year period. Dynamic contrast-enhanced CT data, medical records, and angiography results were reviewed. RESULTS: Thirty-two (86.5%) patients were asymptomatic and incidentally diagnosed with MALS using CT. Seventeen (45.9%) patients exhibited significant arterial collateral circulations and nine (24.3%) were found to have splanchnic artery aneurysms, including one (2.7%) with acute bleeding secondary to aneurysm rupture. Peripancreatic vascular network including pancreaticoduodenal arcades and dorsal pancreatic artery was the most common site for development of both collateral circulations (16/22, 72.7%) and aneurysms (9/16, 56.3%). Splanchnic artery aneurysms were significantly more common in patients with collateral circulations (8/17, 47.1%) compared with those without collateral circulations (1/20, 5%) (P < 0.01). At least one peripancreatic vascular aneurysm was found in five of nine patients with splanchnic artery aneurysms (55.6%). CONCLUSION: Splanchnic artery aneurysms are not uncommon in asymptomatic patients with collateral circulations caused by significant celiac trunk stenosis or obstruction due to median arcuate ligament. Therefore, careful imaging evaluation is necessary in patients with peripancreatic collateral circulations associated with MALS and regular follow-up is recommended for possibility of aneurysm development and rupture. Prophylactic endovascular treatment should be specifically performed in patients with pancreaticoduodenal arcade aneurysms to prevent life-threatening aneurysm rupture regardless of size.

Gastrointestinal Gas and Abdominal Fat Quantity Measured by Three-Dimensional Abdominal Computed Tomography in Patients with Functional Bloating.

BACKGROUND/AIMS: The aim of this study was to assess whether increased intestinal gas or fat content in the abdominal cavity is related to abdominal bloating, using three-dimensional abdominal computed tomography scan. METHODS: Twenty-nine healthy individuals without abdominal bloating and organic disease (15 women; mean age, 49 years; range of age, 23-73 years) and 30 patients with chronic recurrent abdominal bloating-diagnosed with functional bloating (10 women; mean age, 53 years; range of age, 35-75 years) - participated in this study. The mean values of measured parameters were compared using independent sample t-test. RESULTS: The mean volume of total colon gas in bloated patients was similar to that in control subjects. The distribution of intra-abdominal gas was also similar between the two groups. However, the amount of gas in the transverse colon tended to be significantly higher in patients with bloating than in controls (p=0.06). Body mass index was similar between the two groups (23.4±3.2 kg/m2 and 22.3±3.1 kg/m2, respectively). Moreover, no significant differences with respect to circumferential area, subcutaneous fat, visceral fat area, and total fat area were found between the two groups. CONCLUSIONS: Bloating might not just be the result of gastrointestinal gas or intra-abdominal fat. Other contributing factors, such as localized abnormality in gas distribution and visceral hypersensitivity, may be involved.

The capsule appearance of hepatocellular carcinoma in gadoxetic acid-enhanced MR imaging: Correlation with pathology and dynamic CT.

This study aimed to evaluate the capability of gadoxetic acid-enhanced MR (GAeMR) to detect presence of capsule appearance in hepatocellular carcinoma (HCC), and to correlate it with dynamic computed tomography (CT) and pathological features.Sixty-three patients (54: 9 = M: F, mean age 55.8) surgically confirmed HCCs with preoperative CT and GAeMR were included in this retrospective study. Two readers evaluated presence of capsule appearances on CT and GAeMR images in each phase including precontrast (Pre), portal phase (PP), delayed phase (DP), transitional phase (TP), and hepatobiliary phase (HBP). Histologic capsule was compared with CT and GAeMR. Diagnostic performance of CT and GAeMR of each phase for histologic capsule was evaluated and compared by receiver operating characteristic curve. Interobserver agreement was assessed with kappa statistics.Histologically the capsule was complete in 12.7% (8/63) and incomplete in 60.3% (38/63). Four cases (6.3%) were pseudocapsule. Interobserver agreement for capsule appearance on GAeMR was good in Pre (κ = 0.684), moderate in PP (κ = 0.434), poor in TP (κ = 0.187), fair in HBP (κ = 0.395), and moderate on CT in PP (κ = 0.476) and DP (κ = 0.485). Diagnostic performance and sensitivity for the histologic capsule in DP on CT was highest among PP on CT and other phases on GAeMR. DP on CT images showed a higher Az value than PP on CT images with statistical significance (P < .001). PP on MR images revealed higher Az value than PP on CT images.The capsule appearance was most frequently observed in the DP on CT with highest diagnostic performance, and so DP images should be obtained on CT study for liver mass categorization. GAeMR yielded comparable capsule appearance to CT with moderate interobserver agreement. Considering hypointense rim on the HBP as fibrous capsule on pathology should be refrained, and so further study is warranted to correlate HBP hypointense rim with pathologic findings.

High spatial resolution navigated 3D T1-weighted hepatobiliary MR cholangiography using Gd-EOB-DTPA for evaluation of biliary anatomy in living liver donors.

PURPOSE: To determine the feasibility of high-resolution navigated three-dimensional (3D) T1-weighted hepatobiliary MR cholangiography (Nav T1 MRC) using Gd-EOB-DTPA for biliary visualization in living liver donors and to assess added value of 3D T1-weighted hepatobiliary MRCs in improving the confidence and diagnostic accuracy of biliary anatomy in complementary to T2-weighted MRCs. METHODS: Twenty-nine right liver donors underwent 3D T2 MRC, 2D T2 MRC, breath-hold T1-weighted hepatobiliary MRC (BH T1 MRC), and Nav T1 MRC. Two readers independently reviewed and compared 3D/2D MRC set, added BH T1 MRC set, and added Nav T1 MRC set for biliary diagnostic accuracy and confidence. For each MRC, biliary segments visualization and image quality were scored. RESULTS: Both BH T1 MRC and Nav T1 MRC improved accuracy and specificity in biliary diagnosis when added to 3D/2D T2 MRC-alone set, though without statistical significance (R1, 82.8% to 93.1%; R2, 82.8% to 89.7%). The added Nav T1 MRC set showed the highest diagnostic confidence with both readers. Both readers scored Nav T1 MRC with the highest visualization scores for branching ducts and overall ducts. CONCLUSION: Combining T1-weighted hepatobiliary MRCs to 3D/2D T2 MRC set improved accuracy for biliary anatomy diagnosis; time-efficient BH T1 MRC in axial and coronal planes should be considered as a key MRC sequence complementary to T2 MRCs. Given excellent biliary visualization and superior diagnostic confidence, Nav T1 MRC in selected subjects with breath-hold difficulties and inconclusive or complex biliary variations may assist in reaching a correct biliary diagnosis.

Plasma MicroRNA-21, 26a, and 29a-3p as Predictive Markers for Treatment Response Following Transarterial Chemoembolization in Patients with Hepatocellular Carcinoma.

BACKGROUND: We investigated an association between the levels of plasma microRNA (miRNA)-21, -26a, and -29a-3p and treatment outcomes following transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC). METHODS: A total of 198 patients with TACE-treated HCC were followed up for TACE refractoriness and liver transplantation (LT)-free survival. Pretreatment plasma miRNA-21, -26a, and -29a-3p levels were measured using quantitative real-time polymerase chain reaction. RESULTS: During the mean follow-up of 22.3 (range, 0.7-79) months, 118 (59.6%) patients exhibited TACE refractoriness. Multivariate analyses showed that expression of a specific combination of miRNAs (miRNA-21 ≥ 2.5, miRNA-26a ≥ 1.5, and miRNA-29a-3p < 0.4) was associated with early TACE refractoriness (within 1 year; hazard ratio [HR], 2.32; 95% confidence interval [CI], 1.08-4.99; P = 0.031) together with tumor size (HR, 4.62; 95% CI, 1.50-14.21; P = 0.008), and macrovascular invasion (HR, 3.80; 95% CI, 1.19-12.20; P = 0.025). However, miRNA-21, -26a, and -29a-3p levels were not significantly associated with overall TACE refractoriness or LT-free survival. Additionally, large tumor size and macrovascular invasion were common predictive factor of overall TACE refractoriness and survival. CONCLUSION: Combination of plasma miRNA-21, -26a, and -29a-3p expression could predict early TACE refractoriness in patients with TACE-treated HCC.