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We developed a novel method for synthesizing 2-(4-hydroxyaryl)-3,4-fused tricyclic dihydrobenzopyrans with 2,3-syn and 3,4-syn motif based on the acid-promoted cascade cyclization via vinylidene para-quinone methide intermediates. Using easily prepared linear substrates, TFA-promoted cascade cyclization proceeded in the presence of triethylsilane, affording a series of five to seven-membered ring-fused dihydrobenzo pyran derivatives in moderate to excellent yield in a highly diastereoselective manner. The developed method provided new access to potent and selective ERβ agonists. [ABSTRACT FROM AUTHOR]

Objective To evaluate the frequency of hemorrhagic complications on abdominal computed tomography (CT) in patients with warfarin therapy and its correlation with intensity of anticoagulation. Materials and methods We included 646 patients who received warfarin therapy with international normalized ratio (INR) greater than 3.0 and abdominal CT within 1 month after INR measurement. Results Seventy-four patients (11.5%) showed hemorrhagic complications on abdominal CT. Frequency of hemorrhagic complications significantly correlated with intensity of anticoagulation ( P <.001). Conclusion Hemorrhagic complications on abdominal CT in patients with warfarin therapy were not rare, and it occurred more frequently in patients with higher INR. [ABSTRACT FROM AUTHOR]

Background: An electric bed can easily change posture from a lying position and was effective in preventing pressure ulcer.Objective: This study aimed to identify the optimal posture for the prevention of pressure ulcers by analyzing pressure changes applied to the pelvic region.Methods: Pressure changes resulting from lateral rotations of the body using an electronic adjustable bed and changes in the posture and angles of the trunk and knees were assessed. Twelve conditions with varying angles of the trunk and knees (15-35∘ in 5∘ increments) and varying lateral angles (20-35∘ in 5∘ increments) were tested. The pressure (maximum and average) and contact area in the pelvic region of 20 individuals without disabilities were calculated.Results: The conditions in which the average and maximum pressures did not increase according to the increase in angle were 25∘ for the upper body and knee angles and 35∘ for the side.Conclusions: The body pressure changed according to the posture rather than according to physical characteristics. Lateral rotation combined with changes in the angles of the trunk and knees effectively prevented pressure ulcers. Changes in the posture at various angles prevented an increased pressure on the body. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the frequency, CT findings, and fate of multiple infarcted regenerative nodules in patients with liver cirrhosis after variceal bleeding or septic shock. Methods: During a recent 3-year period, 492 patients with hematemesis or melena ( n = 445) and septic shock ( n = 47) in liver cirrhosis visited our hospital. After applying the exclusion criteria, 136 patients with active variceal bleeding and 29 patients with septic shock were finally included in the study. We diagnosed multiple infarcted regenerative nodules based on the findings of the first follow-up (within 30 days) CT after events. We evaluated the shape, number, size, margin, location, and distribution of the infarcted regenerative nodules. Results: Thirty-four patients were diagnosed with multiple infarcted regenerative nodules (20.6% [34/165]): 29 among 136 patients with variceal bleeding (21.3% [29/136]) and 5 among 29 patients with septic shock (17.2% [5/29]). Most of the infarcted regenerative nodules were round in shape, more than ten in number (79.4%), measured 1 cm or less (76.3%), had well-defined margins (61.8%), were present in the periphery (67.6%), and had a clustered distribution (67.6%). Almost all of the infarcted regenerative nodules disappeared on the second follow-up CT (88.9% [16/18]). Conclusions: In cirrhotic patients, multiple infarcted regenerative nodules were not rare (they were found in about one-fifth of the patients) on the first follow-up CT after variceal bleeding or septic shock. Majority of the infarcted regenerative nodules were more than ten in number, measured 1 cm or less, were located in the periphery, and had a clustered distribution. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Our objective was to evaluate whether the enhancement pattern, measured by changes in the signal- (SNRs) and contrast-to-noise ratios (CNRs), of hepatocellular carcinomas (HCCs) on gadoxetic acid-enhanced MRI reflects tumor differentiation. Subjects and methods: Two hundred eighty-five patients with 286 surgically-confirmed HCCs who underwent gadoxetic acid-enhanced MRI were included (11 grade I, 267 grade II, 7 grade III, and 1 grade IV tumor). Unenhanced and dynamic images with a T1-weighted 3D turbo-field-echo sequence were obtained. Relative signal intensities of the tumors with respect to surrounding liver were evaluated and the SNRs and CNRs were calculated. Results: SNR measurements demonstrated a fluctuating pattern (an increase in the SNR, followed by a decrease and a subsequent increase [or a decrease in the SNR followed by an increase and a subsequent decrease]) in 282 of 286 (98.6%) tumors. The SNR measurements also showed a single-peak SNR in the arterial phase (1.0% [3/286]) and 3min delayed images (0.3% [1/286]) followed by a decrease in 4 (1.4% [4/286]) grade II tumors. Nearly all tumors (88.1% [252/286]), 9 (81.8% [9/11]) grade I, 236 (88.4% [236/267]) grade II, 6 (85.7% [6/7]) grade III, and 1 (100% [1/1]) grade IV tumor showed maximum absolute CNRs with negative values, which were most commonly found in 20min delayed images (67.5% [170/252]). The remaining 34 of 286 (11.9%) tumors showed maximum absolute CNRs with positive values. Conclusion: Regardless of the tumor grades, the most common manifestation was a SNR with a fluctuating pattern with time and maximum absolute CNRs with negative values, which were most commonly noted in the hepatobiliary phase. [Copyright &y& Elsevier]

Gastric cancer is a common deadly cancer worldwide. The tumor-node-metastasis (TNM) staging system is one of the most commonly used staging systems, and is accepted and maintained by the International Union against Cancer (UICC) and the American Joint Committee on Cancer (AJCC). The TNM system is well known to effectively predict the prognosis of gastric cancer patients. The latest revision of TNM staging was presented in the 7th edition of the AJCC in 2009. Multi-detector row CT (MDCT) is a powerful test for non-invasive evaluation and can assess metastatic and locoregional staging simultaneously. Current MDCT with isotropic imaging and 3D images has increased the accuracy of T and N staging in patients with gastric cancer. Multi-planar reformatted images permit the radiologist to select the optimal imaging plane to accurately evaluate tumor invasion depth of the gastric wall and perigastric infiltration to identify a fat plane between a tumor and adjacent organs, to avoid partial volume averaging effects, and to differentiate lymph nodes from small perigastric vessels. Thus, MDCT provides a useful all-in-one diagnostic method for the pre-operative evaluation of patients with known, or strongly suspected, gastric cancer according to the 7th AJCC TNM staging system. [ABSTRACT FROM AUTHOR]

We developed a novel rapid mobile robot with zero-moment point (ZMP) stabilization. Most mobile robots cannot move quickly due to their high center of mass and narrow ground contact area. The higher center of mass makes it easier for the mobile robot to tip over. To stabilize mobile robots, we designed a multi-degreeof-freedom inverted pendulum to control the ZMP of mobile robots. Using a feed-forward ZMP stabilization method, we achieved zero change of the ZMP at any input velocity. We proved through experiments that it is possible to move stably at a maximum acceleration of 0.61 g and a maximum velocity of 12.35 km/h using the proposed method. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to evaluate the 'mushroom cap' sign on T2-weighted MR imaging in patients with submucosal tumors in the rectosigmoid colon. Methods: From January 2001 to August 2009, 12 patients with four different diseases presenting or mimicking submucosal tumors in the rectosigmoid colon underwent colonic resection. All patients with deep endometriosis ( n = 6), gastrointestinal stromal tumor ( n = 4), metastasis from ovary cancer ( n = 1), and carcinoid tumor ( n = 1) had either an MRI of the rectum or pelvis before surgery. We evaluated the MRI findings and compared them with the macroscopic and microscopic observations in the resected specimens. Results: In all six cases of deep endometriosis, a characteristic 'mushroom cap' shaped appearance was found on T2-weighted MR imaging. Heterogeneous low signal intensity of the hypertrophic muscularis propria, covered with high signal intensity of the mucosa and submucosa on T2-weighted MR images, looked like a 'mushroom cap' with the pattern of intraluminal endophytic growth. In histological findings, deep endometriosis involved the submucosa ( n = 4) or mucosa ( n = 2). The 'mushroom cap' sign was not present in any of the six other tumors. Conclusion: The 'mushroom cap' sign on T2-weighted MR imaging may be a characteristic sign for diagnosing deep rectosigmoid endometriosis. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: The purpose of this study was to evaluate the incidence of central lower attenuating (CLA) lesion in the ablation zone seen on immediate follow-up CT images after percutaneous radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC), and the correlation of CLA lesions and local tumor progression (LTP). Subjects and methods: The study group included 146 patients with 167 ablation zones that had undergone follow-up CT examinations for more than 12 months after percutaneous RFA. CLA lesions corresponding to index tumors and ablative margins (safety margins) were evaluated in the ablation zones seen on immediate follow-up CT including coronal and sagittal multiplanar reformatted (MPR) images with narrow window width settings. Results: CLA lesions were depicted on 48 of 167 ablation zones (28.7%) on immediate follow-up CT images. Among the 48 ablation zones with CLA lesions, 27 (56.3%, 27/48) had ablative margins on all three of the orthogonal MPR images and they showed no LTP (0%) on follow-up CT examinations. Three of the ablation zones with CLA lesions (6.3%, 3/48) having an ablative margin on one plane only also showed no LTP (0%). LTP was observed in 2 of 18 ablation zones (11.1%) that had CLA lesions without ablative margins on all three planes. In the remaining 119 ablation zones without CLA lesions, 5 (4.2%, 5/119) showed LTP. Conclusion: CLA lesions in ablation zones were occasionally (28.7%) seen on immediate follow-up CT images after RFA for HCCs. The presence of CLA lesions with ablative margins might be a negative predictor of LTP. [Copyright &y& Elsevier]

Abstract: Purpose: This study was designed to evaluate whether a feasibility scoring system for planning sonography is a reliable predictor of a safe and complete ablation in ultrasonography (US)-guided percutaneous radiofrequency ablation (RFA) of hepatocellular carcinomas (HCCs). Materials and methods: We retrospectively evaluated the therapeutic outcomes of 108 consecutive patients (M:F, 78:30; mean age, 57.4 years) with a single nodular HCC (mean diameter, 2.0cm) treated by percutaneous RFA. All patients were assessed for the feasibility of performing an RFA at planning sonography prior to the ablation. The feasibility scoring system consisted of five categories: the safe electrode path (P); the vital organs adjacent to the RFA zone (O); tumor size (S); tumor conspicuity (C); and the heat-sink effect (H). Each category was divided into a four-point scale [1–4]. If a score of 4 in any category was determined, the patient was not considered to be a suitable candidate for percutaneous RFA. We assessed if the score of each category, safety score (P+O), and curability score (S+C+H) correlated with a safe and complete ablation using the chi-squared test and likelihood ratio test for trend. Results: The technical success rate was 100% (108/108) based on CT images obtained immediately after ablation. There was no 30-day mortality after RFA. There were major complications (one case of severe vasovagal reflex, one case of hemoperitoneum and one case of a pseudoaneurysm) in three (2.7%) patients, and minor complications (one case of a biloma, one case of subsegmental infarction and one case of abscess) in three (2.7%) patients. Post-ablation syndrome as a side effect was noted in 38 (35.1%) of 108 patients. The primary technique effectiveness rate at 1 month was 95.1% (105/108). Local tumor progression was noted in eight (7.6%) of 105 patients during the follow-up period (range, 3.0–11.5 months; median, 5.8 months; mean, 5.7 months). There was no significant single category to predict complication and local tumor progression (Fisher''s exact test, p >0.05). Contrary to the safety score for the probability of complication (p >0.05), the curability score was significantly associated with the probability of local tumor progression (likelihood ratio test for trend; p =0.03). Conclusion: The new feasibility scoring system for planning US can be used as objective criteria to predict therapeutic efficacy rather than the safety of percutaneous RFA of an HCC. [Copyright &y& Elsevier]

Abstract: Background: The purpose of this study was to evaluate the change in contrast enhancement of HCC on 1-month follow-up CT after local radiotherapy (RT) as an early predictor of final treatment response. Materials: Fifty patients who underwent local RT for HCCs had both pre-RT and post-RT CT scans including 1-month follow-up CT. We assessed the final treatment response by using the change in maximal tumor size on 6–12-month follow-up CT scan after RT. We also evaluated the change in tumor enhancement between pre-RT and 1-month follow-up CT scans. Results: A final treatment response was achieved in 27 (54%) of 50 patients, who showed either a complete response (n =11) or a partial response (n =16). Compared with non-responsive patients (n =23), responsive patients showed a significant decrease in tumor enhancement on 1-month follow-up CT after RT in both objective and subjective analyses (each P <0.001). Conclusion: The change in contrast enhancement of HCC seen on the 1-month follow-up CT in patients after local RT may be used as an early predictor of final treatment response. [Copyright &y& Elsevier]

Background: The aims of this study are to evaluate and compare the accuracies of isotropic multi-detector row CT (MDCT) including multiplanar reconstruction (MPR) images for preoperative staging of endoscopically diagnosed early gastric cancer (eEGC) and advanced gastric cancer (eAGC). Methods: One hundred and five patients with endoscopically proven gastric cancer underwent isotropic MDCT. Three independent radiologists evaluated T and N staging both on transverse images only and on three orthogonal MPR images. The staging of each tumor was surgico-pathologically confirmed. The receiver operating characteristic (ROC) analysis and the Wilcoxon signed ranked test were used for statistical analyses. Results: In 30 eAGCs, the accuracies for T and N staging with MPR imaging were better than those with transverse imaging (each P < 0.05). In 34 eEGCs, however, only the accuracy of T2 or higher with MPR imaging was higher than that with transverse imaging (P < 0.05). Conclusions: Isotropic MDCT with MPR images including coronal or sagittal reconstructions can improve the accuracies of preoperative T and N staging of eAGC, while having little impact on the accuracy for eEGC. [ABSTRACT FROM AUTHOR]

This study is a retrospective evaluation of the correlations between the presence and integrity of the capsule of nodular hepatocellular carcinomas (HCC) by dynamic CT and histopathology, with histopathologic evidence of tumor propagation to surrounding hepatic parenchyma. Dynamic CT scans of 75 nodular HCCs in 73 patients (61 men, 12 women; age range, 32-81; mean, 53) were evaluated regarding capsule visualization and integrity. Histopathologic findings of HCCs in resected specimens were correlated with the presence of a capsule, tumor invasion onto the capsule, and with the presence of microvascular emboli in the surrounding liver parenchyma. On histopathologic examination, capsules were present in 57 of 75 nodular HCCs; the capsules were invaded by tumor in 18 nodules and there were microvascular emboli around the nodular HCC in 49 cases. Capsule visualization by CT was correlated with the presence of capsule by histopathology (P<0.00). Disruption of capsule by CT was correlated with tumor invasion by histopathology (P=0.003) and with microvascular tumor emboli (P<0.00). The presence and structural integrity of HCC capsules on CT was closely correlated with the presence of capsule on histopathology and the absence of microvascular tumor emboli. [ABSTRACT FROM AUTHOR]

Purpose: To verify changes in the signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of hypervascular hepatocellular carcinomas (HCCs) on ferucarbotran-enhanced dynamic T1-weighted MR imaging.Materials and Methods: Fifty-two patients with 61 hypervascular HCCs underwent ferucarbotran-enhanced dynamic MR imaging, and then hepatic resection. Hypervascular HCCs were identified when definite enhancement was noted during the arterial dominant phase of three-phase MDCT. Dynamic MR Images with T1-weighted fast multiplanar spoiled gradient-recalled echo sequence (TR200/TE4.2) were obtained before and 20 s, and 1, 3, 5, and 10 min, after bolus injection of ferucarbotran. We estimated the signal intensities of tumors and livers, and calculated the SNRs and CNRs of the tumors.Results: On ferucarbotran-enhanced dynamic MR imaging, SNR measurements showed a fluctuating pattern, namely, an increase in SNR followed by a decrease and a subsequent increase (or a decrease in SNR followed by a increase and a subsequent decrease) in 50 (82.0%) of 61 tumors, a single-peak SNR pattern (highest SNR on 20 s, 1, 3, or 5 min delayed images followed by a decrease) in seven (11.5%), and a decrease in SNR followed by an increase in four (6.6%). Maximum absolute CNRs with positive value were noted on 10 min delayed images in 41 (67.2%) tumors, and maximum absolute CNRs with negative value were observed on 20 s delayed images in 12 (19.7%) and on 1 min delayed images in eight (13.1%).Conclusion: Despite showing various SNR and CNR changes, the majority of hypervascular HCCs demonstrated a fluctuating SNR pattern on ferucarbotran-enhanced dynamic MR imaging and a highest CNR on 10 min delayed image, which differed from the classic enhancement pattern on multiphasic CT. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To compare the diagnostic performance of a variety of magnetic resonance imaging (MRI) sequences, in order to identify the most effective ferucarbotran-enhanced sequence for the detection of multiple small hepatic VX2 carcinomas in rabbits. Methods: Fifteen rabbits with experimentally induced 135 VX2 carcinomas in the liver underwent ferucarbotran-enhanced MRI using the following nine pulse sequences: a fat-suppressed fast spin-echo (FSE) sequence with two echo times (TE) (proton density- and T2-weighted images), four different T2*-weighted fast multiplanar GRASS (gradient-recalled acquisition in the steady state) (FMPGR) with the combination of three TEs (9, 12, 15ms, respectively) and two flip angles (20°, 80°, respectively), T2*-weighted fast multiplanar spoiled GRASS (FMPSPGR), T1-weighted FMPSPGR, and dynamic T1-weighted FMPSPGR. All images were reviewed by three radiologists with quantitative and qualitative analysis. Results: Tumor-to-liver contrast-to-noise ratio of the proton density-weighted FSE sequence was significantly higher than those of the others (p <0.05). The lesion conspicuities of proton density- and T2-weighted FSE and T2*-weighted FMPGR (TE/flip angle, 9/20° and 12/20°) images were better and the image artifacts of T2*-weighted FMPGR (TE/flip angle, 15/20° and 12/80°) and T2*-weighted FMPSPGR images were more prominent than those of the others (p <0.05). The lesion detection in T2- and proton density-weighted FSE and T2*-weighted FMPGR (TE/flip angle, 12/20°) images were superior to those of the others and for the detection of very small hepatic tumors of less than 5mm, the sensitivities of these sequences were less than 30%. Conclusion: Ferucarbotran-enhanced T2- and proton density-weighted FSE and T2*-weighed FMPGR (TE/flip angle, 12/20°) images were found to be the most effective pulse sequences for the detection of multiple small hepatic VX2 carcinomas but these sequences were limited in the detection of very small hepatic tumors of less than 5mm in size. [Copyright &y& Elsevier]

Background/Aims: The authors conducted a hospital-based case–control study to evaluate the role of Clonorchis sinensis infection as a risk factor for the development of cholangiocarcinoma (CC), including extrahepatic CC, in Korea. Methods: Cases of 185 patients with CC (intrahepatic, 51; hilar, 53; and distal extrahepatic, 81) and matched controls underwent stool microscopy, pathological examinations, serologic test for C. sinensis using ELISA, skin test for C. sinensis, radiologic examinations, and interview concerning history of eating raw freshwater fish. Results: Radiologic evidence of C. sinensis, history of eating raw freshwater fish, and positive serologic result for C. sinensis were found to be related to an increased risk of CC, with the odds ratios (OR)=8.615 (95% confidence interval [CI]=5.045–16.062), OR=2.385 (95% CI=1.527–3.832), and OR=2.272 (95% CI=1.147–4.811), respectively. The risk factors for distal extrahepatic CC were radiologic evidence of C. sinensis (OR=6.571; 95% CI=3.170–15.943) and history of eating raw freshwater fish (OR=2.6; 95% CI=1.294–5.66). Conclusions: Radiologic evidence of C. sinensis, history of eating raw freshwater fish and positive serologic result for C. sinensis were significantly associated with CC, including extrahepatic CC. [Copyright &y& Elsevier]

Purpose: To assess the utility of contrast-enhanced agent detection imaging (ADI) in the assessment of the therapeutic response to percutaneous radiofrequency (RF) ablation in patients with hepatocellular carcinoma (HCC). Materials and Methods: Ninety patients with a total of 97 nodular HCCs (mean, 2.1+/-1.3 cm; range, 1.0-5.0 cm) treated with percutaneous RF ablation under the ultrasound guidance were evaluated with contrast-enhanced ADI after receiving an intravenous bolus injection of a microbubble contrast agent (SH U 508A). We obtained serial contrast-enhanced ADI images during the time period from 15 to 90 s after the initiation of the bolus contrast injection. All of the patients underwent a follow-up four-phase helical CT at 1 month after RF ablation, which was then repeated at 2-4 month intervals during a period of at least 12 months. The results of the contrast-enhanced ADI were compared with those of the follow-up CT in terms of the presence or absence of residual unablated tumor and local tumor progression in the treated lesions. Results: On contrast-enhanced ADI, technical success was obtained in 94 (97%) of the 97 HCCs, while residual unablated tumors were found in three HCCs (3%). Two of the three tumors that were suspicious (was not proven) for incomplete ablation were subjected to additional RF ablation. The remaining one enhancing lesion that was suspicious of a residual tumor on contrast-enhanced ADI was revealed to be reactive hyperemia at the 1-month follow-up CT. Therefore; the diagnostic concordance between the contrast-enhanced ADI and 1-month follow-up CT was 99%. Of the 94 ablated HCCs without residual tumors on both the contrast-enhanced ADI and 1-month follow-up CT after the initial RF ablation, five (5%) had CT findings of local tumor progression at a subsequent follow-up CT. Conclusion: Despite its limitations in predicting local tumor progression in the treated tumors, contrast-enhanced ADI is potentially useful for evaluating the early therapeutic effect of percutaneous RF ablation for HCCs. [ABSTRACT FROM AUTHOR]

Collaborative robots combined with mobile platforms can move freely and have a wide work area. Technological developments in AI and vision have also led to increased research on recognition of objects and surroundings using mobile manipulators. However, even though such trends have resulted in growing demand for research on mobile manipulators, their high prices make them difficult to purchase. We solved this problem using 3D printing. A mobile manipulator was manufactured by replacing more expensive reducers with 3D printed planetary gear and cycloid gear reducers. As well, a mecanum in-wheel motor equipped with a 3D printed cycloid reducer was developed to increase the usability of the interior space of the mobile platform. The study employed a task-space control algorithm, which controls the mobile platform and the manipulator simultaneously to ensure effective control of the mobile manipulator. Task-space motion control performance was verified through Gazebo simulation and experiment. Additionally, the repeatability of the task-space position control was measured through experiments and its performance was compared with a commercial manipulator. Finally, we have developed a mobile manipulator that can perform similar levels of work as a commercial robot at one tenth the price of a general commercial mobile manipulator. [ABSTRACT FROM AUTHOR]

Background: Stereotactic body radiation therapy is an emerging treatment option for patients with unresectable advanced hepatocellular carcinoma (HCC). Because liver parenchyma neighboring the tumor is unavoidably exposed to irradiation, evaluation of treatment response following radiotherapy for HCC is challenging due to increased peritumoral arterial hyperemia and delayed clearance of contrast agent in the tumor. Purpose: To explore which change of magnetic resonance imaging (MRI) features between pre- and post-radiotherapy could help evaluate viability of HCC. Material and Methods: Thirty-nine patients who underwent MRI before and immediately after radiotherapy for HCC were enrolled. Imaging features were assessed before and within three months after radiotherapy and changes of those imaging features were correlated with (i) tumor response at six months after radiotherapy and (ii) time to progression (TTP). Results: On post-radiotherapy MRI, the short-term responders showed significantly higher incidence of negative typical HCC features including arterial enhancement with washout (P = 0.032), hyper-intense T2 signal intensity (P = 0.021), and hyper-intensity on DWI (P < 0.001). On multivariate Cox hazard analysis to estimate TTP, hazard ratios of modified RECIST and disappearance of arterial enhancement with washout were 2.18 and 2.79 (P = 0.087 and 0.029, respectively). Conclusion: Disappearance of arterial enhancement with washout on post-radiotherapy would be strong features for prediction of treatment response after radiotherapy of HCC. [ABSTRACT FROM AUTHOR]

Background Adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR) algorithms have the potential to reduce dose while maintaining image quality. Purpose To compare computed tomography (CT) image quality and diagnostic performance among three reconstruction techniques - ASIR, MBIR, and filtered back projection (FBP) - after transcatheter arterial chemoembolization (TACE) of hepatocellular carcinomas (HCC). Material and Methods Of 60 patients that underwent initial TACE for HCCs, half underwent dynamic liver CT with conventional scanning protocol, and the other half with dose reduction to approximately 60% of conventional exposure. All images were reconstructed using three algorithms: FBP, ASIR, and MBIR. For objective analysis, image noise and signal-to-noise ratio (SNR) were compared. For subjective analysis, three radiologists independently assessed image quality. Ability to detect viable HCCs was also evaluated. Results MBIR and ASIR produced images with less noise and higher SNR compared with FBP regardless of radiation dosage ( P < 0.017). However, in terms of subjective parameters, such as image blotchiness, artifacts, and overall quality, MBIR was inferior to FBP and ASIR ( P < 0.001). Regarding diagnostic performance, there were no significant differences among reviewers in the detection of viable HCCs depending on the reconstruction algorithm, regardless of the dose reduction protocol ( P > 0.017). Conclusion Although subjective evaluations suggest that MBIR images are of lower quality compared with FBP and ASIR regardless of radiation dosage, there were no significant differences among reconstruction algorithms in diagnosis of viable HCC after TACE. [ABSTRACT FROM AUTHOR]

The article examines the risk factors of radiation in patients who are experiencing the procedure of peripherally-inserted central catheterization. It states the evaluation on the use of flat panel detector-based mobile C-arm fluoroscopy and conventional angiography equipment. It also emphasizes the estimation and comparison of dose-area product (DAP), tube voltage and tube current in statistical tests.

Objectives: To develop a prediction model with computed tomography (CT) images and to build a nomogram incorporating known clinicopathologic variables for individualized estimation of epithelial-to-mesenchymal transition (EMT) subtype gastric cancer. Methods: Patients who underwent primary resection of gastric cancer (GC) and molecular subgroup analysis (n = 451) were reviewed. Multivariable analysis using a stepwise variable selection method was performed to build a predictive model for EMT subtype GC. A nomogram using the results of the multivariable analysis was constructed. An optimal cutoff value of total prognostic points of the nomogram for the prediction of EMT subtype was determined. The predictive model for the EMT subtype was internally validated by bootstrap resampling method. Results: There were 88 patients with EMT subtype and 363 patients with non-EMT subtype based on transcriptome analysis. The patient's age, Lauren classification, and mural stratification on CT were variables selected for the predictive model. The area under the curve (AUC) of the model was 0.865, and the validated AUC of the bootstrap sample was 0.860. The optimal cutoff value of total prognostic points for the prediction of EMT subtype was 94.622, with 90.9% sensitivity, 67.2% specificity, and 71.8% accuracy. Conclusion: A predictive model using patient's age, Lauren classification, and mural stratification on CT for EMT molecular subtype GC was made. A nomogram was built which would serve as a useful screening tool for an individualized estimate of EMT subtype. Key Points: • A predictive model for epithelial-to-mesenchymal transition (EMT) subtype incorporating patient's age, Lauren classification, and mural stratification on CT was built. • The predictive model had high diagnostic accuracy (area under the curve (AUC) = 0.865) and was validated (bootstrap AUC = 0.860). • Adding CT findings to clinicopathologic variables increases the accuracy of the predictive model than using only. [ABSTRACT FROM AUTHOR]

Abstract: Objective: The purposes of this study are to evaluate the ex vivo and in vivo efficacy of radiofrequency ablation (RFA) on different porcine tissues by the ablation of three different sites simultaneously. Materials and methods: A multichannel RFA system, enables three separate tumors to be ablated simultaneously, was used. RFA procedures were applied to normal porcine liver, kidney, and muscle together ex vivo (n =12) and in vivo (n =17). Pre-impedances, defined as baseline systemic impedances of tissues before beginning RFA, and the areas of ablation zones were measured and compared. Results: The areas of ablation zones among three organs had a significant difference in decreasing order as follows: liver, muscle, and kidney in the ex vivo study (p =0.001); muscle, liver, and kidney in the in vivo study (p <0.0001). The areas of ablation zones between ex vivo and in vivo had a significant difference in the liver and muscle (each p <0.05). There was no significant correlation between the areas of ablation zones and pre-impedances in both studies. Conclusions: Renal RFA produced the smallest ablation zone in both in vivo and ex vivo studies. Muscular RFA demonstrated the largest ablation zone in the in vivo study, and hepatic RFA showed the largest ablation zone in the ex vivo study. This variability in the tissues should be considered for performing an optimized RFA for each organ site. [Copyright &y& Elsevier]

Abstract: Aim: To date, no data are available on the use of PET/CT for preoperative staging of gastric cancer. We attempted to evaluate the value of PET/CT for preoperative staging of advanced gastric cancer, and to compare the use of PET/CT with contrast-enhanced CT (CECT). Materials and methods: We analyzed PET/CT of 78 patients with surgically proven advanced gastric cancer who had undergone preoperative CECT. Qualitative analysis was conducted by assessing the presence of primary tumors and metastases with PET/CT and CECT. Results: Among 71 patients who underwent a gastrectomy, 69 primary tumors (93%) were diagnosed by PET/CT, while 64 primary tumors (90%) were detected by CECT (p =0.55). For regional lymph node metastasis, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT vs. CECT were 41% vs. 25% (p =0.00019), 100% vs. 92% (p =0.31), 100% vs. 98% (p =0.46), 26% vs. 42% (p =0.14), and 51% vs. 72% (p =0.00089), respectively. Conclusion: Overall, PET/CT showed comparable diagnostic performance to CECT in diagnosing primary tumors and regional lymph node metastases, though PET/CT was inferior to CECT for the sensitivity and accuracy in diagnosing regional lymph node metastases. Nevertheless, PET/CT would be useful when CECT findings were equivocal due to its high positive predictability. [Copyright &y& Elsevier]

Abstract: Purpose: To compare the in vivo gastric injury observed during radiofrequency (RF) ablation of the liver abutting the stomach before and after the intragastric administration of chilled saline. Materials and methods: Twenty RF ablation zones were created in the livers of 10 pigs with a 1-cm-exposed active tip of an internally cooled electrode under ultrasound guidance for 10min. Ten RF ablation zones were created before (non-saline group) and after (saline group) the intragastric administration of approximately 1000mL of chilled saline, and 20 RF ablation zones were made in the posterior part of the left lobe abutting the stomach. The frequency and severity of the thermal injury observed in the stomach of the two groups were compared histologically. Results: All the resected gastric specimens showed thermal injuries of varying degrees of severity. The largest diameter of the gastric injury was significantly smaller in the saline group (mean 1.5cm; range 1.3–1.8cm) than in the non-saline group (mean 2.1cm; range 1.8–2.4cm) (p =0.000). The saline group showed significantly less thermal injury to the muscular layer of the gastric wall by the histopathology (p =0.033). Conclusions: The intragastric administration of chilled saline might be a useful technique for reducing the severity of gastric injury during RF ablation of the liver abutting the stomach. [Copyright &y& Elsevier]

Abstract: To evaluate the clinical significance of indeterminate, small, low-attenuating nodular lesions on helical dynamic computed tomography (CT) in chronic liver diseases, CT images were reviewed retrospectively in 281 patients. Indeterminate, low-attenuating nodular lesions less than 20 mm in diameter were followed for 24 to 35 months. Of 127 nodules in 73 patients, 21 nodules turned out to be hepatocellular carcinomas (16%), 25 nodules (20%) became larger, while the remaining 81 nodules (64%) remained unchanged or disappeared. Some low-attenuating nodules larger than 10 mm in diameter may develop into hepatocellular carcinoma. [Copyright &y& Elsevier]

Background: Sarcopenia has been underscored as a significant predictor of poor prognosis in cancer patients undergoing immunotherapy with programmed death-1 (PD-1) inhibitors. We aimed to investigate the prognostic significance of computed tomography (CT)-determined sarcopenia in patients with microsatellite-stable (MSS) gastric cancer (GC) treated with PD-1 inhibitors. Methods: We retrospectively assessed patients with MSS GC who had been treated with PD-1 inhibitors from March 2016 to June 2019. Pre-treatment sarcopenic status was determined by analyzing L3 skeletal muscle index with abdominal CT. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan–Meier method, and the differences in survival probability according to sarcopenic status were compared using the log-rank test. Cox proportional hazards regression analyses were performed to identify predictors of PFS and OS. Results: Of 149 patients with MSS GC (mean age, 57.0 ± 12.3 years; 93 men), 79 (53.0%) had sarcopenia. Patients with sarcopenia had significantly shorter PFS than patients without sarcopenia (median, 1.4 months vs. 2.6 months; P = 0.026). Sarcopenia was independently associated with shorter PFS (adjusted hazard ratio [HR], 1.79; 95% confidence interval [CI], 1.10−2.93; P = 0.020). Patients with sarcopenia had shorter OS than patients without sarcopenia (median, 3.6 months vs. 4.9 months; P = 0.052), but sarcopenia itself was not a significant prognostic factor for OS (adjusted HR, 1.01; 95% CI, 0.58−1.75; P = 0.974). Conclusions: CT-determined sarcopenia is an independent prognostic factor for PFS in patients with MSS GC treated with PD-1 inhibitors. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • MRI findings were able to discriminate IPNB with an invasive carcinoma from IPNB with intraepithelial neoplasia. • MRI findings of IPNB with an invasive carcinoma were linked to worse clinical outcome. • Tumor multiplicity on MRI was an independent factor for RFS of IPNB after surgery. Background & Aims Imaging characteristics for discriminating the malignant potential of intraductal papillary neoplasm of the bile duct (IPNB) still remain unclear. This study aimed to define the magnetic resonance (MR) imaging findings that help to differentiate IPNB with an associated invasive carcinoma from IPNB with intraepithelial neoplasia and to investigate their significance with respect to long-term outcomes in patients with surgically resected IPNB. Methods This retrospective study included 120 patients with surgically resected IPNB who underwent preoperative MR imaging with MR cholangiography before surgery from January 2008 and December 2017 in two tertiary referral centers. Clinical and MR imaging features of IPNB with intraepithelial neoplasia (n = 34) and IPNB with an associated invasive carcinoma (n = 86) were compared. Regarding significant features for discriminating IPNB with or without an associated invasive carcinoma, recurrence-free survival (RFS) rates were evaluated. Results Significant MR imaging findings for differentiating IPNB with an associated invasive carcinoma from IPNB with intraepithelial neoplasia were intraductal visible mass, tumor size ≥2.5 cm, multiplicity of the tumor, bile duct wall thickening, and adjacent organ invasion (all p ≤0.002). The 1-, 3-, and 5-year RFS rates for surgically resected IPNB were 93.8%, 79.1%, and 70.0%, respectively. RFS rates were significantly lower in patients with each significant MR imaging finding of IPNB with an associated invasive carcinoma than in those without significant MR imaging findings (all p ≤0.039). Conclusions MR imaging with MR cholangiography may be helpful in differentiating IPNB with an associated invasive carcinoma from IPNB with intraepithelial neoplasia. Significant MR imaging findings of IPNB with an associated invasive carcinoma have a negative impact on RFS. Lay summary Significant magnetic resonance imaging findings that differentiated between an intraductal papillary neoplasm of the bile duct (IPNB) with an associated invasive carcinoma and an IPNB with intraepithelial neoplasia were intraductal visible mass, tumor size ≥2.5 cm, multiplicity of the tumor, bile duct wall thickening, and adjacent organ invasion. Significant magnetic resonance imaging findings of invasive IPNB have a negative impact on recurrence-free survival. [ABSTRACT FROM AUTHOR]

In this paper, CMOS wafer level ring oscillator frequency variability improvement >40% is demonstrated by either spatial source/drain activation or ion implantation super scan in FinFET technology. Yield improvement (up to 17%) is verified with better within wafer uniformity and with no intrinsic device performance degradation. Furthermore, the combination of super scan and spatial source/drain activation is suggested for optimized variability improvement benefits from individual device type uniformity tuning (super scan) and all device type uniformity tuning (from spatial S/D activation). [ABSTRACT FROM AUTHOR]

In this study, the effects of high in-situ boron (B) doping in embedded source/drain (S/D) silicon germanium (SiGe) stressor of p-channel Fin Field Effect Transistors (FinFETs) in a 14 nm technology node were investigated. The device results were correlated to physical characteristics of B doped S/D regions which were probed using Transmission Electron Microscopy (TEM), Electron Energy Loss Spectroscopy (EELS) and Low Energy Electron Induced X-ray Emission Spectroscopy (LEXES) on representative device structures. B doping was established to be around low-E20 atoms/cm 3 range as measured by LEXES. Reduction in on-state resistance (R ON ) and an increase in drive current (I ON ) was observed with higher B doping in SiGe but physical constraints, especially B segregation offered manufacturable challenges. These observed results are expected to critically help in SiGe stressor based S/D junction optimization of advanced FinFET Complementary Metal-Oxide-Semiconductor (CMOS) devices. [ABSTRACT FROM AUTHOR]

Opisthorchis viverrini is a group 1 carcinogen that causes cholangiocarcinoma (CCA). Although opisthorchiasis is known to be severely endemic to several areas along the Mekong River in Lao PDR, the CCA status of residents of this region is still under investigation. In this study, we analyzed the results of abdominal ultrasonography (US) performed on 6113 residents in 9 provinces (Vientiane Municipality, Savannakhet, Phongsaly, Khammouane, Saravane, Champasak, Vientiane, Xieng Khuouang, and Luang Prabang provinces) of Lao PDR from 2007 to 2011. Overall, 51 cases (0.83%) were detected with suspected CCA. The CCA rates in Vientiane Municipality and in Savannakhet and Khammouane provinces were 1.45%, 1.58%, and 1.09%, respectively. However, in the other 6 provinces, the rate of CCA averaged only 0.26%. In the 3 provinces with higher rates of CCA, bile duct dilatation (grade ≥ 2) was also significantly more prevalent ( P   <  0.0001). These results are concordant with previous reports showing a higher endemicity of opisthorchiasis in Vientiane Municipality and in Savannakhet and Khammouane provinces. [ABSTRACT FROM AUTHOR]

In this work, we investigated the effect of so-called WF (Work Function) setting anneal (high temperature annealing on TiN/HfO 2 stack) on gate stack properties. It was found that intermixed layer created in-between TiN and HfO 2 during WF setting anneal has negative fixed charge and reduces pFET V t (positive V t shift). In addition, higher anneal temperature further reduces pFET V t while keeping nFET V t almost unchanged. This could be explained by passivation of oxygen vacancies in HfO 2 with diffused oxygen from TiN layer. By combining these effects, one can further push effective work function towards valence band edge which enables wider coverage of transistor V t option. [ABSTRACT FROM AUTHOR]

Purpose: To compare computed tomography (CT) findings in patients with pancreatic metastasis from renal cell carcinoma (pRCC) and patients with hypervascular pancreatic neuroendocrine tumour (pNET) with a focus on the relative percentage washout (RPW).Methods: We evaluated 16 patients with 37 pRCCs and 28 patients with 31 hypervascular pNETs using a protocol consisting of arterial and portal phase CT. Imaging findings were analyzed for comparison between the two groups. The RPW of each tumour using biphasic CT was obtained by two observers for evaluation of diagnostic performance. Interobserver agreement of each value and optimal cut-off level of RPW for discrimination between groups were evaluated.Results: Tumour multiplicity showed significant difference in both groups. The mean RPW of the pRCC group (observer 1, 27.0%; observer 2, 29.4%) was significantly higher than that of the pNET group (observer 1, 0.5%; observer 2, 3.2%) (p<0.001 for each observer). Interobserver agreement for both attenuation values and RPWs was excellent. A RPW value of 19% was selected as the optimal cut-off for pRCC determination, and showed good performance (accuracy 83.8%, sensitivity 83.8%, and specificity 83.9%).Conclusion: With multiplicity, RPW of the tumour on CT could be helpful for differentiating pRCCs from hypervascular pNETs. [ABSTRACT FROM AUTHOR]

Background: Improving gastric accommodation and gastric emptying is an attractive physiological treatment target in patients with functional dyspepsia (FD). We evaluated the effect of DA-9701, a new drug for FD, on gastric motor function after a meal in healthy volunteers using magnetic resonance imaging (MRI). Methods: Forty healthy volunteers were randomly allocated to receive either DA-9701 or placebo. After 5 days of treatment, subjects underwent gastric MRI (60 min before and 15, 30, 45, 60, 90, and 120 min after a liquid test meal). Gastric volume was measured through 3-dimensional reconstruction from MRI data. We analyzed 4 outcome variables including changes in total gastric volume (TGV), proximal TGV, and proximal to distal TGV ratio after a meal and gastric emptying rates after adjusting values at the pre-test meal. Results: Changes in TGV and proximal TGV after a meal did not differ between the DA-9701 and placebo groups (difference between groups -25.9 mL, 95% confidence interval [CI] -54.0 to 2.3 mL, P = 0.070 and -2.9 mL, 95% CI -30.3 to 24.5 mL, P = 0.832, respectively). However, pre-treatment with DA-9701 increased postprandial proximal to distal TGV ratio more than placebo (difference between groups 0.93, 95% CI 0.08 to 1.79, P = 0.034). In addition, pre-treatment with DA-9701 significantly increased gastric emptying as compared with placebo (mean difference between groups 3.41%, 95% CI 0.54% to 6.29%, P = 0.021, by mixed model for repeated measures). Conclusion: Our results suggested that DA-9701 enhances gastric emptying and does not significantly affect gastric accommodation in healthy volunteers. Further studies to confirm whether DA-9701 enhances these gastric motor functions in patients with FD are warranted. Trial Registration: ClinicalTrials.gov [ABSTRACT FROM AUTHOR]

Objective To investigate the early imaging findings and growth rate of pancreatic ductal adenocarcinoma (PDAC), and to assess whether MR imaging detects early PDAC better than CT. Materials and methods The institutional review board approved this retrospective study and waived the requirement for informed consent. Twenty-two patients were included, and two radiologists, by consensus, assessed the presence of focal lesions, interruption of the main pancreatic duct (MPD), MPD dilatation, and pancreatitis, volume doubling time (VDT) of PDAC on prediagnostic MR imaging. Two other observers independently reviewed three image sets (CT images, unenhanced MR images, and unenhanced and contrast-enhanced MR images) for the detection of early PDAC. Paired Wilcoxon signed rank test and receiver operating characteristic (ROC) curve analysis were used for statistical analyses. Results In 20 (90.9%) patients, prediagnostic MR exams showed abnormality, and all of them showed focal lesions on the first abnormal prediagnostic MR exams. Thirteen lesions (65%) showed no MPD interruption and one lesion (5%) was accompanied by pancreatitis. The mean VDT of PDAC was 151.7 days (range, 18.3–417.8 days). Diagnostic performance of unenhanced MR images ( Az , 0.971–0.989) and combined unenhanced and contrast-enhanced MR images ( Az , 0.956–0.963) was significantly better than that of CT images ( Az , 0.565–0.583; p < 0.01) for both observers, Conclusion The most common early imaging finding of PDAC on prediagnostic MR exams was a focal lesion with no MPD interruption with a mean volume doubling time of five months. MR imaging was superior to CT for the detection of early PDAC. [ABSTRACT FROM AUTHOR]

Objective: To determine reliable MRI features of autoimmune pancreatitis (AIP) in the proximal pancreas that could allow its differentiation from pancreatic ductal adenocarcinoma (PDAC). Methods: Twenty-three patients with AIP and 61 patients with PDAC in the proximal pancreas underwent MRI. Two observers analyzed MRI for lesion morphology, hypointensity degree on T1-weighted images, enhancement pattern during dynamic phases, capsule-like rim, presence of cysts and duct penetrating sign, morphology of bile duct, and icicle appearance and tortuosity of the upstream pancreatic duct. Sensitivity and specificity for the diagnosis of AIP were calculated for each category or combined. Results: When isointensity on the portal and late phase of MRI and/or the icicle sign of pancreatic duct are applied, 100 % sensitivity for the diagnosis of AIP in the proximal pancreas was achieved. Applying both mild T1 hypointensity similar to the spleen and the icicle sign enabled 100 % specificity for the diagnosis of AIP by differentiating it from PDAC. Conclusion: The combination of the icicle sign in the upstream pancreatic duct and mild T1 hypointensity or isointensity on portal and late phase of dynamic MRI could be reliable MR features for the diagnosis of AIP in the proximal pancreas by allowing its differentiation from PDAC. Key Points: • The icicle sign of the pancreatic duct is useful for diagnosing AIP. • Mild T1 hypointensity similar to the spleen is useful for diagnosing AIP. • Isointensity on portal and late phases MRI is useful for diagnosing AIP. [ABSTRACT FROM AUTHOR]

Purpose To investigate the impact of intra-tumoral fat detected by chemical-shift MR imaging in predicting the MVI of HCC. Materials and methods Gadoxetic acid-enhanced MR imaging of 365 surgically proven HCCs from 365 patients (306 men, 59 women; mean age, 55.6 years) were evaluated. HCCs were classified into two groups, fat-containing and non-fat-containing, based on the presence of fat on chemical-shift images. Fat-containing HCCs were subdivided into diffuse or focal fatty change groups. Logistic regression analyses were used to identify clinical and MR findings associated with MVI. Results Based on MR imaging, 66 tumors were classified as fat-containing HCCs and 299 as non-fat-containing HCCs. Among the 66 fat-containing HCCs, 38 (57.6%) showed diffuse fatty changes and 28 (42.4%) showed focal fatty changes. MVI was present in 18 (27.3%) fat-containing HCCs and in 117 (39.1%) non-fat-containing HCCs ( P = 0.07). Univariate analysis revealed that serum alpha-fetoprotein (AFP) and tumor size were significantly associated with MVI ( P < 0.001). A multiple logistic regression analysis showed that log AFP (odds ratio 1.178, P = 0.0016), tumor size (odds ratio 1.809, P < 0.001), and intra-tumoral fat (odds ratio 0.515, P = 0.0387) were independent variables associated with MVI. Conclusion Intra-tumoral fat detected with MR imaging may suggest lower risk for MVI of HCC and, therefore, a possibly more favorable prognosis, but the clinical value of this finding is uncertain. [ABSTRACT FROM AUTHOR]

The article reports on the importance of magnetic resonance imaging (MRI) in people with chronic liver disease. Topics discussed include the patients management, the liver cirrhosis diagnosis, and the treatment for liver cancer. Also mentioned are the health management, the hypervascular hepatocellular carcinoma (HCC) patients, and the liver diseases management.

Background: Gastrointestinal stromal tumors (GISTs) and non-GIST subepithelial tumors (SETs) account for about 75 and 25 % of gastric hypoechoic SETs ≥2 cm, respectively. Therefore, identifying preoperative predictive factors for GISTs are required to refine surgical indications. Methods: We performed a retrospective review of 375 surgically resected gastric hypoechoic SETs ≥2 cm. Demographic data and tumor characteristics based on upper endoscopy and CT findings were compared between GIST and non-GIST SETs originating from muscularis propria layer (leiomyomas, Schwannomas, glomus tumors, and ectopic pancreas). Results: In cardia, leiomyomas were found twice more frequently than GISTs (63.6 versus 31.8 %). Perilesional lymph node enlargement (PLNE) was found only in patients with GIST or Schwannomas. Patients with GIST showed a significantly lower rate of PLNE than those with Schwannomas (3.5 versus 29.0 %). In multivariate analysis, tumor site outside cardia (odds ratio, 9.157), absence of PLNE (odds ratio, 11.519), old age, large tumor size, exophytic growth pattern, and ulceration or dimpling were identified as independent preoperative predictive factors for GISTs versus non-GIST SETs. Conclusions: The effort for preoperative pathologic diagnosis such as endosonography-guided tissue sampling might be positively considered for SETs at cardia and SETs with PLNE where the possibility of GIST is low. [ABSTRACT FROM AUTHOR]

Objective The purpose of this study was to investigate the value of enhancement kinetics and ancillary imaging findings on gadoxetic acid-enhanced and diffusion-weighted (DW) MR imaging for diagnosing hepatocellular carcinomas (HCCs) without the typical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease. Materials and methods Eighty-two surgically confirmed HCCs without the typical enhancement pattern (hypervascular in the arterial phase, followed by washout on the portal or equilibrium phases) on triple-phase MDCT were enrolled in this study. The patients were classified into four categories based on the CT density pattern of arterial and equilibrium phases (isodense–isodense, hypodense–hypodense, isodense–hypodense, and hyperdense–isodense) compared to liver parenchyma. Signal intensity of HCCs on T2-weighted images (T2WI), arterial phase, 3 min late-phase, hepatobiliary phase (HBP) and DW images with a b value of 800 s/mm 2 were qualitatively evaluated, and ADC values were measured. Fisher's exact test and Chi-square test were used to compare the frequency and trend of hyperintensity on T2WI, hypointensity on HBP images, hyperintensity on DW images, and histopathologic grades between groups with different CT density patterns. Kruskal–Wallis test was used to compare the ADC value between groups. Results Thirty and 52 HCCs were categorized as hypervascular (hyperdense–isodense) and non-hypervascular HCCs (3, isodense–isodense; 37, hypodense–hypodense; 12, isodense–hypodense), respectively. Most HCCs showed hyperintensity on T2WI (77/82, 93.9%) and DW images (81/82, 98.8%) and hypointensity on HBP images (80/82, 97.6%). Thirty-eight HCCs (38/82, 46.3%) showed typical HCC enhancement pattern on dynamic MR images. There were no significant differences in the frequency and trend of signal intensity on T2WI, HBP images, DW images, and histopathologic grades with regard to the four CT density patterns ( p < 0.05). No significant difference in mean ADC values between groups was identified ( p < 0.05). Conclusion Gadoxetic acid-enhanced and DW MR imaging can help diagnose HCCs with atypical enhancement patterns on multiphasic CT in patients with chronic liver disease. [ABSTRACT FROM AUTHOR]

The article presents a retrospective cohort study on the long-term outcomes of patients who received transarterial chemoembolization (TACE) as the first line of treatment for hepatocellular carcinoma (HCC) infeasible for ultrasound (US)-guided radiofrequency ablation (RFA). The long-term outcomes assessed by the researchers include the patterns of tumor progression and the factors that contributed to patient survival. Details on the materials and methods used by the researchers are discussed.

Purpose There are pros and cons to the use of gadoxetic acid in hepatocellular carcinoma (HCC) workup due to the potential for high false positive diagnosis. This study was conducted to investigate the preoperative diagnostic performance of gadoxetic acid-enhanced MRI protocol including diffusion-weighted imaging (DWI) with emphasis on tumor characterization developed in high risk HCC patients. Materials and methods We included 144 patients (102 men, 42 women; age range 33–74 years) with chronic viral hepatitis or cirrhosis and 183 focal hepatic tumors (size range, 0.4–11.0 cm; mean, 3.2 cm), including 148 HCCs, 13 cholangiocarcinomas, 12 hemangiomas, three hepatocellular adenomas, two focal nodular hyperplasias, and five other tumors. All patients underwent gadoxetic acid-enhanced MRI protocol with DWI. MRIs were independently interpreted by three observers for the detection and characterization of hepatic tumors. Results Sensitivities for detecting all 183 liver tumors were 98.4%, 97.8%, and 96.2% for each observer, respectively, with a 97.5% for pooled data. Among 183 hepatic tumors, 91.3% (n = 167), 87.4% (n = 160), and 86.9% (n = 159) were correctly characterized according to their reference standard by each observer, respectively. In 13 cholangiocarcinomas, one to three were misinterpreted as HCC, and the remaining tumors were correctly characterized by each observer. The accuracies (Az) of MRI for HCC diagnosis were 0.952 for observer 1, 0.906 for observer 2, and 0.910 for observer 3, with 0.922 for pooled data. There was good inter-observer agreement. Conclusion The gadoxetic acid-enhanced MRI including DWI showed a reasonable performance for tumor characterization with high sensitivity for tumor detection in patients with chronic liver disease, despite concerns of high false positive diagnosis of hypervascular tumors. [ABSTRACT FROM AUTHOR]

Angiomyolipomas (AMLs) are relatively rare hamartomatous or benign tumors that occasionally occur as part of tuberous sclerosis complex (TSC). Mutations in either of the two genes, TSC 1 and TSC 2, have been attributed to the development of TSC. Between 1994 and January 2009, 83 patients were diagnosed with AML at the Samsung Medical Center. In that group of patients, 5 (6%) had AML with TSC (AML-TSC). Mutational analysis of the TSC 2 gene was performed using 7 samples from the 5 AML-TSC patients and 14 samples from 14 patients with sporadic AML without TSC (AML-non-TSC). From this analysis, mutations in TSC genes were identified in 5 samples from the AML-TSC patients (mutation detection rate = 71%) and 3 samples from AML-non-TSC patients (mutation detection rate = 21%). In the case of AML-TSC, 6 mutations were found including 3 recurrent mutations and 3 novel mutations, while in the case of AML-non-TSC, 4 mutations were identified once, including 1 novel mutation. Also MLPA analysis of the TSC2 gene showed that TSC2 exon deletion is more frequently observed in AML-TSC patients than in AML-non-TSC patients. This is the first mutation and multiplex ligation-dependent probe amplification (MLPA) analyses of TSC 2 in Korean AMLs that focus on TSC. This study provides data that are representative of the distribution of mutations and exon deletions at TSC genes in clinically diagnosed AML-TSC cases of the Korean population. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: To compare the diagnostic performance of the noncontrast MRI including DWI to the standard MRI for detecting hepatic malignancies in patients with chronic liver disease. Materials and methods: We included 135 patients with 136 histologically-confirmed hepatocellular carcinomas (HCCs), 12 cholangiocarcinomas, and 34 benign lesions (≤ 2.0 cm), and 22 patients with cirrhosis but no focal liver lesion who underwent 3.0 T liver MRI. Noncontrast MRI set (T1- and T2-weighted images and DWI) and standard MRI set (gadoxetic acid-enhanced and noncontrast MRI) were analyzed independently by three observers to detect liver malignancies using receiver operating characteristic analysis. Results: The Az value of the noncontrast MRI (mean, 0.906) was not inferior to that of the combined MRI (mean, 0.924) for detecting malignancies by all observers (P >0.05). For each observer, no significant difference was found in the sensitivity and specificity between the two MRI sets for detecting liver malignancies and distinguishing them from benign lesions (P >0.05), whereas negative predictive value was higher with the combined MRI than with the noncontrast MRI (P =0.0001). When using pooled data, the sensitivity of the combined MRI (mean 94.8%) was higher than that of the noncontrast MRI (mean, 91.7%) (P =0.001), whereas specificity was equivalent (78.6% vs 77.5%). Conclusion: Noncontrast MRI including DWI showed reasonable performance compared to the combined gadoxetic acid-enhanced and noncontrast MRI set for detecting HCC and cholangiocarcinoma and differentiating them from benign lesions in patients with chronic liver disease. [Copyright &y& Elsevier]

Objectives: To assess the added value of diffusion-weighted imaging (DWI) to conventional magnetic resonance imaging (MRI) for differentiating benign from malignant bile duct strictures. Methods: Twenty-seven patients with a benign stricture and 42 patients with a malignant stricture who had undergone gadoxetic acid-enhanced MRI with DWI were enrolled. Qualitative (signal intensity, dynamic enhancement pattern) and quantitative (wall thickness and length) analyses were performed. Two observers independently reviewed a set of conventional MRI and a combined set of conventional MRI and DWI, and receiver operating characteristic (ROC) curve analysis was assessed. Results: Benign strictures showed isointensity (18.5-70.4 %) and a similar enhancement pattern (22.2 %) to that of normal bile duct more frequently than malignant strictures (0-40.5 % and 0 %) on conventional MRI ( P < 0.05). Malignant strictures (90.5-92.9 %) showed hypervascularity on arterial and portal venous phase images more frequently than benign strictures (37.0-70.4 %) ( P < 0.01) On DWI, all malignant strictures showed hyperintensity compared with benign cases (70.4 %) ( P < 0.001). Malignant strictures were significantly thicker and longer than benign strictures ( P < 0.001). The diagnostic performance of both observers improved significantly after additional review of DWI. Conclusions: Adding DWI to conventional MRI is more helpful for differentiating benign from malignant bile duct strictures than conventional MRI alone. Key points: • Accurate diagnosis and exclusion of benign strictures of bile duct are important. • Diffusion-weighted MRI helps to distinguish benign from malignant bile duct strictures. • DWI plus conventional MRI provides superior diagnostic accuracy to conventional MRI alone. [ABSTRACT FROM AUTHOR]

The article focuses on the techniques in predicting benign pancreatic neuroendocrine tumors (NETs). It is mentioned that the NETs have a wide variety of biological behavior, ranging from completely benign to highly aggressive tumors and abdominal magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) that may be useful for differentiating benign pancreatic NETs from non-benign pancreatic NETs.

Purpose: To determine the feasibility of using blood oxygenation level-dependent (BOLD) MRI in the characterization of hepatic tumors. Methods: A total of 100 patients with 43 hepatocellular carcinomas (HCCs), 36 metastases, 17 cholangiocarcinomas, and 23 hemangiomas underwent gadoxetic acid-enhanced and BOLD MRI at 3T. BOLD MRI was performed using a multiple fast-field echo sequence (TR/TE, 290/10-28; slice thickness 5 mm) to generate 20 T2*-weighted images. The T2* value of each tumor were calculated. On a color-coded T2* map, tumors were classified into five categories of high signal intensity (strong, moderate, rim, mild) and iso-intensity, which was correlated with the enhancement pattern on dynamic phases by two observers. Results: The mean T2* value (ms) of hemangiomas (97.3 ± 20.2) was the highest, followed by HCCs (48.4 ± 12.7), metastases (37.1 ± 10.5), and cholangiocarcinomas (36.6 ± 11.1). These values were significantly different (hemangioma vs. others tumors and HCC vs. metastasis or cholangiocarcinoma) ( P ≤ 0.001). The agreement between the T2* color map and dynamic images was moderate for all tumors ( k = 0.544), good for tumors >2.0 cm ( k = 0.666), and fair for tumors ≤2.0 cm ( k = 0.334). With the gadoxetic acid-enhanced MRI used as a reference, the sensitivities of BOLD MRI (T2* color map) for displaying hypervascularity of HCC (categories of 1-3) were 81.0 % ( n = 34/42) and 78.6 % ( n = 33/42) for both observers. Conclusion: Liver BOLD MRI has a potential to predict the vascular pattern of hepatic tumors. [ABSTRACT FROM AUTHOR]

The article presents a study which evaluates the potential of magnetic resonance imaging (MRI) in differentiating ectopic pancreas from submucosal tumors in the upper gastrointestinal tract (UGI) tract. It is inferred that the gastric body was the most common location for submucosal tumors and the duodenum for ectopic pancreas. According to the study, MRI with diffusion-weighted imaging (DWI) is a valuable tool for differentiating ectopic pancreas from submucosal tumors.

Objective: To evaluate the risk factors affecting early diffuse recurrence within 1 year of percutaneous ultrasound-guided radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC).Methods: Out of 146 patients who received transcatheter arterial chemoembolisation (TACE) for treatment of recurrent HCC after percutaneous ultrasound-guided RFA, we selected 23 patients with early diffuse recurrence. Early diffuse recurrence was defined as three or more new recurrent HCCs within 1 year of initial RFA. As a control group, we selected 23 patients, matched exactly for age and sex, in which there was no local tumour progression or new recurrence after RFA. To analyse the risk factors, we examined patient factors and tumour factors.Results: Recurrent tumours occurred from 30 to 365 days after RFA (median time, 203 days). Univariate analysis indicated that larger tumour size and poorly defined margin were significant risk factors (P < 0.05). Multivariate analysis indicated that poorly defined margin was a significant risk factor (P < 0.05).Conclusion: Larger tumour size and poorly defined margin may be risk factors for early diffuse recurrence of HCC within 1 year of RFA. Tumours with such risk factors should be treated with a combination of TACE to minimise the potential for therapeutic failure. [ABSTRACT FROM AUTHOR]

Background & Aims: The aim was to assess 10-year outcomes of radiofrequency ablation as a first-line therapy of early-stage hepatocellular carcinoma with an analysis of prognostic factors. Methods: From April 1999 to April 2011, 1305 patients (male:female=993:312; mean age, 58.4years) with 1502 early-stage hepatocellular carcinomas (mean size, 2.2cm) were treated with percutaneous radiofrequency ablation as a first-line option. Follow-up period ranged from 0.4 to 146.6months (median, 33.4months). We assessed the 10-year follow-up results of recurrences and survival with the analyses of prognostic factors. Results: Recurrences occurred in 795 patients (1–17 times), which were managed with various therapeutic modalities. The cumulative local tumor progression rates were 27.0% and 36.9% at 5 and 10years, respectively, for which the only significant risk factor was large tumor size (B=0.584, p =0.001). Cumulative intrahepatic distant and extrahepatic recurrence rates were 73.1% and 88.5%, and 19.1% and 38.2% at 5 and 10years, respectively. Corresponding overall survival rates were 59.7% and 32.3%, respectively. Poor survival was associated with old age (B=0.043, p =0.010), Child-Pugh class B (B=−1.054, p<0.001), absence of antiviral therapy during follow-up (B=−0.699, p =0.034), and presence of extrahepatic recurrence (B=0.971, p =0.007). Conclusions: Ten-year survival outcomes after percutaneous radiofrequency ablation as a first-line therapy of hepatocellular carcinoma were excellent despite frequent tumor recurrences. Overall survival was influenced by age, Child-Pugh class, antiviral therapy, or extrahepatic recurrence. [ABSTRACT FROM AUTHOR]