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PurposeTo investigate the utility of preoperative multiparametric magnetic resonance imaging (mpMRI)-based clinical-radiomic analysis combined with machine learning (ML) algorithms in predicting the expression of the Ki-67 proliferative index and p53 tumor suppressor protein in patients with meningioma.MethodsThis multicenter retrospective study included 483 and 93 patients from two centers. The Ki-67 index was classified into high (Ki-67≥5%) and low (Ki-67ResultsIn the multivariate analysis, larger tumor volumes (pConclusionThe present study developed clinical-radiomic ML models to non-invasively predict Ki-67 and p53 expression in meningioma using mpMRI features, and provides a novel non-invasive strategy for assessing cell proliferation.

PurposeTo develop and validate deep learning-based automatic brain segmentation for East Asians with comparison to data for healthy controls from Freesurfer based on a ground truth.MethodsA total of 30 healthy participants were enrolled and underwent T1-weighted magnetic resonance imaging (MRI) using a 3-tesla MRI system. Our Neuro I software was developed based on a three-dimensional convolutional neural networks (CNNs)-based, deep-learning algorithm, which was trained using data for 776 healthy Koreans with normal cognition. Dice coefficient (D) was calculated for each brain segment and compared with control data by paired t-test. The inter-method reliability was assessed by intraclass correlation coefficient (ICC) and effect size. Pearson correlation analysis was applied to assess the relationship between D values for each method and participant ages.ResultsThe D values obtained from Freesurfer (ver6.0) were significantly lower than those from Neuro I. The histogram of the Freesurfer results showed remarkable differences in the distribution of D values from Neuro I. Overall, D values obtained by Freesurfer and Neuro I showed positive correlations, but the slopes and intercepts were significantly different. It was showed the largest effect sizes ranged 1.07–3.22, and ICC also showed significantly poor to moderate correlations between the two methods (0.498 ≤ ICC ≤ 0.688). For Neuro I, D values resulted in reduced residuals when fitting data to a line of best fit, and indicated consistent values corresponding to each age, even in young and older adults.ConclusionFreesurfer and Neuro I were not equivalent when compared to a ground truth, where Neuro I exhibited higher performance. We suggest that Neuro I is a useful alternative for the assessment of the brain volume.

Aging process is associated with gradual change of liver function and structure. The goal of this study was to evaluate age-related hemodynamic changes in the portal vein (PV) using four-dimensional (4D) flow MRI in healthy adults. A total of 120 healthy subjects were enrolled and categorized into groups A (n = 25, 30–39 years), B (n = 31, 40–49 years), C (n = 34, 50–59 years), and D (n = 30, 60–69 years). All subjects underwent 4D flow data acquisition using a 3-T MRI system to measure the hemodynamic parameters in the main PV. The clinical characteristics and 4D flow parameters were compared among the groups using analysis of variance and analysis of covariance after controlling for significant covariates, accordingly. The outcome metric applying the age-related quadratic model to estimate the age at which 4D flow parameters are the highest (the peak age) as well as the rates of age-related 4D flow changes was estimated. The average area, average through-plane velocity, peak velocity magnitude, average net flow, peak flow, and net forward volume in group D were significantly lower than those in groups A, B and C (P P P

Direct comparative results of patients with early stiffness after arthroscopic rotator cuff repair (ARCR) with and without steroid injection are still unclear. This study aimed to evaluate the clinical and structural effect of intra-articular steroid injection for early stiffness after ARCR.From 2011 and 2016, a total of 417 patients who underwent ARCR for less than medium-sized tears with 35.8 ± 22.6 months follow-up were retrospectively analyzed. Patients with shoulder stiffness [forward flexion (FF) 120˚] or pain at 2 months after ARCR were performed intra-articular steroid injection, and four groups were established [+ stiffness/ + injection (SI, 158 patients), + stiffness/-injection (SNI, 92 patients), -stiffness/ + injection (NSI, 33 patients), and -stiffness/-injection (NSNI, 134 patients)]. Shoulder range-of-motion (ROM) and functional score changes for over two years were analyzed, and six month tendon integrity were evaluated using magnetic resonance imaging.Comparing SI and SNI group, ROM (except internal rotation) and functional score changes did not differ during the early period (2-6 and 2-12 months). However, comparing whether steroid injected (SI/NSI) or not (SNI/NSNI), the formers showed significantly higher improvement of both ROM and functional scores during the early and late period (2-24 months). A six month tendon integrity was not different across four groups and whether steroid injected or not.Intra-articular steroid injections do not appear to have a short-term clinical improving effect by comparing patients with stiff shoulders after ARCR with and without steroid injections. However, intra-articular steroid injection at two months after ARCR did not affect the tendon integrity at post-operative six months.

In this study, we investigated the effects of boron content on the toughness of a 500 MPa-class structural steel weld. Submerged arc welding was performed using welding consumables with boron contents of 0, 0.001, and 0.003 wt% for heat input conditions of 34, 42, and 56 kJ/cm, respectively. The addition of boron reduced the grain boundary ferrite (GBF) and ductile–brittle transition temperature, resulting in improved impact toughness. Moreover, the addition of 0.001 wt% boron further increased the toughness of the weld metal. This was because the presence of boron at the austenite grain boundaries reduced its surface energy, thus delaying ferrite nucleation. In addition, the minor boron element prevented the formation of grain boundary ferrite (GBF) structures during solidification, and an acicular ferrite structure was created in the alloy during sufficiently slow cooling rates (higher heat input condition).

High-strength alloys of Al-xZn-3Cu (x = 20, 30, 40 wt pct) are developed for die-casting process. The maximum tensile strength of the developed alloy is 435 MPa, with a stain to fracture of ~ 4 pct. Microstructural investigation shows that the grain size of α-Al gradually decreases and the area of the Zn-rich region increases as the amount of Zn increases. Local symmetry investigation reveals that the major phase of α-Al contains very fine nanoprecipitations of Zn phase (

Magnetic resonance imaging (MRI) has become a crucial tool for evaluating mediastinal masses considering that several lesions that appear indeterminate on computed tomography and radiography can be differentiated on MRI. Using a three-compartment model to localize the mass and employing a basic knowledge of MRI, radiologists can easily diagnose mediastinal masses. Here, we review the use of MRI in evaluating mediastinal masses and present the images of various mediastinal masses categorized using the International Thymic Malignancy Interest Group's three-compartment classification system. These masses include thymic hyperplasia, thymic cyst, pericardial cyst, thymoma, mediastinal hemangioma, lymphoma, mature teratoma, bronchogenic cyst, esophageal duplication cyst, mediastinal thyroid carcinoma originating from ectopic thyroid tissue, mediastinal liposarcoma, mediastinal pancreatic pseudocyst, neurogenic tumor, meningocele, and plasmacytoma.

This study aimed at investigating the feasibility of bioluminescence imaging (BLI) with engineered Salmonella typhimurium (ΔppGpp S. typhimurium) for visualizing acute hypoxic/ischemic bowels. At the start of 12- or 24-h reperfusion, ΔppGpp S. typhimurium was injected into the lateral tail veins of rats in which three segments of the small intestine were respectively subjected to 2, 3, and 4 h of ischemia. BLI and magnetic resonance imaging were performed at each reperfusion time point. Bioluminescence was exclusively detected in the hypoxic/ischemic segment of the intestine, showing the ability of ΔppGpp S. typhimurium to specifically target and proliferate in a hypoxic/ischemic area. Serial monitoring of these rat models revealed a progressive increase in bacterial bioluminescence in the ischemic intestines in conjunction with viable bacterial counts. The viable bacterial counts were positively correlated with lactate dehydrogenase levels after 24 h of reperfusion following 3 or 4 h of ischemia as well as interleukin-6 levels after 24 h of reperfusion following 4 h of ischemia. Our findings demonstrated that BLI was able to detect the acute hypoxic/ischemic bowel via monitoring of the distribution, internalization, and activity of administered ΔppGpp S. typhimurium. These findings may be useful for the early diagnosis of ischemic bowel disease., Graphical Abstract, Genetically engineered bacteria, ΔppGpp S. typhimurium, showed the ability to specifically target and proliferate in acute hypoxic/ischemic bowel, which could be detected via monitoring of the distribution, internalization, and activity of administered ΔppGpp S. typhimurium using bioluminescence imaging. These findings may be useful for early diagnosis of acute mesenteric ischemia.

Background of the Study.The purpose of this study was to test a mediation model that describes the pathwaysthrough which female North Korean defectors’ perceived physical health and Post-traumatic stress disorder(PTSD) symptoms may be associated with their quality of life. Specifically, we aimed to investigate whether socialsupport would mediate the association between North Korean defectors’ perceived physical health and PTSDsymptoms and their quality of life. Methods. The study sample included 172 female North Korean defectorsliving in South Korea. Participants completed a health condition checklist, the Posttraumatic Stress DisorderChecklist-Civilian Version (PLC-C), the Multidimensional Scale of Perceived Social Support (MSPSS), andthe Korean version of the Short-Form 8-Item Health Survey (SF-8). Results. The structural equation modelconfirmed the hypothesized mediation model, with the following indices: χ2 (38) = 86.184, CFI = 0.97, NFI =0.95, TLI = 0.96, RMSEA = 0.08 (90% CI: 0.06 - 0.10). Discussion. Our findings could help counselors understandunique issues that women refugees may experience as well as protective factors in their life (i.e., social support).

The goal of this study was to determine the diagnostic performance of in vivo quantitative proton magnetic resonance spectroscopy (1H-MRS) to identify the presence of esophageal varices needing treatment (VNT), as well as investigate its correlation with clinical characteristics in patients with liver cirrhosis. Forty cirrhotic patients without VNT showing the negative red color sign, and 40 cirrhotic patients with VNT showing positive red color sign underwent laboratory tests, esophago-gastro-duodenoscopy, and 1H-MRS with single-voxel localization in the cirrhotic liver parenchyma. The levels of lactate + triglyceride (TG) and choline in cirrhotic patients with VNT were significantly higher than those in cirrhotic patients without VNT. In multivariate analysis, spleen diameter, platelet count, and platelet count/spleen diameter ratio, as well as lactate + TG, and choline were associated with the presence of VNT. Moreover, lactate + TG and choline levels were positively correlated with spleen diameter and negatively correlated with platelet count in the combined group of cirrhotic patients with and without VNT. Our study demonstrated that higher hepatic lactate + TG and choline levels in cirrhotic patients in conjunction with longer spleen diameter, lower platelet counts, and lower ratios of platelet count to spleen diameter were associated with the presence of esophageal VNT and the risk of developing variceal bleeding. Therefore, in vivo 1H-MRS might be an effective tool for diagnosing and predicting esophageal VNT in patients with liver cirrhosis.

Hydatid disease in humans is a parasitic disease typically caused by the larvae of Echinococcus granulosus. Although the disease can occur in any body part, it most frequently affects the liver. Hydatid disease is usually diagnosed incidentally and presents with various types of cystic lesion in the infected anatomical locations. Among the many potential complications of hepatic hydatid cysts, including rupture, infection, biliary communication, and peritoneal seeding, spontaneous rupture of the cyst into the hollow viscera is exceptionally rare and has been reported in less than 0.5% of cases. We report the case of a patient with hepatic hydatid disease complicated by spontaneous rupture into stomach causing gastric ulcer and peritoneal seeding.

Primary angiosarcomas of the kidney are very rare, but highly aggressive tumors showing poor prognosis. Patients frequently complain of flank pain, hematuria, or a palpable mass. We present a case of primary renal angiosarcoma occurring in a 61-year-old man. CT images depicted a huge exophytic mass (16 cm in diameter) in the right kidney, exhibiting extensive hemorrhage. The mass showed centripetal peripheral nodular enhancement on dynamic contrast-enhanced images. Furthermore, MR imaging revealed a tangled mesh of tumor vessels in the periphery of the mass. We suggest its inclusion in the differential diagnosis of cases of hemorrhagic renal tumors with prominent vasculature.

Alport Syndrome (AS) is a genetic disorder characterized by impaired kidney function. The development of a noninvasive tool for early diagnosis and monitoring of renal function during disease progression is of clinical importance. Hyperpolarized 13C MRI is an emerging technique that enables non-invasive, real-time measurement of in vivo metabolism. This study aimed to investigate the feasibility of using this technique for assessing changes in renal metabolism in the mouse model of AS. Mice with AS demonstrated a significant reduction in the level of lactate from 4- to 7-week-old, while the levels of lactate were unchanged in the control mice over time. This reduction in lactate production in the AS group accompanied a significant increase of PEPCK expression levels, indicating that the disease progression in AS triggered the gluconeogenic pathway and might have resulted in a decreased lactate pool size and a subsequent reduction in pyruvate-to-lactate conversion. Additional metabolic imaging parameters, including the level of lactate and pyruvate, were found to be different between the AS and control groups. These preliminary results suggest that hyperpolarized 13C MRI might provide a potential noninvasive tool for the characterization of disease progression in AS.

Background: The goal of this study was to determine the diagnostic performance of in vivo quantitative proton magnetic resonance spectroscopy (1H-MRS) to identify the presence of esophageal varices needing treatment (VNT), as well as to investigate its correlation with clinical variables in patients with liver cirrhosis. Methods: Forty cirrhotic patients without VNT showing negative red color sign, and 40 cirrhotic patients with VNT showing positive red color sign underwent laboratory tests, esophago-gastro-duodenoscopy, and 1H-MRS with single-voxel localization in cirrhotic liver parenchyma. Results: The levels of lactate+triglyceride (TG) and choline in cirrhotic patients with VNT were significantly higher than those of cirrhotic patients without VNT. Lactate+TG and choline levels were positively correlated with spleen diameter and negatively correlated with platelet count in the combined group of cirrhotic patients with and without VNT. In cirrhotic patients with VNT, older age, longer spleen diameter, lower platelet counts, and lower ratios of platelet count/spleen diameter were independently associated with an increase of lactate+TG and choline metabolites in the presence of esophageal VNT. Additionally, the area under the curve used to distinguish cirrhotic liver with VNT from cirrhotic liver without VNT was 1.00 (95% confidence interval [CI]: 0.95–1.00) for lactate+TG and 0.67 (95% CI 0.55–0.77) for choline. Conclusions: Our study demonstrated that higher hepatic lactate+TG and choline levels in cirrhotic patients in conjunction with longer spleen diameter, lower platelet counts, and lower ratios of platelet count to spleen diameter were associated with the presence of esophageal VNT and the risk of developing variceal bleeding. Therefore, in vivo, 1H-MRS may be an effective tool for diagnosing and predicting esophageal VNT in patients with liver cirrhosis.

OBJECTIVE To evaluate whether androgen receptor expression in triple-negative breast cancer (TNBC) is associated with F-fluorodeoxyglucose (FDG) uptake and to identify predictive factors of F-FDG uptake in TNBC. METHODS We retrospectively assessed data of 156 surgically resected primary TNBC in 156 consecutive patients who underwent F-FDG PET/computed tomography between July 2013 and May 2017. Clinicopathologic features, including androgen receptor expression, were categorized and the distribution of maximum standardized uptake value (SUVmax) was compared between the groups. We also evaluated the correlations between the predictive factors and SUVmax. RESULTS Median SUVmax was higher in the androgen receptor-negative group than in the androgen receptor-positive group (8.8 vs. 7.1, P = 0.026) with negative correlation between androgen receptor and SUVmax (P = 0.041, correlation coefficient (r) = -0.163). On multivariate regression analysis, tumor size (>20 mm), histological grade, Ki-67 (≥14%), and the presence of ductal carcinoma in situ (DCIS) were significantly associated with SUVmax (P

To compare the per-patient diagnostic performance of simulated abbreviated MRI (AMRI) to that of conventional MRI (CMRI) with full-sequence dynamic gadoxetic acid (GA) enhancement for early-stage hepatocellular carcinoma (HCC) screening in high-risk patients.A total of 201 consecutive patients at high-risk for HCC, who underwent 3T liver MRI, were included in this retrospective study. The AMRI protocol comprised T2-weighted imaging, hepatobiliary phase imaging after GA injection, and diffusion-weighted imaging. For each patient, two AMRI and CMRI image sets were independently reviewed by two radiologists. Inter-reader agreement was assessed using Cohen's kappa value. A composite reference standard was used to determine the diagnostic performance of each image set for each reader.A total of 93 HCCs were detected in 79 patients. The inter-reader agreement was almost perfect for both image sets (κ = 0.839, 0.948). In AMRI, the per-patient sensitivity and negative predictive values (NPV) were 94.9% and 96.4%, respectively. In CMRI, the per-patient sensitivity and NPV were 96.2% and 97.5%, respectively.AMRI, using only three sequences, had a comparable diagnostic performance to CMRI in screening early-stage HCC. AMRI could be an alternative HCC screening tool for high-risk HCC patients.고위험 환자에서 초기 간암 선별 검사로써 단축 자기공명영상 검사의 환자별 진단능을기존의 고식적 간 자기공명영상검 사와 비교하고자 한다.간암 고위험군에서 간 자기공명영상 검사를 시행 받은 총 201명의 환자에 대해연구를 시행하였다. 단축 자기공명영상 검사 군의 프로토콜은 T2 강조영상, 담도기 T1 강조영상, 확산강조영상 등으로 구성되며, 두 명의 영상의학과 의사가 각각 의 환자에 대해 후향적으로 단축 자기공명영상검사 군 및 고식적 자기공명영상검사 군, 두 군의 영상을 독립적으로 평가하였다. 두 연구자 간 일관성은 Cohen's kappa 값을 이용하여 비교하였다. 복합적인참조표준을 이용하여 두 군에서 각각 진단능을 평가하여 비교하였다.79 명의 환자에서 총 93개의 간암이 발견되었다. 두 연구자 간 일관성은 두 군에서 모두매우 양호하였다(κ = 0.839, 0.948). 단축 자기공명영상검사 군에서 민감도 및 음성예측도는각각 94.9% 및 96.4%였으며, 이는 고식적 자기공명영상검사군과 큰 차이를 보이지 않았다 (96.2%, 97.5%).단축 자기공명영상검사는 고식적 자기공명영상검사에 비교하여 임상적으로 허용 가능한민감도와 음성예측도를 갖는다. 따라서 간암 고위험군 환자에서 간암 선별검사로써 새로운 대안이 될 수 있을 것이다.

Liver cirrhosis (LC) can develop hepatocellular carcinoma (HCC). However, noninvasive early diagnosis of HCCs in the cirrhotic liver is still challenging. We aimed to quantify the hepatic metabolites in normal control (NC), cirrhotic liver without HCC, cirrhotic liver with HCC (CLH), and early-stage HCC groups using proton magnetic resonance spectroscopy (1H-MRS) with a long echo-time (TE) and to assess the potential association between the levels of hepatic metabolites in these four groups and aging and enzymatic activity. Thirty NCs, 30 viral hepatitis-induced LC patients without HCC, and 30 viral hepatitis-induced LC patients with HCC were included in this study. 1H-MRS measurements were performed on a localized voxel of the normal liver parenchyma (n = 30) from NCs, cirrhotic liver parenchyma (n = 30) from LC patients without HCC, and each of the cirrhotic liver parenchyma (n = 30) and HCC (n = 30) from the same patients in the CLH group. Generalized estimating equations were used to evaluate potential risk factors for changes in metabolite levels. Potential associations between metabolite levels and age and serum enzymatic activities were assessed by correlation analysis. The levels of lactate+triglyceride (Lac+TG) and choline (Cho) in HCC were significantly higher compared to those in LC and CLH. A potential risk factor for changes in the Lac+TG and Cho levels was age, specifically 60&ndash, 80 years of age. In particular, the Lac+TG level was associated with a high odds ratio of HCC in males aged 60&ndash, 80 years. The Lac+TG and Cho concentrations were positively correlated with lactate dehydrogenase and alkaline phosphatase activities, respectively. Our findings suggested that 1H-MRS measurement with a long TE was useful in quantifying hepatic Lac+TG and Cho levels, where higher Lac+TG and Cho levels were most likely associated with HCC-related metabolism in the viral hepatitis-induced cirrhotic liver. Further, the level of Lac+TG in HCC was highly correlated with older age and lactate dehydrogenase activity.

Developmental anomalies and anatomic variants of the pancreas vary widely, and most of them are encountered incidentally during radiologic evaluation. However, some of these anomalies and variants are potentially pathologic and may cause various clinical presentations in childhood or adulthood. The early identification of these entities in various imaging modalities including ultrasound, computed tomography (CT), and magnetic resonance (MR) imaging would be valuable in making correct diagnoses and, in turn, preventing unnecessary additional procedures. In order to differentiate these entities, it is fundamental to understand the embryologic development and normal anatomical structure of the pancreas. In this article, we review the embryology and normal anatomy of the pancreas, and diagnostic pitfalls of developmental anomalies and anatomic variants in various pancreatic imaging modalities.

Background & aims Despite a number of studies addressing the pathophysiology of hepatic IRI, a gold standard test for early diagnosis and evaluation of IRI remains elusive. This study investigated the metabolic alterations in a rat model of hepatic IRI using the in vivo hyperpolarized ¹³C MRS and metabolic imaging. Methods Hyperpolarized 13 C MRS with IVIM-DWI was performed on the liver of 7 sham-operated control rats and 7 rats before and after hepatic IRI. Results The hepatic IRI-induced rats showed significantly higher ratios of [1-13 C] alanine/pyruvate, [1-13 C] alanine/tC, [1-13 C] lactate/pyruvate and [1-13 C] lactate/tC compared with both sham-operated controls and rats before IRI, whereas [1-13 C] pyruvate/tC ratio was decreased in IRI-induced rats. In IVIM-DWI study, apparent diffusion coefficient (ADC), f and D values in rats after hepatic IRI were significantly lower than those of rats before IRI and sham-operated controls. The levels of [1-13 C] alanine and [1-13 C] lactate were negatively correlated with ADC, f and D values, whereas the level of [1-13 C] pyruvate was positively correlated with these values. Conclusions The levels of [1-13 C] alanine, [1-13 C] lactate and [1-13 C] pyruvate in conjunction with IVIM-DWI will be helpful to evaluate the hepatic IRI as well as these findings can be useful in understanding the biochemical mechanism associated with hepatic damage.

Background Transdiaphragmatic extension of pyogenic liver abscess is the rarest cause of pericarditis and pleural empyema. It is a rapidly progressive and highly lethal infection with mortality rates reaching 100% if left untreated. However, the transmission route, treatment methods and prognosis have not been well studied. Case presentation A 65-year-old male patient presented with a fever, dyspnea, and right upper quadrant abdominal pain. Computed tomography of the chest and abdomen showed huge liver abscess without full liquefaction in the left lobe, large amount of left pleural effusion, and mild pericardial effusion, and the patient was treated with parenteral antibiotics and pigtail insertion at the left pleura. However, four days later, cardiac tamponade was developed and surgical drainage of the abscess and pericardium was performed. Klebsiella pneumonia was isolated from pleural empyema. Twenty-five days after surgery, the patient was discharged without any complications. Conclusions Herein, we report a rare case of pleural empyema and pericarditis in that resulted from the extension of huge pyogenic liver abscess. Early surgical treatment may have prevented progression of the pericarditis to the more dismal purulent pericarditis. We also review pertinent English literature on pericarditis as a complication of PLA.

The cooling efficiency of aluminum die-casting molds is critical to prevent soldering, extend mold life and manufacture high quality castings. In this paper, we discuss a method of inserting a pure copper (Cu) lining using explosive expansion bonding process. A pure Cu bush was inserted into a cooling channel of die casting mold and bonded to the inner surface of the cooling channel through explosive bonding technology to form a copper lining in the cooling channel to improve the cooling performance of high pressure die casting (HPDC) mold fabricated from SKD61 material. Furthermore, the microstructure and mechanical properties of the bonding zone between the SKD61 tool steel and pure Cu lining were analyzed. By changing the thickness of the Cu bush, stand-off distance between the Cu bush and the predrilled cooling hole, and mold heat treatment sequence, the optimal explosive bonding process parameters were established for these cases. A high-frequency induction heating-cooling system was used to examine, the performance of the cooling channel sample bonded with pure copper lining, and it was confirmed that the cooling rate was improved by 12 %. After inserting the pure copper lining into the cooling channel for a practical die casting application, it was confirmed that the mold temperature was lowered, and soldering was prevented. The explosive bonding technology used in this study is an effective method to bond pure copper lining onto the inner surface of a cooling channel, thereby providing an alternative approach to increasing the cooling efficiency.

In this study, an explosive welding process was developed and tested to improve the cooling efficiency of a die casting mold, which was blocked on one side. After explosive welding, the microstructure and mechanical properties of the SKD61–pure Cu cylindrical molds were investigated. The stand-off distance and flyer material (Cu) thickness increased with the wave height (pocket morphology) at the interface of the sample. The shear strength also increased with the flyer material thickness and the stand-off distance. The thermal conductivity and cooling performance were also characterized, and it was revealed that the cooling effect of the SKD61 tool alloy + Cu explosive-welded sample was faster than that of the non-explosive-welded sample (approximately 15.8% of the cooling time decreased upon cooling from 270 °C to 25 °C). Data availability The raw/processed data required to reproduce the current findings cannot be publicly available at this time as the data also forms part of an ongoing study.

Summary Background CT radiation is arguably carcinogenic. Results from single-centre studies, mostly retrospective, have advocated lowering the CT radiation dose for the diagnosis of appendicitis. However, adoption of low-dose CT has been slow. We aimed to assess the effectiveness of low-dose CT compared with standard-dose CT in the diagnosis of appendicitis in adolescents and young adults. Methods We did this pragmatic, multicentre, randomi s ed controlled non-inferiority trial at 20 South Korean teaching hospitals with little experience with low-dose CT. Patients aged 15–44 years with suspected appendicitis were randomly assigned (1:1), via computer-generated random assignments (permuted block sizes of two, four, six, and eight) concealed in sequentially numbered envelopes, to receive low-dose CT (2 mSv) or standard-dose CT (≤8 mSv). Randomisation was stratified by site. Group allocation was concealed from patients, outcome assessors, and adverse event adjudicators; care providers, site pathologists, and data collectors were aware of allocation. The primary endpoint was the negative (unnecessary) appendectomy rate among all appendectomies, with a non-interiority margin of 4·5% for low-dose versus standard-dose CT. Primary analy s is was by modified intention to treat, which included all patients who received an appendectomy in the group to which they were assigned. This trial is registered with ClinicalTrials.gov, number NCT01925014. Findings Between Dec 4, 2013, and Aug 18, 2016, we assigned 1535 patients to the low-dose CT group and 1539 patients to the standard-dose CT group. 22 (3·9%) of 559 patients had a negative appendectomy in the low-dose group versus 16 (2·7%) of 601 patients in the standard-dose group (difference 1·3%, 95% CI −0·8 to 3·3; p=0·0022 for the non-inferiority test). We recorded 43 adverse events in 43 (2·8%) of 1535 patients in the low-dose group and 41 adverse events in 40 (2·6%) of 1539 patients in the standard-dose group. One life-threatening adverse event of anaphylaxis caused by an iodinated contrast material occurred in the low-dose group. Interpretation Radiation dose of appendiceal CT for adolescents and young adults can be reduced to 2 mSv without impairing clinical outcomes. In view of the vast number of appendiceal CT examinations done worldwide, use of low-dose CT could prevent a sizeable number of radiation-associated cancers in the future. Funding Korea Health Industry Development Institute, Seoul National University Bundang Hospital, Dasol Life Science, and Bracco Imaging Korea.

AIM To compare the value of contrast-enhanced abdominal computed tomography (CT) and fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for detecting gastric carcinoma recurrence. METHODS We retrospectively examined data from 2475 patients who underwent both contrast-enhanced abdominal CT and FDG PET/CT for the surveillance of gastric carcinoma curative resection. Patients had an interval of less than 1 mo between their CT and PET/CT scans. Sixty patients who had recurrence were enrolled. Among 1896 patients who did not have recurrence, 60 were selected by simple random sampling. All CT and PET/CT images were reviewed retrospectively by two reviewers blinded to all clinical and pathologic information except curative resection due to gastric carcinoma. RESULTS The pathological stage of the recurrence group was statistically significantly higher than that of the control group (P < 0.001). In the 60 patients who had recurrence, there were 79 recurrent lesions. Forty-four patients had only one location of recurrence, 13 patients had two locations, and 3 patients had three. In the detection of patient-based overall recurrence, no statistically significant differences existed between the two modalities (P = 0.096). However, for peritoneal carcinomatosis, CT had a statistically significantly higher sensitivity compared to PET/CT (96% vs 50%, P = 0.001). Adenocarcinoma was the most common type of gastric carcinoma. On the pathology-based analysis, CT also had a statistically significantly higher sensitivity compared to PET/CT (98% vs 80%, P = 0.035). CONCLUSION Contrast-enhanced CT was superior to PET/CT in the detection of peritoneal carcinomatosis and pathologic type of adenocarcinoma.

OBJECTIVE To explore the features that predict size increase and development of potential malignant features in incidentally detected, unilocular cystic pancreatic lesions (CPLs) less than 3 cm in diameter, during subsequent follow-up. MATERIALS AND METHODS We retrieved data of patients diagnosed with unilocular CPLs less than 3 cm in diameter during the period from November 2003 through December 2014, using a computerized search. All serial CT and MR images were analyzed to identify the number, size, and location of CPLs; dilatation of the main pancreatic duct; and occurrence of worrisome features and high-risk stigmata of malignancy in the lesion. The characteristics of CPLs were compared between the increase (i.e., size increase during subsequent follow-up) and no-increase groups. For CPLs in the increase group, subgroup analysis was performed according to the lesion size at the last follow-up (< 3 cm vs. ≥ 3 cm). RESULTS Among 553 eligible patients, 132 (23.9%) had CPLs that increased in size, and 421 (76.1%) had CPLs that did not, during follow-up. Of the 132, 12 (9.1%) CPLs increased to diameters ≥ 3 cm at the final follow-up. Among the various factors, follow-up duration was a significant independent factor for an interval size increase of CPLs (p < 0.001). In the increase group, initial cyst size was a significant independent factor to predict later size increase to or beyond 3 cm in diameter (p < 0.001), and the initial cyst diameter ≥ 1.5 cm predicted such a growth with a sensitivity and specificity of 83% and 72%, respectively. No significant factors to predict the development of potential malignant features were identified. CONCLUSION Follow-up duration was associated with an interval size increase of CPLs. Among the growing CPLs, initial cyst size was associated with future lesion growth to and beyond 3 cm.

Despite the economy of material cost and excellent toughness of Cu-based amorphous alloys, especially Cu50Zr50, their poor corrosion resistance to a chloride medium limits their widespread applications. In this study, corrosion tests were performed on the Cu50Zr50 amorphous alloy with different degrees of short-range order, which were prepared by annealing below the glass transition temperature (T g). It was found that the corrosion resistance of amorphous alloys is improved to a significant level when the alloys were heated below T g. Calorimetric studies showed that thermally activated relaxation process of created disorder, which occurs during sub-T g annealing, is responsible for the improvement in the corrosion resistance. Molecular dynamics simulations performed on the Cu–Zr amorphous alloys demonstrated that the relaxation process of the alloys is associated with the formation of energetically stable icosahedra and icosahedron-like structures. Our study highlights the effects of sub-T g annealing on the improvement in the corrosion resistance of the amorphous alloys from the viewpoint the relaxation process of the short-range orders.

To prospectively compare multidetector-row CT (MDCT) and MR imaging (MRI) in the assessment of the ablative margin (AM) and index tumor immediately after radiofrequency (RF) ablation for hepatocellular carcinoma (HCC) and assess whether non-contrast MRI with limited sequences (T1- and T2-weighted imaging only) was superior to a conventional MDCT protocol. A total of 33 consecutive patients with 42 HCCs were included in this study. Both MDCT and MR images were independently reviewed by two radiologists regarding the ability to visually discriminate between the AM and index tumor, and the AM status within ablation zones. The AM status was classified as AM-plus (AM completely surrounding the tumor), AM-zero (AM was partly discontinuous, without protrusion of the tumor), and AM-minus (AM was partly discontinuous, with protrusion of the tumor). During the follow-up period, the cumulative local tumor progression rates were analyzed using the Kaplan–Meier method and Cox proportional hazards model. To determine the added value of contrast-enhanced MR images, both reviewers separately evaluated the two sets (unenhanced and enhanced) of MR images. Visual discrimination between the AM and index tumor was possible in four (9.5%) and 34 (81%) of the 42 ablation zones using MDCT and MRI, respectively (p

Accessory breast tissue results from failed regression of primitive mammary tissue and is most often located in the axilla. Accessory breast tissue itself is normal and should not be misdiagnosed as an abnormality. Both benign and malignant diseases that occur in the normal breast can also develop in accessory breast tissue in the axilla. In this pictorial essay, we show sonographic findings of normal accessory breast tissue in the axilla and various lesions that occur in accessory axillary breast tissue, along with other imaging findings and pathologic features.