Precise pulsed magnetic field mapping using a compact pick-up probe for a pulsed sextupole magnet.

A pulsed sextupole magnet was used for beam injection at the KEK-Photon Factory (KEK-PF). During the top-up injection, oscillation of the stored beam was observed. To investigate this issue, a compact pick-up probe has been developed for measuring peak fields around the zero-magnetic-field region where the stored beam passes. The probe has two coils: a main coil and a background coil. The width and length of the main coil are only 3.2 and 5.8 mm, respectively. The voltage signal from the background coil is subtracted from that of the main coil to obtain an effective voltage signal. The results show that the peak field of a pulsed magnet can be measured with a sufficient accuracy for magnetic field mapping. A magnetic field signal with an amplitude of 2.2 × 10-4 T was measured clearly. The longitudinal field structure that contains the magnetic field generated by the eddy-current effect was observed, which explains the oscillation of the stored beam at the KEK-PF.

SAKE: first-principles electron transport calculation code.

We developed and implemented a numerical code called SAKE, which stands for (simulation code for atomistic Kohn-Sham equation). We developed it for first-principle electron transport calculations based on density-functional theory and non-equilibrium Green's function formalism. First, we present the central calculation parts of the formalism of the electronic states and transport properties for open and non-equilibrium systems. We show specific computational techniques, such as the use of a complex contour integration for charge density from the density matrix, which is compared with the calculation method of summing the residues of the Fermi-Dirac distribution, as well as the efficient achievement of the self-consistent procedures. Thereafter, for applications of the present computation code, SAKE, we present first-principle calculation results of three different systems. We first analyze electronic structures of polythiophene molecular wires, compare summation techniques for the density matrix. We show thermoelectric properties of an n-type antiferromagnetic semiconductor CuFeS2 as a second application. The electrical conductance, electrical thermal conductance, and the Seebeck coefficients with carrier doping are examined, and the analytical form of the Seebeck coefficient is briefly described. For the third application, we analyze the electron transport properties of polyaniline molecular wires under structural deformations, i.e. rotations around the transport direction. The thermally averaged current-voltage characteristics are also analyzed. The results show that the current decreases as the temperature increases which are determined based on the competition between the thermal energy and the electronic energy, which increases with the rotation angle.

Evaluation of the fat plane of the pancreatic groove using multidetector CT.

AIM: To assess the pancreatic groove fat plane in the normal population and compare this with the fat plane in patients with groove pancreatitis or carcinoma using multidetector computed tomography (CT). MATERIAL AND METHODS: The pancreatic groove fat plane was evaluated retrospectively in 460 normal subjects (normal group), and in 25 patients with groove pancreatitis or carcinoma (pathology group) using 5 mm- and 1 mm-thick slices of unenhanced axial multidetector CT images. Two investigators independently assessed the degree of pancreatic groove fat plane visualisation using a four-point scale (grade 1: visualisation of 0-25%, grade 2: 26-50%, grade 3: 51-75%, grade 4: 76-100%). Pancreatic parenchymal condition, age, sex, body mass index, diabetes mellitus, and dyslipidaemia were also evaluated. RESULTS: The interobserver agreement for the visualisation grades was almost perfect (k-value = 0.95). In the normal group, grade 4 visualisation of the pancreatic groove fat plane was more common in those aged >80 years (78.6%) compared with younger age groups. Pancreatic atrophy and fatty infiltration significantly improved fat plane visualisation. In the pathology group, grade 4 visualisation of the pancreatic groove fat plane was not seen in either groove carcinoma or pancreatitis. A cut-off point of ≤50% visualisation of the pancreatic groove fat plane showed 95% sensitivity and 82% specificity for detecting possible abnormalities in older patients (>60 years). The clinical factors investigated were not significantly related to pancreatic groove fat plane visualisation. CONCLUSION: Pancreatic groove fat plane visualisation could be a good predictor for detecting groove abnormalities.

Toll-like receptor 3 in nasal CD103+ dendritic cells is involved in immunoglobulin A production.

Intranasal inoculation with influenza hemagglutinin subunit with polyinosine-polycytidylic (polyI:C), a synthetic analog for double-stranded RNA, enhances production of vaccine-specific immunoglobulin (Ig) A, which is superior to IgG in prophylactic immunity. The mechanism whereby polyI:C skews to IgA production in the nasal-associated lymph tissue (NALT) was investigated in mouse models. Nasally instilled polyI:C was endocytosed into CD103+ dendritic cells (DCs) and induced T-cell activation, including interferon (IFN)-γ production. According to knockout mouse studies, polyI:C activated the Toll-like receptor 3 signal via the adapter TICAM-1 (also called TRIF), that mainly caused T-cell-dependent IgA production. Nasal CD103+ DCs activated transforming growth factor-ß signaling and activation-induced cytidine deaminase upon polyI:C stimulation. IgA rather than IgG production was impaired in Batf3-/- mice, where CD103+ DCs are defective. Genomic recombination occurred in IgA-producing cells in association with polyI:C-stimulated DCs and nasal microenvironment. PolyI:C induced B-cell-activating factor expression and weakly triggered T-cell-independent IgA production. PolyI:C simultaneously activated mitochondrial antiviral signaling and then type I IFN receptor pathways, which only minimally participated in IgA production. Taken together, CD103+ DCs in NALT are indispensable for the adjuvant activity of polyI:C in enhancing vaccine-specific IgA induction and protective immunity against influenza viruses.

Thermal ablation and immunomodulation: From preclinical experiments to clinical trials.

Accumulating evidence has shown that thermal ablation can induce spontaneous distant tumor regression, which is also known as abscopal effect. Abscopal effect might depend upon the activation of antitumor immune response. However, such responses induced by thermal ablation had been thought to be usually weak and that they rarely induce distant tumor regression. Recently, results of several preclinical and clinical studies have suggested that thermal ablation can induce therapeutically effective systemic antitumor immune response if appropriate immunomodulators are combined. To elucidate the mechanisms of these promising strategies, effects of thermal ablation on the immune system are overviewed. Furthermore, recent promising preclinical and clinical studies examining enhancement of systemic antitumor immune response by combining thermal ablation and immunomodulation are summarized.

Percutaneous drainage of pancreatic fistula following pancreatectomy with CT-fluoroscopic guidance.

PURPOSE: To evaluate the clinical utility of percutaneous drainage of pancreatic fistula following pancreatectomy with real-time CT-fluoroscopic guidance. MATERIAL AND METHODS: During January 2007 through March 2013, of 295 patients who underwent pancreatectomy, 20 patients received percutaneous drainage of pancreatic fistula with real-time CT-fluoroscopic guidance. The mean diameter of pancreatic fluid collections was 8.1±2.7 (SD)cm (range: 3.5-15.0cm). Feasibility, safety, and clinical success were evaluated. Primary and secondary clinical successes were defined respectively as the resolution of pancreatic fistula by initial drainage alone, and after additional intervention. Factors affecting primary clinical success and the drainage period were also evaluated. RESULTS: Drainage catheters were placed in planned sites in all patients. No major complication occurred except in 1/20 patient (5%) who experienced endotoxin shock. Primary and secondary clinical success rates were, respectively, 50% (10/20) and 90% (18/20). An amylase level greater than 30,000IU/L in the fluid collection was a significant factor lowering the primary clinical success rate (P<0.02) and prolonging the drainage period (>30 days) (P<0.02). CONCLUSION: Real-time CT-fluoroscopic guided drainage is a feasible, safe, and useful therapeutic option for the management of pancreatic fistula after pancreatectomy. The fluid amylase level is a useful indicator to predict refractory pancreatic fistula.

Changes in liver stiffness on real-time tissue elastography before and after occlusion of spontaneous portosystemic shunts.

PURPOSE: This study was conducted to evaluate changes in liver stiffness, volume, and function before and after occlusion of spontaneous portosystemic shunt. MATERIALS & METHODS: Twenty-four patients (13 men and 11 women) with a mean age of 68.2 years±10.1 (SD) (age range, 49-82 years) underwent percutaneous occlusion of spontaneous portosystemic shunt because of gastric varices (n=17) or hepatic encephalopathy (n=7) from March 2011 to June 2013. The liver fibrosis index indicating liver stiffness was calculated by using ultrasound elastography before and after shunt occlusion. Liver volume and liver profile were also evaluated. RESULTS: Spontaneous portosystemic shunt occlusion was uneventfully performed in all patients. The mean liver fibrosis index was significantly decreased from 2.7±1.0 before shunt occlusion to 2.0±0.9 (P<0.001) at 1 month, 2.2±1.0 at 3 months (P=0.004), and 1.6±0.7 at 6 months (P=0.001) afterwards. A significant increase in the liver volume was observed from 1035.3±340.1mL before shunt occlusion to 1116.8±298.4mL (P=0.006) at 1 month and 1174.2±354.1mL (P<0.001) at 3 months afterwards. Significant improvement in the Child-Pugh score was also found at 1 month (6.2±1.4, P<0.001), 3 months (6.5±1.1, P=0.022), and 6 months (6.0±0.9, P=0.004) after shunt occlusion as compared with that (7.2±1.9) before. CONCLUSION: The liver stiffness decreases along with an increase in liver volume and improvement in liver function after spontaneous portosystemic shunt occlusion.

Comparison of CT Fluoroscopy-Guided Manual and CT-Guided Robotic Positioning System for In Vivo Needle Placements in Swine Liver.

PURPOSE: To compare CT fluoroscopy-guided manual and CT-guided robotic positioning system (RPS)-assisted needle placement by experienced IR physicians to targets in swine liver. MATERIALS AND METHODS: Manual and RPS-assisted needle placement was performed by six experienced IR physicians to four 5 mm fiducial seeds placed in swine liver (n = 6). Placement performance was assessed for placement accuracy, procedure time, number of confirmatory scans, needle manipulations, and procedure radiation dose. Intra-modality difference in performance for each physician was assessed using paired t test. Inter-physician performance variation for each modality was analyzed using Kruskal-Wallis test. RESULTS: Paired comparison of manual and RPS-assisted placements to a target by the same physician indicated accuracy outcomes was not statistically different (manual: 4.53 mm; RPS: 4.66 mm; p = 0.41), but manual placement resulted in higher total radiation dose (manual: 1075.77 mGy/cm; RPS: 636.4 mGy/cm; p = 0.03), required more confirmation scans (manual: 6.6; RPS: 1.6; p < 0.0001) and needle manipulations (manual: 4.6; RPS: 0.4; p < 0.0001). Procedure time for RPS was longer than manual placement (manual: 6.12 min; RPS: 9.7 min; p = 0.0003). Comparison of inter-physician performance during manual placement indicated significant differences in the time taken to complete placements (p = 0.008) and number of repositions (p = 0.04) but not in other study measures (p > 0.05). Comparison of inter-physician performance during RPS-assisted placement suggested statistically significant differences in procedure time (p = 0.02) and not in other study measures (p > 0.05). CONCLUSIONS: CT-guided RPS-assisted needle placement reduced radiation dose, number of confirmatory scans, and needle manipulations when compared to manual needle placement by experienced IR physicians, with equivalent accuracy.

Performance of intra-procedural 18-fluorodeoxyglucose PET/CT-guided biopsies for lesions suspected of malignancy but poorly visualized with other modalities.

PURPOSE: We sought to evaluate the safety and the diagnostic success rate of percutaneous biopsies performed under intra-procedural (18)F-deoxyglucose (FDG) positron-emission tomography/computed tomography (PET/CT) guidance for lesions difficult to see with conventional cross-sectional imaging. METHODS: From 2011 to 2013, consecutive clinically indicated percutaneous PET/CT-guided biopsies of 106 masses (mean size, 3.3 cm; range, 0.7-15.9 cm; SD, 2.9 cm) in bones (n = 33), liver (n = 26), soft tissues (n = 18), lung (n = 15) and abdomen (n = 14) were reviewed. The biopsy procedures were performed following injection of a mean of 255 MBq (SD, 74) FDG. Mean maximal standardized uptake value (SUV) of lesions was 8.8 (SD, 6.3). A systematic review of the histopathological results and outcomes was performed. RESULTS: Biopsies were positive for malignancy in 76 cases (71.7%, 76/106) and for benign tissue in 30 cases (28.3%, 30/106). Immediate results were considered adequate for 100 PET/CT biopsies (94.3%, 100/106) requiring no further exploration, and for the six others (5.7%, 6/106) benign diagnoses were confirmed after surgery (n = 4) or follow-up (n = 2). The consequent overall sensitivity and the diagnostic success of biopsy were therefore 100%. No significant differences in terms of detection of malignancy were observed between the different locations. Lesions > 2 cm or with SUV > 4 were not significantly more likely to be malignant. Complications occurred after four biopsies (3.7%, 4/106). CONCLUSION: Intra-procedural PET/CT guidance appears as a safe and effective method and allows high diagnostic success of percutaneous biopsies for metabolically active lesions.

CT-fluoroscopy in chest interventional radiology: sliding scale of imaging parameters based on radiation exposure dose and factors increasing radiation exposure dose.

AIM: To verify the usefulness of a sliding scale of imaging parameters to reduce radiation exposure during chest interventional radiology (IR), and to identify factors that increase radiation exposure in order to obtain acceptable computed tomography (CT)-fluoroscopy image quality. MATERIALS AND METHODS: The institutional review board approved this retrospective study, for which the need for informed consent was waived. Interventional radiologists determined the optimal CT-fluoroscopy imaging parameters using the sliding scale based on the radiation exposure dose. The imaging parameters were changed from those generating low radiation (120 kV/10 mA, 1.2 mGy/s) to others generating higher radiation exposure until acceptable image quality was obtained for each procedure. Validation of the imaging parameter sliding scale was done using regression analysis. Factors that increase radiation exposure were identified using multiple regression analysis. RESULTS: In 125 patients, 217 procedures were performed, of which 72 procedures (33.2%, 72/217) were performed with imaging parameters of minimum radiation exposure, but increased radiation exposure was necessary in 145 (66.8%, 145/217). Significant correlation was found between the radiation exposure dose and the percentage achievement of acceptable image quality (R(2) = 0.98). Multivariate regression analysis showed that high body weight (p < 0.0001), long device passage (p < 0.0001), and lesions above the aortic arch (p = 0.04) were significant independent factors increasing radiation exposure. CONCLUSION: Although increased radiation exposure dose might be necessary to obtain acceptable chest CT-fluoroscopy images depending on the patient, lesion, and procedure characteristics, a sliding scale of imaging parameters helps to reduce radiation exposure.

Pulmonary thin-section CT findings in acute Moraxella catarrhalis pulmonary infection.

OBJECTIVE: Moraxella catarrhalis is an important pathogen in the exacerbation of chronic obstructive pulmonary disease. The aim of this study was to assess the clinical and pulmonary thin-section CT findings in patients with acute M. catarrhalis pulmonary infection. METHODS: Thin-section CT scans obtained between January 2004 and March 2009 from 292 patients with acute M. catarrhalis pulmonary infection were retrospectively evaluated. Clinical and pulmonary CT findings in the patients were assessed. Patients with concurrent infection including Streptococcus pneumoniae (n = 72), Haemophilus influenzae (n = 61) or multiple pathogens were excluded from this study. RESULTS: The study group comprised 109 patients (66 male, 43 female; age range 28-102 years; mean age 74.9 years). Among the 109 patients, 34 had community-acquired and 75 had nosocomial infections. Underlying diseases included pulmonary emphysema (n = 74), cardiovascular disease (n = 44) or malignant disease (n = 41). Abnormal findings were seen on CT scans in all patients and included ground-glass opacity (n = 99), bronchial wall thickening (n = 85) and centrilobular nodules (n = 79). These abnormalities were predominantly seen in the peripheral lung parenchyma (n = 99). Pleural effusion was found in eight patients. No patients had mediastinal and/or hilar lymph node enlargement. CONCLUSIONS: M. catarrhalis pulmonary infection was observed in elderly patients, often in combination with pulmonary emphysema. CT manifestations of infection were mainly ground-glass opacity, bronchial wall thickening and centilobular nodules.

Intractable bronchopleural fistula caused by radiofrequency ablation: endoscopic bronchial occlusion with silicone embolic material.

A 58-year-old man with primary lung cancer underwent lung radiofrequency (RF) ablation. Pneumothorax developed 12 days after lung RF ablation. Despite chest drainage for 1 month, air leakage continued through a bronchopleural fistula. Bronchial occlusion was performed with a silicone embolus, causing cessation of the air leakage.

Case report: Radiofrequency ablation for the treatment of painful isolated wound recurrence after resection of gastric cancer.

A 75-year-old woman underwent radiofrequency (RF) ablation for the treatment of two painful disseminated tumours that appeared and rapidly became larger at the anterior abdominal wound 16 months after she had undergone surgery for gastric cancer. RF ablation was performed under CT-fluoroscopic guidance for both tumours, which measured 5 cm and 3 cm in maximum diameter. Pain was relieved immediately after RF ablation, and both tumours showed significant involution upon physical examination and CT studies. The patient is still alive 15 months after RF ablation, with no evidence of tumour recurrence.

Complications after lung radiofrequency ablation: risk factors for lung inflammation.

This retrospective study was conducted to review the complications of lung radiofrequency (RF) ablation and to clarify the effects of inflammation after lung RF ablation on mortality and morbidity. Complications were evaluated by reviewing medical records on an RF session basis. The C-reactive protein (CRP) value was used as an indicator of inflammation and was measured before and every 1-2 days during the hospital stay after RF ablation. The relationships between CRP values and patient baselines were evaluated to identify factors affecting lung inflammation. 130 patients who underwent 327 lung RF ablation sessions were enrolled in this study. The major complication rate was 18.3% (60/327). Inflammation-related complications such as interstitial pneumonia (n = 2) and aseptic pleuritis (n = 2) developed in four sessions (1.2%). Death occurred in two patients with interstitial pneumonia (0.6%). The mean CRP value increased significantly from 1.3+/-2.6 mg dl(-1) to 3.4+/-5.6 mg dl(-1) (p<0.01) after RF ablation. Large tumour size (>or=2 cm) and previous external-beam radiotherapy were significant factors associated with an increased CRP value in both univariate and multivariate analyses. In conclusion, although the incidence rate is low, fatal lung inflammation may develop after lung RF ablation. Large tumour size and previous external-beam radiotherapy are risk factors for severe lung inflammation.

Predictive factors for distant recurrence of HCV-related hepatocellular carcinoma after radiofrequency ablation combined with chemoembolization.

BACKGROUND: Radiofrequency ablation (RFA) therapy for hepatocellular carcinoma has enabled good local control to be possible. However, after successful local control, distant recurrences frequently occur in the remnant liver. AIM: To identify the predictive factors for distant recurrence after RFA. METHODS: A total of 117 patients with initial non-advanced hepatocellular carcinoma with HCV who underwent RFA in our hospital were selected for this study. After transcatheter chemoembolization, RFA was performed under real-time computed tomography-fluoroscopic guidance. We studied survival rates, local (adjacent to treated tumour) and distant (intrahepatic site distant from the treated tumours) recurrence rates, as well as predictive factors for distant recurrence. RESULTS: After RFA, survival rates were 98.2% and 64.7% at 1 and 5 years, respectively. Child B patients had a significantly worse survival than Child A. Recurrence rates were 2.4% at 5 years for local, and 17.1% and 76.9% at 1 and 5 years, respectively, for distant. The Kaplan-Meier method revealed significantly high recurrence rates in cases with low albumin levels (Alb < 3.5 g/dL), high aspartate aminotransferase levels (AST > 60 IU/L), high alanine aminotransferase levels (ALT > 60 IU/L), low platelet counts (Plt < 10 x 10(4)/microL), and high alpha-fetoprotein levels (AFP > 50 ng/mL). On multivariate analysis, low Alb levels and high AST levels were independent predictive factors for distant recurrence. CONCLUSIONS: Although RFA enables good local control for initial hepatocellular carcinoma, distant recurrence is observed at high rates in HCV patients. Low albumin and high AST levels are predictive factors for distant recurrence.

Cervical oesophageal stent placement via a retrograde transgastric route.

During attempted oesophageal stent placement in a patient with cervical oesophageal cancer in whom swallowing of even saliva was impossible, transoral access to the cervical oesophagus was unsuccessful. Under ultrasound and fluoroscopy guidance, percutaneous gastric puncture was performed, and using an angiographic catheter and guidewire, access to the oesophagus by a retrograde transgastric route was successfully achieved. The obstructed segment of the oesophagus was traversed. It was then possible to pull the guidewire through the mouth and place an oesophageal stent via an antegrade approach.

Malignant lymphoma with tumor thrombus in the portal venous system.

We report a case of malignant lymphoma presenting with tumor thrombus of the portal venous system. Computed tomography showed a mass in the portal vein and mesenteric lymphadenopathy. Filling defects in the dilated portal vein also were identified by angiography. This type of the lymphoma is extremely rare, but it should be considered in the differential diagnosis of portal vein thrombus.

Attenuation of hypercapnic carbon dioxide chemosensitivity after postinfarction exercise training: possible contribution to the improvement in exercise hyperventilation.

OBJECTIVE: To elucidate the responsible mechanisms of increased slope of minute ventilation relative to carbon dioxide production (VE/VCO(2)) during exercise after acute myocardial infarction without overt signs of heart failure, patients who had an acute myocardial infarction were examined after participating in a three month supervised exercise training programme. DESIGN: Exercise testing, hypercapnic CO(2) chemosensitivity measurement (rebreathing method), and pulmonary function test were repeated at entry and after three months in 50 acute myocardial infarction patients with neither symptoms nor signs of heart failure who completed the training programme. Ten patients who performed initial inhospital training served as controls. RESULTS: Age, peak oxygen uptake, left ventricular ejection fraction, CO(2) chemosensitivity, respiratory parameters (percentage of predicted normal vital capacity (%VC), forced expiratory volume in one second, and carbon monoxide transfer factor (%TLCO)) were all significantly correlated with VE/VCO(2) slope. Multivariate regression analysis showed that age (beta = 0.29, p = 0.01), %TLCO (beta = -0.27, p = 0.01), and CO(2) chemosensitivity (beta = 0.49, p < 0.001) were independent determinants of VE/VCO(2) slope. After three months, there was no significant change in these parameters in the control group. Peak oxygen uptake, %TLCO, and %VC and attenuation in CO(2) chemosensitivity increased significantly in the training group. The VE/VCO(2) slope decreased marginally (p = 0.11). The changes in VE/VCO(2) slope were correlated only with those in CO(2) chemosensitivity (r = 0.50, p < 0.001). CONCLUSION: After acute myocardial infarction, exercise hyperventilation is seen in association with aging, enhanced hypercapnic CO(2) chemosensitivity, and reduced TLCO, even in the absence of overt heart failure. The correlation of VE/VCO(2) attenuation after training with the reduction in CO(2) chemosensitivity suggests that exercise training may reduce increased VE/VCO(2) slope, at least partially by reducing CO(2) chemosensitivity.