The impact of uncertainty in society on the use of traditional, complementary and alternative medicine: a comparative study on visits to alternative/traditional/folk health care practitioners

Background: While traditional, complementary and alternative medicine (TCAM) is gaining increased interest worldwide, the structural factors associated with the usage of TCAM at the social level have not been sufficiently explored. We aim to understand the social structure of uncertainty in society that affects the TCAM usage for men and women. Methods: We studied 32 countries using data from the International Social Survey Programme and the World Bank. In this study, we defined TCAM usage as visits to an alternative/traditional/folk health care practitioner during the past 12 months. We performed a correlation analysis and used a generalized linear model . Results: The prevalence of TCAM usage in terms of visits to practitioners was 26.1% globally, while usage varied across the 32 countries. Generalized linear models showed that unemployment rate was associated with the prevalence of TCAM usage in terms of visits to practitioners. Conclusions: At the social-structural level TCAM usage involving visits to practitioners was related to job insecurity. Job insecurity led to a decrease in TCAM usage regarding visits to practitioners. These findings suggest that it is necessary to consider the social-structural factors of uncertainty in society when designing health policies related to TCAM

Noise simulation system for determining imaging conditions in digital radiography

Reduction of exposure dose and improvement in image quality can be expected to result from advances in the performance of imaging detectors. We propose a computerized method for determining optimized imaging conditions by use of simulated images. This study was performed to develop a prototype system for image noise and to ensure consistency between the resulting images and actual images. An RQA5 X-ray spectrum was used for determination of input-output characteristics of a flat-panel detector (FPD). The number of incident quantum to the detector per pixel (counts/pixel) was calculated according to the pixel size of the detector and the quantum number in RQA5 determined in IEC6220-1. The relationship among tube current-time product (mAs), exposure dose (C/kg) at the detector surface, the number of incident quanta (counts/pixel), and pixel values measured on the images was addressed, and a conversion function was then created. The images obtained by the FPD was converted into a map of incident quantum numbers and input into random-value generator to simulate image noise. In addition, graphic user interface was developed to observe images with changing image noise and exposure dose levels, which have trade-off relationship. Simulation images provided at different noise levels were compared with actual images obtained by the FPD system. The results indicated that image noise was simulated properly both in objective and subjective evaluation. The present system could allow us to determine necessary dose from image quality and also to estimate image quality from any exposure dose. © 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE)

Review of a simple noise simulation technique in digital radiography

Reduction of exposure dose and improvement in image quality can be expected to result from advances in the performance of imaging detectors. A number of researchers have reported on methods for simulating reduced dose images. The simplest method provides reduced dose images by adding white Gaussian noise with a certain standard deviation to the original image. Our aim in this study was to develop and validate a system with a graphic user interface for simulating reduced dose images by a simple method. Here, we describe a technical approach with the use of a flat-panel detector system, and we validated the simulation performance in reducing the dose objectively and subjectively. In addition, the technical limitations and possible solutions to the simple method are suggested based on the validation results presented in this paper. © 2012 Japanese Society of Radiological Technology and Japan Society of Medical Physics.発行後1年より全文公開

Simulation approach for the evaluation of tracking accuracy in radiotherapy: A preliminary study

Real-time tumor tracking in external radiotherapy can be achieved by diagnostic (kV) X-ray imaging with a dynamic flat-panel detector (FPD). It is important to keep the patient dose as low as possible while maintaining tracking accuracy. A simulation approach would be helpful to optimize the imaging conditions. This study was performed to develop a computer simulation platform based on a noise property of the imaging system for the evaluation of tracking accuracy at any noise level. Flat-field images were obtained using a direct-type dynamic FPD, and noise power spectrum (NPS) analysis was performed. The relationship between incident quantum number and pixel value was addressed, and a conversion function was created. The pixel values were converted into a map of quantum number using the conversion function, and the map was then input into the random number generator to simulate image noise. Simulation images were provided at different noise levels by changing the incident quantum numbers. Subsequently, an implanted marker was tracked automatically and the maximum tracking errors were calculated at different noise levels. The results indicated that the maximum tracking error increased with decreasing incident quantum number in flat-field images with an implanted marker. In addition, the range of errors increased with decreasing incident quantum number. The present method could be used to determine the relationship between image noise and tracking accuracy. The results indicated that the simulation approach would aid in determining exposure dose conditions according to the necessary tracking accuracy. © The Author 2012. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Therapeutic Radiology and Oncology

Single C−F Bond Activation of the CF3 Group with a Lewis Acid: CF3‐Cyclopropanes as Versatile 4,4‐Difluorohomoallylating Agents

The selective activation of one C−F bond (single activation) of the CF3 group on cyclopropanes was achieved for the first time. When (trifluoromethyl)cyclopropanes were treated with arenes, allylsilanes, silyl enol ethers, or hydrosilanes in the presence of Me2AlCl, fluoride elimination and the subsequent ring opening proceeded to afford 4,4‐difluorohomoallylated products. In the absence of external nucleophiles, an alkyl group of AlR3 was effectively introduced to provide the corresponding 1,1‐difluoroalkenes

Association of perivascular fat attenuation on computed tomography and heart failure with preserved ejection fraction

Aims　Heart failure with a preserved ejection fraction (HFpEF) is associated with chronic inflammation. We aimed to investigate the association between pericoronary adipose tissue attenuation (PCATA) on coronary computed tomography angiography as a novel noninvasive marker of pericoronary inflammation and the presence of HFpEF. Methods and results　This retrospective study included 607 outpatients (median age, 65 years; 50% male) who underwent both echocardiography and coronary computed tomography angiography. Patients with obstructive coronary artery disease were excluded from this study. PCATA was compared between patients with and without HFpEF, which was diagnosed according to the Heart Failure Association (HFA)-PEFF score. PCATA was assessed at the proximal 40-mm segments of all three major coronary arteries on coronary computed tomography angiography. Patients with HFpEF had higher PCATA in all coronary arteries compared to the control participants: left anterior descending artery (LAD), -65.2 +/- 6.9 Hounsfield units (HU) vs. -68.1 +/- 6.7 HU; left circumflex artery (LCX), -62.7 +/- 6.8 HU vs. -65.4 +/- 6.6 HU; and right coronary artery (RCA), -63.6 +/- 8.5 HU vs. -65.5 +/- 7.7 HU (P Conclusions　High PCATA score was significantly associated with the presence of HFpEF. Our results suggest that inflammation in the pericoronary artery adipose tissue is one of the underlying mechanisms of HFpEF

Simulation system for understanding the lag effect in fluoroscopic images

Real-time tumor tracking in external radiotherapy can be achieved by diagnostic (kV) X-ray imaging with a dynamic flat-panel detector (FPD). It is crucial to understand the effects of image lag for real-time tumor tracking. Our purpose in this study was to develop a lag simulation system based on the image lag properties of an FPD system. Image lag properties were measured on flat-field images both in direct- and indirect-conversion dynamic FPDs. A moving target with image lag was simulated based on the lag properties in all combinations of FPD types, imaging rates, exposure doses, and target speeds, and then compared with actual moving targets for investigation of the reproducibility of image lag. Image lag was simulated successfully and agreed well with the actual lag as well as with the predicted effect. In the indirect-conversion FPD, a higher dose caused greater image lag on images. In contrast, there were no significant differences among dose levels in a direct-conversion FPD. There were no relationships between target speed and amount of image blurring in either type of FPD. The maximum contour blurring and the rate of increase in pixel value due to image lag were 1.1 mm and 10.0 %, respectively, in all combinations of imaging parameters examined in this study. Blurred boundaries and changes in pixel value due to image lag were estimated under various imaging conditions with use of the simulation system. Our system would be helpful for a better understanding of the effects of image lag in fluoroscopic images. © 2012 Japanese Society of Radiological Technology and Japan Society of Medical Physics

Diagnostic Performance of Cardiac Computed Tomography for Detecting Patent Foramen Ovale: Evaluation Using Transesophageal Echocardiography and Catheterization as Reference Standards

Background: Patent foramen ovale (PFO) is associated with various diseases such as cryptogenic stroke, migraine, and platypnea-orthodeoxia syndrome. This study aimed to evaluate the diagnostic performance of cardiac computed tomography (CT) for PFO detection. Materials and Methods: Consecutive patients diagnosed with atrial fibrillation and who underwent catheter ablation with pre-procedural cardiac CT and transesophageal echocardiography (TEE) were enrolled in this study. The presence of PFO was defined as (1) the confirmation of PFO using TEE and/or (2) the catheter crossing the interatrial septum (IAS) into the left atrium during ablation. CT findings indicative of PFO included (1) the presence of a channel-like appearance (CLA) on the IAS and (2) a CLA with a contrast jet flow from the left atrium to the right atrium. The diagnostic performance of both a CLA alone and a CLA with a jet flow was evaluated for PFO detection. Results: Altogether, 151 patients were analyzed in the study (mean age, 68 years; men, 62%). Twenty-nine patients (19%) had PFO confirmed by TEE and/or catheterization. The diagnostic performance of a CLA alone was as follows: sensitivity, 72.4%; specificity, 79.5%; positive predictive value (PPV), 45.7%; negative predictive value (NPV), 92.4%. The diagnostic performance of a CLA with a jet flow was as follows: sensitivity, 65.5%; specificity, 98.4%; PPV, 90.5%; NPV, 92.3%. The diagnostic performance of a CLA with a jet flow was statistically superior to that of a CLA alone (p = 0.045), and the C-statistics were 0.76 and 0.82, respectively. Conclusion: A CLA with a contrast jet flow in cardiac CT has a high PPV for PFO detection, and its diagnostic performance is superior to that of a CLA alone

Effects of image lag on real-time target tracking in radiotherapy

There is a concern that image lag may reduce accuracy of real-time target tracking in radiotherapy. This study was performed to investigate influence of image lag on the accuracy of target tracking in radiotherapy. Fluoroscopic image: were obtained using a direct type of dynamic flat-panel detector (FPD) system under conditions of target tracking during radiotherapy. The images continued to be read out after X-irradiations and cutoff, and image lag properties in the system were then determined. Subsequently, a tungsten materials plate with a precision edge was mounted on to a motor control device, which provided a constant velocity. The plate was moved into the center of the detector at movement rate of 1 and 20 mm/s, covering lung tumor movement of normal breathing, and MTF and profile curves were measured on the edges covering and uncovering the detector. A lung tumor with blurred edge due to image lag was simulated using the results and then superimposed on breathing chest radiographs of a patient. The moving target with and without image lag was traced using a template-matching technique. In the results, the target could be traced within a margin for error ii external radiotherapy. The results indicated that there was no effect of image lag on target tracking in usual breathing speed in a radiotherapy situation. Further studies are required to investigate influence by the other factors, such a: exposure dose, target size and shape, imaging rate, and thickness of a patient\u27s body. © 2010 SPIE