Automatic detection of liver tumor motion by fluoroscopy images

Background: A method to track liver tumor motion signals from fluoroscopic images without any implanted gold fiducial markers was proposed in this study to overcome the adverse effects on precise tumor irradiation caused by respiratory movement

Materials and Methods: The method was based on the following idea: [i] Before treatment, a series of fluoroscopic images corresponding to different breathing phases and tumor positions were acquired after patient set-up; [iii] The wavelet transform method and Canny edge detection algorithm were used to detect motion trajectory of the diaphragm; [iv] The motion curves of center of lipiodol in the images were obtained by mathematical morphology and median filtering algorithm. The method was evaluated using by five sequences of fluoroscopic images from TACE patients who received transcatheter arterial chemoembolization therapy

Results: The position of liver tumor was significantly affected by respiratory motion; the motion trajectories of the diaphragm and lipiodolagreed well with the manually marked locations in amplitude and period; the motion trajectories of the diaphragm and lipiodol almost had similar period and amplitude in one treatment fraction. The respiratory period and amplitude of the same patient in different fractions had no significant differences; however, the difference was obvious for different patients. The proposed lipiodol detection methods can effectively reflect the relevant rules of tumor location caused by respiratory movement

Conclusion: Direct tracking of liver tumor motion in fluoroscopic images is feasible. The automatic detection method can reflect the characteristics of respiratory and tumor motions, which can save much time and significantly improve measurement precision compared with manual measurement

Costo económico de la discapacidad causada por lesiones de tránsito en México durante 2012 / Economic cost of permanent disability caused by road traffic injuries in Mexico in 2012 / Custo econômico da incapacidade causada por acidentes de trânsito no México no ano de 2012

Para estimar el costo económico de la discapacidad permanente causada por lesiones de tránsito en México durante 2012, desde las perspectivas del Sistema de Salud y de la Sociedad, se realizó un estudio de costos que utiliza metodología bottom-up, considerando costos directos médicos (hospitalización, consultas ambulatorias y de rehabilitación y prótesis), y costos indirectos (pérdida de productividad del lesionado y cuidador) con una aproximación de capital humano. La discapacidad causada por lesiones de tránsito tiene un alto costo para el sistema de salud y la sociedad mexicana. Desde la perspectiva del sistema de salud, el costo en pesos mexicanos de la discapacidad permanente fue de US$269.529.480,72, equivalente a US$1.496,33 por persona. Desde la perspectiva de la sociedad, se estimaron US$3.445,45 durante el primer año. En promedio, se estimó un costo total de US$4.941,77 por persona, resultando en un total de US$1.119.761.632,53 en 2012. Los resultados de este estudio evidencian la necesidad de diseñar e implementar políticas más enérgicas y eficientes para el control de las lesiones de tránsito en México.

This study estimated the economic costs of permanent disability caused by road traffic injuries in Mexico during 2012. From the health system's perspective, a bottom-up approach was used to calculate direct medical costs (hospitalization, outpatient care, rehabilitation, and prostheses). From society's perspective, using a human capital approach, indirect costs were associated with loss of productivity for the victims and their caregivers. Permanent disability due to road traffic injuries takes a high toll on the health system and Mexican society. From the health system perspective, the cost was US$269,529,480.72, or US$1,496.33 per victim. The estimated average cost to society was US$3,445.45 during the first year. The total average cost per victim was US$4,941.77, resulting in a total economic cost of US$1,119,761,632.53 during 2012. The study's findings highlight the need to design and implement more rigorous and efficient public polices to control and prevent road traffic injuries in Mexico.

Para estimar o custo econômico da incapacidade permanente causada por acidentes de trânsito no México no ano de 2012, com base nas perspectivas do Sistema de Saúde e da sociedade, foi realizado um estudo de custos utilizando-se a metodologia bottom-up, considerando por um lado os custos diretos médicos (hospitalização, consultas ambulatoriais e de reabilitação e próteses) e, por outro, os custos indiretos associados à perda de produtividade do acidentado e cuidador, usando-se a aproximação metodológica do capital humano. A incapacidade causada por acidentes de trânsito tem um alto custo para o sistema de saúde e sociedade mexicana. Baseando-se na perspectiva do sistema de saúde, o custo em pesos mexicanos da incapacidade permanente foi de US$269.529.480,72, equivalente a US$1.496,33 por pessoa. Com base na perspectiva da sociedade, estimou-se em US$3.445,45 no primeiro ano. Em média, estimou-se um custo total de US$4.941,77 por pessoa, resultando num total de US$1.119.761.632,53 em 2012. Os resultados deste estudo evidenciam a necessidade de delinear e implementar políticas mais rígidas no México.

Fasting does not induce gastric emptying in rats

PURPOSE: To evaluate the effect of fasting on gastric emptying in mice. METHODS: Twenty-eight mice were distributed into three study groups: a normal group (N=4): normal standard animals; a total fasting group (N=12): subjected to food and water deprivation and a partial fasting group (N=12): subjected to food deprivation only. The fasting groups were subdivided into three subgroups of four animals each, according to the date of euthanasia: 24, 48 and 72 hours. Was analyzed: the gastric volume, degree of the gastric wall distention and the presence of food debris in gastrointestinal tract. RESULTS: The mean gastric volume was 1601 mm3in the normal group, 847 mm3in total fasting group and 997 mm3in partial fasting group. There was difference between the fasting groups in any analyzed period (p<0.05). Regarding the presence of food debris in the gastrointestinal tract and the degree of distension of the stomach, there was no difference between the groups that underwent total or partial fasting (p>0.05). CONCLUSION: Total fasting or only-solids deprivation does not induce gastric emptying in mice. .

Computational Discrimination of Breast Cancer for Korean Women Based on Epidemiologic Data Only

Breast cancer is the second leading cancer for Korean women and its incidence rate has been increasing annually. If early diagnosis were implemented with epidemiologic data, the women could easily assess breast cancer risk using internet. National Cancer Institute in the United States has released a Web-based Breast Cancer Risk Assessment Tool based on Gail model. However, it is inapplicable directly to Korean women since breast cancer risk is dependent on race. Also, it shows low accuracy (58%-59%). In this study, breast cancer discrimination models for Korean women are developed using only epidemiological case-control data (n = 4,574). The models are configured by different classification techniques: support vector machine, artificial neural network, and Bayesian network. A 1,000-time repeated random sub-sampling validation is performed for diverse parameter conditions, respectively. The performance is evaluated and compared as an area under the receiver operating characteristic curve (AUC). According to age group and classification techniques, AUC, accuracy, sensitivity, specificity, and calculation time of all models were calculated and compared. Although the support vector machine took the longest calculation time, the highest classification performance has been achieved in the case of women older than 50 yr (AUC = 64%). The proposed model is dependent on demographic characteristics, reproductive factors, and lifestyle habits without using any clinical or genetic test. It is expected that the model could be implemented as a web-based discrimination tool for breast cancer. This tool can encourage potential breast cancer prone women to go the hospital for diagnostic tests.

Time Efficiency and Diagnostic Accuracy of New Automated Myocardial Perfusion Analysis Software in 320-Row CT Cardiac Imaging

OBJECTIVE: We aimed to evaluate the time efficiency and diagnostic accuracy of automated myocardial computed tomography perfusion (CTP) image analysis software. MATERIALS AND METHODS: 320-row CTP was performed in 30 patients, and analyses were conducted independently by three different blinded readers by the use of two recent software releases (version 4.6 and novel version 4.71GR001, Toshiba, Tokyo, Japan). Analysis times were compared, and automated epi- and endocardial contour detection was subjectively rated in five categories (excellent, good, fair, poor and very poor). As semi-quantitative perfusion parameters, myocardial attenuation and transmural perfusion ratio (TPR) were calculated for each myocardial segment and agreement was tested by using the intraclass correlation coefficient (ICC). Conventional coronary angiography served as reference standard. RESULTS: The analysis time was significantly reduced with the novel automated software version as compared with the former release (Reader 1: 43:08 +/- 11:39 min vs. 09:47 +/- 04:51 min, Reader 2: 42:07 +/- 06:44 min vs. 09:42 +/- 02:50 min and Reader 3: 21:38 +/- 3:44 min vs. 07:34 +/- 02:12 min; p or = 0.75) for myocardial attenuation in 93% and for TPR in 82%. Diagnostic accuracy for the two software versions was not significantly different (p = 0.169) as compared with conventional coronary angiography. CONCLUSION: The novel automated CTP analysis software offers enhanced time efficiency with an improvement by a factor of about four, while maintaining diagnostic accuracy.

Comparison of Usual Interstitial Pneumonia and Nonspecific Interstitial Pneumonia: Quantification of Disease Severity and Discrimination between Two Diseases on HRCT Using a Texture-Based Automated System

OBJECTIVE: To evaluate the usefulness of an automated system for quantification and discrimination of usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP). MATERIALS AND METHODS: An automated system to quantify six regional high-resolution CT (HRCT) patterns: normal, NL; ground-glass opacity, GGO; reticular opacity, RO; honeycombing, HC; emphysema, EMPH; and consolidation, CONS, was developed using texture and shape features. Fifty-four patients with pathologically proven UIP (n = 26) and pathologically proven NSIP (n = 28) were included as part of this study. Inter-observer agreement in measuring the extent of each HRCT pattern between the system and two thoracic radiologists were assessed in 26 randomly selected subsets using an interclass correlation coefficient (ICC). A linear regression analysis was used to assess the contribution of each disease pattern to the pulmonary function test parameters. The discriminating capacity of the system between UIP and NSIP was evaluated using a binomial logistic regression. RESULTS: The overall ICC showed acceptable agreement among the system and the two radiologists (r = 0.895 for the abnormal lung volume fraction, 0.706 for the fibrosis fraction, 0.895 for NL, 0.625 for GGO, 0.626 for RO, 0.893 for HC, 0.800 for EMPH, and 0.430 for CONS). The volumes of NL, GGO, RO, and EMPH contribute to forced expiratory volume during one second (FEV1) (r = 0.72, beta values, 0.84, 0.34, 0.34 and 0.24, respectively) and forced vital capacity (FVC) (r = 0.76, beta values, 0.82, 0.28, 0.21 and 0.34, respectively). For diffusing capacity (DLco), the volumes of NL and HC were independent contributors in opposite directions (r = 0.65, beta values, 0.64, -0.21, respectively). The automated system can help discriminate between UIP and NSIP with an accuracy of 82%. CONCLUSION: The automated quantification system of regional HRCT patterns can be useful in the assessment of disease severity and may provide reliable agreement with the radiologists' results. In addition, this system may be useful in differentiating between UIP and NSIP.

Metabonomics and its perspective on forensic medicine / 法医学杂志

Metabolomics is a new study, which use chromatography, mass spectrometry, nuclear magnetic resonance (NMR), capillary electrophoresis (CE) techniques on the cells, organs and other body fluids and metabolites in samples were isolated, purified and testing, re-use bioinformatics tools on the obtained data are analyzed to obtain one or a set of biomarker information. Based on analysis of the literatures in recent years, metabolomics was summarized from history, concept, advantage, methods, application, difficulties and challenges, journals and books, websites, and its application in forensic medicine was forecasted. As a new branch of global system biology, metabonomics developed rapidly, and its perspective on forensic medicine was feasible and very optimistic.

Feasibility of Automated Quantification of Regional Disease Patterns Depicted on High-Resolution Computed Tomography in Patients with Various Diffuse Lung Diseases

OBJECTIVE: This study was designed to develop an automated system for quantification of various regional disease patterns of diffuse lung diseases as depicted on high-resolution computed tomography (HRCT) and to compare the performance of the automated system with human readers. MATERIALS AND METHODS: A total of 600 circular regions-of-interest (ROIs), 10 pixels in diameter, were utilized. The 600 ROIs comprised 100 ROIs that represented six typical regional patterns (normal, ground-glass opacity, reticular opacity, honeycombing, emphysema, and consolidation). The ROIs were used to train the automated classification system based on the use of a Support Vector Machine classifier and 37 features of texture and shape. The performance of the classification system was tested with a 5-fold cross-validation method. An automated quantification system was developed with a moving ROI in the lung area, which helped classify each pixel into six categories. A total of 92 HRCT images obtained from patients with different diseases were used to validate the quantification system. Two radiologists independently classified lung areas of the same CT images into six patterns using the manual drawing function of dedicated software. Agreement between the automated system and the readers and between the two individual readers was assessed. RESULTS: The overall accuracy of the system to classify each disease pattern based on the typical ROIs was 89%. When the quantification results were examined, the average agreement between the system and each radiologist was 52% and 49%, respectively. The agreement between the two radiologists was 67%. CONCLUSION: An automated quantification system for various regional patterns of diffuse interstitial lung diseases can be used for objective and reproducible assessment of disease severity.

Diagnosis of regional cerebral blood flow abnormalities using SPECT: agreement between individualized statistical parametric maps and visual inspection by nuclear medicine physicians with different levels of expertise in nuclear neurology

INTRODUCTION: Visual analysis is widely used to interpret regional cerebral blood flow (rCBF) SPECT images in clinical practice despite its limitations. Automated methods are employed to investigate between-group rCBF differences in research studies but have rarely been explored in individual analyses. OBJECTIVES: To compare visual inspection by nuclear physicians with the automated statistical parametric mapping program using a SPECT dataset of patients with neurological disorders and normal control images. METHODS: Using statistical parametric mapping, 14 SPECT images from patients with various neurological disorders were compared individually with a databank of 32 normal images using a statistical threshold of p<0.05 (corrected for multiple comparisons at the level of individual voxels or clusters). Statistical parametric mapping results were compared with visual analyses by a nuclear physician highly experienced in neurology (A) as well as a nuclear physician with a general background of experience (B) who independently classified images as normal or altered, and determined the location of changes and the severity. RESULTS: Of the 32 images of the normal databank, 4 generated maps showing rCBF abnormalities (p<0.05, corrected). Among the 14 images from patients with neurological disorders, 13 showed rCBF alterations. Statistical parametric mapping and physician A completely agreed on 84.37 percent and 64.28 percent of cases from the normal databank and neurological disorders, respectively. The agreement between statistical parametric mapping and ratings of physician B were lower (71.18 percent and 35.71 percent, respectively). CONCLUSION: Statistical parametric mapping replicated the findings described by the more experienced nuclear physician. This finding suggests that automated methods for individually analyzing rCBF SPECT images may be a valuable resource to complement visual inspection in clinical practice.

Comparison of shape analysis methods for Guinardia citricarpa ascospore characterization

Among the diseases affecting the commercial citrus production, the citrus black spot (CBS) is considered to cause substantial losses. The analyses of particles in suspension in the orchards and collected into a disc have been applied as a preventive action trying to identify the presence of fungus spores before symptom appearance. In this paper, we show the results of several shape analysis methods applied to the fungus, the first step to the aimed computer aided vision system, capable to assist the identification process. Experiments and comparative results among the methods are presented in this paper, showing that better results were obtained applying the curvature method.

Técnicas diferentes para análise de imagens de Plácido podem melhorar precisão da videoceratografia / Different techniques for Plácido image analysis may improve precision of videokeratography

OBJETIVOS: A videoceratografia é tecnologia que vem sendo utilizada para análise da superfície da córnea desde meados dos anos 80. O objetivo deste trabalho é o desenvolvimento de diferentes técnicas para a detecção de bordas em imagens de Plácido e a comparação dos resultados obtidos em cada algoritmo, visando as conseqüências para o cálculo da curvatura axial. Métodos: Foram capturadas imagens de Plácido de 4 diferentes superfícies esféricas utilizando o equipamento Eyesys system 2000. Cada imagem foi salva no formato bitmap em disco rígido de um computador pessoal IBM PC. Seis algoritmos de processamento de imagem foram desenvolvidos utilizando técnicas documentadas na literatura. Os métodos considerados foram: (1) Derivada numérica de primeira ordem, (2) Derivada de Fourier de primeira ordem, (3) Derivada de Fourier de segunda ordem, (4) Filtro de Marr-Hildreth, (5) Filtro de Canny e (6) Laplaciano morfológico (morfologia matemática). Cada um dos algoritmos foi testado e analisado para imagens de Plácido. Resultados: As distâncias radiais do centro das imagens de Plácido às bordas obtidas por cada algoritmo foram comparadas com uma simulação computacional do sistema VK. A média do desvio padrão em pixels/milímetros/dioptria para todas as esferas para os métodos (1)-(6), respectivamente, foi: (1) 33,1695/0,7961/0,79, (2) 32,79/0,7870/0,7724, (3) 60,7150/1,4572/1,4192, (4)18,97/0,4553/0,4572, (5) 46,33/1,1119/1,0917, (6) 20,55/0,4932/0,48. Conclusão: Pesquisadores e oftalmologistas devem ficar atentos na escolha de equipamentos de videoceratografia e também quando comparar medidas de equipamentos diferentes, uma vez que podem ocorrer diferenças relacionadas ao método de processamento de imagens utilizado pelo fabricante. Demonstramos neste trabalho que o método de Marr-Hildreth é mais preciso que o método de Fourier ou métodos como derivada numérica.

A semi-automatic computerized method to measure baroreflex-mediated heart rate responses that reduces interobserver variability

Arterial baroreflex sensitivity estimated by pharmacological impulse stimuli depends on intrinsic signal variability and usually a subjective choice of blood pressure (BP) and heart rate (HR) values. We propose a semi-automatic method to estimate cardiovascular reflex sensitivity to bolus infusions of phenylephrine and nitroprusside. Beat-to-beat BP and HR time series for male Wistar rats (N = 13) were obtained from the digitized signal (sample frequency = 2 kHz) and analyzed by the proposed method (PRM) developed in Matlab language. In the PRM, time series were low-pass filtered with zero-phase distortion (3rd order Butterworth used in the forward and reverse direction) and presented graphically, and parameters were selected interactively. Differences between basal mean values and peak BP (deltaBP) and HR (deltaHR) values after drug infusions were used to calculate baroreflex sensitivity indexes, defined as the deltaHR/deltaBP ratio. The PRM was compared to the method traditionally (TDM) employed by seven independent observers using files for reflex bradycardia (N = 43) and tachycardia (N = 61). Agreement was assessed by Bland and Altman plots. Dispersion among users, measured as the standard deviation, was higher for TDM for reflex bradycardia (0.60 ± 0.46 vs 0.21 ± 0.26 bpm/mmHg for PRM, P < 0.001) and tachycardia (0.83 ± 0.62 vs 0.28 ± 0.28 bpm/mmHg for PRM, P < 0.001). The advantage of the present method is related to its objectivity, since the routine automatically calculates the desired parameters according to previous software instructions. This is an objective, robust and easy-to-use tool for cardiovascular reflex studies.