Search results for "Algorithm"

SU-FF-T-329: Monte Carlo Dosimetric Study of the Flexisource Ir-192 HDR Source

2006

Purpose:Brachytherapy with high dose rate (HDR) sources of 192 Ir is a usual practice in clinical brachytherapy today. The TG43 U1 update report recommends that accurate dose distribution data of the brachytherapysource in use should be obtained experimentally or by Monte Carlo (MC), to be used as input in the HDR Treatment Planning System (TPS). The purpose of this study is to obtain the dose rate distribution in liquid water media for the Flexisource HDR 192 Ir source (Isodose Control GmbH, Germany) using the Monte Carlo method to obtain the TG43 U1 parameters and the 2‐D rectangular dose rate table. Material and methods: The MC code GEANT4 (7.1 version) was used to estimate dose rate in …

How registers could enhance knowledge and characterization of genetic dyslipidaemias: The experience of the LIPIGEN in Italy and of other networks fo…

2020

Familial hypercholesterolemia (FH) is a common genetic disorder of lipid metabolism, still underdiagnosed and undertreated in the general population. Pathology registers could play a crucial role in the creation of a comprehensive and integrated global approach to cover all aspects of this disease. Systematic data collection of patients affected by FH has increased dramatically worldwide in the past few years. Moreover, results from registers already established for the longest time showed their potentialities in the implementation of the knowledge of FH, comparing country-specific approaches and providing real-world data about identification, management and treatment of FH individuals in t…

Direct-acting antivirals for hepatitis C virus infections in patients co-infected with human immunodeficiency virus

2011

Summary Nearly three-quarters of human immunodeficiency virus–hepatitis C virus (HIV-HCV) coinfected patients in France currently need to be cured of their chronic HCV infection. The increase in sustained virological response rates obtained with the recently available HCV protease inhibitors in treatment-naive genotype-1 patients has generated considerable hope in these co-infected patients. However, several particularities (such as a higher baseline HCV load, more advanced liver fibrosis, frequent co-morbidities, and the risk of toxicity and drug–drug interactions) have not allowed the direct extrapolation of the results observed in HCV-monoinfected patients to patients with HIV-HCV co-inf…

The safe (sequential algorithm for fibrosis evaluation) biopsy: A new approach to stage fibrosis in chronic hepatitis C

2008

A leptin missense mutation associated with hypogonadism and morbid obesity

1998

Evidence-based medicine and the problem of healthy volunteers

2017

Abstract Healthy controls are subjects without the disease being studied but may have other conditions indirectly affecting outcome. In the present epidemics of obesity a few subjects with undiagnosed nonalcoholic fatty liver disease enter clinical studies as controls, producing biased results. Stricter selection criteria should be considered to prevent this risk.

Automatic detection of lung nodules in CT datasets based on stable 3D mass–spring models

2012

We propose a computer-aided detection (CAD) system which can detect small-sized (from 3 mm) pulmonary nodules in spiral CT scans. A pulmonary nodule is a small lesion in the lungs, round-shaped (parenchymal nodule) or worm-shaped (juxtapleural nodule). Both kinds of lesions have a radio-density greater than lung parenchyma, thus appearing white on the images. Lung nodules might indicate a lung cancer and their early stage detection arguably improves the patient survival rate. CT is considered to be the most accurate imaging modality for nodule detection. However, the large amount of data per examination makes the full analysis difficult, leading to omission of nodules by the radiologist. We…

A CAD system for nodule detection in low-dose lung CTs based on region growing and a new active contour model

2007

A computer-aided detection (CAD) system for the selection of lung nodules in computer tomography (CT) images is presented. The system is based on region growing (RG) algorithms and a new active contour model (ACM), implementing a local convex hull, able to draw the correct contour of the lung parenchyma and to include the pleural nodules. The CAD consists of three steps: (1) the lung parenchymal volume is segmented by means of a RG algorithm; the pleural nodules are included through the new ACM technique; (2) a RG algorithm is iteratively applied to the previously segmented volume in order to detect the candidate nodules; (3) a double-threshold cut and a neural network are applied to reduce…

Magnetic resonance cholangiopancreatography

2002

With the introduction of endoscopic retrograde cholangio-pancreatography in the early 1970s, gastroenterologists have a lot of diagnostic options in the biliopancreatic system to their disposal. Meanwhile, magnetic resonance cholangiopancreatography (MRCP) has become a competitive replacement for diagnostic ERCP with the advantage of avoiding complications related to endoscopic techniques. Mounting evidence suggests that both MRCP and MRI (magnetic resonance imaging) have a profound influence of diagnostic algorithms in a variety of hepatobiliary and pancreatic diseases.

Graph-matching based CTA.

2009

Separating bone, calcification, and vessels in computer tomography angiography (CTA) allows for a detailed diagnosis of vessel stenosis. This paper presents a new, graph-based technique that solves this difficult problem with high accuracy. The approach requires one native data set and one that is contrast enhanced. On each data set, an attributed level-graph is derived and both graphs are matched by dynamic programming to differentiate between bone, on one hand side, and vessel/calcification on the other hand side. Lumen and calcified regions are then separated by a profile technique. Evaluation is based on data from vessels of pelvis and lower extremities of elderly patients. Due to subst…