Search results for "Algorithm"
showing 10 items of 4887 documents
Improved usability of the minimal model of insulin sensitivity based on an automated approach and genetic algorithms for parameter estimation.
2006
Minimal model analysis of glucose and insulin data from an IVGTT (intravenous glucose tolerance test) is widely used to estimate insulin sensitivity; however, the use of the model often requires intervention by a trained operator and some problems can occur in the estimation of model parameters. In the present study, a new method for minimal model analysis, termed GAMMOD, was developed based on genetic algorithms for the estimation of model parameters. Such an algorithm does not require the fixing of initial values for the parameters (that may lead to unreliable estimates). Our method also implements an automated weighting scheme not requiring manual intervention of the operator, thus impro…
Professional continuous glucose monitoring in subjects with type 1 diabetes: retrospective hypoglycemia detection.
2013
Background: An important task in diabetes management is detection of hypoglycemia. Professional continuous glucose monitoring (CGM), which produces a glucose reading every 5 min, is a powerful tool for retrospective identification of unrecognized hypoglycemia. Unfortunately, CGM devices tend to be inaccurate, especially in the hypoglycemic range, which limits their applicability for hypoglycemia detection. The objective of this study was to develop an automated pattern recognition algorithm to detect hypoglycemic events in retrospective, professional CGM. Method: Continuous glucose monitoring and plasma glucose (PG) readings were obtained from 17 data sets of 10 type 1 diabetes patients und…
[Fabry disease in Italy: first epidemiologic and collaborative study].
2005
The authors sought to define the prevalence of Fabry disease and to establish the incidence and its natural history in Italy. The aim of this study was to point out the first clinical signs and symptoms to perform an early diagnosis and hence to start a specific therapeutic treatment. Fabry disease is an inborn error of metabolism caused by the deficiency of the lysosomal enzyme alpha-galactosidase A. Fabry disease is a severe X-linked disorder presenting with a higher morbidity between the third and the fourth decade of life. Fabry disease may be confused with other diseases or completely misdiagnosed: its frequency is estimated worldwide to be 1:117000. In Italy, 65 patients have been ide…
Dynamic image denoising for voxel-wise quantification with Statistical Parametric Mapping in molecular neuroimaging.
2018
Purpose PET and SPECT voxel kinetics are highly noised. To our knowledge, no study has determined the effect of denoising on the ability to detect differences in binding at the voxel level using Statistical Parametric Mapping (SPM). Methods In the present study, groups of subject-images with a 10%- and 20%- difference in binding of [123I]iomazenil (IMZ) were simulated. They were denoised with Factor Analysis (FA). Parametric images of binding potential (BPND) were produced with the simplified reference tissue model (SRTM) and the Logan non-invasive graphical analysis (LNIGA) and analyzed using SPM to detect group differences. FA was also applied to [123I]IMZ and [11C]flumazenil (FMZ) clinic…
Association study of suicidal behavior and affective disorders with a genetic polymorphism in ABCG1, a positional candidate on chromosome 21q22.3
2000
The gene that codes for the ABC transporter ABCG1 is located in a chromosomal susceptibility region (21q22.3) for affective disorders. Genetic variations in ABCG1 have been associated with affective disorders in Japanese males. In this study, we investigated the distribution of a G2457A polymorphism in patients with affective disorders, suicide attempters with various psychiatric diagnoses and healthy subjects. We initially found a trend towards a modest association with affective disorders in males (p = 0.046 for allele frequencies and p = 0.046 for AA versus GG). We conducted a replication study with independent patients and controls. There was no association with affective disorders, eit…
An algorithm for oncologic scalp reconstruction.
2010
Background: Modern reconstructive surgery allows for radical resection and reconstruction of any scalp tumor. However, a significant number of patients are still not treated optimally because of incomplete reconstructive guidelines. Methods: The treatment of scalp tumors was documented in 60 patients over a 10-year period. Data regarding tumor type, size, and localization; reconstructive procedure; oncologic, functional, and aesthetic outcome; and complications were collected and analyzed retrospectively. These data were correlated to recurrence and survival rates. The findings extracted from the data were amalgamated to produce the proposed reconstructive algorithm. Results: Five reconstru…
Motion index: A new parameter to evaluate the diastole by M-Mode imaging
2009
AIM: Heart failure with normal left ventricle (LV) ejection fraction is commonly understood as diastolic heart failure because this expression implies the presence of LV diastolic dysfunction diagnosed by specific echocardiographic findings, such as slow LV relaxation and increased LV stiffness. In this work the authors propose a new parameter named Motion Index, which is measurable by M-Mode technique and it is likely linked to diastolic dysfunction. METHODS: A patient population composed by 134 subjects was enrolled. They all were in New York Heart Association (NYHA) functional class II. Echocardiogram carried out in all patients allowed the authors to distinguish 2 patient arms depending…
Search for a gene responsible for Floating-Harbor syndrome on chromosome 12q15q21.1.
2012
International audience; Floating-Harbor syndrome (FHS) is characterized by characteristic facial dysmorphism, short stature with delayed bone age, and expressive language delay. To date, the gene(s) responsible for FHS is (are) unknown and the diagnosis is only made on the basis of the clinical phenotype. The majority of cases appeared to be sporadic but rare cases following autosomal dominant inheritance have been reported. We identified a 4.7 Mb de novo 12q15-q21.1 microdeletion in a patient with FHS and intellectual deficiency. Pangenomic 244K array-CGH performed in a series of 12 patients with FHS failed to identify overlapping deletions. We hypothesized that FHS is caused by haploinsuf…
Intra‐ and interreader reproducibility of PI‐RADSv2: A multireader study
2018
Background The Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) has been in use since 2015; while interreader reproducibility has been studied, there has been a paucity of studies investigating the intrareader reproducibility of PI-RADSv2. Purpose To evaluate both intra- and interreader reproducibility of PI-RADSv2 in the assessment of intraprostatic lesions using multiparametric magnetic resonance imaging (mpMRI). Study type Retrospective. Population/subjects In all, 102 consecutive biopsy-naive patients who underwent prostate MRI and subsequent MR/transrectal ultrasonography (MR/TRUS)-guided biopsy. Field strength/sequences Prostate mpMRI at 3T using endorectal with phased…
Noise estimation from averaged diffusion weighted images: Can unbiased quantitative decay parameters assist cancer evaluation?
2013
Purpose Multiexponential decay parameters are estimated from diffusion-weighted-imaging that generally have inherently low signal-to-noise ratio and non-normal noise distributions, especially at high b-values. Conventional nonlinear regression algorithms assume normally distributed noise, introducing bias into the calculated decay parameters and potentially affecting their ability to classify tumors. This study aims to accurately estimate noise of averaged diffusion-weighted-imaging, to correct the noise induced bias, and to assess the effect upon cancer classification. Methods A new adaptation of the median-absolute-deviation technique in the wavelet-domain, using a closed form approximati…