Search results for "Enhancement."

2020

One crucial parameter to evaluate the state of the heart after myocardial infarction (MI) is the viability of the myocardial segment, i.e., if the segment recovers its functionality upon revascularization. MRI performed several minutes after the injection of a contrast agent (delayed enhancement-MRI or DE-MRI) is a method of choice to evaluate the extent of MI, and by extension, to assess viable tissues after an injury. The Emidec dataset is composed of a series of exams with DE-MR images in short axis orientation covering the left ventricle from normal cases or patients with myocardial infarction, with the contouring of the myocardium and diseased areas (if present) from experts in the dom…

Automatic Processing Scheme for Low Laser Invasiveness Electro Optical Frequency Mapping mode

2016

International audience; Electro optical techniques are efficient backside contactless techniques usually used for design debug and defect location in modern VLSI. Unfortunately, the signal to noise ratio is quite low and depends on laser power with potential device stress due to long acquisition time or high laser power, especially in up to date technologies. Under these conditions, to maintain a good signal or image quality, specific signal or image processing techniques can be implemented. In this paper, we proposed a new spatial filtering by stationary wavelets and contrast enhancement which allows the use of low laser power and short acquisition time in image mode.

Janus Micelles Induced by Olefin Metathesis

2008

A facile one-step procedure for hydrophobic modification and simultaneous TEM contrast enhancement via a regioselective olefin metathesis reaction using Grubbs' catalyst is presented. Polyether diblock copolymers were investigated, and both the chain ends of the hydrophilic and the hydrophobic block were hydrophobically modified. Modification of the hydrophilic block results in nonsymmetric supramolecular structures (Janus micelles) which self-assemble into larger hierarchically organized super-micelles.

Möglichkeiten der 16-Schicht-CT bei der linksventrikulären Funktionsbestimmung: Beurteilung zweier unterschiedlicher Software-Tools zur quantitativen…

2004

PURPOSE To determine global and regional left ventricular (LV) function from retrospectively gated multidetector row computed tomography (CT) by using two different semiautomated analysis tools and to correlate the results with those of magnetic resonance imaging (MRI). MATERIALS AND METHODS Nineteen patients (5 females, 14 males, mean age 69 years) underwent 16-slice spiral-CT (MS-CT) with standard technique without administration of beta-blockers for a decrease in the cardiac rate. Ten series of images were reconstructed at every 10 % of the RR-interval. With commercially available software capable of semiautomated contour detection, end-diastolic and end-systolic LV volumes (EDV and ESV)…

Malignes fibröses Histiozytom

1988

Malignant fibrous histiozytoma (MHF) is a pleomorphic sarcoma of ubiquituous origin. The clinical and radiological features of the tumor are illustrated by 23 patients with MFH of soft tissue and 4 MFH of bone. On conventional radiography MFH appears as a soft tissue tumor, sometimes with bone involvement; on sonography it is usually non-homogeneous and hypoechogenic with areas of necrosis. On CT the masses are homogeneous or inhomogeneous (10-60 HU.) containing areas of decreased density. Contrast enhancement was about 10-20 HU. Angiographically the tumor appears as hypo- or hypervascular with pathologic vessels. The morphology of MFH in diagnostic imaging including magnetic resonance tomo…

Mammographic images segmentation based on chaotic map clustering algorithm

2013

Background: This work investigates the applicability of a novel clustering approach to the segmentation of mammographic digital images. The chaotic map clustering algorithm is used to group together similar subsets of image pixels resulting in a medically meaningful partition of the mammography. Methods: The image is divided into pixels subsets characterized by a set of conveniently chosen features and each of the corresponding points in the feature space is associated to a map. A mutual coupling strength between the maps depending on the associated distance between feature space points is subsequently introduced. On the system of maps, the simulated evolution through chaotic dynamics leads…

Diagnóstico etilógico de la disfunción ventricular izquierda con tomografia computerizada: comparación con coronariografía y cardiorresonancia

2012

[EN] Introduction and objectives To evaluate the capability of multidetector computed tomography to diagnose the coronary etiology of left ventricular dysfunction compared with using invasive coronary angiography and magnetic resonance. Methods Forty consecutive patients with left ventricular dysfunction of uncertain etiology underwent invasive coronary angiography and contrast magnetic resonance. All patients were evaluated with multidetector computed tomography including coronary calcium presence and score, noninvasive coronary angiography, and myocardial tissue assessment. Results The sensitivity and specificity of the presence of coronary calcium to identify left ventricular dysfunction…

Anatomical variants and anomalies of the coronary tree studied with MDCT coronary angiography

2010

Le anomalie delle arterie coronariche sono presenti alla nascita nella maggior parte dei casi asintomatiche ma possono manifestarsi con sintomatologia severa quale angina pectoris o addirittura l’arresto cardiaco. L’angiografia coronarica mediante tomografia computerizzata multistrato (TCMS) permette, tramite ricostruzioni multiplanari secondo piani curvilinei e riformattazioni 3D, la visualizzazione dell’albero coronarico e delle sue varianti ed anomalie in maniera non invasiva, fornendo migliore e più accurata alternativa alla angiografia coronarica (AC). Lo scopo di questo pictorial consiste nella descrizione mediante immagini TCMS con ricostruzioni multiplanari e 3D delle principali var…

Measuring Spatiotemporal Dependencies in Bivariate Temporal Random Sets with Applications to Cell Biology

2008

Analyzing spatiotemporal dependencies between different types of events is highly relevant to many biological phenomena (e.g., signaling and trafficking), especially as advances in probes and microscopy have facilitated the imaging of dynamic processes in living cells. For many types of events, the segmented areas can overlap spatially and temporally, forming random clumps. In this paper, we model the binary image sequences of two different event types as a realization of a bivariate temporal random set and propose a nonparametric approach to quantify spatial and spatiotemporal interrelations using the pair correlation, cross-covariance, and the Ripley K functions. Based on these summary st…

From Conservation to Revitalization. Ambiguous and Critical Conditions in the Heritage Conservation Experiences of Erice

2022

The plans and the evolutionary trends of policies and practices implemented in Erice old town, in the south of Italy, in the western part of Sicily, can be considered a case study of total conservation as highly representative of Italian urban planning of the last 60 years. This paper aims to deal with the actual problems and the perspective of sustainable development of the historical centre of Erice, by adopting the approach of urban and territorial regeneration. This paper also highlights the historical and cultural context in which the Gubbio Charter (issued in 1960) is affirmed; i.e. the most appropriate approaches to historical urban centres; what we can learn from Erice’s integral co…