Search results for "Subtraction"
showing 10 items of 112 documents
SPET/CT image co-registration in the abdomen with a simple and cost-effective tool
2002
Fusion of morphology and function has been shown to improve diagnostic accuracy in many clinical circumstances. Taking this into account, a number of instruments combining computed tomography (CT) with positron emission tomography (PET) or single-photon emission tomography (SPET) are appearing on the market. The aim of this study was to evaluate a simple and cost-effective approach to generate fusion images of similar quality. For the evaluation of the proposed approach, patients with neuroendocrine abdominal tumours with liver metastases were chosen, since the exact superimposition in the abdomen is more difficult than in other regions. Five hours following the injection of 110 MBq (111)In…
Evaluation of washout using subtraction MRI for the diagnosis of hepatocellular carcinoma in cirrhotic patients with spontaneously T1-hyperintense no…
2023
Purpose: The purpose of this study was to assess the value of subtraction imaging on post-arterial phase images (i.e., portal venous, delayed/transitional and hepatobiliary phases) for the non-invasive diagnosis of hepatocellular carcinoma (HCC) in spontaneously hyperintense nodules on T1-weighted imaging in patients with cirrhosis. Materials and methods: Forty-five patients with a total 55 hepatic nodules that were spontaneously hyperintense on T1-weighted images were initially retrieved. All patients underwent MRI examination of the liver using extracellular agent. Each nodule was assessed for sensitivity and specificity using LI-RADS (Liver Imaging Reporting and Data System) during two r…
Conceptual knowledge‐based strategy training in single‐digit calculation: a single case intervention study in a child with specific language impairme…
2009
The aim of this single‐case intervention study was to examine whether a conceptual knowledge‐based strategy training would improve the accuracy of single‐digit arithmetical calculation in a child with specific language impairment. The intervention concerned an11‐year‐old Finnish‐speaking child with specific language impairment. He was trained individually once a week for three months. On the basis of his baseline performance single‐digit arithmetical problems were divided into ‘well‐known arithmetical problems’ and ‘error‐prone arithmetical problems’. Error‐prone problems were taught in meaningful relation to well‐known problems, which he repeatedly solved correctly by using arithmetical fa…
Rotation-Invariant Texture Retrieval via Signature Alignment Based on Steerable Sub-Gaussian Modeling
2008
This paper addresses the construction of a novel efficient rotation-invariant texture retrieval method that is based on the alignment in angle of signatures obtained via a steerable sub-Gaussian model. In our proposed scheme, we first construct a steerable multivariate sub-Gaussian model, where the fractional lower-order moments of a given image are associated with those of its rotated versions. The feature extraction step consists of estimating the so-called covariations between the orientation subbands of the corresponding steerable pyramid at the same or at adjacent decomposition levels and building an appropriate signature that can be rotated directly without the need of rotating the im…
Invariant Feature Matching for Image Registration Application Based on New Dissimilarity of Spatial Features
2016
An invariant feature matching method is proposed as a spatially invariant feature matching approach. Deformation effects, such as affine and homography, change the local information within the image and can result in ambiguous local information pertaining to image points. New method based on dissimilarity values, which measures the dissimilarity of the features through the path based on Eigenvector properties, is proposed. Evidence shows that existing matching techniques using similarity metrics--such as normalized cross-correlation, squared sum of intensity differences and correlation coefficient--are insufficient for achieving adequate results under different image deformations. Thus, new…
Favignana Quarry Island. Mediterranean landscapes between description and transformation
2022
The essay takes a critical look at part of the extensive research on the Mediterranean landscape conducted by the authors, particularly on the architecture of the quarry landscape in Sicily. The case study investigated concerns the island of Favignana and the complex relationship that the quarry landscape has represented in the relations between this island of the Egadi archipelago and the Mediterranean basin. The essay adopts five keywords that represent many access tools for an anthropogeographical understanding of the island. The essay interprets Favignana as an island of wind and water through geography. But it extends its dimension to architecture, looking at its landscape as a single …
The limits of subtractive politics: Agamben and Rousseau’s inheritance
2020
The article critically engages with Giorgio Agamben’s reading of Rousseau in order to explore the affinities between the two authors’ subtractive approach to political subjectivation. In The Kingdom and the Glory. Agamben argues that Rousseau’s Social Contract reproduces, in a secularized manner, the providential paradigm of government, whose origins Agamben finds in early Christianity. This paradigm establishes a fictitious articulation between transcendent sovereignty and immanent government, presenting particular acts of government as emanating from general divine laws. We shall demonstrate that Rousseau was neither unaware of the problematic character of this paradigm nor did he venture…
Multispectral images-based background subtraction using Codebook and deep learning approaches
2020
This dissertation aims to investigate the multispectral images in moving objects detection via background subtraction, both with classical and deep learning-based methods. As an efficient and representative classical algorithm for background subtraction, the traditional Codebook has first been extended to multispectral case. In order to make the algorithm reliable and robust, a self-adaptive mechanism to select optimal parameters has then been proposed. In this frame, new criteria in the matching process are employed and new techniques to build the background model are designed, including box-based Codebook, dynamic Codebook and fusion strategy. The last attempt is to investigate the potent…
Two-dimensional parametric parenchymal blood flow in transarterial chemoembolisation for hepatocellular carcinoma: perfusion change quantification an…
2020
Aim To evaluate the feasibility and potential value of two-dimensional (2D) parametric parenchymal blood flow (2D-PPBF) for the assessment of perfusion changes during transarterial chemoembolisation with drug-eluting beads (DEB-TACE) and to analyse correlations of 2D-PPBF parameters and tumour response. Materials and methods Thirty-two patients (six women, 26 men, mean age: 67±8.9 years) with unresectable hepatocellular carcinoma (HCC) who underwent their first DEB-TACE were included in this study. To quantify perfusion changes using 2D-PPBF, the acquired digital subtraction angiography (DSA) series were post-processed. Ratios were calculated between the reference region of interest (ROI) a…
Retinal image quality and visual stimuli processing by simulation of partial eye cataract
2016
Visual stimuli were demonstrated on a 4.3’’ mobile phone screen inside a “Virtual Reality” adapter that allowed separation of the left and right eye visual fields. Contrast of the retina image thus can be controlled by the image on the phone screen and parallel to that at appropriate geometry by the AC voltage applied to scattering PDLC cell inside the adapter. Such optical pathway separation allows to demonstrate to both eyes spatially variant images, that after visual binocular fusion acquire their characteristic indications. As visual stimuli we used grey and different color (two opponent components to vision – red-green in L*a*b* color space) spatially periodical stimuli for left and ri…