Search results for "POSITRON EMISSION TOMOGRAPHY"

Active contour algorithm with discriminant analysis for delineating tumors in positron emission tomography.

2019

Abstract In the context of cancer delineation using positron emission tomography datasets, we present an innovative approach which purpose is to tackle the real-time, three-dimensional segmentation task in a full, or at least nearly full automatized way. The approach comprises a preliminary initialization phase where the user highlights a region of interest around the cancer on just one slice of the tomographic dataset. The algorithm takes care of identifying an optimal and user-independent region of interest around the anomalous tissue and located on the slice containing the highest standardized uptake value so to start the successive segmentation task. The three-dimensional volume is then…

The diagnostic possibilities of Positron Emission Tomography (PET)

2014

Se describen los principios de la tomografía por emisión de positrones (PET) como procedimiento diagnóstico de reciente introducción en el campo de las Ciencias de la Salud. Las aplicaciones clínicas principales se dan en un grupo concreto de especialidades: la cardiología, neurología, psiquiatría y sobre todo la oncología. La tomografía por emisión de positrones es una técnica de diagnóstico por la imagen no invasiva de uso clínico. Se trata de una excelente herramienta para el estudio de la estadificación y la posible malignización de los tumores de cabeza y cuello, la detección de metástasis y linfoadenopatías no valorables clínicamente, así como para el diagnóstico de recidivas tumorale…

Immunohistochemical expression of glucose transporter 1 in keratin-producing odontogenic cysts

2016

Background: Keratin-producing odontogenic cysts (KPOCs) are a group of cystic lesions that are often aggressive, with high rates of recurrence and multifocality. KPOCs included orthokeratinised odontogenic cyst (OOC) and parakeratotic odontogenic cysts, which are now considered true tumours denominated keratocystic odontogenic tumours (KCOTs). GLUT1 is a protein transporter that is involved in the active uptake of glucose across cell membranes and that is overexpressed in tumours in close correlation with the proliferation rate and positron emission tomography (PET) imaging results. Methods: A series of 58 keratin-producing odontogenic cysts was evaluated histologically and immunohistochemi…

An Unusual Presentation of Zollinger-Ellison Syndrome

2013

Abstract Zollinger-Ellison syndrome is an often progressive, persistent and frequently life-threatening disease, described for the first time as characterized by ulceration of the upper jejunum, hypersecretion of gastric acid and non-beta islet cell tumors of the pancreas; this syndrome is due to the hypersecretion of gastrin. We report a case of Zollinger-Ellison syndrome presenting as severe esophagitis evolving in stenosis, which demonstrates how a delayed diagnosis may induce risk of disease spreading. In this setting new diagnostic approaches, such as somatostatin receptor scanning and positron emission tomography with 68 Ga-labeled octreotide, could be particularly useful, as well as …

Current Practices in the Management of Pulmonary Ground-Glass Opacities: A Survey of SICT Members

2018

Background Several gray areas and controversies exist concerning the management of pulmonary ground-glass opacities (GGOs), and there is a lack of consensus among clinicians on this topic. One of the main aims of the Italian Society of Thoracic Surgery is to promote education and research, so we decided to perform a survey on this topic to estimate current trends in practice in a large sample of thoracic surgeons. Methods A total of 160 thoracic surgeons responded, namely, completed our questionnaire (response rate, 53%; 160 of 302). The survey was composed of 36 questions divided into six subsections: (1) demographic characteristics of the respondents; (2) terminology and taxonomy; (3) rad…

Synthesis of 2-amino-6-(2-[18F]fluoro-pyridine-4-ylmethoxy)-9-(octyl-β-d-glucosyl)-purine: a novel radioligand for positron emission tomography studi…

2002

Abstract The synthesis of the novel glucose conjugated O6-methylguanine-DNA methyltransferase (MGMT) inhibitor 2-amino-6-(2-[18F]fluoro-pyridine-4-ylmethoxy)-9-(octyl-α- d -glucosyl)-purine is reported. This compound might serve as a radiotracer for the determination of the MGMT status of tumour tissue.

ChemInform Abstract: Synthesis of 2-Amino-6-(2- [18F] fluoro-pyridine-4-ylmethoxy)-9-(octyl-β-D-glucosyl)-purine: A Novel Radioligand for Positron Em…

2010

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…

Impact of prompt gamma emission of 44Sc on quantification in preclinical and clinical PET systems

2021

Abstract 44Sc is an increasingly investigated positron emitter for use in positron emission tomography (PET) imaging. However, 44Sc is a non-pure positron emitter, since prompt photons are co-emitted during the decay process. This study investigates coincidence energy spectra of 44Sc and its impact on PET quantification on a preclinical and clinical PET system in comparison with 18F. The raw data of the coincidence events revealed characteristic differences comparing the photon energy distribution of 44Sc and 18F. Due to prompt gamma emission of 44Sc, activity recovery is underestimated on PET systems. However, clinical PET imaging of 44Sc with acceptable quantitative accuracy appears feasi…

2017

In the context of radiopharmacy and molecular imaging, the concept of theranostics entails a therapy-accompanying diagnosis with the aim of a patient-specific treatment. Using the adequate diagnostic radiopharmaceutical, the disease and the state of the disease are verified for an individual patient. The other way around, it verifies that the radiopharmaceutical in hand represents a target-specific and selective molecule: the “best one” for that individual patient. Transforming diagnostic imaging into quantitative dosimetric information, the optimum radioactivity (expressed in maximum radiation dose to the target tissue and tolerable dose to healthy organs) of the adequate radiotherapeutica…