Search results for "030218 nuclear medicine & medical imaging"
showing 10 items of 1054 documents
Synthesis and evaluation of zirconium-89 labelled and long-lived GLP-1 receptor agonists for PET imaging
2020
Contains fulltext : 220838.pdf (Publisher’s version ) (Open Access) INTRODUCTION: Lately, zirconium-89 has shown great promise as a radionuclide for PET applications of long circulating biomolecules. Here, the design and synthesis of protracted and long-lived GLP-1 receptor agonists conjugated to desferrioxamine and labelled with zirconium-89 is presented with the purpose of studying their in vivo distribution by PET imaging. The labelled conjugates were evaluated and compared to a non-labelled GLP-1 receptor agonist in both in vitro and in vivo assays to certify that the modification did not significantly alter the peptides' structure or function. Finally, the zirconium-89 labelled peptide…
TAVI imaging: over the echocardiography
2020
Aortic valve stenosis (AS) is a common valvular heart disease. Recently, transcatheter aortic valve implantation (TAVI) has changed the treatment of severe AS in elderly patients with contraindications to traditional surgical replacement. Echocardiography is conventionally used as the first imaging modality to assess the presence and severity of AS and to provide anatomical and functional information. Nowadays, imaging techniques play a crucial role in the planning of TAVI to define suitable candidates. Computed tomography (CT) is essential to display the anatomy of the aortic valve complex (including aortic annulus, Valsalva sinuses, coronary arteries ostia, sinotubular junction), thoracoa…
Valvular Heart Disease
2013
Valvular heart disease (VHD) refers to a wide spectrum of cardiac disorders that affect a large number of patients. Echocardiography is still considered the pivotal imaging method to evaluate the cardiac valves. However, echocardiography has some intrinsic limitations due to operator dependence and patient habitus. In the last two decades three-dimensional techniques such as magnetic resonance imaging (MRI) and computed tomography (CT) have provided valuable assessment of VHD. MRI overcomes the limitation of the poor acoustic window of echocardiography without ionizing radiation. Nowadays, MRI aims to be considered as the reference standard for imaging cardiac valves because of the improved…
Retention of Pb isotopes in glass surfaces for retrospective assessment of radon exposure
2006
Abstract In recent years there has been increasing interest in radio-epidemiological techniques to retrospectively measure the radon dose exposure by determining the activity of 210Pb, the longest-lived 222Rn progeny, in glass surface layers. In this study the diffusion of 39 keV 209Pb+ ions implanted into glass using the IGISOL facility has been studied under conditions that mimic the recoil implantation of 210Pb from 222Rn. The resulting depth distributions of 209Pb were then measured after heat treatment in vacuum at different temperatures by a sputter erosion technique. The diffusion coefficient could be described by an Arrhenius equation D = D0exp(−H/kT) where D 0 = 0.30 - 0.24 + 1.14 …
Focused Ultrasound Effects on Osteosarcoma Cell Lines
2019
MRI guided Focused Ultrasound (MRgFUS) has shown to be effective therapeutic modality for non-invasive clinical interventions in ablating of uterine fibroids, in bone metastasis palliative treatments, and in breast, liver, and prostate cancer ablation. MRgFUS combines high intensity focused ultrasound (HIFU) with MRI images for treatment planning and real time thermometry monitoring, thus enabling non-invasive ablation of tumor tissue. Although in the literature there are several studies on the Ultrasound (US) effects on cell in culture, there is no systematic evidence of the biological effect of Magnetic Resonance guided Focused Ultrasound Surgery (MRgFUS) treatment on osteosarcoma cells, …
Abstract ID: 133 Fast and accurate 3D dose distribution computations using artificial neural networks
2017
In radiation therapy, the trade-off between accuracy and speed is the key of the algorithms used in Treatment Planning Systems (TPS). For photon beams, commercial solutions generally relies on analytic algorithms, biased Monte Carlo, or heavily parallelized Monte Carlo on Graphics Processing Units (GPU). Alternatively, we propose an algorithm using Artificial Neural Network (ANN) to compute the dose distributions resulting from ionizing radiations inside a phantom [1] , [2] . We present an evolution of this platform taking into account modulated field sizes and shapes, and various orientations of the beam to the phantom. Firstly, tomodensitometry-based phantoms are created to validate the d…
Comparison of gamma-ray coincidence and low-background gamma-ray singles spectrometry
2011
Aerosol samples have been studied under different background conditions using gamma-ray coincidence and low-background gamma-ray singles spectrometric techniques with High-Purity Germanium detectors. Conventional low-background gamma-ray singles counting is a competitive technique when compared to the gamma-gamma coincidence approach in elevated background conditions. However, measurement of gamma-gamma coincidences can clearly make the identification of different nuclides more reliable and efficient than using singles spectrometry alone. The optimum solution would be a low-background counting station capable of both singles and gamma-gamma coincidence spectrometry.
Osteonecrosis in Hodgkin lymphoma treated by BEACOPP
2018
S-Detect characterization of focal solid breast lesions: a prospective analysis of inter-reader agreement for US BI-RADS descriptors
2020
Background: To assess inter-reader agreement for US BI-RADS descriptors using S-Detect: a computer-guided decision-making software assisting in US morphologic analysis. Methods: 73 solid focal breast lesions (FBLs) (mean size: 15.9 mm) in 73 consecutive women (mean age: 51 years) detected at US were randomly and independently assessed according to the BI-RADS US lexicon, without and with S-Detect, by five independent reviewers. US-guided core-biopsy and 24-month follow-up were considered as standard of reference. Kappa statistics were calculated to assess inter-operator agreement, between the baseline and after S-Detect evaluation. Agreement was graded as poor (≤ 0.20), moderate (0.21–0.40)…
Cone-beam computed tomography and its applications in dental and maxillofacial radiology.
2020
Cone-beam computed tomography (CBCT) was first used in dental and maxillofacial radiology (DMFR) at the end of the 1990s. Since then, it has been successfully established as the standard three-dimensional radiographic imaging technique in DMFR, with a wide variety of applications in this field. This manuscript briefly reviews the background information on the technology and summarises available data on effective dose and dose optimisation. In addition, typical clinical applications and indications of the technique in DMFR are presented.