Search results for " Emission"

Head–Neck Cancer Delineation

2021

Head–Neck Cancer (HNC) has a relevant impact on the oncology patient population and for this reason, the present review is dedicated to this type of neoplastic disease. In particular, a collection of methods aimed at tumor delineation is presented, because this is a fundamental task to perform efficient radiotherapy. Such a segmentation task is often performed on uni-modal data (usually Positron Emission Tomography (PET)) even though multi-modal images are preferred (PET-Computerized Tomography (CT)/PET-Magnetic Resonance (MR)). Datasets can be private or freely provided by online repositories on the web. The adopted techniques can belong to the well-known image processing/computer-vision a…

Cardiovascular imaging in the diagnosis and monitoring of cardiotoxicity: cardiovascular magnetic resonance and nuclear cardiology

2016

Chemotherapy-induced cardiotoxicity (CTX) is a determining factor for the quality of life and mortality of patients administered potentially cardiotoxic drugs and in long-term cancer survivors. Therefore, prevention and early detection of CTX are highly desirable, as is the exploration of alternative therapeutic strategies and/or the proposal of potentially cardioprotective treatments. In recent years, cardiovascular imaging has acquired a pivotal role in this setting. Although echocardiography remains the diagnostic method most used to monitor cancer patients, the need for more reliable, reproducible and accurate detection of early chemotherapy-induced CTX has encouraged the introduction o…

Air pollution exposure during pregnancy and reduced birth size: a prospective birth cohort study in Valencia, Spain

2010

Abstract Background Maternal exposure to air pollution has been related to fetal growth in a number of recent scientific studies. The objective of this study was to assess the association between exposure to air pollution during pregnancy and anthropometric measures at birth in a cohort in Valencia, Spain. Methods Seven hundred and eighty-five pregnant women and their singleton newborns participated in the study. Exposure to ambient nitrogen dioxide (NO2) was estimated by means of land use regression. NO2 spatial estimations were adjusted to correspond to relevant pregnancy periods (whole pregnancy and trimesters) for each woman. Outcome variables were birth weight, length, and head circumf…

Otoacoustic emissions: a new method to diagnose hearing impairment in children.

1993

Otoacoustic emissions (OAEs) are epiphenomena of sensitive, amplifying processes during hearing which can be detected in persons with normal inner ear function. They originate from the cochlea and are interpreted as an energy leakage of cochlear processes, perhaps resulting from active outer hair cell movements. OAEs travel from the cochlea through the middle ear to the external auditory canal where they can be detected using sensitive miniature microphones. Transient evoked (TEOAE) tests allow to otoacoustic emissions non-invasively check the integrity of the cochlea. In the neonatal period, registration of OAEs can be accomplished during natural sleep. In infants and neonates TEOAEs can b…

Non Invasive Imaging of Myocardial Infarction with Computed Tomography and Magnetic Resonance

2012

Myocardial infarction is a major cause of death and disability worldwide. Myocardial infarction may represent a major catastrophic event leading to severe hemodynamic failure or sudden death or it may occur repeatedly in patients with established heart disease. In this context, the role of imaging techniques may become useful for the understanding of the determinants in a preclinical setting before acute coronary events, and for an accurate and correct diagnosis of myocardial infarction. Three-dimensional noninvasive imaging techniques, such as Cardiac CT (CCT) and Cardiac MR imaging (CMR) were widely developed in the last two decades. These imaging techniques may provide new insights into …

Update on diagnostic strategies of pulmonary embolism

1999

Acute pulmonary embolism is a frequent disease with non-specific findings, high mortality, and multiple therapeutic options. A definitive diagnosis must be established by accurate, non-invasive, easily performed, cost-effective, and widely available imaging modalities. Conventional diagnostic strategies have relied on ventilation-perfusion scintigraphy complemented by venous imaging. If the results are inconclusive, pulmonary angiography, which is regarded as the gold standard, is to be performed. Recently, marked improvements in CT and MRI and shortcomings of scintigraphy led to an update of the diagnostic strategy. Spiral CT is successfully employed as a second-line procedure to clarify i…

Visualizing the atherosclerotic plaque: a chemical perspective.

2014

Atherosclerosis is the major underlying pathologic cause of coronary artery disease. An early detection of the disease can prevent clinical sequellae such as angina, myocardial infarction, and stroke. The different imaging techniques employed to visualize the atherosclerotic plaque provide information of diagnostic and prognostic value. Furthermore, the use of contrast agents helps to improve signal-to-noise ratio providing better images. For nuclear imaging techniques and optical imaging these agents are absolutely necessary. We report on the different contrast agents that have been used, are used or may be used in future in animals, humans, or excised tissues for the distinct imaging moda…

Erfassung von Neurotransmitterinteraktionen mit PET und SPECT durch pharmakologische Challenge-Paradigmen

2000

Functional brain imaging with positron emission tomography (PET) and single photon emission computerized tomography (SPECT) enables the in vivo study of specific neurochemical processes in the context of normal regulatory mechanisms and pathophysiological alterations of the brain. By combining these methods with pharmacological challenge-paradigms, the study of functional interactions of different neurotransmitter systems is possible. This review will present data from animal and healthy volunteer studies as well as first data from investigations in different patient populations with regard to this research direction. Especially, interactions of different neurotransmitter systems with the d…

Corticobasal syndrome-like variant of Creutzfeldt–Jakob disease: clinical description of two cases

2014

New Trends in Detectors for Medical Imaging

2010

The improvement of medical imaging instrumentation is based both on the enhancement of the performance of the detectors employed in their construction and on the development of novel techniques and methods that allow full exploitation of the advantages of the new instrumentation.