Search results for "positron"
showing 10 items of 1346 documents
Imaging Approach for Evaluation of Focal Liver Lesions
2009
Focal liver lesions are common in the general population. Radiology (imaging) plays a pivotal role for the diagnosis, staging, treatment planning, and follow-up of focal liver lesions. To maximize lesion detection and characterization, imaging needs to be performed with appropriate equipment by using protocols carefully designed on the basis of the underlying clinical context. In addition, the decision of an imaging modality cannot be based on the diagnostic accuracy of an imaging test solely but must also consider patient safety and cost-effectiveness.
Fever of unknown origin and anaemia as a form of presentation of a rhabdomyosarcoma
2011
Abstract We report a case of fever of unknown origin, in its classical presentation. A wide range of studies were unrevealing, but finally a positron emission tomography/computed tomography allowed us to establish the diagnosis of rhabdomyosarcoma in the pelvic region.
PET Lung Ventilation/Perfusion Imaging Using 68Ga Aerosol (Galligas) and 68Ga-Labeled Macroaggregated Albumin
2012
Pulmonary imaging using ventilation/perfusion (V/P) single-photon emission tomography (V/P scan) with Tc-99m-labeled radiotracers is a well-established diagnostic tool for clinically suspected pulmonary embolism (PE). Ga-68 aerosol (Galligas) and Ga-68-labeled macroaggregated albumin (MAA) are potential tracers for positron emission tomography (PET) lung V/P imaging and could display an advantage over conventional V/P scans in terms of sensitivity and specificity. After radiochemical and animal studies, the clinical applicability of Ga-68 aerosol (Galligas) and Ga-68-labeled MAA was investigated in an exploratory study in patients with clinical suspicion of PE. PET scans were acquired using…
Die Positronenemissionstomographie zur pr�operativen Lymphknotendiagnostik bei �sophaguskarzinom
2003
Vorraussetzung fur Indikation und Wahl des geeigneten operativen Verfahrens bei Patienten mit Osophaguskarzinom ist ein genaues praoperatives Staging. Ziel der prospektiven Studie war es, zu klaren, ob eine Positronenemissionstomographie mit 18F-Fluoro-Deoxyglukose (FDG-PET) die Genauigkeit des praoperativen Lymphknotendiagnostik gegenuber der Computertomographie (CT) erhoht und die Wahl des operativen Zugangs zur Osophagusresektion beeinflusst. 58 Patienten, 46 Manner und 12 Frauen (Alter 61 Jahre im Mittel), erhielten bei histologisch gesichertem Osophaguskarzinom im Rahmen des Stagings ein FDG-PET von Hals, Thorax und Abdomen sowie ein CT von Thorax und Abdomen. Sensitivitat, Spezifitat …
Can Early Postoperative O-(2-18FFluoroethyl)-l-Tyrosine Positron Emission Tomography After Resection of Glioblastoma Predict the Location of Later Tu…
2019
Objective Glioblastoma inevitably recurs despite aggressive therapy. Therefore, it would be helpful to predict the location of tumor recurrence from postoperative imaging to customize further treatment. O-(2-18Ffluoroethyl)- l -tyrosine (FET) positron emission tomography (PET) might be a helpful technique, because tumor tissue can be differentiated from normal brain tissue with high specificity. Methods Thirty-two consecutive patients with perioperative and follow-up imaging data available were included. On postoperative FET-PET, the tumor/normal brain (TTB) ratio around the resection cavity borders was measured. Increased TTB ratios were recorded and anatomically correlated with the site o…
Alterations in 18F-FDG accumulation into neck-related muscles after neck dissection for patients with oral cancers
2015
Background: 18 F-fluoro-2-deoxy-D-glucose ( 18 F-FDG) accumulations are commonly seen in the neck-related muscles of the surgical and non-surgical sides after surgery with neck dissection (ND) for oral cancers, which leads to radiologists having difficulty in diagnosing the lesions. To examine the alterations in 18 F-FDG accumulation in neck-related muscles of patients after ND for oral cancer. Material and Methods: 18 F-FDG accumulations on positron emission tomography (PET)-computed tomography (CT) in neck-related muscles were retrospectively analyzed after surgical dissection of cervical lymph nodes in oral cancers. Results: According to the extent of ND of cervical lymph nodes, the rate…
68 ga-dotatoc pet/ct follow up after single or hypofractionated gamma knife icon radiosurgery for meningioma patients
2021
68Ga-DOTATOC represents a useful tool in tumor contouring for radiosurgery planning. We present a case series of patients affected by meningiomas on who we performed 68Ga-DOTATOC positron emission tomography (PET)/CT pre-operatively, a subgroup of which also underwent a post-operative 68Ga-DOTATOC PET/CT to evaluate the standardized uptake value (SUV) modification after Gamma Knife ICON treatment in single or hypofractionated fractions. Twenty patients were enrolled/included in this study: ten females and ten males. The median age was 52 years (range 33–80). The median tumor diameter was 3.68 cm (range 0.12–22.26 cm), and the median pre-radiotherapy maximum SUV value was 11 (range 2.3–92). …
Analytical model for the long- distance tracer-transport in plants
2011
International audience; Recent investigations of long-distance transport in plants using non-invasive tracer techniques such as C radiolabeling monitored by positron emission tomography (PET) combined with magnetic resonance imaging (MRI) revealed the need of dedicated methods to allow a quantitative data analysis and comparison of such experiments. A mechanistic compartmental tracer transport model is presented, defined by a linear system of partial differential equations (PDEs). This model simplifies the complexity of axial transport and lateral exchanges in the transport pathways of plants (e.g. the phloem) by simulating transport and reversible exchange within three compartments using j…
Performance Enhancement of a Small Animal Positron Emission Tomograph based on Continuous Crystals and Silicon Photomultipliers
2017
La tomografía por emisión de positrones (PET, por sus siglas en inglés) es una técnica de Medicina Nuclear que permite obtener de manera no invasiva imágenes funcionales “in vivo” marcando un compuesto orgánico con un emisor de positrones. Los tomógrafos PET requieren un alta resolución espacial y sensibilidad para estimar con precisión la distribución del radiotrazador en el animal. Frente a los bloques pixelados comúnmente utilizados en PET, los detectores que consisten en la combinación de cristales continuos acoplados a fotodetectores segmentados pueden ofrecer una mayor eficiencia y una alta resolución espacial. Esta última depende de la precisión de los algoritmos de determinación de …
Case Report: Unmasking Hypercalcemia in Patients With Neuroendocrine Neoplasms. Experience From Six Italian Referral Centers
2021
BackgroundHypercalcemia is a common paraneoplastic syndrome which can occur in up to 10% of patients with advanced neoplasms. Paraneoplastic parathyroid hormone-related protein (PTHrP) represents the most frequent cause of this syndrome. In neuroendocrine neoplasms (NENs) paraneoplastic hypercalcemia is rare.Case SeriesThe present series includes all patients with NENs and paraneoplastic hypercalcemia from four Italian centres: (I) A 40-year-old man was hospitalized for repeated episodes of falls, hyposthenia and drowsiness. Severe hypercalcemia was found. Metastatic pancreatic G2 NEN and PTHrP-related hypercalcemia were diagnosed. The patient started therapy with somatostatin analogs (SSA)…