Three-Dimensional Imaging of Surface Chemical Processes in Catalysis Using High-Resolution Positron Emission Tomography

ChemPlusChem ◽  
2013 ◽  
Vol 78 (8) ◽  
pp. 830-836 ◽  
Author(s):  
Eva Sarkadi-Pribóczki ◽  
Ivan Valastyan ◽  
Jozsef Molnar
Keyword(s):  
Positron Emission Tomography ◽  
High Resolution ◽  
Three Dimensional ◽  
Chemical Processes ◽  
Emission Tomography ◽  
Surface Chemical ◽  
Three Dimensional Imaging ◽  
Positron Emission

scholarly journals Imaging the heart in pulmonary hypertension: an update

2015 ◽  
Vol 24 (138) ◽  
pp. 653-664 ◽  
Author(s):  
Ekkehard Grünig ◽  
Andrew J. Peacock
Keyword(s):  
Positron Emission Tomography ◽  
Pulmonary Hypertension ◽  
High Resolution ◽  
Three Dimensional ◽  
Emission Tomography ◽  
High Resolution Computed Tomography ◽  
Right Heart Catheterisation ◽  
Positron Emission ◽  
Technological Advances ◽  
The Right

Noninvasive imaging of the heart plays an important role in the diagnosis and management of pulmonary hypertension (PH), and several well-established techniques are available for assessing performance of the right ventricle, the key determinant of patient survival. While right heart catheterisation is mandatory for establishing a diagnosis of PH, echocardiography is the most important screening tool for early detection of PH. Cardiac magnetic resonance imaging (CMRI) is also a reliable and practical tool that can be used as part of the diagnostic work-up. Echocardiography can measure a range of haemodynamic and anatomical variables (e.g. pericardial effusion and pulmonary artery pressure), whereas CMRI provides complementary information to echocardiography via high-resolution, three-dimensional imaging. Together with echocardiography and CMRI, techniques such as high-resolution computed tomography and positron emission tomography may also be valuable for screening, monitoring and follow-up assessments of patients with PH, but their clinical relevance has yet to be established. Technological advances have produced new variants of echocardiography, CMRI and positron emission tomography, and these permit closer examination of myocardial architecture, motion and deformation. Integrating these new tools into clinical practice in the future may lead to more precise noninvasive determination of diagnosis, risk and prognosis for PH.

scholarly journals Detection of Thirty-Second Cognitive Activations in Single Subjects with Positron Emission Tomography: A New Low-Dose H215O Regional Cerebral Blood Flow Three-Dimensional Imaging Technique

1993 ◽  
Vol 13 (4) ◽  
pp. 617-629 ◽  
Author(s):  
David A. Silbersweig ◽  
Emily Stern ◽  
Christopher D. Frith ◽  
Connie Cahill ◽  
Leonard Schnorr ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Three Dimensional ◽  
Emission Tomography ◽  
Acquisition Time ◽  
Cognitive State ◽  
Bolus Administration ◽  
Functional Neuroanatomy ◽  
Three Dimensional Imaging ◽  
Positron Emission ◽  
Single Subjects

Positron emission tomography regional CBF (rCBF) studies of cognitive processes have traditionally required 30–60 mCi of H215O per scan and intersubject averaging to achieve statistical significance. However, intersubject anatomical, functional, and disease variability can make such an approach problematic. A new method that produces significant results in single subjects is presented. It is based upon high-sensitivity three-dimensional imaging and a “slow” bolus administration of >15 mCi of H215O per scan. The method is validated in four normal volunteers using control and auditory-language activation tasks with four scans per condition and statistical parametric mapping analysis. It is demonstrated that the rCBF distribution associated with the cognitive state is detected during the arrival of radiotracer in the brain. This occurs over 30 s and constitutes a critical temporal window during which stimulation should be performed. A 90-s acquisition time is found to produce results of greater significance than a 60-s acquisition time. The implications of the results and the functional neuroanatomical findings are discussed. This method is suitable for the study of individual functional neuroanatomy in many neuropsychological, pharmacologic, and symptom states in normal subjects and in patients with psychiatric and neurologic disorders.

scholarly journals [18F]fluoro-2-deoxy-d-glucose ([18F]FDG) positron emission tomography imaging of thymic carcinoid tumor presenting with recurrent Cushing’s syndrome

2005 ◽  
Vol 152 (4) ◽  
pp. 521-525 ◽  
Author(s):  
Athina Markou ◽  
Patrick Manning ◽  
Banu Kaya ◽  
Sam N Datta ◽  
Jamshed B Bomanji ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
High Resolution ◽  
Carcinoid Tumor ◽  
Fdg Pet ◽  
Pet Scan ◽  
Emission Tomography ◽  
Thymic Carcinoid ◽  
Acth Secretion ◽  
Positron Emission ◽  
Thymic Carcinoid Tumor

We report a case of a young woman with Cushing’s syndrome (CS), in whom although endocrine investigations and negative pituitary imaging were suggestive of ectopic ACTH secretion, the results of inferior petrosal sinus (IPS) sampling after coricotropin-releasing hormone (CRH) stimulation were suggestive of pituitary ACTH hypersecretion. 111In-labelled octreotide and high-resolution computer tomography (CT) revealed a lesion possibly responsible for the ACTH source in the thymus. Thymectomy confirmed concomitant ectopic CRH and probable ACTH production by a thymic neuroendocrine carcinoma. After an 8-year remission period the patient developed a clinical and biochemical relapse. A high-resolution computed tomography (CT) scan of the thorax showed a 2-cm nodule in the thymic bed, which was positive on a [18F]fluoro-2-deoxy-d-glucose ([18F]FDG) positron emission tomography (PET) scan. However, a repeated thymectomy did not result in remission. A repeat [18F]FDG PET study showed persistent disease in the thymic bed and also uptake in the adrenals. The patient underwent bilateral adrenalectomy, which resulted in clinical remission. A further [18F]FDG PET scan 8 months later showed no progression of the thymic tumor and confirmed complete excision of the adrenals. This is a rare case of concomitant CRH and ACTH secretion from a thymic carcinoid tumor; the case illustrates the usefulness of functional imaging with [18F]FDG PET in the diagnosis, management and follow-up of neuroendocrine tumors.

Positron Emission Tomography (PET) for Flow Measurement

2011 ◽  
Vol 301-303 ◽  
pp. 1316-1321 ◽  
Author(s):  
Arthur E. Ruggles ◽  
Bi Yao Zhang ◽  
Spero M. Peters
Keyword(s):  
Positron Emission Tomography ◽  
Pet Imaging ◽  
Three Dimensional ◽  
Bulk Water ◽  
Emission Tomography ◽  
Optical Methods ◽  
Imaging Method ◽  
Analysis And Design ◽  
Pet Tracer ◽  
Positron Emission

Positron Emission Tomography (PET) produces a three dimensional spatial distribution of positron-electron annihilations within an image volume. Various positron emitters are available for use in aqueous, organic and liquid metal flows. Preliminary experiments at the University of Tennessee at Knoxville (UTK) injected small flows of PET tracer into a bulk water flow in a four rod bundle. The trajectory and diffusion of the tracer in the bulk flow were then mapped using a PET scanner. A spatial resolution of 1.4 mm is achieved with current preclinical Micro-PET imaging equipment resulting in 200 MB 3D activity fields. A time resolved 3-D spatial activity profile was also measured. The PET imaging method is especially well suited to complex geometries where traditional optical methods such as LDV and PIV are difficult to apply. PET methods are uniquely useful for imaging in opaque fluids, opaque pressure boundaries, and multiphase studies. Several commercial and shareware Computational Fluid Dynamics (CFD) codes are currently used for science and engineering analysis and design. These codes produce detailed three dimensional flow predictions. The models produced by these codes are often difficult to validate. The development of this experimental technique offers a modality for the comparison of CFD outcomes with experimental data. Developed data sets from PET can be used in verification and validation exercises of simulation outcomes.

Design Considerations of Phoswich Detectors for High Resolution Positron Emission Tomography

2009 ◽  
Vol 56 (1) ◽  
pp. 182-188 ◽  
Author(s):  
Lars Eriksson ◽  
Charles L. Melcher ◽  
Marita Eriksson ◽  
Harold Rothfuss ◽  
Ron Grazioso ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
High Resolution ◽  
Emission Tomography ◽  
Design Considerations ◽  
Positron Emission ◽  
Phoswich Detectors
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