Fast point spread function computation from aperture functions in high-resolution positron emission tomography

1988 ◽  
Vol 7 (1) ◽  
pp. 2-12 ◽  
Author(s):  
D. Schmitt ◽  
B. Karuta ◽  
C. Carrier ◽  
R. Lecomte
Keyword(s):  
Positron Emission Tomography ◽  
High Resolution ◽  
Point Spread Function ◽  
Emission Tomography ◽  
Function Computation ◽  
Point Spread ◽  
Positron Emission ◽  
Spread Function

scholarly journals Positron Emission Tomography Partial Volume Correction: Estimation and Algorithms

2002 ◽  
Vol 22 (8) ◽  
pp. 1019-1034 ◽  
Author(s):  
John A. D. Aston ◽  
Vincent J. Cunningham ◽  
Marie-Claude Asselin ◽  
Alexander Hammers ◽  
Alan C. Evans ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Point Spread Function ◽  
Spillover Effects ◽  
Partial Volume Correction ◽  
Emission Tomography ◽  
Partial Volume ◽  
Point Spread ◽  
Positron Emission ◽  
Spread Function ◽  
Tissue Fraction

Partial volume effects in positron emission tomography (PET) lead to quantitative under- and over-estimations of the regional concentrations of radioactivity in reconstructed images and corresponding errors in derived functional or parametric images. The limited resolution of PET leads to “tissue-fraction” effects, reflecting underlying tissue heterogeneity, and “spillover” effects between regions. Addressing the former problem in general requires supplementary data, for example, coregistered high-resolution magnetic resonance images, whereas the latter effect can be corrected for with PET data alone if the point-spread function of the tomograph has been characterized. Analysis of otherwise homogeneous region-of-interest data ideally requires a combination of tissue classification and correction for the point-spread function. The formulation of appropriate algorithms for partial volume correction (PVC) is dependent on both the distribution of the signal and the distribution of the underlying noise. A mathematical framework has therefore been developed to accommodate both of these factors and to facilitate the development of new PVC algorithms based on the description of the problem. Several methodologies and algorithms have been proposed and implemented in the literature in order to address these problems. These methods do not, however, explicitly consider the noise model while differing in their underlying assumptions. The general theory for estimation of regional concentrations, associated error estimation, and inhomogeneity tests are presented in a weighted least squares framework. The analysis has been validated using both simulated and real PET data sets. The relations between the current algorithms and those published previously are formulated and compared. The incorporation of tensors into the formulation of the problem has led to the construction of computationally rapid algorithms taking into account both tissue-fraction and spillover effects. The suitability of their application to dynamic and static images is discussed.

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.

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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