scholarly journals Penalized Maximum Likelihood Algorithm for Positron Emission Tomography by Using Anisotropic Median-Diffusion

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Qian He ◽  
Lihong Huang
Keyword(s):  
Positron Emission Tomography ◽  
Maximum Likelihood ◽  
Expectation Maximization ◽  
Emission Tomography ◽  
Edge Preservation ◽  
Penalized Maximum Likelihood ◽  
Positron Emission ◽  
Maximum Likelihood Expectation Maximization ◽  
Positive Effect

Nowadays, positron emission tomography (PET) is widely used in engineering. In this paper, a novel penalized maximum likelihood (PML) algorithm is presented for improving the quality of PET images. The proposed algorithm fuses an anisotropic median-diffusion (AMD) filter to the maximum-likelihood expectation-maximization (MLEM) algorithm. The fusing algorithm shows its positive effect on image reconstruction and denoising. Experimental results present that the proposed method denoises and reconstructs images with high quality. Furthermore, by comparing with other classical reconstructing algorithms, this novel algorithm shows better performance in the edge preservation.

scholarly journals Measurement of Regional Cerebral Blood Flow with Positron Emission Tomography: A Comparison of [15O]Water to [11C]Butanol with Distributed-Parameter and Compartmental Models

1993 ◽  
Vol 13 (5) ◽  
pp. 733-747 ◽  
Author(s):  
Robert P. Quarles ◽  
Mark A. Mintun ◽  
Kenneth B. Larson ◽  
Joanne Markham ◽  
Ann Mary MacLeod ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Visual Stimulation ◽  
Human Subjects ◽  
Volume Of Distribution ◽  
Emission Tomography ◽  
Low Flow ◽  
Distributed Parameter ◽  
Positron Emission ◽  
The One

To further our understanding of the best way to measure regional CBF with positron emission tomography (PET), we directly compared two candidate tracers ([15O]water and [11C]butanol, administered intravenously) and two popular implementations of the one-compartment (IC) model: the autoradiographic implementation representing a single PET measurement of tissue radioactivity over 1 min and a dynamic implementation representing a sequence of measurements of tissue radioactivity over 200 s. We also examined the feasibility of implementing a more realistic, and thus more complex, distributed-parameter (DP) model by assigning fixed values for all of its parameters other than CBF and tracer volume of distribution ( Vd), a requirement imposed by the low temporal resolution and statistical quality of PET data. The studies were performed in three normal adult human subjects during paired rest and visual stimulation. In each subject seven regions of interest (ROIs) were selected, one of which was the primary visual cortex. The corresponding ROI were anatomically equivalent in the three subjects. Regional CBF, Vd, tracer arrival delay, and dispersion were estimated for the dynamic data curves. A total of 252 parameter sets were estimated. With [11C]butanol both implementations of the IC model provided similar results ( r = 0.97). Flows estimated using the 1C models were lower (p < 0.01) with [15O]water than with [11C]butanol. In comparison with the IC model, the constrained version of the DP used in these studies performed inadequately, overestimating high flow and underestimating low flow with both tracers, possibly as the result of the necessity of assigning fixed values for all of its parameters other than CBF and Vd.

Traditional Versus Up-Front [18F] Fluorodeoxyglucose–Positron Emission Tomography Staging of Non–Small-Cell Lung Cancer: A Dutch Cooperative Randomized Study

2006 ◽  
Vol 24 (12) ◽  
pp. 1800-1806 ◽  
Author(s):  
Gerarda J.M. Herder ◽  
Henk Kramer ◽  
Otto S. Hoekstra ◽  
Egbert F. Smit ◽  
Jan Pruim ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Positron Emission Tomography ◽  
Final Stage ◽  
Clinical Stage ◽  
Randomized Study ◽  
Tnm Staging ◽  
Emission Tomography ◽  
Positron Emission

Purpose We investigated whether application of positron emission tomography (PET) immediately after first presentation might simplify staging while maintaining accuracy, as compared with traditional strategy in routine clinical setting. Methods At first presentation, patients with a provisional diagnosis of lung cancer without overt dissemination were randomly assigned to traditional work-up (TWU) according to international guidelines or early PET followed by histologic/cytologic verification of lesions, or imaging and follow-up. Patients with [18F] fluorodeoxyglucose (18FDG) –avid, noncentral tumors without suspicion of mediastinal or distant metastases on PET proceeded directly to thoracotomy. Follow-up in presumed benign lesions was at least 12 months. In patients treated with surgery or neoadjuvant therapy, the quality of staging was measured by comparing the clinical stage to the final stage (combination of peroperative staging and 6 months of follow-up). To investigate test substitution, we analyzed the number of (non)invasive tests to achieve clinical TNM staging, and its associated costs. Results Between 1999 and 2001, 465 patients (233 TWU, 232 PET) were enrolled at 22 hospitals. The mean (standard deviation) number of procedures to finalize staging was equal in the TWU arm and the PET arm: 7.9 (2.0) v 7.9 (1.9), P = .90, respectively. Mediastinoscopies occurred significantly less often in the PET arm. Agreement between clinical and final stage was good in both arms (κ = .85 v .78; P = .07). Costs did not differ significantly. Conclusion Up-front 18FDG-PET in patients with (suspected) lung cancer does not reduce the overall number of diagnostic test, but it maintains quality of TNM staging with the use of less invasive surgery.

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