Biomedical Image Processing / Medical Image Processing
Seyedeh Zahra Islami Rad; Reza Gholipour Peyvandi
Volume 10, Issue 1 , May 2016, , Pages 49-57
Abstract
Positron emission tomography (PET) system is used in order to diagnose physiology changes in the body. Thus, the goal of the PET studies is to obtain a good quality and detailed image of organs by the PET scanner. The PET system performance and output image quality depend on the parameters including ...
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Positron emission tomography (PET) system is used in order to diagnose physiology changes in the body. Thus, the goal of the PET studies is to obtain a good quality and detailed image of organs by the PET scanner. The PET system performance and output image quality depend on the parameters including spatial resolution, scatter fraction, sensitivity, RMS contrast and SNR which the system was evaluated based on them. In this paper, system features and tomography method for the IRI-microPET system are considered, firstly. Then, image reconstruction algorithms (MLEM, SART, and FBP) were performed on sinogram and the performance and the acquired images quality were evaluated. The radial and tangential resolutions of 1.81 mm and 1.90 mm for 18F at the center of FOV were measured. The scatter fraction of 7.1% for the mouse phantom and the sensitivity of 1.74% in 4 ns timing window was measured. Finally, images quality was compared by RMS contrast and SNR factors, which MLEM algorithm has superiorityin comparison with the other reconstructed algorithms.The acquired results from IRI-MicroPET system were compared with available commercial animal PET scanner which the results show the good agreement between data.
Biomedical Signal Processing / Medical Signal Processing / Biosignal Processing
Mahdi Zolfagharzadeh Kermani; Mohammad Ali Khalilzadeh; Majid Ghoshuni; Peyman Hashemian
Volume 9, Issue 3 , December 2015, , Pages 243-251
Abstract
Evaluation and measurement of parameters associated with methamphetamine craving can be a valuable tool in the management and intervention programs related to methamphetamine use and dependence. We believe that quantitative electroencephalography (EEG) have brought about a revolution in identification ...
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Evaluation and measurement of parameters associated with methamphetamine craving can be a valuable tool in the management and intervention programs related to methamphetamine use and dependence. We believe that quantitative electroencephalography (EEG) have brought about a revolution in identification the neurologic infrastructure of craving processing. This study has been conducted aimed to design and develop a new method to measure baseline craving in methamphetamine-dependent patients using EEG signals in neurofeedback therapy for separation of the three modes of low, medium, and high craving. For this purpose, 10 methamphetamine abusers were selected by available method in terms of age, sex and IQ. All patients received 10 sessions of neurofeedback therapy with alpha-theta protocol. During the period of treatment with neurofeedback, before and 60 minutes after each training session, at rest state, on Pz, for 2 minutes and 10 seconds EEG was recorded. To labeling EEG signals we have used Desire for Drug Questionnaire (DDQ). After collecting the required data from signals, time, frequency and nonlinear features were extracted. Then by calculating the linear correlation coefficient of the two variables and variance analysis on three levels optimized and effective features were selected. Finally, using fuzzy classifier, those features were separated into three classes of low, medium and high craving. According to the results, separation accuracy of EEG signals in three classes by K-fold Cross-Validation (KCV)method was 96.67% and test data was 75.15%. This study showed in addition to estimating baseline craving in methamphetamine abusers by quantifying EEG we can optimize the number of training sessions for participants.