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Approximately 30% of epilepsy patients are medically intractable. Epilepsy surgery may offer cure or palliation, and neuromodulation and direct drug delivery are being developed as alternatives. Successful treatment requires correct localization of seizure onset zones and understanding surrounding functional cortex to avoid iatrogenic disability. Several neurophysiologic and imaging localization techniques have inherent individual weaknesses which can be overcome by multimodal analysis. We review common noninvasive techniques, then illustrate the value of multimodal analysis to localize seizure onset for targeted treatment.

Medical image classification is currently a challenging task that can be used to aid the diagnosis of different brain diseases. Thus, exploratory and discriminative analysis techniques aiming to obtain representative features from the images play a decisive role in the design of effective Computer Aided Diagnosis (CAD) systems, which is especially important in the early diagnosis of dementia. In this work, we present a technique that allows using specific time series analysis techniques with 3D images. This is achieved by sampling the image using a fractal-based method which preserves the spatial relationship among voxels. In addition, a method called Empirical functional PCA (EfPCA) is presented, which combines Empirical Mode Decomposition (EMD) with functional PCA to express an image in the space spanned by a basis of empirical functions, instead of using components computed by a predefined basis as in Fourier or Wavelet analysis. The devised technique has been used to classify images from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) and the Parkinson Progression Markers Initiative (PPMI), achieving accuracies up to 93% and 92% differential diagnosis tasks (AD versus controls and PD versus Controls, respectively). The results obtained validate the method, proving that the information retrieved by our methodology is significantly linked to the diseases.

We describe the fabrication and characterization of organic photodiodes on solution cast ITO (tin doped indium oxide) bottom electrodes. ITO coatings were produced by gravure printing process on PET and PEN substrates. The sheet resistance could be decreased by heat treatment at 120°C under forming gas atmosphere (N₂/H₂) to 1.5 kΩ. The transmission of the ITO coated PET and PEN substrates is more than 80% in the visible range. The printed films were hardened under UV-irradiation at low temperatures (< 130°C) and used as the bottom electrode of an organic photodiode (OPD), consisting of a stacked layer of copper phthalocyanine (p-type material), perylene tetracarboxylic bisbenzimidazole (n-type material) and Aluminium tris(8-hydroxyquinoline). The performance of the photodiodes with printed ITO on plastic substrates could be improved by adding a smoothing layer of PEDOT/PSS (Baytron® P) on the ITO coated films and was then similar to the performance of photodiodes with semi-transparent gold as anode. These results demonstrate the suitability of the printed ITO layers as bottom electrode for organic photodiodes. Furthermore the influence of different treatments (forming gas and oxygen plasma treatment) of the ITO bottom electrode on the current-voltage characteristics of the OPDs was studied.

This study investigates the possibility of using an Artificial Neural Network (ANN) for reconstructing Positron Emission Tomography (PET) images. The network is trained with simulated data which include physical effects such as attenuation and scattering. Once the training ends, the weights of the network are held constant. The network is able to reconstruct every type of source distribution contained inside the area mapped during the learning. The reconstruction of a simulated brain phantom in a noiseless case shows an improvement if compared with Filtered Back-Projection reconstruction (FBP). In noisy cases there is still an improvement, even if we do not compensate for noise fluctuations. These results show that it is possible to reconstruct PET images using ANNs. Initially we used a Dec Alpha; then, due to the high data parallelism of this reconstruction problem, we ported the learning on a Quadrics (SIMD) machine, suited for the realization of a small medical dedicated system. These results encourage us to continue in further studies that will make possible reconstruction of images of bigger dimension than those used in the present work (32 × 32 pixels).

Positron Emission Tomography (PET) images can be reconstructed using Fourier transform methods. This paper describes the performance of a fully 3-D Backprojection-Then-Filter (BPF) algorithm on the Cray T3E machine and on a cluster of workstations. PET reconstruction of small animals is a class of problems characterized by poor counting statistics. The low-count nature of these studies necessitates 3-D reconstruction in order to improve the sensitivity of the PET system: by including axially oblique Lines Of Response (LORs), the sensitivity of the system can be significantly improved by the 3-D acquisition and reconstruction. The BPF method is widely used in clinical studies because of its speed and easy implementation. Moreover, the BPF method is suitable for on-time 3-D reconstruction as it does not need any sinogram or rearranged data. In order to investigate the possibility of on-line processing, we reconstruct a phantom using the data stored in the list-mode format by the data acquisition system. We show how the intrinsically parallel nature of the BPF method makes it suitable for on-line reconstruction on a MIMD system such as the Cray T3E. Lastly, we analyze the performance of this algorithm on a cluster of workstations.

The purpose of this study was to examine whether pain-induced brain activation was suppressed by acupuncture analgesia. We investigated the suppression of the pain-induced neuronal activation in specific brain areas of three male rhesus monkeys (aged four years old) using positron emission tomography (PET), in which changes in the regional cerebral blood flow (rCBF) were examined as an index of the neuronal activation. The brain areas such as the thalamus, insula and anterior cingulate cortex were activated by heating the tail of monkeys in 47°C water compared to the heating at 37°C. Those activations were suppressed by electroacupuncture (EA) with a 2 sec alteration of the frequency of 4 Hz/60 Hz at the right ST36 (the upper anterior tibial muscle) and the right LI4 (the back palm between the first and second metacarpal) acupoints. Meanwhile, this EA analgesic effect was confirmed by prolonging the tail withdrawal latencies from hot water in the temperature range from 45 to 50°C.These brain areas were corresponded to the pain-related areas as reported in previous studies. In conclusion, we were able to visualize the acupuncture analgesia in the CNS. We also detected the brain areas activated or inactivated by acupuncture. The areas that responded to acupuncture stimulation at 47°C water were different from the regions at 37°C. We consider that this difference in the response to acupuncture may support the variation of the clinical efficacy of acupuncture in patients bearing pain or other disorders.

Radioisotopes are crucial in medical imaging for the diagnosis and monitoring of disease. The current status of radioisotope production is outlined and examples of their use are provided.

Solar energy has been widely used as a kind of renewable power generation in recent years. In a photovoltaic (PV) system, polyethylene terephthalate (PET) is the core component of backsheet and affects the reliability of the system. In this paper, the effect of temperature on partial discharge (PD) of PET is studied. As shown by the PD measurement system, the amplitude of PD of PET films decreases significantly with temperature increasing. The mechanism of PD degradation, which is closely related to the operational temperature and the chemical change of the insulation backsheet, has been investigated.

Polyethylene terephthalate (PET) films with thickness 40$\mu$m are irradiated with 3keV argon ion beams with different fluence ranging from $0.5\times 10^{18}$ions.cm${}^{-2}$ to $2\times 10^{18}$ions.cm${}^{-2}$ using locally designed broad ion source. The changes in the PET structure are characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) and scanning electron microscope (SEM) techniques. The XRD patterns show that the peak intensity decreases with irradiation and the particle size decreases from 65.75 Å for the un-irradiated to 52.80 Å after irradiation. The FTIR indicates partial decrease and reduction in the intensity of the bands due to the degradation of the polymer after ion irradiation. The optical energy band gap decreases from 3.14eV to 3.05eV and the number of carbon cluster increases from 119 to 126 after ion irradiation. The results show a slight increase in the electrical conductivities and the dielectric constant ($\epsilon$). The results indicate the effectiveness of using PET films as capacitors and resistors in industrial applications.

Subjective cognitive decline (SCD), characterized by self-perceived subtle cognitive impairment ahead of the appearance of explicit and measurable cognitive deficits, is regarded as the preclinical manifestation of the pathological change continuum of Alzheimer’s disease (AD). We were committed to exploring the amyloid and glucose metabolic signatures related to imminent brain metabolic changes in SCD subjects. This study included 39 subjects (mean age = 71.9 years; 14 males and 25 females) diagnosed with SCD disease and 39 gender-matched healthy controls (HCs) (mean age = 75.2; 16 males and 23 females) with brain [18F] fluorodeoxyglucose positron emission tomography (PET) images and [18F] florbetapir PET images. The standardized uptake value ratios (SUVRs) of PET images within the regions of interest (ROIs) were calculated. Inter-group SUVR differences were assessed by two-sample $t$-testing and receiver operating characteristic curve (ROC) analyses. A generalized linear model (GLM) was employed to evaluate the correlations between amyloid and FDG uptake. Compared with HCs, SCD subjects showed significantly increased amyloid SUVR, as well as significantly increased glucose SUVR in the olfactory, amygdala, thalamus, heschl gyrus, superior and middle temporal gyrus and temporal pole (all $P<0.05$). The amyloid SUVR of thalamus was found to have a better ROC result (area under the curve (AUC): 0.77, 95% confidence interval (CI): 0.66–0.86) in the HC group, as was the case with the glucose SUVR of the middle temporal gyrus (AUC: 0.83, 95% CI: 0.73–0.91). There were significant positive correlations between amyloid and glucose SUVRs ($P<0.05$). The amyloid SUVR of the thalamus showed a significantly better main effect (odd ratio $=$ 2.91, 95% CI: 1.44–6.7, $P<0.001$), and the glucose SUVR of the heschl gyrus indicated an enhanced main effect (odd ratio $=$ 5.08, 95% CI: 1.86–18.15, $P<0.001$). SCD subjects demonstrated significant amyloid accumulation and glucose hypermetabolism in specific brain regions, and amyloid pathology overlapped with regions of glucose abnormality. These findings may advance the understanding of imminent pathological changes in the SCD stage and help to provide clinical guidelines for interventional management.

Metal complexes have been used as medicinal compounds. Metals have advantageous features over organic compounds. Significant applications of metal complexes are in the field of nuclear medicine. Radiopharmaceuticals are drugs containing radioisotopes used for diagnostic and therapeutic purposes.

The generalized targeting strategy for molecular imaging probe consists of three essential parts: (i) reporter unit or payload, (ii) carrier, and (iii) targeting system. Medicinal radiopharmaceutical chemistry pays special consideration to radioisotopes, as a reporter unit for diagnostic application or as a payload for therapeutic application. Targeting is achieved by a few approaches but the most common is the bifunctional chelator approach. While designing a radiopharmaceutical, a range of issues needs to be considered including properties of metal radioisotopes, bifunctional chelators, linkers, and targeting molecules. Designing radiopharmaceuticals requires consideration of two key words: "compounds of biological interest" and "fit for intended use." The ultimate goal is the development of new diagnostic methods and treatment.

Diagnostic metal radiopharmaceuticals are used for SPECT and PET applications. Technetium chemistry constitutes a major portion of SPECT and gallium chemistry constitutes a major portion of PET. Therapeutic radiopharmaceuticals can be constructed by using alpha-, beta minus-, or Auger electron-emitting radiometals. Special uses of medicinal radiopharmaceuticals include internal radiation therapy, brachytherapy, immunoPET, radioimmunotherapy, and peptide receptor radionuclide imaging and therapy.

The flame retardancy of aromatic thermotropic liquid crystal phosphorus-containing copolyester, TLCP, on PET was investigated. The results show that the presence of TLCP promotes char formation of the substrate and enhances thermal stability of char, hence delay its decomposition. SEM pictures show that the char formed from PET/TLCP is more compact, therefore is more resistant to fire and heat than that from pure PET. Evolved gas analysis by I.R measurements indicates that TLCP would decompose to produce phosphorus containing small molecular compounds in pyrolysis process. Phosphorus- containing volatile compounds are detected in gas pyrolytical products. It is suggested that TLCP could play an important role of flame retardancy in vapor phase. TLCP could inhibit the generation of combustible volatile in the pyrolytical process of PET, and therefore prevent the fire propagation during the combustion since combustible volatile is necessary for the generation of fire.

PET/SiO₂ layers were chemically modified to maintain immobilization of functional single molecules. GFP molecules provide an ideal system due to their stability and intrinsic fluorescence. GFP in vivo biotinylated within its NH₂-terminal region and attached on the substrate via the biotin–streptavidin bond was further investigated with confocal microscopy, atomic force microscopy (AFM) and spectroscopic ellipsometry (SE). AFM revealed monolayered donut-like structures representing assemblies of biotin–streptavidin–biotin–GFP immobilized onto PET/SiO₂ surfaces via mPEG. In particular, regions with an approximate height of 12 nm, which approaches the molecular dimensions of the above complex given by molecular modeling, could be detected. The dimensions of the donut-like structures suggest a close-to-each-other positioning of the GFP molecules — which, however, retain their functionality, as evidenced by confocal microscopy.

The control of ionic transportation inside the multi asymmetric conical nanopores in polyethylene terephthalate (PET) membrane was investigated. The conical nanopores were prepared by chemical etching in irradiated PET foil using etchant (9 M NaOH) and stopping solution (1 M NaCl $+$ 1 M HCOOH). The behavior of ionic current was recorded under stepping voltage $-$2V to $+$2V at different molar concentrations of potassium halides (KCl, KBr and KI) under symmetric bathing condition in electrochemical cell. It is found that the presence of multiple ionic species and the occurrence of counterion condensation of charge regulated polyelectrolyte play an effective role in ionic current rectification (ICR). The electrical conductance of conical nanopores may be estimated by measuring the ionic current rectification properties of track-etched nanopores. The charge transport properties vary with molar concentration and pH of electrolyte. Moreover, ICR may be used as a voltage gating phenomena with wide technological applications.

Multi-modality image registration and fusion play an increasingly important role in medicine. 3-D image reconstruction, object recognition, and medical imaging analysis, are just a few examples. Medical images provide essential information for clinical diagnosis. Good image quality can yield more accurate patient information, which can then be used for better clinical decision making.

X-ray computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and single photon emission computed tomography (SPECT) are clinically established imaging modalities. Among them, CT and MRI images are anatomical imaging with high spatial resolutions. However their physiological information is limited. On the other hand, although SPECT and PET can provide physiological information, both spatial resolutions are too poor to provide clear anatomical information. Thus, it would be advantageous to combine images from multi-modality images so that the resulting image can provide both physiological and anatomical information with high spatial resolution for use in clinical diagnosis and therapy.

In order to generate an overlapping image from different-modality images, image registration and various fusion techniques have been employed. In the past studies, artificial neural network (ANN) has been used in registration and fusion of multi-modality remote sensing data for the reconstruction of 3-D models of terrain regions and medical images. In this study, we apply multilayer back propagation (BP) and conjugate gradient back propagation (CGBP) NN model to train PET and MRI images. We use Matlab and Borland C++ Builder to implement the network training frame and find out the optimal training model for accurate image registration. Further, we evaluate the accuracy of the image registration using NN by phantom images. Our study shows that, the registration errors are less than 5mm, and using appropriate opacity is better to show the fusion image than using interleaved pixels with independent color scale. Finally, we use Borland C++ Builder to implement a user-friendly window-based interface for image registration and fusion system.

The quality of traditional two-dimensional image reconstruction for PET has been efficiently improved by three-dimensional image reconstruction, but the sensitivity of the data and the quality of the image are restricted by the limit of modality physics. In analytical image reconstruction algorithm, 3DRP method compensates the unmeasured events by forward projection based on the initial direct image estimate. However, the original 3DRP method merely depends on the parallel projections without taking into account the oblique projections. In our proposed 3DRP-SSRB method, we improve the first image estimate by incorporating the rebinned oblique data. SSRB method was used to perform the rebinning operation to make uses of the oblique projection data to improve the sensitivity information. And then project the improved image estimate forward and reconstruct the final image. Conflicting parameters of reconstructed image quality of 3DRP are experimented by simulated three-dimensional phantom study with regard to both system sensitivity and image quality factors. PET simulation software package was used to conduct the experiment along with the MATLAB software to evaluate the effectiveness of two-dimensional FBP, 3DRP, and our proposed 3DRP-SSRB methods. The result demonstrated its better image quality by having better mean squared error numbers in most of output image slices.

Stem cell research is undergoing a critical transition from being a discipline of the basic sciences to being recognised as a potential component of medical practice. Cell transplants to replace cells lost due to injury or degenerative diseases, for which there are currently no cures, are being pursued in a wide range of experimental models.

The monitoring of cellular grafts, non-invasively, is an important aspect of the ongoing efficiency and safety assessment of cell-based therapies. Magnetic resonance imaging (MRI) methods are potentially well suited for such an application as they produce non-invasive "images" of opaque tissues. For transplanted stem cells to be visualised and tracked by MRI, they need to be tagged so that they are "MR visible". We are developing and implementing a programme of molecular imaging in pre-clinical models that is directed towards improving our understanding of stem cell migration in the context of the whole organism.

In order to achieve these goals we are engineering novel MRI contrast agents and developing specific tagging molecules to deliver efficient amounts of contrast agents into stem cells. The intracellular contrast agents are based on either paramagnetic nanoparticles, such as dextran-coated iron oxide, or other MR contrast agents. Methods for monitoring implanted stem cells non-invasively in vivo will greatly facilitate the clinical realisation and optimisation of the opportunities of stem cell-based therapies.

The development of cell therapies in animal models and patients requires robust in vivo imaging techniques to track the administration, migration, integration, division and fate of administered stem cells and to monitor any morphological and physiological effects on the damaged tissue after therapy. This chapter outlines the well-established imaging modalities such as CT (computed tomography), MRI (magnetic resonance imaging), PET (positron emission tomography), SPECT (single photon emission computed tomography), and EBUS (endobronchial ultrasound) and discusses recent advances in biophotonic technologies including OCT (optical coherence tomography), DOI (diffuse optical imaging), and CLSM (confocal laser scanning microscopy) and their integration with endoscopy for in situ, in vivo cellular level imaging. Comparisons are made of sensitivity and spatial resolution for detecting stem cells in vivo, as well as imaging the lung in small animal models and patients. We also outline the challenges of labelling stem cells in vivo and the role of responsive agents to visualise the local physiological conditions.

Recent advances in brain imaging techniques have allowed the visualization of brain areas involved in higher brain function including cognition, emotion, and will. One of the fascinating targets of imaging is the human mind. Quality of Life (QOL) is a self-evaluated measure of the present state of our own existence, both mentally and physically. Herein, we present example images showing brain areas related to QOL. Because brain images are objective and reproducible, they can potentially provide an objective measure of QOL, which is subjective and difficult to define.

The target of this study is to clarify the changes in the regional glucose metabolism after exercise in volunteers at three levels of exercise loads (mild, moderate and severer) in terms of VO_2max. In parallel, absolute brain metabolic rate of glucose was also calculated and compared between the resting control and task groups. Quantitative and semi-quantitative approach has been applied to measure the absolute and regional brain glucose metabolism respectively. Brain mapping technique with global correction revealed significant activations (p < 0.001 uncorrected, extent threshold > 40 voxel) by exercise in primary and motor association cortices using SPM 2 (statistical parametric mapping) software. Ergometer cycling induced activated areas were pronounced in prefrontal activation for mild load, premotor, motor and parietal activation for higher loads. These regions are mainly involved in elaboration and sensory association area of movements. Metabolic reductions were found in the posterior parts of the brain. The average LCMRglc for brain was gradually decreased with the increases of exercise loads.