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Band selection is a key strategy to address the challenges of managing large hyperspectral datasets and reduce the dimensionality problem associated with the simultaneous analysis of hundreds of spectral bands. However, the computational complexity of traditional methods makes the algorithms difficult to be deployed on board satellites. This is especially true for Small Satellites with limited computational and power resources. Moreover, existing band selection techniques often require the hypercube to be processed at least at Level-1B product, i.e., the bands need to be finely aligned before selecting them, demanding more computational resources for the on-board computer. This study presents a novel neural network-based approach for on-board band selection using data with coarse band-to-band aligned. This methodology not only simplifies the pre-processing requirements, but also opens new possibilities for efficient hyperspectral imaging from space on-board Small Satellites, such as classification, change and target detection., This project was part of the project "GENESIS: GNSS Environmental and Societal Missions – Subproject UPC", Grant PID2021-126436OB-C21 funded by the Ministerio de Ciencia e Investigación (MCIN)/Agencia Estatal de Investigación (AEI)/10.13039/501100011033 and EU FEDER “Una manera de hacer Europa”, and by a FPU fellowship from the Spanish Ministry of Education. Part of this work has also been possible thanks to the Italian Space Agency (ASI) that granted access to its PRISMA database (http://prisma.asi.it/)., Peer Reviewed, Postprint (published version)

Image coregistration is a mandatory procedure for radar applications such as synthetic aperture radar change detection. The spatial coregistration can be easily handled with geo-reference, whereas radiometric coregistration requires much more effort due to the randomness of noise and clutter. The performance of a coregistration method is usually measured by the correlation coefficient that is desire to be close to unity. However, the currently used methods cannot provide coregistration with such correlation coefficient value. The paper introduces an image extra-coregistration method that helps to increase the correlation coefficient between the radar images close to unity. This strongly supports radar applications such as change detection. © 2022 IEEE.

Image coregistration is a mandatory procedure for radar applications such as synthetic aperture radar change detection. The spatial coregistration can be easily handled with geo-reference, whereas radiometric coregistration requires much more effort due to the randomness of noise and clutter. The performance of a coregistration method is usually measured by the correlation coefficient that is desire to be close to unity. However, the currently used methods cannot provide coregistration with such correlation coefficient value. The paper introduces an image extra-coregistration method that helps to increase the correlation coefficient between the radar images close to unity. This strongly supports radar applications such as change detection. © 2022 IEEE.

Image coregistration is a mandatory procedure for radar applications such as synthetic aperture radar change detection. The spatial coregistration can be easily handled with geo-reference, whereas radiometric coregistration requires much more effort due to the randomness of noise and clutter. The performance of a coregistration method is usually measured by the correlation coefficient that is desire to be close to unity. However, the currently used methods cannot provide coregistration with such correlation coefficient value. The paper introduces an image extra-coregistration method that helps to increase the correlation coefficient between the radar images close to unity. This strongly supports radar applications such as change detection. © 2022 IEEE.

Image coregistration is a mandatory procedure for radar applications such as synthetic aperture radar change detection. The spatial coregistration can be easily handled with geo-reference, whereas radiometric coregistration requires much more effort due to the randomness of noise and clutter. The performance of a coregistration method is usually measured by the correlation coefficient that is desire to be close to unity. However, the currently used methods cannot provide coregistration with such correlation coefficient value. The paper introduces an image extra-coregistration method that helps to increase the correlation coefficient between the radar images close to unity. This strongly supports radar applications such as change detection. © 2022 IEEE.

Image coregistration is a mandatory procedure for radar applications such as synthetic aperture radar change detection. The spatial coregistration can be easily handled with geo-reference, whereas radiometric coregistration requires much more effort due to the randomness of noise and clutter. The performance of a coregistration method is usually measured by the correlation coefficient that is desire to be close to unity. However, the currently used methods cannot provide coregistration with such correlation coefficient value. The paper introduces an image extra-coregistration method that helps to increase the correlation coefficient between the radar images close to unity. This strongly supports radar applications such as change detection. © 2022 IEEE.

Image coregistration is a mandatory procedure for radar applications such as synthetic aperture radar change detection. The spatial coregistration can be easily handled with geo-reference, whereas radiometric coregistration requires much more effort due to the randomness of noise and clutter. The performance of a coregistration method is usually measured by the correlation coefficient that is desire to be close to unity. However, the currently used methods cannot provide coregistration with such correlation coefficient value. The paper introduces an image extra-coregistration method that helps to increase the correlation coefficient between the radar images close to unity. This strongly supports radar applications such as change detection. © 2022 IEEE.

Незважаючи на зростаючий інтерес до спільного використання оптичних і радарних знімків, проблема їх кореєстрації залишається актуальною. Метою магістерської дисертації є розроблення модифікованого алгоритму для підвищення якості кореєстрації оптичних і супутникових знімків. Для досягнення мети було виконано наступні завдання: проаналізовано об’єкт та предмет дослідження, проведено аналіз існуючих методів кореєстрації, визначено вимоги до системи, створено модифікований алгоритм кореєстрації, реалізовано програмне забезпечення на основі розробленого алгоритму та проведено аналіз для реалізації проекту як стартапу. Об’єктом дослідження є супутникові знімки. Предметом дослідження є кореєстрація оптичних і радарних супутникових знімків. Результати магістреської дисертації впроваджені та активно використовуються ТОВ «АГРО ФЛОУ СИСТЕМ»., Despite the growing interest in sharing optical and radar images, the problem of registering them remains relevant. The purpose of the master's thesis is to develop a modified algorithm for improving the quality of registration of optical and satellite images. To achieve this goal, the following tasks were performed: the object and subject of the study were analyzed, the existing methods of registration were analyzed, the requirements for the system were determined, the modified algorithm of registration was created, the software was developed on the basis of the developed algorithm, and the analysis was carried out for realization. project as a startup. The object of the study is satellite imagery. The subject of the study is the registration of optical and radar satellite images. The results of the master's thesis are implemented and are being actively used by AGRO FLOW SYSTEM LLC.

Laser speckle imaging (LSI) is a wide-field optical technique that enables superficial blood flow quantification. LSI is normally performed in a mounted configuration to decrease the likelihood of motion artifact. However, mounted LSI systems are cumbersome and difficult to transport quickly in a clinical setting for which portability is essential in providing bedside patient care. To address this issue, we created a handheld LSI device using scientific grade components. To account for motion artifact of the LSI device used in a handheld setup, we incorporated a fiducial marker (FM) into our imaging protocol and determined the difference between highest and lowest speckle contrast values for the FM within each data set (Kbest and Kworst). The difference between Kbest and Kworst in mounted and handheld setups was 8% and 52%, respectively, thereby reinforcing the need for motion artifact quantification. When using a threshold FM speckle contrast value (KFM) to identify a subset of images with an acceptable level of motion artifact, mounted and handheld LSI measurements of speckle contrast of a flow region (KFLOW) in in vitro flow phantom experiments differed by 8%. Without the use of the FM, mounted and handheld KFLOW values differed by 20%. To further validate our handheld LSI device, we compared mounted and handheld data from an in vivo porcine burn model of superficial and full thickness burns. The speckle contrast within the burn region (KBURN) of the mounted and handheld LSI data differed by <4 % when accounting for motion artifact using the FM, which is less than the speckle contrast difference between superficial and full thickness burns. Collectively, our results suggest the potential of handheld LSI with an FM as a suitable alternative to mounted LSI, especially in challenging clinical settings with space limitations such as the intensive care unit.

Background: Goal: To develop a 3D visualization tool that accurately and intuitively displays critical cerebral components in epilepsy pre/post surgery.Limitations of current technology:2D images; Not patient-specific; Lock of coregistration; Non user-friendly. Faculty Adviser: Daniel Shrey, Ph.D., Children’s Hospital Orange County; Beth Lopour, Ph.D., UC Irvine Department of Biomedical Engineering | Joffre Olaya, M.D., Pediatric Neurosurgeon

Background: Goal: To develop a 3D visualization tool that accurately and intuitively displays critical cerebral components in epilepsy pre/post surgery.Limitations of current technology:2D images; Not patient-specific; Lock of coregistration; Non user-friendly. Faculty Adviser: Daniel Shrey, Ph.D., Children’s Hospital Orange County; Beth Lopour, Ph.D., UC Irvine Department of Biomedical Engineering | Joffre Olaya, M.D., Pediatric Neurosurgeon

[EN] This work presents a Positron Emission Tomography (PET) image analysis tool and its application to the study of rat brain glucose consumption (PETra comes from PET+rat). The described methodology has four steps: a preprocessing of PET images, a coregistration of these images with an atlas, a semiautomatic segmentation of the regions of interest in the rat brain and a 3D reconstruction of these regions to obtain the volumes of interest. Brain glucose uptake was quantified as Standardized Uptake Value (SUV). This tool was applied to nine Wistar rats, young (4-7 months) and old (22-24 months) groups, to study the effect of aging on brain glucose consumption and the difference between sexes. Results showed a lower glucose uptake in old rats than in young rats, regardless gender; while young female rats showed higher glucose consumption than young male rats, whereas these differences disappeared with aging. The developed tool allows the quantification of glucose in rat brain. Results show the accuracy of the tool to define ranges of variation in a population of young and old rats, showing a decrease in glucose consumption in aging.

[EN] This work presents a Positron Emission Tomography (PET) image analysis tool and its application to the study of rat brain glucose consumption (PETra comes from PET+rat). The described methodology has four steps: a preprocessing of PET images, a coregistration of these images with an atlas, a semiautomatic segmentation of the regions of interest in the rat brain and a 3D reconstruction of these regions to obtain the volumes of interest. Brain glucose uptake was quantified as Standardized Uptake Value (SUV). This tool was applied to nine Wistar rats, young (4-7 months) and old (22-24 months) groups, to study the effect of aging on brain glucose consumption and the difference between sexes. Results showed a lower glucose uptake in old rats than in young rats, regardless gender; while young female rats showed higher glucose consumption than young male rats, whereas these differences disappeared with aging. The developed tool allows the quantification of glucose in rat brain. Results show the accuracy of the tool to define ranges of variation in a population of young and old rats, showing a decrease in glucose consumption in aging.

This paper will present the project RAPIDMAP. The project is part of CONCERT-Japan, an ERA-NET initiative funded through the FP7 INCO project frame for enhancing research cooperation between European countries and Japan on two topics, one of which is Resilience Against Disasters. The project started in June 2013 and has a duration of 2 years. In the paper, we will outline the aims of the project, methodologies and techniques to be developed and some test data. Remote Sensing (RS) and Geographic Information System (GIS) are powerful technologies for collecting useful information on the damages of disasters in short time. However, since many different types of RS data are available (satellite, aerial, UAV, terrestrial), data co-registration, information integration and feature extraction need reliable and advanced methodologies. In the RAPIDMAP project, we will develop practical ways to integrate RS data processing tools in near-real-time and allow users to use this data soon after the disasters by means of WebGIS tools. This will help not only decision makers but also end-users in the disaster area. The key components of this project are: (1) Near-real-time monitoring: the procedure of near-real-time monitoring with satellites as well as Unmanned Airborne Vehicles (UAV) will be set up and demonstrated. (2) Data co-registration: in disasters, various images as well as maps come from different sources. The co-registration of multiple images is a key technology for information integration. In this project, a system to co-register multiple images in near-real-time will be developed. (3) Data fusion and change detection: one of the advantages of RS is to collect information with multiple sensors. Various methods for fusing optical with active microwave (SAR) sensor data for information extraction and change detection will be developed. (4) Decision Support System (DSS) based on WebGIS technologies: the collected and integrated information has to be easily accessible and v

Positron Emission Tomography (PET) systems designed specifically for small animal imaging have a unique set of requirements for successful operation. This work investigates a limited angle tomography microPET system, in contrast to conventional cylindrical systems. Initial studies included measurements of spatial resolution, uniformity, contrast-to-noise ratios, resolution recovery coefficients, and detector deadtime. A subsequent investigation was performed to ascertain the use of Factor Analysis in mitigating artifacts caused by the limited angle tomography. Three separate studies were conducted: a dual-isotope experiment, a semi quantitative study, and mouse models. The results indicate potential use of Factor Analysis with possible limitations due to noise or uptake.A more rigorous investigation into the limits of Factor Analysis was performed using Principal Component Analysis. Using the definitions of correlation and covariance matrices, the results of uniform phantom studies were used to measure uniformity, signal-to-noise ratio, and noise distribution. This analysis was applied to the limited angle tomographic system and a conventional cylindrical system. The results were insightful and in strong agreement with Poisson statistics.Multimodality coregistration between systems was also performed using a rigid body least-squares transformation ("Horn's method"). Spherical phantoms were imaged to obtain calibration data within each system. In addition to deriving the transformation between a pair of systems, a metric was computed to estimate the error associated with the coregistration. Once computed, the transformation was applied to independently acquired mice studies from each pair of systems. The method proved fairly successful, and a number of improvements are suggested.The rigid body nature of the transformation also allowed for a convenient method of measuring spatial linearity. Coregistration between synthetic grid-like images, and actual images of grid-l

Positron Emission Tomography (PET) systems designed specifically for small animal imaging have a unique set of requirements for successful operation. This work investigates a limited angle tomography microPET system, in contrast to conventional cylindrical systems. Initial studies included measurements of spatial resolution, uniformity, contrast-to-noise ratios, resolution recovery coefficients, and detector deadtime. A subsequent investigation was performed to ascertain the use of Factor Analysis in mitigating artifacts caused by the limited angle tomography. Three separate studies were conducted: a dual-isotope experiment, a semi quantitative study, and mouse models. The results indicate potential use of Factor Analysis with possible limitations due to noise or uptake.A more rigorous investigation into the limits of Factor Analysis was performed using Principal Component Analysis. Using the definitions of correlation and covariance matrices, the results of uniform phantom studies were used to measure uniformity, signal-to-noise ratio, and noise distribution. This analysis was applied to the limited angle tomographic system and a conventional cylindrical system. The results were insightful and in strong agreement with Poisson statistics.Multimodality coregistration between systems was also performed using a rigid body least-squares transformation ("Horn's method"). Spherical phantoms were imaged to obtain calibration data within each system. In addition to deriving the transformation between a pair of systems, a metric was computed to estimate the error associated with the coregistration. Once computed, the transformation was applied to independently acquired mice studies from each pair of systems. The method proved fairly successful, and a number of improvements are suggested.The rigid body nature of the transformation also allowed for a convenient method of measuring spatial linearity. Coregistration between synthetic grid-like images, and actual images of grid-l

The processes of tumor growth and treatment response are associated with the up-regulation of numerous proteins, yet current clinical imaging methods of cancer characterization monitor only gross morphology. This study combines specialized in vivo magnetic resonance imaging (MRI) with matrix-assisted laser desorption ionization (MALDI) analysis of healthy and tumorous ex vivo specimens in order to examine the proteomic influences on contrast in MRI. During the current research period, protocols were developed to image and correlate data from breast cancer metastases to bone. MRI data acquisition was expanded from that of the previous research period to include gadolinium contrast-enhanced, diffusion-weighted, and relaxometric data in an intra-tibial mouse model of metastatic breast cancer. Multi-parametric MRI data were collected for eight mice at each of three time points. Acquisition of MALDI data for each mouse is currently underway. Coregistration of proteomic and MRI hind limb data will incorporate both rigid and non-rigid methods in order to fuse the two datasets based on fiducial markers in the absence of a non-deformable stereotactic frame. Data analysis will focus on identification of specific (groups of) proteins that most strongly correlate with variations in multi-parametric MRI data. This work represents a basic yet vital step towards the long-term objective of facilitating clinical assessment of tumor status via non-invasive imaging techniques., The original document contains color images.

Hand-held based optical imaging devices using near-infrared (NIR) light are currently developed toward clinical translation of the technology. However, none of the NIR devices developed to date have attempted 3D tomography since they are not able to coregister the image to the tissue geometry. The objective for the work described herein is the clinical translation of a hand-held optical imager with automated coregistration facilities toward 3D tomography. Studies were performed in vivo with normal human subjects to demonstrate fast (near real-time) 2D fluorescence imaging for target detection prior to 3D tomography. The results showed that 0.23 cm3 and 0.45 cu cm fluorescent targets placed behind the breast tissue were detected through ~2.5 cm deep tissue. Parallely, studies were performed on phantoms composed of minced chicken breast and 1% Liposyn solution to demonstrate coregistered imaging in vitro. The results showed that the 3D tracking system was able to track the position of the probe in real-time and accurately coregister the image to the geometry of the object. Additionally, deeper targets can be detected upon summation of multiple coregistered images. These results demonstrate the potential of the device to perform 3D tomographic imaging in human subjects via coregistered imaging on complex breast geometries., The original document contains color images.

Geologically young gullies have been proposed to be evidence of recent liquid water on Mars. This dissertation details work I have done to address issues surrounding the Martian gullies and recent water on Mars. In order to determine the elevations at which gullies occur, I created a set of Interactive Data Language programs and Unix C-shell scripts to coregister Mars Orbiter Laser Altimeter topography with high resolution Mars images. My scripts represent the first public method that does this. Recently, the Mars Orbiter Camera detected changes in the form of new bright deposits in two gullies. The High Resolution Imaging Science Experiment (HiRISE) camera detected more gullies with bright deposits. I used my scripts to identify some of the best candidates for liquid water formation based on their shallow average slopes. A Digital Elevation Model (DEM) was produced using HiRISE stereo images of my selected candidates in Hale Crater. I model two gullies with bright slope deposits in Hale Crater and find that both water-rich and sediment-rich flows could reproduce the bright deposits’ locations and morphologies. Since liquid water is rarely stable on Mars today, I suggest that dry flows formed the bright deposits. The channel gradient where flows deposit, the apex slope, can tell us whether a flow was likely dry and non-fluidized (slopes ~21°) or fluidized (shallower slopes). I measured the apex slope of 75 gullies located in five HiRISE DEMs. I find that 72% of the gullies studied were likely emplaced by a fluidized flow. I also find that modified gullies are more likely to have a fluidized emplacement than relatively fresh gullies. My results suggest that there is no evidence requiring water-rich flows in gullies today. Understanding the concept of water on Mars is crucial to understanding NASA’s Mars Exploration Strategy, “Follow the Water.” I undertook a study investigating alternative conceptions about water on Mars held by middle school science teachers to unde

Image alignment is without doubt the most crucial step in SAR Interferometry. Interferogram formation requires images to be coregistered with an accuracy of better than 1/8 pixel to avoid significant loss of phase coherence. Conventional interferometric precise coregistration methods for full-resolution SAR data (Single-Look Complex imagery, or SLC) are based on the cross-correlation of the SLC data, either in the original complex form or as squared amplitudes. Offset vectors in slant range and azimuth directions are computed on a large number of windows, according to the estimated correlation peaks. Then, a two-dimensional polynomial of a certain degree is usually chosen as warp function and the polynomial parameters are estimated through LMS fit from the shifts measured on the image windows. In case of rough topography and long baselines, the polynomial approximation for the warp function becomes inaccurate, leading to local misregistrations. Moreover, these effects increase with the spatial resolution and then with the sampling frequency of the sensor, as first results on TerraSAR-X interferometry confirm. An improved, DEM-assisted image coregistration procedure can be adopted for providing higher-order prediction of the offset vectors. Instead of estimating the shifts on a limited number of patches and using a polynomial approximation for the transformation, this approach computes pixel by pixel the correspondence between master and slave by using the orbital data and a reference DEM. This study assesses the performance of this approach with respect to the standard procedure. In particular, both analytical relationships and simulations will evaluate the impact of the finite vertical accuracy of the DEM on the final coregistration precision for different radar postings and relative positions of satellites. The two approaches are compared by processing real data at different carrier frequencies and using the interferometric coherence as quality figure., Mathematical Geodesy & Positioning, Aerospace Engineering

Image alignment is without doubt the most crucial step in SAR Interferometry. Interferogram formation requires images to be coregistered with an accuracy of better than 1/8 pixel to avoid significant loss of phase coherence. Conventional interferometric precise coregistration methods for full-resolution SAR data (Single-Look Complex imagery, or SLC) are based on the cross-correlation of the SLC data, either in the original complex form or as squared amplitudes. Offset vectors in slant range and azimuth directions are computed on a large number of windows, according to the estimated correlation peaks. Then, a two-dimensional polynomial of a certain degree is usually chosen as warp function and the polynomial parameters are estimated through LMS fit from the shifts measured on the image windows. In case of rough topography and long baselines, the polynomial approximation for the warp function becomes inaccurate, leading to local misregistrations. Moreover, these effects increase with the spatial resolution and then with the sampling frequency of the sensor, as first results on TerraSAR-X interferometry confirm. An improved, DEM-assisted image coregistration procedure can be adopted for providing higher-order prediction of the offset vectors. Instead of estimating the shifts on a limited number of patches and using a polynomial approximation for the transformation, this approach computes pixel by pixel the correspondence between master and slave by using the orbital data and a reference DEM. This study assesses the performance of this approach with respect to the standard procedure. In particular, both analytical relationships and simulations will evaluate the impact of the finite vertical accuracy of the DEM on the final coregistration precision for different radar postings and relative positions of satellites. The two approaches are compared by processing real data at different carrier frequencies and using the interferometric coherence as quality figure., Mathematical Geodesy & Positioning, Aerospace Engineering

Dedicated small-animal tomographs are nowadays available for the three major modalities PET, MRI, and CT. Utilization of all three techniques for true multimodality imaging requires the solution of several technical problems including reproducible animal positioning, overcoming file format incompatibilities and coregistration of the different image volumes, preferably without application of markers. Methods: We developed an isolation chamber and adapter for imaging devices, enabling physiologic animal control, reproducible positioning, pathogen barrier, anesthesia, probe application and the use of catheter systems. Furthermore, we developed the necessary software for file format conversions and coregistration of the image volumes. The basis is the animal holder system, consisting of the fixing adapters and the animal chamber that could be positioned in our three tomographs (microPET P4, SkyScan 1178, and BioScan 70/30 USR). The animal holder system is temperature-controled. It allows gas anesthesia of the animals and could be used as a closed system. The bed is air heated. In the different modalities the data are stored in different formats using different image matrix and pixel sizes. In order to analyze the data they are converted to a common data format (Siemens ECAT7) and the pixel sizes are adjusted. Residual differences in the relative positioning of the animals are corrected via coregistration. We implemented a mutual information algorithm using the conjugate gradient maximization method. Validation studies showed a good coregistration of the images from PET, CT, and MRI. In longitudinal [18F]FDG studies the coregistration allowed to compare the tumor SUVmax data between different studies. Conclusion: Multimodality imaging of small animal PET, -CT, and MRI allows the direct comparison and quantification of regional PET, CT, and MRI/MRS parameters enabling the characterization of functional and anatomical changes during tumor development and therapy. The proje

Dedicated small-animal tomographs are nowadays available for the three major modalities PET, MRI, and CT. Utilization of all three techniques for true multimodality imaging requires the solution of several technical problems including reproducible animal positioning, overcoming file format incompatibilities and coregistration of the different image volumes, preferably without application of markers. Methods: We developed an isolation chamber and adapter for imaging devices, enabling physiologic animal control, reproducible positioning, pathogen barrier, anesthesia, probe application and the use of catheter systems. Furthermore, we developed the necessary software for file format conversions and coregistration of the image volumes. The basis is the animal holder system, consisting of the fixing adapters and the animal chamber that could be positioned in our three tomographs (microPET P4, SkyScan 1178, and BioScan 70/30 USR). The animal holder system is temperature-controled. It allows gas anesthesia of the animals and could be used as a closed system. The bed is air heated. In the different modalities the data are stored in different formats using different image matrix and pixel sizes. In order to analyze the data they are converted to a common data format (Siemens ECAT7) and the pixel sizes are adjusted. Residual differences in the relative positioning of the animals are corrected via coregistration. We implemented a mutual information algorithm using the conjugate gradient maximization method. Validation studies showed a good coregistration of the images from PET, CT, and MRI. In longitudinal [18F]FDG studies the coregistration allowed to compare the tumor SUVmax data between different studies. Conclusion: Multimodality imaging of small animal PET, -CT, and MRI allows the direct comparison and quantification of regional PET, CT, and MRI/MRS parameters enabling the characterization of functional and anatomical changes during tumor development and therapy. The proje

Radiation oncology was these 20 last years revolutionized by the 3-dimensional conformal radiotherapy (3D-CRT) and its technical evolution, the intensity modulated radiotherapy (IMRT). Thanks to steep dose gradient dose distribution, these techniques allow to conform the prescribed dose to the Planning Target Volume (PTV) while significantly decreasing the dose delivered to the Organs at Risk (OAR). One critical step remains the accurate definition of the Gross Tumor Volume (GTV). If the GTV is underestimated, there is a risk of missing part of the target. If the GTV is overestimated, the risk is to overirradiate normal tissues. Today's gold standard for GTV definition is the Computed Tomography (CT) scanner. We though know that its poor soft tissues contrast is a factor of variability for target definition purpose. AIMS : It can be hypothesized that, for Head and Neck Squamous Cell Carcinomas located in the oropharynx or the laryngo-hypopharynx, the use of other anatomical (like Magnetic Resonance Imaging - MRI) or functional (like positron emission tomography with either 11C-methionine - MET-PET- or 18F-fluorol-deoxy-glucose - FDG-PET) imaging modalities could complement CT for GTV delineation, and have an impact on subsequent CTV and PTV delineation and dose distribution to the non target tissues outside the PTV. RESULTS : We could demonstrate that, providing an adequate and controlled methodology concerning image coregistration and tumor volume delineation on functional images, differences were observed for the delineation of primary tumor volume or GTV according to the modality used. Moreover, the trends were the same for both locations studied (oropharyngeal and laryngo-hypopharyngeal) : CT, MRI and MET-PET volumes were not significantly different in absolute volumes, but there was no total overlap, each imaging modality having the tendency to visualize different types and relatively specific pathways of tumor extension (e.g. : cartilages in MRI). What was ver, INTRODUCTION : La radiothérapie moderne a terriblement évolué ces 20 dernières années grâce au développement de la radiothérapie conformationnelle tridimensionnelle (3D-CRT) et de son évolution technique, la radiothérapie par modulation d'intensité (IMRT). Grâce à la création de gradients de dose très raides, ces techniques permettent de conformer au mieux la distribution de la dose au "Planning Target Volume" (PTV) tout en diminuant de manière significative la dose délivrée aux Organes à Risque (OAR). La précision de la définition du "Gross Tumor Volume" (GTV) ou volume tumoral macroscopique reste une étape cruciale dans le sens où une sous-estimation du volume augmente le risque de sous-doser la dose délivrée à la tumeur. Dans l'autre sens, la surestimation du volume tumoral conduit immanquablement à une surirradiation des tissus sains. La tomographie computée par scanner (CT) est l'imagerie de référence pour la définition du GTV. Cependant, le manque de constraste entre tissus mous - à fortiori entre la tumeur et les tissus environnants- constitue un facteur de variabilité reconnu quant à la précision de délimitation du GTV. BUTS : Pour les cancers de la sphère cervico-maxillo-faciale, en particulier pour les tumeurs épithéliales oropharyngées et laryngo-hypopharyngées, démontrer que l'usage complémentaire d'une autre imagerie anatomique comme la résonance magnétique (IRM) ou fonctionnelle comme la tomographie par émission de positrons utilisant soit la méthionine marquée au carbone 11 (MET-TEP), soit le fluoro-déoxy-glucose marqué au fluor 18 (FDG-TEP) peut améliorer la précision de la délimitation GTV. Dans ce cas, démontrer également que cela a un impact sur la délimitation des CTV et PTV sous-jacents et, in fine, sur la distribution de la dose aux tissus sains extérieurs au PTV. RESULTATS : Moyennant l'utilisation adéquate et contrôlée de méthodes de corégistration des images et de délimitation automatique des volumes en imagerie fonctionnelle, nous avons pu, (MED 3)--UCL, 2005

Tato semestrální práce se zabývá různými možnostmi registrace medicínských obrazů. Na začátku jsou uvedeny základní vlastnosti DKI dat. V dalších kapitolách je zaměřena na metody, které odstraňují pohybové artefakty a geometrické nepřesnosti. Těmito metodami jsou převzorkování, vyhlazování transformace a optimalizace. V práci je dále popsán software provádějící samotnou registraci. Na konci se věnuje metodami srovnávající úspěšnost registrací., This semestral thesis deals with several options of medical images registration. Basic properties of DKI data are presented in the begining. In the following chapters it is focused on methods, which are removing motion distortion and geometrical inaccuracies. These methods are oversampling, transformation smoothing and optimalization. Software doing registration itself is also covered in this thesis. Methods of comparing registration success rates are described in the end.

Tato bakalářská práce se zabývá koregistrací difuzně vážených dat magnetické rezonance s vysokými b-hodnotami. Cílem je porovnat vybrané metody koregistrace na reálných datech a kvantifikovat kvalitu výstupu. V teoretické části je popsán princip difuzního zobrazování, vliv b-hodnoty na obraz a různé metody předzpracování dat se zaměřením na možnosti koregistrace obrazů s různým kontrastem. Dále jsou prezentovány dostupné softwarové nástroje a metody hodnocení kvality koregistrace. V praktické části je provedeno předzpracování difuzních dat, včetně koregistrace vybranými metodami, a analyzována kvalita pomocí statistických metod., This bachelor thesis deals with the coregistration of diffusion-weighted MRI data with high b-values. The aim is to compare selected coregistration methods on real data and to quantify the quality of the output. The theoretical part presents the principle of diffusion imaging, the effect of b-value on the image and different methods of data preprocessing with a focus on the possibilities of coregistration of images with varying contrast. In addition, available software tools and methods for assessing the quality of coregistration are introduced. In the practical portion of the paper, preprocessing of diffusion data, including coregistration by the selected methods, is performed and the quality is analyzed using statistical measures.

Tato semestrální práce se zabývá různými možnostmi registrace medicínských obrazů. Na začátku jsou uvedeny základní vlastnosti DKI dat. V dalších kapitolách je zaměřena na metody, které odstraňují pohybové artefakty a geometrické nepřesnosti. Těmito metodami jsou převzorkování, vyhlazování transformace a optimalizace. V práci je dále popsán software provádějící samotnou registraci. Na konci se věnuje metodami srovnávající úspěšnost registrací., This semestral thesis deals with several options of medical images registration. Basic properties of DKI data are presented in the begining. In the following chapters it is focused on methods, which are removing motion distortion and geometrical inaccuracies. These methods are oversampling, transformation smoothing and optimalization. Software doing registration itself is also covered in this thesis. Methods of comparing registration success rates are described in the end.

Tato bakalářská práce se zabývá koregistrací difuzně vážených dat magnetické rezonance s vysokými b-hodnotami. Cílem je porovnat vybrané metody koregistrace na reálných datech a kvantifikovat kvalitu výstupu. V teoretické části je popsán princip difuzního zobrazování, vliv b-hodnoty na obraz a různé metody předzpracování dat se zaměřením na možnosti koregistrace obrazů s různým kontrastem. Dále jsou prezentovány dostupné softwarové nástroje a metody hodnocení kvality koregistrace. V praktické části je provedeno předzpracování difuzních dat, včetně koregistrace vybranými metodami, a analyzována kvalita pomocí statistických metod., This bachelor thesis deals with the coregistration of diffusion-weighted MRI data with high b-values. The aim is to compare selected coregistration methods on real data and to quantify the quality of the output. The theoretical part presents the principle of diffusion imaging, the effect of b-value on the image and different methods of data preprocessing with a focus on the possibilities of coregistration of images with varying contrast. In addition, available software tools and methods for assessing the quality of coregistration are introduced. In the practical portion of the paper, preprocessing of diffusion data, including coregistration by the selected methods, is performed and the quality is analyzed using statistical measures.

Většina existujících nástrojů pro zpracování medicínských obrazů podporuje několik modalit, datových typů a nabízí širokou paletu funkcí, ale často se specializují na rozbor snímků mozku. Předmětem práce je analýza současných technik pro koregistraci 3D MRI snímků a jejich využití na vyšetření prostaty. Cílem je kvalitní a rychlá metoda koregistrace T2 morfologických snímků s důrazem na experimentální T2 sekvenci, která by mohla mít uplatnění při diagnostice karcinomu prostaty., Most of the current medical image processing toolboxes support several modalities, data types and they offer a plethora of functions, however, they are often specialized on brain image analysis. The subject of this work is an overview of current techniques used in 3D MRI image coregistration and their adoption for prostate examination. The goal is a rapid high-quality coregistration method of T2 morphologic images with emphasis on the experimental T2 sequence, which could be used in the diagnosis of prostate cancer.

Tato semestrální práce se zabývá různými možnostmi registrace medicínských obrazů. Na začátku jsou uvedeny základní vlastnosti DKI dat. V dalších kapitolách je zaměřena na metody, které odstraňují pohybové artefakty a geometrické nepřesnosti. Těmito metodami jsou převzorkování, vyhlazování transformace a optimalizace. V práci je dále popsán software provádějící samotnou registraci. Na konci se věnuje metodami srovnávající úspěšnost registrací., This semestral thesis deals with several options of medical images registration. Basic properties of DKI data are presented in the begining. In the following chapters it is focused on methods, which are removing motion distortion and geometrical inaccuracies. These methods are oversampling, transformation smoothing and optimalization. Software doing registration itself is also covered in this thesis. Methods of comparing registration success rates are described in the end.

Tato semestrální práce se zabývá různými možnostmi registrace medicínských obrazů. Na začátku jsou uvedeny základní vlastnosti DKI dat. V dalších kapitolách je zaměřena na metody, které odstraňují pohybové artefakty a geometrické nepřesnosti. Těmito metodami jsou převzorkování, vyhlazování transformace a optimalizace. V práci je dále popsán software provádějící samotnou registraci. Na konci se věnuje metodami srovnávající úspěšnost registrací., This semestral thesis deals with several options of medical images registration. Basic properties of DKI data are presented in the begining. In the following chapters it is focused on methods, which are removing motion distortion and geometrical inaccuracies. These methods are oversampling, transformation smoothing and optimalization. Software doing registration itself is also covered in this thesis. Methods of comparing registration success rates are described in the end.

Tato bakalářská práce se zabývá koregistrací difuzně vážených dat magnetické rezonance s vysokými b-hodnotami. Cílem je porovnat vybrané metody koregistrace na reálných datech a kvantifikovat kvalitu výstupu. V teoretické části je popsán princip difuzního zobrazování, vliv b-hodnoty na obraz a různé metody předzpracování dat se zaměřením na možnosti koregistrace obrazů s různým kontrastem. Dále jsou prezentovány dostupné softwarové nástroje a metody hodnocení kvality koregistrace. V praktické části je provedeno předzpracování difuzních dat, včetně koregistrace vybranými metodami, a analyzována kvalita pomocí statistických metod., This bachelor thesis deals with the coregistration of diffusion-weighted MRI data with high b-values. The aim is to compare selected coregistration methods on real data and to quantify the quality of the output. The theoretical part presents the principle of diffusion imaging, the effect of b-value on the image and different methods of data preprocessing with a focus on the possibilities of coregistration of images with varying contrast. In addition, available software tools and methods for assessing the quality of coregistration are introduced. In the practical portion of the paper, preprocessing of diffusion data, including coregistration by the selected methods, is performed and the quality is analyzed using statistical measures.

Tato bakalářská práce se zabývá koregistrací difuzně vážených dat magnetické rezonance s vysokými b-hodnotami. Cílem je porovnat vybrané metody koregistrace na reálných datech a kvantifikovat kvalitu výstupu. V teoretické části je popsán princip difuzního zobrazování, vliv b-hodnoty na obraz a různé metody předzpracování dat se zaměřením na možnosti koregistrace obrazů s různým kontrastem. Dále jsou prezentovány dostupné softwarové nástroje a metody hodnocení kvality koregistrace. V praktické části je provedeno předzpracování difuzních dat, včetně koregistrace vybranými metodami, a analyzována kvalita pomocí statistických metod., This bachelor thesis deals with the coregistration of diffusion-weighted MRI data with high b-values. The aim is to compare selected coregistration methods on real data and to quantify the quality of the output. The theoretical part presents the principle of diffusion imaging, the effect of b-value on the image and different methods of data preprocessing with a focus on the possibilities of coregistration of images with varying contrast. In addition, available software tools and methods for assessing the quality of coregistration are introduced. In the practical portion of the paper, preprocessing of diffusion data, including coregistration by the selected methods, is performed and the quality is analyzed using statistical measures.

Tato bakalářská práce se zabývá koregistrací difuzně vážených dat magnetické rezonance s vysokými b-hodnotami. Cílem je porovnat vybrané metody koregistrace na reálných datech a kvantifikovat kvalitu výstupu. V teoretické části je popsán princip difuzního zobrazování, vliv b-hodnoty na obraz a různé metody předzpracování dat se zaměřením na možnosti koregistrace obrazů s různým kontrastem. Dále jsou prezentovány dostupné softwarové nástroje a metody hodnocení kvality koregistrace. V praktické části je provedeno předzpracování difuzních dat, včetně koregistrace vybranými metodami, a analyzována kvalita pomocí statistických metod., This bachelor thesis deals with the coregistration of diffusion-weighted MRI data with high b-values. The aim is to compare selected coregistration methods on real data and to quantify the quality of the output. The theoretical part presents the principle of diffusion imaging, the effect of b-value on the image and different methods of data preprocessing with a focus on the possibilities of coregistration of images with varying contrast. In addition, available software tools and methods for assessing the quality of coregistration are introduced. In the practical portion of the paper, preprocessing of diffusion data, including coregistration by the selected methods, is performed and the quality is analyzed using statistical measures.

Tato semestrální práce se zabývá různými možnostmi registrace medicínských obrazů. Na začátku jsou uvedeny základní vlastnosti DKI dat. V dalších kapitolách je zaměřena na metody, které odstraňují pohybové artefakty a geometrické nepřesnosti. Těmito metodami jsou převzorkování, vyhlazování transformace a optimalizace. V práci je dále popsán software provádějící samotnou registraci. Na konci se věnuje metodami srovnávající úspěšnost registrací., This semestral thesis deals with several options of medical images registration. Basic properties of DKI data are presented in the begining. In the following chapters it is focused on methods, which are removing motion distortion and geometrical inaccuracies. These methods are oversampling, transformation smoothing and optimalization. Software doing registration itself is also covered in this thesis. Methods of comparing registration success rates are described in the end.

Tato bakalářská práce se zabývá koregistrací difuzně vážených dat magnetické rezonance s vysokými b-hodnotami. Cílem je porovnat vybrané metody koregistrace na reálných datech a kvantifikovat kvalitu výstupu. V teoretické části je popsán princip difuzního zobrazování, vliv b-hodnoty na obraz a různé metody předzpracování dat se zaměřením na možnosti koregistrace obrazů s různým kontrastem. Dále jsou prezentovány dostupné softwarové nástroje a metody hodnocení kvality koregistrace. V praktické části je provedeno předzpracování difuzních dat, včetně koregistrace vybranými metodami, a analyzována kvalita pomocí statistických metod., This bachelor thesis deals with the coregistration of diffusion-weighted MRI data with high b-values. The aim is to compare selected coregistration methods on real data and to quantify the quality of the output. The theoretical part presents the principle of diffusion imaging, the effect of b-value on the image and different methods of data preprocessing with a focus on the possibilities of coregistration of images with varying contrast. In addition, available software tools and methods for assessing the quality of coregistration are introduced. In the practical portion of the paper, preprocessing of diffusion data, including coregistration by the selected methods, is performed and the quality is analyzed using statistical measures.

Tato semestrální práce se zabývá různými možnostmi registrace medicínských obrazů. Na začátku jsou uvedeny základní vlastnosti DKI dat. V dalších kapitolách je zaměřena na metody, které odstraňují pohybové artefakty a geometrické nepřesnosti. Těmito metodami jsou převzorkování, vyhlazování transformace a optimalizace. V práci je dále popsán software provádějící samotnou registraci. Na konci se věnuje metodami srovnávající úspěšnost registrací., This semestral thesis deals with several options of medical images registration. Basic properties of DKI data are presented in the begining. In the following chapters it is focused on methods, which are removing motion distortion and geometrical inaccuracies. These methods are oversampling, transformation smoothing and optimalization. Software doing registration itself is also covered in this thesis. Methods of comparing registration success rates are described in the end.

Většina existujících nástrojů pro zpracování medicínských obrazů podporuje několik modalit, datových typů a nabízí širokou paletu funkcí, ale často se specializují na rozbor snímků mozku. Předmětem práce je analýza současných technik pro koregistraci 3D MRI snímků a jejich využití na vyšetření prostaty. Cílem je kvalitní a rychlá metoda koregistrace T2 morfologických snímků s důrazem na experimentální T2 sekvenci, která by mohla mít uplatnění při diagnostice karcinomu prostaty., Most of the current medical image processing toolboxes support several modalities, data types and they offer a plethora of functions, however, they are often specialized on brain image analysis. The subject of this work is an overview of current techniques used in 3D MRI image coregistration and their adoption for prostate examination. The goal is a rapid high-quality coregistration method of T2 morphologic images with emphasis on the experimental T2 sequence, which could be used in the diagnosis of prostate cancer.