the post congratulations to pavlo karasyuk on his successful msc thesis defense appeared first on rezniklab and posted by pavlo karasyuk.

the post congratulations: oleksandr bubon completed phd appeared first on rezniklab and posted by pavlo karasyuk.

the post congratulations to oleksandr grynko on winning the ontario graduate scholarship (ogs) appeared first on rezniklab and posted by pavlo karasyuk.

abstract

although polycrystalline lead oxide (pbo) has a long history of application in optoelectronics and imaging, the transport mechanism for electrons in this material has not yet been clarified. using the photo-generated charge extraction by linear increasing voltage (photo-celiv) technique, we provide the temperature- and field-dependences of electron mobility in poly-pbo. it is found that electrons undergo dispersive transport, i.e. their mobility decreases in the course of time. multiple trapping of electrons from the conduction band into the developed band tail is revealed as the dominant transport mechanism. this differs dramatically from the dispersive transport of holes in the same material, dominated by topological factors and not by energy disorder.

continue reading the article: http://iopscience.iop.org/article/10.1088/1361-6463/50/3/035103/meta

the post congratulations to oleksii semeniuk on publishing a paper in journal of physics d applied physics appeared first on rezniklab and posted by pavlo karasyuk.

congratulations to anastasiia mishchenko who completed her phd.

the post congratulations: anastasiia mishchenko completed phd appeared first on rezniklab and posted by pavlo karasyuk.

semiconductor-based direct conversion detectors revolutionized radiation medical imaging since they allowed diagnostic capabilities not achievable with other detector approaches. the areas of highest impact are x-ray radiography and nuclear medicine. semiconductor detectors are also of a great significance to the field of x-ray computed tomography (ct) as they promise significant increase in intrinsic energy and spatial resolutions needed for better energy and material resolved ct imaging. cadmium zinc telluride (czt) is a material of choice for direct conversion ct detectors. recently, czt has been successfully employed in gamma cameras operating in ct-relevant energy range. however, for use in ct, czt has to demonstrate electronic properties that satisfy the requirement of high x-ray fluxes typical for ct; this includes prevention of possible buildup of space charge and related dynamic polarization of a detector material. therefore, the overall objective of this project is to investigate transport of photo-generated charge carriers in czt (i.e, electron and hole mobilities and their temperatures and field dependencies) and to evaluate the potential of czt photoconductor to be used in advanced ct detectors.

the post solid-state detectors for advanced ct appeared first on rezniklab and posted by pavlo karasyuk.

breast cancer accounts for approximately 26% of all cancers diagnosed today. like other cancers, breast cancer is most successfully treated if the disease is diagnosed early. the major problem is distinguishing between benign and malignant masses. women are forced to contemplate prophylactic mastectomy because predictive power of current imaging is poor.
radialis corporation (a spin-off company of the tbrhri and 阿根廷vs墨西哥竞猜 ) is manufacturing an advanced positron emission mammography (pem) system for molecular (or functional) imaging of breast cancer. pem detects small cancerous breast lesions based on their increased glucose metabolism and such its imaging performance is inherently independent on breast tissue density.
the core technology of the pem system was developed in our research laboratory under the supervision of dr. alla reznik. radialis pem employs 2 planar high-resolution detector heads placed on both sides of gently steadied breast (see figure above). pem only requires breast immobilization rather than compression and hence completely eliminates pain. during image acquisition, detectors fully cover the entire breast that allows for improved sensitivity capable of significant radiation dose reduction in comparison with commercially available scanners. large field-of-view detector design enables high-resolution. tumors as small as 1.2 mm will be detectable by the initial results of radials’s pem system.
radialis’s pem technology can be used as an adjuvant technique for breast cancer detection, and an integral part of the surveillance protocol of women at high and intermediate lifetime risk of breast cancer. technological advances used will reduce manufacturing cost for pem devices, thus positively influence people health.

for more information, please see an article “using positron emission mammography to detect breast cancer” or our latest publication on the topic: “evaluation of a high-sensitivity organ-targeted pet camera”.

the post low-dose organ-targeted positron emission tomography appeared first on rezniklab and posted by pavlo karasyuk.

abstract

although polycrystalline lead oxide (pbo) belongs to the most promising photoconductors for optoelectronic and large area detectors applications, the charge transport mechanism in this material still remains unclear. combining the conventional time-of-flight and the photo-generated charge extraction by linear increasing voltage (photo-celiv) techniques, we investigate the transport of holes which are shown to be the faster carriers in poly-pbo. experimentally measured temperature and electric field dependences of the hole mobility suggest a highly dispersive transport. in order to analyze the transport features quantitatively, the theory of the photo-celiv is extended to account for the dispersive nature of charge transport. while in other materials with dispersive transport the amount of dispersion usually depends on temperature, this is not the case in poly-pbo, which evidences that dispersive transport is caused by the spatial inhomogeneity of the material and not by the energy disorder.

continue reading the article: http://www.nature.com/articles/srep33359

the post congratulations to oleksii semeniuk on publishing a paper in scientific reports – nature appeared first on rezniklab and posted by pavlo karasyuk.

the annual summer school on medical imaging project presentation competition was held in august 2016. congratulations on getting 1st place:

participant (student): keren mayorov (on the left)
supervisor: dr. alla reznik
project title: image reconstruction for organ specific positron emission tomography

participant (student): brandon baldassi (on the right)
supervisor: dr. alla reznik
project title: characterization of cadmium zinc telluride as a material for solid state detectors in advanced computed tomography

more information about competition program can be found here.

reznik’s group wish you all the best in your future endeavors.

the post summer school on medical imaging 2016 competition winners appeared first on rezniklab and posted by pavlo karasyuk.