Inclusion of organ deformation in dose calculations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135079/1/mp9039.pd

Management of pediatric radiation dose using GE fluoroscopic equipment

In this article, we present GE Healthcare’s design philosophy and implementation of X-ray imaging systems with dose management for pediatric patients, as embodied in its current radiography and fluoroscopy and interventional cardiovascular X-ray product offerings. First, we present a basic framework of image quality and dose in the context of a cost–benefit trade-off, with the development of the concept of imaging dose efficiency. A set of key metrics of image quality and dose efficiency is presented, including X-ray source efficiency, detector quantum efficiency (DQE), detector dynamic range, and temporal response, with an explanation of the clinical relevance of each. Second, we present design methods for automatically selecting optimal X-ray technique parameters (kVp, mA, pulse width, and spectral filtration) in real time for various clinical applications. These methods are based on an optimization scheme where patient skin dose is minimized for a target desired image contrast-to-noise ratio. Operator display of skin dose and Dose-Area Product (DAP) is covered, as well. Third, system controls and predefined protocols available to the operator are explained in the context of dose management and the need to meet varying clinical procedure imaging demands. For example, fluoroscopic dose rate is adjustable over a range of 20:1 to adapt to different procedure requirements. Fourth, we discuss the impact of image processing techniques upon dose minimization. In particular, two such techniques, dynamic range compression through adaptive multiband spectral filtering and fluoroscopic noise reduction, are explored in some detail. Fifth, we review a list of system dose-reduction features, including automatic spectral filtration, virtual collimation, variable-rate pulsed fluoroscopic, grid and no-grid techniques, and fluoroscopic loop replay with store. In addition, we describe a new feature that automatically minimizes the patient-to-detector distance, along with an estimate of its dose reduction potential. Finally, two recently developed imaging techniques and their potential effect on dose utilization are discussed. Specifically, we discuss the dose benefits of rotational angiography and low frame rate imaging with advanced image processing in lieu of higher-dose digital subtraction

Evaluating Performance of Web Applications in (Cloud) Virtualized Environments

Web applications usually involve a number of different software libraries and tools (usually referred to as frameworks) each carrying out specific task/s and generating the corresponding overhead. In this paper, we show how to evaluate and even find out several configuration performance characteristics by using virtualized environments which are now used in data centers and cloud environments. We use specific and simple web software architectures as proof of concept, and explain several experiments that show performance issues not always expected from a conceptual point of view. We also explain that adding software libraries and tools also generate performance analysis complexities. We also shown that as an application is shown to scale, the problems to identify performance details and bottlenecks also scale, and the performance analysis also requires deeper levels of details.Instituto de Investigación en Informátic

Revenue-driven scheduling in drone delivery networks with time-sensitive service level agreements

Drones are widely anticipated to be used for commercial service deliveries, with potential to contribute to economic growth, estimated at £42 billion in the UK alone by the year 2030. Alongside air traffic control algorithms, drone-based courier services will have to make intelligent decisions about how to deploy their limited resources in order to increase profits. This paper presents a new scheduling algorithm for optimising the revenue of a drone courier service provider in these highly utilised time-sensitive service delivery systems. The first input to the algorithm is a monotonically decreasing value over time function which describes the service level agreement between the service provider and its customers. The second is the anticipated drone flight-time duration distribution. Our results show that the newly-developed scheduling algorithm, Least Lost Value, inspired by concepts for real-time computational workload processing, is able to successfully route drones to extract increased revenue to the service provider in comparison with two widely-used scheduling algorithms: First Come First Served and Shortest Job First, in terms of realised revenue

Current Diagnostic Possibilities for the Initial Forms of External Endometriosis

Background. Routine use of ultrasound methods does not always allow detecting endometriosis in the early stages. It is necessary to develop more accurate criteria for the diagnosis of endometriosis in its initial stages of development. Objective: to assess ultrasound and biological markers of endometriosis “small” forms of different localization in infertile women.Material and methods. Ultrasound examination of 208 infertile patients with initial stages of external endometriosis (1–15 points by revised American Fertility Society (rAFS) classificatoon) was performed (main group). The control group consisted of 195 healthy women of childbearing age. To verify the diagnosis, it is suggested to use a panel of biomarkers, including interleukins (IL) 1β and 6, CA125, HE4 as well as the ROMA (Risk of Ovarian Malignancy Algorithm) index in the dynamics of the menstrual cycle.Results. On ultrasound scans, 56 (94.9%) patients had small one- and two-sided ovarian cysts corresponding to endometriosis stage 1–2 (rAFS), and in 3 (5.4%) of them, the ultrasound result was questionable. Detectability during the initial ultrasound examination in the Douglas space was 76.9%, in the rest of cases the ultrasound picture was doubtful. Peritoneal endometriosis was detected only in 5 patients. In the remaining cases (88.9%), additional studies were necessary, including surgical (laparoscopy). The average content of CA125 in the main group on days 3–5 of the menstrual cycle was 42.6 (2.1) U/ml, on days 21–23 – 39.6(2.2) U/ml (p=0.32); in the control group, 5.1 (0.4) and 4.8 (0.7) U/ml, respectively (p = 0.71). The increase in CA125 in the main group was almost 8 times higher than in the control group, however, according to the indicators of HE4 and the ROMA index, statistically significant differences in the groups were not obtained. In the dynamics of the menstrual cycle, the content of ILs in the main group significantly decreased by days 21–23 of the cycle, while the content of CA125 and HE4 remained practically unchanged. Such sharp fluctuations of the considered biomarkers were not detected in the control group. However, even on days 21–23 of the cycle, the average content of ILs and CA125 in women of the main group remained statistically significantly higher than in the control group.Conclusion. In infertile women with dubious ultrasound criteria of external endometriosis, the use of IL1β and IL-6, which stimulate the immune inflammatory response, as well as tumor markers CA125, HE4 and ROMA index allows to differentiate the disease in the initial stages

The prediction of radiationâ induced liver dysfunction using a local dose and regional venous perfusion model

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134805/1/mp1081.pd

DESIGN, CONSTRUCTION, AND TESTING OF A FLYING PREY SIMULATOR

ABSTRACT The goal of this research project is to investigate the neuronal control of flying prey interception in dragonflies b