PURPOSE Small-field dosimetry is challenging, and the main limitations of most dosimeters are insufficient spatial resolution, water nonequivalence, and energy dependence. The purpose of this study was to compare plastic scintillation detectors (PSDs) to several commercial stereotactic dosimeters by measuring total scatter factors and dose profiles on a CyberKnife system. METHODS Two PSDs wer...

The scope of this work was to apply a method for estimation of total scatter factors of the smallest beams of the Cyberknife radiosurgery system to newly available solid-state detectors: the PTW 60008 diode, the SunNuclear EdgeDetector diode, and the Thomson and Nielsen TN502RDM micromosfet. The method is based on a consistency check between Monte Carlo simulation of the detectors and experimen...

Multi-dimensional Visual Tracking (MVT) problems include visual tracking tasks where the system state is defined by a high number of variables corresponding to multiple model components and/or multiple targets. A MVT problem can be modeled as a dynamic optimization problem. In this context, we propose an algorithm which hybridizes Particle Filters (PF) and the Scatter Search (SS) metaheuristic,...

The transmission dependent convolution subtraction method which is one of the methods for scatter correction of SPECT was applied to the assessment of CBF using SPECT and I-123-IMP. The effects of scatter correction on regional distribution of CBF were evaluated on a pixel by pixel basis by means of an anatomic standardization technique. SPECT scan was performed on six healthy men. Image recons...

Simultaneous Tl-201/Tc-99m dual isotope myocardial perfusion SPECT is seriously hampered by down-scatter from Tc-99m into the Tl-201 energy window. This paper presents and optimises the ordered-subsets-expectation-maximisation-(OS-EM-) based reconstruction algorithm, which corrects the down-scatter using an efficient Monte Carlo (MC) simulator. The algorithm starts by first reconstructing the T...

PURPOSE To evaluate whether correlations exist between objective and subjective measures of vision quality as a consequence of cataract and whether this may qualify the Objective Scatter Index as a supplementary means of cataract assessment. METHODS A prospective multicenter, cross-sectional study was conducted in 10 centers across France in patients undergoing cataract extraction surgery (le...

The study was to explore the feasibility of improving cone-beam CT (CBCT) number (corresponding to the Hounsfield units in computed tomography) consistency using a scatter-correction algorithm, with the aim of using CBCT images for treatment planning with density correction. A scatter correction algorithm was applied to a Varian OBI CBCT and an Elekta XVI CBCT, and was evaluated for improving C...

It is important to consider variations in material parameters in the design of automotive structures in order to obtain a robust and reliable design. However, expensive tests are required to gain complete knowledge of the material behavior and its associated variation. Consequently, due to time and cost constraints, simplifiedmaterial scatter modeling techniques based on scatter data of typical...

The Scatter Search (SS) is a deterministic strategy that has been applied successfully to some combinatorial and continuous optimization problems. Cuckoo Search (CS) is heuristic search algorithm which is inspired by the reproduction strategy of cuckoos. This paper presents enhanced scatter search algorithm using CS algorithm. The improvement provides Scatter Search with random exploration for ...