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Showing 1 to 9 of 9 for “"Hounsfield unit"”.
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Factors Influencing Contrast Resolution of Cone Beam CT Using the CB MercuRay
… landmarks in both quality and quantity. Hounsfield Unit (HU) values represent a grayscale that is standardized on CT machines relative to the density of water and air. It has been reported that the HU value represents an actual value of the bone density. However, recent studies at Loma …
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Development and Implementation of An Anthropomorphic Pediatric Spine Phantom For The Assessment of Craniospinal Irradiation Procedures In Proton Therapy
… by measuring the relative stopping power and Hounsfield unit of potential phantom materials. The materials selected as bone, tissue, and cartilage substitutes were Techron HPV Bearing Grade (RSP 1.3, HU 595.6), solid water (RSP 1.004, HU 16), and blue water (RSP 1.07, HU 86), respectively. The …
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Improving Cone-Beam Computed Tomography Based Adaptive Radiation Therapy with Deep Learning
… images with reduced artifacts and more accurate Hounsfield Unit values, as found in CT scans. Second, the model's generalizability is investigated and discussed, along with potential solutions to address the generalizability problem. Third, two DL models are designed to extract and combine …
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Investigating the ability to use the CT scan projection radiograph to monitor adolescent idiopathic scoliosis
… The phantom was validated by comparing the Hounsfield unit (HU) of its vertebrae with those of a human and an animal. Additionally, comparisons of signal-to-noise ratio (SNR) to those from a commercially available phantom were made. The angle of the curve in the phantom was measured directly …
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Evaluation and Clinical Implementation of a Dual-Energy CT Stopping-Power Ratio Mapping Technique for Proton-Therapy Treatment Planning
… SPR distribution from vendor-reconstructed Hounsfield Unit (HU) images. Unfortunately, this approach fails to disambiguate the dependence of HU on differences in density and composition of the underlying tissue and has been shown to have an overall inherent uncertainty of 2-3.5% or 1-6 mm in …
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Imaging Techniques for Proton Range Determination in Proton Therapy
… The current standard practice is to map SPR from Hounsfield Unit (HU) values of a single-energy computed tomography (SECT) scan through a stoichiometric calibration technique. This technique is subjected to a variety of factors that congregate on the uncertainties in SPR estimation, including the …
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Optimization of Image Guided Radiation Therapy for Lung Cancer Using Limited-angle Projections
… inherently has the same image quality and Hounsfield unit (HU) accuracy as 4D-CT and therefore can potentially improve the accuracy of on-board dose verification. Both XCAT and CIRS phantom studies were performed for the dosimetric study. Various inter-fractional variations featuring …