Quantification and correction of mv scatter
WebJul 1, 2024 · The average pixel values of MV- and kV-scatter (i.e., the MV- and kV-scatter values) at the center of each map were calculated and normalized to the MV-scatter value under the reference conditions ... WebAn MV-scatter correction experiment with one full arc image acquisition and two square field sizes (FSs) was conducted. Measurement- and estimation-based corrections were performed using the database. The image contrast was calculated at each angle. Results: The MV-scatter increased with a larger FS and dose rate. The MV-scatter value factor ...
Quantification and correction of mv scatter
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WebJul 25, 2024 · The Pearson's coefficients of determination for each field size are 1, and the intercepts of the fitted lines are 0. ... (MV + kV), kV-scatter-corrected image (kVScorr), MV-scatter-corrected image (MVScorr), MV- and kV-scatter-corrected image (MVkVScorr) for flat panel detectors1 (FPD1) and FPD2 obtained at segments 2 and 11, ... WebOct 30, 2024 · An MV-scatter correction experiment was also performed, in which an MV-scatter map was subtracted from a kV image acquired during MV beam ... The Pearson’s coefficient of determination for each MV beam energy was almost 1 and the intercept of the fitted linear line was almost 0. Figure 6. Dose rate dependencies for (a) 6 ...
WebJul 25, 2024 · The maximum kV-scatter value was 0.48 with a fully open kV collimator aperture. In the phantom experiment, the intensity ratios of kV images with MV- and kV-scatter were decreased from the reference ones. After correction of kV-scatter only, MV-scatter only, and both MV- and kV-scatter, the intensity ratios gradually improved. … WebMay 23, 2012 · The 2D correction (a) outperforms the uniform correction method (b), implying that the shape of the MV scatter image (figure 3) is important for correction. Furthermore, comparing methods (a) and (c), which used a different phantom, it is apparent that the MV scatter contribution is somewhat dependent on the patient geometry (this is …
WebSep 1, 2001 · Measurements were made of the "a" factor for 4, 6, 10, and 23 MV x rays at scattering angles between 30 degrees and 135 degrees and show that the 6 and 10 MV "a' factor data are consistent with published data, and the 23 MV data are also consistent with recently published data at 18 and 25 MV. NCRP Report No. 49, published in 1976, …
WebDec 11, 2024 · The MV-scatter correction experiment showed that the correction improved the image contrast, even when using the estimation-based correction method. Furthermore, the data generated in this study can be used for validating MC simulations of concurrent MV and kV beam irradiation geometry for patient-specific MV-scatter correction.
WebScatter fractions were measured on a medical linear accelerator (Clinac 2100c, 6 MV) for a typical imaging geometry using an ionization chamber and a silicon diode. After correction for the energy dependence of the chamber and diode, the scatter fractions generated by the Monte Carlo simulations were found to be in excellent agreement with the measured … nettoyer watercoolingWebThe analysis of the cross-sensitivity to scattering for different lter tapes revealed a large increase of the C factor at the three stations when the single scattering albedo (SSA) of the collected particles was above 25 0.90-0.95, with up to a 3-fold increase above the average values. The result of the cross-sensitivity to scattering displayed a i\u0027m sorry mom in spanishWebConclusions: The MV-scatter was strongly dependent on the FS, dose rate, and FPD position. The MV-scatter correction improved the image contrast. Advances in knowledge: The MV-scatters on the True - Beam linac kV imaging subsystem were quantified with various MV beam parameters, and strongly depended on the fieldsize, dose rate, and flat panel ... nettoyer tennis blanche en cuirWebJun 6, 2013 · After the scatter correction, the beam hardening correction was made by using the fan beam projections taken from a water equivalent cylindrical phantom with little scatter. In this study, 180 full MV-projections for a Catphan500 phantom with a bone equivalent annulus were acquired over 360 degree using 6 MV photon beams, with 0–180 … nettoyer virus windows 11WebkV‐scatter (i.e., the MV‐ and kV‐scatter values) at the center of each map were cal-culated and normalized to the MV‐scatter value under the reference conditions (MV‐ and kV‐scatter value factor, respectively). In addition, an MV‐ and kV‐scatter correction experiment with intensity‐modulated beams was performed using a phan- i\\u0027m sorry once againWebThe MV-scatter was strongly dependent on the FS, dose rate, and FPD position. The MV-scatter correction improved the image contrast. The MV-scatters on the TrueBeam linac kV imaging subsystem were quantified with various MV beam parameters, and strongly depended on the fieldsize, dose rate, and flat panel detector position. The MV-scatter ... nettoyer w7Webnoise ratio lost due to MV scatter. From the patient study, the corrected CBCT scored 20 significantly higher than the uncorrected images in terms of the ability to identify the boundary between the prostate and surrounding soft tissue. In summary, a simple MV scatter correction method has been developed and, using both phantom and patient i\u0027m sorry paragraph to girlfriend