This work aims to improve the characterization of petrophysical properties by accurately estimating subsurface porosity using seismic and well data. The study includes Bayesian Linearized Inversion obtain elastic parameters (e.g., compressional e shear wave velocities densities). reduces processing uncertainty provides a reliable substitute for standard Amplitude versus Offset inversion method. Furthermore, incorporating sparse spike wavelets with refines output, facilitating extraction...

The plastic scintillator (PS) is a promising dosimeter for brachytherapy and other low-energy photon applications because of its high sensitivity approximate tissue equivalence. As part our project to develop new PS material which maximizes radiological equivalence water, we have measured the response, (light output/unit air kerma), bremsstrahlung (20 57 keV average energies) x-rays as well photons emitted by , sources, all were calibrated in terms kerma. systems studied standard commercial...

To accurately quantify the local difference between two contour surfaces in two- or three-dimensional space, a new, robust point-to-surface distance measure is developed.To evaluate and visualize surface differences, measures have been utilized. However, previously well-known critical shortfalls. Previous termed "normal (ND)," "radial distance," "minimum (MD)" can report erroneous results at certain points where under comparison meet conditions. These skewed are due to monodirectional...

A dosimetric study of a seed for permanent interstitial brachytherapy, the Theragenics Corporation Model 200 (TheraSeed ® ), has been undertaken utilizing Monte Carlo photon‐transport (MCPT) simulations. All quantities recommended by American Association Physicists in Medicine (AAPM) Task Group 43 (TG‐43) [Med. Phys. 22 , 209–234 (1995)] report have calculated. This source contains graphite pellets coated with palladium metal, within which radioactive is distributed. Due to significant...

Purpose: A quantitative and objective metric, the medical similarity index (MSI), has been developed for evaluating accuracy of a image segmentation relative to reference segmentation. The MSI uses consideration function (MCF) as its basis. Methods: Currently, no indices provide evaluations with considerations. Variations in can occur due individual skill levels relevance—curable or palliative intent, boundary uncertainty volume averaging, contrast levels, spatial resolution, unresolved...

Purpose: To develop a new metric for image registration that incorporates the (sub)pixelwise differential importance along spatial location and to demonstrate its application guided radiation therapy (IGRT). Methods: It is well known rigid‐body with mutual information dependent on size of subset which alignment analysis based [the designated region interest (ROI)]. Therefore, careful review manual adjustments resulting are frequently necessary. Although there were some investigations...

Purpose To assess stereotactic radiotherapy (SRT)/stereotactic body (SBRT) practices by polling clinics participating in multi-institutional clinical trials. Methods The NRG Oncology Medical Physics Subcommittee distributed a survey consisting of 23 questions, which covered general technologies, policies, and procedures used the Radiation field for delivery SRT/SBRT (9 questions), site-specific questions brain SRT, lung SBRT, prostate SBRT (14 questions). Surveys were to 1,996 institutions...

This article proposes quantitative analysis tools and digital phantoms to quantify intrinsic errors of deformable image registration (DIR) systems establish quality assurance (QA) procedures for clinical use DIR utilizing local global error methods with clinically realistic phantoms. Landmark-based verifications are suitable only images significant feature points. To address this shortfall, we adapted a deformation vector field (DVF) comparison approach new techniques the results. Digital...

This paper compares experimentally measured and calculated dose-rate distributions for a novel liquid-filled brachytherapy balloon applicator (the GliaSite RTS), designed the treatment of malignant brain-tumor resection-cavity margins. work is intended to comply with American Association Physicists in Medicine (AAPM) Radiation Therapy Committee's recommendations [Med. Phys. 25, 2269–2270 (1998)] dosimetric characterization low-energy photon interstitial sources. Absolute low radiochromic...

Purpose To reduce patient and procedure identification errors by human interactions in radiotherapy delivery surgery, a Biometric Automated Patient Procedure Identification System (BAPPIS) was developed. BAPPIS is treatment verification system using fingerprints. Methods The developed C++, the Microsoft Foundation Class Library, Oracle database system, fingerprint scanner. register patient, requires three steps: capturing photograph web camera for photo identification, taking at least two...

A new experimental method using dual-energy CT tissue-quantization (DECTQ) is proposed to identify compositional and geometric characteristics of tissue heterogeneities in around low-energy seed implant sites. The based on the assumption that total attenuation coefficient an arbitrary material can be expressed as a linear combination mass coefficients two basis materials. authors have validated energy range from 10-1000 keV demonstrating all cross-section data needed for Monte Carlo...

To develop a volume-independent conformity metric called the Gaussian Weighted Conformity Index (GWCI) to evaluate stereotactic radiosurgery/radiotherapy (SRS/SRT) plans for small brain tumors.A signed bi-directional local distance (BLD) between prescription isodose line and target contour is determined each point along tumor (positive represents under-coverage). A similarity score function (SF) derived from function, penalizing under- over-coverage at by assigning standard deviations of...

Purpose: To develop a robust registration algorithm for medical images, emphasizing the of plan images with cone beam computed tomography (CBCT) IGRT. Our Spatial Weighted Mutual Information (SWMI) technique assigns greater importance to user‐selected volume, allowing medically ‘important’ areas dominate process. Method and Materials: (MI) is most popular measure image due its robustness multi‐modal capability. However, MI does have difficulty where organ deformation present. We reformulated...

Purpose: To introduce an indicator which can show the deformable image registration (DIR) accuracy, and be used for commissioning DIR systems. Methods: Inaccurate produce inaccurate composite dose when we add doses from multiple treatment plans. Deformation Error Histogram(DEH) QA procedure were proposed to overcome shortfall of landmark approach. Our method conducted a DVM comparison approach instead using significant visible feature points feasibility DEH, Lung Liver cancer patient. Each...

The concept of uncertainty is fundamental in seismic inversion modeling, as it pertains to the imprecision or lack certainty inherent model's results. In this work, we present a comprehensive study that integrates machine learning, sensitivity analysis on well data, and sparse spike wavelet enhance quality Bayesian Linearized Inversion (BLI). Furthermore, was conducted assess diverse combinations attributes facilitate identification optimal model configuration ensure robust Subsequently,...

Purpose: Monte Carlo simulations have been undertaken to quantify the dosimetry of tumors that absorbed nanoparticle gold as radiosensitizers and irradiated with various radiotherapy modalities. Method Materials: EGSnrcMP BEAMnrcMP, well known documented Photon Transport simulation codes are used for therapy simulations. Previous measurements uptake ratio's provide a basis generating new radiation interaction cross sections use in transport Cross generated by software checked against using...

Purpose: The final goal of this research is to develop a patient repositioning system using 3D optical laser scanner. We investigated the magnitude human and errors, which determines accuracy system. also scanned four breast patients test efficacy Method Materials: A handheld surface scanning acquires images, are registered reference image rigid body transformation. resultant registration generates position adjustment match images. evaluated error associated with positioning technique. To...

Purpose: To determine if clinical variations in the Dosimetric Leaf Gap (DLG) or Transmission Factor (TF) are detectable a 3D secondary calculation, 1D log file‐based analysis hardware‐based quality assurance of realistic patient plans. Methods: DLG values and TF were selected based on surveys 17 clinics. The minimum, maximum, representative used generation 30 6MV Six patients created Eclipse 11 planned for three sites: SBRT Lung, Prostate, Prostate with Lymph Nodes(P/S/L). Each site was...