bluuebunny/crossref_metadata_2025_split huggingface dataset:
WE‐G‐207‐03: Mask Guided Image Reconstruction (MGIR): A Novel Method for Ultra‐Low‐Dose 3D and Enhanced 4D Cone‐Beam Computer‐Tomography
Authors: Park C , Zhang H , Chen Y , Fan Q , Kahler D , Li J , Liu C , Lu B 
Published: June 2015

Purpose:Recently, compressed sensing (CS) based iterative reconstruction (IR) method is receiving attentions to reconstruct high quality cone beam computed tomography (CBCT) images using sparsely sampled or noisy projections. The aim of this study is to develop a novel baseline algorithm called Mask Guided Image Reconstruction (MGIR), which can provide superior image quality for both low‐dose 3DCBCT and 4DCBCT under single mathematical framework.Methods:In MGIR, the unknown CBCT volume was mathematically modeled as a combination of two regions where anatomical structures are 1) within the priori‐defined mask and 2) outside the mask. Then we update each part of images alternatively thorough solving minimization problems based on CS type IR. For low‐dose 3DCBCT, the former region is defined as the anatomically complex region where it is focused to preserve edge information while latter region is defined as contrast uniform, and hence aggressively updated to remove noise/artifact. In 4DCBCT, the regions are separated as the common static part and moving part. Then, static volume and moving volumes were updated with global and phase sorted projection respectively, to optimize the image quality of both moving and static part simultaneously.Results:Examination of MGIR algorithm showed that high quality of both low‐dose 3DCBCT and 4DCBCT images can be reconstructed without compromising the image resolution and imaging dose or scanning time respectively. For low‐dose 3DCBCT, a clinical viable and high resolution head‐and‐neck image can be obtained while cutting the dose by 83%. In 4DCBCT, excellent quality 4DCBCT images could be reconstructed while requiring no more projection data and imaging dose than a typical clinical 3DCBCT scan.Conclusion:The results shown that the image quality of MGIR was superior compared to other published CS based IR algorithms for both 4DCBCT and low‐dose 3DCBCT. This makes our MGIR algorithm potentially useful in various on‐line clinical applications.Provisional Patent: UF#15476; WGS Ref. No. U1198.70067US00
WE‐G‐207‐06: 3D Fluoroscopic Image Generation From Patient‐Specific 4DCBCT‐Based Motion Models Derived From Physical Phantom and Clinical Patient Images
Authors: Dhou S , Cai W , Hurwitz M , Williams C , Rottmann J , Mishra P , Myronakis M , Cifter F , Berbeco R , Ionascu D , Lewis J 
Published: June 2015

Purpose:Respiratory‐correlated cone‐beam CT (4DCBCT) images acquired immediately prior to treatment have the potential to represent patient motion patterns and anatomy during treatment, including both intra‐ and inter‐fractional changes. We develop a method to generate patient‐specific motion models based on 4DCBCT images acquired with existing clinical equipment and used to generate time varying volumetric images (3D fluoroscopic images) representing motion during treatment delivery.Methods:Motion models are derived by deformably registering each 4DCBCT phase to a reference phase, and performing principal component analysis (PCA) on the resulting displacement vector fields. 3D fluoroscopic images are estimated by optimizing the resulting PCA coefficients iteratively through comparison of the cone‐beam projections simulating kV treatment imaging and digitally reconstructed radiographs generated from the motion model. Patient and physical phantom datasets are used to evaluate the method in terms of tumor localization error compared to manually defined ground truth positions.Results:4DCBCT‐based motion models were derived and used to generate 3D fluoroscopic images at treatment time. For the patient datasets, the average tumor localization error and the 95th percentile were 1.57 and 3.13 respectively in subsets of four patient datasets. For the physical phantom datasets, the average tumor localization error and the 95th percentile were 1.14 and 2.78 respectively in two datasets. 4DCBCT motion models are shown to perform well in the context of generating 3D fluoroscopic images due to their ability to reproduce anatomical changes at treatment time.Conclusion:This study showed the feasibility of deriving 4DCBCT‐based motion models and using them to generate 3D fluoroscopic images at treatment time in real clinical settings. 4DCBCT‐based motion models were found to account for the 3D non‐rigid motion of the patient anatomy during treatment and have the potential to localize tumor and other patient anatomical structures at treatment time even when inter‐fractional changes occur.This project was supported, in part, through a Master Research Agreement with Varian Medical Systems, Inc., Palo Alto, CA. The project was also supported, in part, by Award Number R21CA156068 from the National Cancer Institute.
WE‐G‐207‐08: Imaging Dose Reduction and Scatter Removal in Cone Beam CT Via Random Undersampling: A Simulation Study
Authors: Shen C , Chen L , Xu Y , Tian Z , Ng M , Zeng T , Lou Y , Zhu L , Jia X 
Published: June 2015

Purpose:Cone‐beam CT (CBCT) is widely used in image‐guided radiation therapy. The high imaging dose from repeated uses is a clinical concern and its image quality is impeded by a large amount of scattered photons. We propose to solve these two problems via a random undersampling method. We have performed Monte Carlo (MC) simulation studies for an initial test of the method.Methods:We propose to place a moving beam blocker with a random blocking pattern in front of the x‐ray source. It blocks a projection with a random pattern, which varies among projections. Scatter signal is measured in the deliberately created shadows, which is further interpolated to the entire projection. After removing the interpolated scatter from the total signal in the un‐blocked area, the cleaned data were used for CBCT reconstruction under a Tight Frame (TF) based iterative method. The random sampling yields a projection matrix that has a better numerical property compared to regular undersampling, permitting better image reconstruction.Results:360 CBCT projections of a head‐and‐neck cancer patient were generated via MC simulations. We first reconstructed CBCTs using 90 full projections with only primary data. The RMS error was 16%. When scattered photons were included in the projection, reduced contrast was observed and the RMS error was 22%. In our proposed method, 360 projections were used, but each of them was randomly blocked by 75% of pixels. Scatter estimation and was performed and the corrected data were used in reconstruction, yielding a reconstruction error of 15%. In these two approaches, the imaging doses were both reduced by ∼75% compared to a full scan with 360 unblocked projections.Conclusion:we proposed a method to solve the imaging dose and scatter problem in CBCT in a unified manner. Preliminary simulation studies demonstrated its efficacy.
WE‐G‐201‐00: Mobile Viewing Devices
Authors: Walz‐Flannigan Alisa 
Published: June 2015

Many health care organizations are adopting mobile applications for patient care. These tools can provide the opportunity for improvements in timely access to patient images. With new possibilities for patient image viewing, it is sensible to take a closer look at what handheld devices might provide and how they are being used.Three speakers: a radiologist, an imaging research scientist, and a clinical medical physicist provide input into different aspects of image viewing on handheld devices.1. Patrick Luetmer, M.D., RadiologistProvides a radiologist's perspective of how mobile technologies best fit into patient care workflows, including how patient image viewing is done differently on a mobile platform compared to a PACS workstation and what types of decisions are being made from handheld devices.2. Aldo Badano, Ph.D., Imaging Research ScientistProvides an overview of technological properties of handheld devices and describes how image viewing with handheld devices impacts the image information that is visible under ideal and clinical conditions.3. Dr. Alisa Walz‐Flannigan, Ph.D., Clinical Medical PhysicistProvides an overview of different strategies for setup and quality control as relevant for handheld devices.This session is related to the ongoing work of Task Group No. 260 “Considerations for the Use of Handheld Devices for Viewing Medical Images”.Learning Objectives:

To understand how mobile devices for image viewing are being used to enhance patient care
To understand how technological properties of various mobile devices combine with device usage to impact the information visible in a medical image
To gain awareness of different options for configuring and testing handheld devices for medical image viewing
Dr. Aldo Badano has the following: Cooperative Research and Development Agreement (CRADA #123‐07) with BARCO.
WE‐G‐201‐01: A Radiologist Perspective on Mobile View Devices
Authors: Luetmer P. 
Published: June 2015

Many health care organizations are adopting mobile applications for patient care. These tools can provide the opportunity for improvements in timely access to patient images. With new possibilities for patient image viewing, it is sensible to take a closer look at what handheld devices might provide and how they are being used.Three speakers: a radiologist, an imaging research scientist, and a clinical medical physicist provide input into different aspects of image viewing on handheld devices.1. Patrick Luetmer, M.D., RadiologistProvides a radiologist's perspective of how mobile technologies best fit into patient care workflows, including how patient image viewing is done differently on a mobile platform compared to a PACS workstation and what types of decisions are being made from handheld devices.2. Aldo Badano, Ph.D., Imaging Research ScientistProvides an overview of technological properties of handheld devices and describes how image viewing with handheld devices impacts the image information that is visible under ideal and clinical conditions.3. Dr. Alisa Walz‐Flannigan, Ph.D., Clinical Medical PhysicistProvides an overview of different strategies for setup and quality control as relevant for handheld devices.This session is related to the ongoing work of Task Group No. 260 “Considerations for the Use of Handheld Devices for Viewing Medical Images”.Learning Objectives:

To understand how mobile devices for image viewing are being used to enhance patient care
To understand how technological properties of various mobile devices combine with device usage to impact the information visible in a medical image
To gain awareness of different options for configuring and testing handheld devices for medical image viewing
Dr. Aldo Badano has the following: Cooperative Research and Development Agreement (CRADA #123‐07) with BARCO.
WE‐G‐201‐03: Setup, QC, and Usage Considerations for Mobile Image Viewing Platforms
Authors: Walz‐Flannigan A. 
Published: June 2015

Many health care organizations are adopting mobile applications for patient care. These tools can provide the opportunity for improvements in timely access to patient images. With new possibilities for patient image viewing, it is sensible to take a closer look at what handheld devices might provide and how they are being used.Three speakers: a radiologist, an imaging research scientist, and a clinical medical physicist provide input into different aspects of image viewing on handheld devices.1. Patrick Luetmer, M.D., RadiologistProvides a radiologist's perspective of how mobile technologies best fit into patient care workflows, including how patient image viewing is done differently on a mobile platform compared to a PACS workstation and what types of decisions are being made from handheld devices.2. Aldo Badano, Ph.D., Imaging Research ScientistProvides an overview of technological properties of handheld devices and describes how image viewing with handheld devices impacts the image information that is visible under ideal and clinical conditions.3. Dr. Alisa Walz‐Flannigan, Ph.D., Clinical Medical PhysicistProvides an overview of different strategies for setup and quality control as relevant for handheld devices.This session is related to the ongoing work of Task Group No. 260 “Considerations for the Use of Handheld Devices for Viewing Medical Images”.Learning Objectives:

To understand how mobile devices for image viewing are being used to enhance patient care
To understand how technological properties of various mobile devices combine with device usage to impact the information visible in a medical image
To gain awareness of different options for configuring and testing handheld devices for medical image viewing
Dr. Aldo Badano has the following: Cooperative Research and Development Agreement (CRADA #123‐07) with BARCO.
WE‐G‐210‐00: Advances in Breast Ultrasound Imaging
Authors: Duric Neb 
Published: June 2015

This session focuses on recent developments in breast ultrasound imaging, covering clinical practice as well as clinical and pre‐clinical research. Current status of ultrasound screening will be reviewed, followed by discussions of emerging technologies at various stages of regulatory and technical development. The session strives to provide the attendee with a view of a continuum of imaging advances starting with the present and spanning the near and long term future.Learning Objectives:

Understand current state of ultrasound screening for breast cancer
Learn about current availability of whole breast ultrasound
Appreciate the current barriers to stronger adoption of screening ultrasound
Learn about attempts to drive adoption of screening ultrasound (e.g. breast density laws)
Learn about ultrasound tomography as an emerging technique for breast imaging
Learn about the regulatory status of emerging techniques such as ultrasound tomography
Learn about the developmental status of combined 3‐D ultrasound and Mammography systems
Learn about photo‐acoustic imaging and its potential future role in breast imaging
WE‐G‐210‐02: Ultrasound Tomography: A Breast Imaging Modality Whose Time Has Come
Authors: Duric N. 
Published: June 2015

This session focuses on recent developments in breast ultrasound imaging, covering clinical practice as well as clinical and pre‐clinical research. Current status of ultrasound screening will be reviewed, followed by discussions of emerging technologies at various stages of regulatory and technical development. The session strives to provide the attendee with a view of a continuum of imaging advances starting with the present and spanning the near and long term future.Learning Objectives:

Understand current state of ultrasound screening for breast cancer
Learn about current availability of whole breast ultrasound
Appreciate the current barriers to stronger adoption of screening ultrasound
Learn about attempts to drive adoption of screening ultrasound (e.g. breast density laws)
Learn about ultrasound tomography as an emerging technique for breast imaging
Learn about the regulatory status of emerging techniques such as ultrasound tomography
Learn about the developmental status of combined 3‐D ultrasound and Mammography systems
Learn about photo‐acoustic imaging and its potential future role in breast imaging
TH‐A‐213‐00: Small Field Dosimetry: Overview of AAPM TG‐155 and the IAEAAAPM Code of Practice
Authors: Das Indra 
Published: June 2015

Modern radiotherapy techniques such as SRS/SRT, SBRT, IMRT, VMAT as well as specialized machines such as Tomotherapy, CyberKnife and Gamma Knife use small photon fields with at least one dimension <3 cm. Dosimetry in such small fields is challenging because of large detector perturbations due to non‐equilibrium conditions, occlusion of the primary photon source and large dose gradients across the field. Many small‐size dosimeters have been proposed for use in small fields. However, their characteristics especially the volume averaging and fluence perturbations have only recently been adequately understood. An IAEA‐AAPM working group has provided a framework for reference dosimetry in non‐compliant beams and the measurement of field output factors small fields (1). The AAPM TG‐155 (2) has adopted this framework to provide guidelines on relative dosimetry. This course explains the code of practice for absolute dosimetry that is under review and discusses the availability of correction factors to convert detector readings to doses. TG‐155 defines small field conditions, provides recommendations for suitable detectors and recommendations for good working practice for relative dosimetry (PDD, TMR, output factor, etc.) and dose calculations based on the new formulation. It also discusses beam modeling and dose calculations as a critical step in clinical utilization of small field radiotherapy.

Alfonso et al, Med Phys 35, 5179–5186 (2008).
Das et al, Med Phys (under review, 2014)
Learning Objectives:

Concepts and recommended procedures in the IAEA‐AAPM code of practice for dosimetry of small fields.
Physics of dosimetry in non‐equilibrium conditions and definition of small fields
Recommended procedures for relative dosimetry in TG‐1554.
Choice of detectors for small field dosimetry, perturbations and corrections for dosimetry
Understand the detector properties required for small field measurements
Understand the advantages and limitations of commercially available detectors for small field dosimetry
Research supported with operating grants from CIHR, NSERC, and BIOWin, a program funded at the Universite Catholique Louvain by the Walloon Government (Belgium). Student stipends supported by Medical Physics Research Training Network funded by the Collaborative Research and Training Experience program of the NSERC.Seuntjens: support by Sun Nuclear Corporation
TH‐A‐213‐01: Small Field Dosimetry: Overview of AAPM TG‐155
Authors: Das I. 
Published: June 2015

Modern radiotherapy techniques such as SRS/SRT, SBRT, IMRT, VMAT as well as specialized machines such as Tomotherapy, CyberKnife and Gamma Knife use small photon fields with at least one dimension <3 cm. Dosimetry in such small fields is challenging because of large detector perturbations due to non‐equilibrium conditions, occlusion of the primary photon source and large dose gradients across the field. Many small‐size dosimeters have been proposed for use in small fields. However, their characteristics especially the volume averaging and fluence perturbations have only recently been adequately understood. An IAEA‐AAPM working group has provided a framework for reference dosimetry in non‐compliant beams and the measurement of field output factors small fields (1). The AAPM TG‐155 (2) has adopted this framework to provide guidelines on relative dosimetry. This course explains the code of practice for absolute dosimetry that is under review and discusses the availability of correction factors to convert detector readings to doses. TG‐155 defines small field conditions, provides recommendations for suitable detectors and recommendations for good working practice for relative dosimetry (PDD, TMR, output factor, etc.) and dose calculations based on the new formulation. It also discusses beam modeling and dose calculations as a critical step in clinical utilization of small field radiotherapy.

Alfonso et al, Med Phys 35, 5179–5186 (2008).
Das et al, Med Phys (under review, 2014)
Learning Objectives:

Concepts and recommended procedures in the IAEA‐AAPM code of practice for dosimetry of small fields.
Physics of dosimetry in non‐equilibrium conditions and definition of small fields
Recommended procedures for relative dosimetry in TG‐1554.
Choice of detectors for small field dosimetry, perturbations and corrections for dosimetry
Understand the detector properties required for small field measurements
Understand the advantages and limitations of commercially available detectors for small field dosimetry
Research supported with operating grants from CIHR, NSERC, and BIOWin, a program funded at the Universite Catholique Louvain by the Walloon Government (Belgium). Student stipends supported by Medical Physics Research Training Network funded by the Collaborative Research and Training Experience program of the NSERC.Seuntjens: support by Sun Nuclear Corporation
TH‐A‐213‐02: IAEA/AAPM Code of Practice for the Dosimetry of Static Small Photon Fields
Authors: Seuntjens J. 
Published: June 2015

Modern radiotherapy techniques such as SRS/SRT, SBRT, IMRT, VMAT as well as specialized machines such as Tomotherapy, CyberKnife and Gamma Knife use small photon fields with at least one dimension <3 cm. Dosimetry in such small fields is challenging because of large detector perturbations due to non‐equilibrium conditions, occlusion of the primary photon source and large dose gradients across the field. Many small‐size dosimeters have been proposed for use in small fields. However, their characteristics especially the volume averaging and fluence perturbations have only recently been adequately understood. An IAEA‐AAPM working group has provided a framework for reference dosimetry in non‐compliant beams and the measurement of field output factors small fields (1). The AAPM TG‐155 (2) has adopted this framework to provide guidelines on relative dosimetry. This course explains the code of practice for absolute dosimetry that is under review and discusses the availability of correction factors to convert detector readings to doses. TG‐155 defines small field conditions, provides recommendations for suitable detectors and recommendations for good working practice for relative dosimetry (PDD, TMR, output factor, etc.) and dose calculations based on the new formulation. It also discusses beam modeling and dose calculations as a critical step in clinical utilization of small field radiotherapy.

Alfonso et al, Med Phys 35, 5179–5186 (2008).
Das et al, Med Phys (under review, 2014)
Learning Objectives:

Concepts and recommended procedures in the IAEA‐AAPM code of practice for dosimetry of small fields.
Physics of dosimetry in non‐equilibrium conditions and definition of small fields
Recommended procedures for relative dosimetry in TG‐1554.
Choice of detectors for small field dosimetry, perturbations and corrections for dosimetry
Understand the detector properties required for small field measurements
Understand the advantages and limitations of commercially available detectors for small field dosimetry
Research supported with operating grants from CIHR, NSERC, and BIOWin, a program funded at the Universite Catholique Louvain by the Walloon Government (Belgium). Student stipends supported by Medical Physics Research Training Network funded by the Collaborative Research and Training Experience program of the NSERC.Seuntjens: support by Sun Nuclear Corporation