bluuebunny/crossref_metadata_2025_split huggingface dataset:
TU‐A‐M100J‐01: Quality Assurance and Acceptance Testing of Gamma Camera and SPECT Systems
Authors: Halama J 
Published: July 2007

The general purpose gamma camera and those configured for SPECT are the bread‐and‐butter imaging instruments in nuclear medicine, and remains the principle component in systems specifically designed for cardiac SPECT. Routine maintenance, calibration, and quality control of these imaging systems is crucial for providing the nuclear physician or radiologist images of high quality without artifact, the bane of nuclear medicine imaging. Acceptance testing, for the most part, provides baseline measurements that are used as reference data for future comparisons.Performance measurements and quality assurance testing of gamma camera and SPECT have been quite variable. The vendors are very specific about calibration procedures that are done one site, but the quality assurance testing by the customer are left up to the individual laboratories that vary to a large part based on the expertise of the staff. Federal and state radiation safety regulatory agencies purposely do not include any gamma camera quality assurance testing in their regulations. There are now two nuclear medicine accreditation programs, one by the American College of Radiology (ACR) and the other by the Intersocietal Commission for Accreditation of Nuclear Medicine Laboratories (ICANL), that have sought to standardize nuclear medicine imaging and quality assurance procedures performed. Also specified are the qualifications of the personnel who perform and interpret the imaging results.This lecture will provide an overview of the gamma camera and SPECT calibrations, performance measurements, and quality assurance tests, whether they are for acceptance testing or routine quality control. NEMA, ACR and ICANL accreditation program documents, and AAPM Task Group reports will be used as a backdrop for the presentation. A discussion of common image artifacts and how to avoid and correct them will also be included.Educational Objectives:1. Learn the basic gamma camera and SPECT performance measurements and quality assurance test procedures.2. Become familiar with the test procedures and the frequency of testing prescribed by the ACR and ICANL accreditation programs.3. Be able to identify common gamma camera and SPECT image artifacts and how to correct them.
TU‐A‐BRA‐01: EPID, MVCT
Authors: Pouliot J 
Published: July 2007

The Mega‐Voltage Cone‐Beam CT (MVCBCT) system provides a 3D image of the patient anatomy in the actual treatment position that can be tightly aligned to the planning CT, allowing daily verification and correction of the patient position moments before the dose delivery. Integrated onto a linear accelerator, the system consists of a new a‐Si flat panel adapted for MV imaging and a workflow application allowing the automatic acquisition of projection images at low dose rate, CBCT image reconstruction, CT to CBCT image registration and couch position adjustment. MVCBCT provides accurate electron density and allows studies of dosimetrical impact of setup error, anatomical changes or in presence of implanted metallic objects.This lecture will provide an overview of the physics characteristics of MV and MV CBCT imaging, acquisition and reconstruction, image registration, alignment precision and quality assurance procedures. A description of the workflow and a survey of the clinical applications, indications and protocols will be presented. Finally, current challenges and future developments will be addressed.Educational objectives1. Understand the basics of MV Cone‐Beam CT imaging.2. Understand the possibilities of daily 3D Imaging for patient alignment and other applications.3. Understand the clinical roles of Image‐Guided (IGRT) and Dose‐ Guided (DGRT) Radiation Therapy.This work was supported by Siemens Oncology Care Systems.
TU‐SAMS‐L100J‐02: Determination of Dose From CT Examinations: Estimating Organ Dose Using Monte Carlo‐Based Methods
Authors: McNitt‐Gray M 
Published: July 2007

Radiation dose from computed tomography has been an important issue for medical physicists for some time. This issue has increased in significance in the past several years due to advances in multidetector CT, which have resulted in increased utilization in areas such as pediatric CT, cardiac CT and even screening applications. Some of the key issues currently facing the medical physics community are assessing dose to patients from these various exams. One of the key building blocks to these assessments is the estimation of organ dose.The purpose of this presentation is to describe an approach to estimating organ doses to patients using Monte Carlo‐based simulation methods. In this approach, both the scanner and patient are modeled in some detail and a CT exam may be simulated.The detailed modeled of the CT scanner is created by including information such as the source spectra and filtration, its geometry, beam collimation and the path that the source travels around the patient (such as the path during a helical CT exam). The development, testing and validation of these models will be discussed.Patient models generally fall into two categories. The first consists of geometric descriptions of organs (based on cones, cylinders, etc.) such as the MIRD phantom. The second consists of voxelized descriptions of patient anatomy that are created based on actual patient scans. In these, radiosensitive organs are identified in the image data to create a voxelized model of the patient geometry. For both types of models, there are challenges to create models representing patients of different sizes, ages and genders.Once both the scanner and patient are modeled, then different scan protocols can be simulated using a Monte Carlo based software package (such as MCNP or EGS). This involves selecting a scanner model, a patient model and then selecting a set of technical parameters, such as one would do for an actual scan — including body region being examined, etc. The Monte Carlo software then simulates the specified scan and tallies absorbed dose in each voxel or geometric unit of the patient model, which then allows the calculation of either mean organ dose or the distribution of dose within an organ.In this presentation, the results of this approach in several applications will be described, including: (a) dose to the fetus in pregnant women of early, middle and late gestational ages, (b) comparing dose to glandular breast tissue from thoracic CT scans both with and without tube current modulation.Educational Objectives:1. Understand the Monte Carlo simulation based approach to estimating radiation dose to radiosensitive organs from CT scans.2. Understand the current limitations of the Monte Carlo based approach.3. Describe the results of some current applications of this approach to estimating fetal dose as well as breast dose reduction from tube current modulation.
TU‐SAMS‐AUD‐01: QA for Linacs and MLC Used for IMRT
Authors: Xia P 
Published: July 2007

Intensity‐modulated radiotherapy (IMRT) has become a part of our routine treatment for external beam radiotherapy. Most quality assurance procedures set for linear accelerators and multi‐leaf collimators (MLC) have been designed for conventional external beam radiotherapy. With IMRT, radiation portals are often irregular, small, off‐center, and abutting in the middle of the target volumes, which require specific IMRT QA for the linear accelerators and MLCs. Some of the QA issues are related to the specific IMRT delivery method, and the specific treatment planning system. This course will discuss: (1) the characteristics of three major MLC collimators and the specific QA related to the unique MLC design; (2) additional QA for linear accelerators pertinent to the small MU and small field sizes used in IMRT; (3) tools often used to perform these QA tasks; (4) specific QA issues for different IMRT delivery methods, step and shoot vs sliding window.Educational Objectives:1. Understand the characteristics of three major MLC systems.2. Understand different IMRT delivery methods and their specific QA issues.3. Understand effect of QA on the IMRT delivery accuracy.
TU‐B‐L100E‐01: Medical Response Planning for Nuclear/Radiological Emergencies: Roles of the Medical Physicist
Authors: Ansari A 
Published: July 2007

Medical health physicists working in a clinical setting have a number of key roles in preparing for and responding to a nuclear or radiological emergency, such as a terrorist attack involving a radiological dispersal device or an improvised nuclear device. Their first responsibility, of course, is to assist hospital administrators and facility managers in developing radiological emergency response plans for their facilities and train staff prior to an emergency. During a hospital's response to a nuclear or radiological emergency, medical health physicists may be asked to (1) evaluate the level of radiological contamination in or on incoming victims; (2) help the medical staff evaluate and understand the significance of the levels of radioactivity with which they are dealing; (3) orient responding medical staff with principles of dealing with radioactive contaminants; (4) provide guidance to staff on decontamination of patients and facilities; and (5) assist local public health authorities in monitoring people who are not injured but who have been or are concerned that they may have been exposed to radioactive materials or radiation as a result of the incident. Medical health physicists may also be called upon to communicate with staff, patients, and the media on radiological issues related to the event. The Centers for Disease Control and Prevention (CDC) is developing guidance in the areas of radiological population monitoring, handling contaminated fatalities, and using hospital equipment for emergency monitoring. CDC is also developing training and information materials that may be useful to medical health physicists who are called upon to assist in developing facility response plans or respond to a nuclear or radiological incident.Educational Objectives:1. Understand how the medical community will be involved in respond to a nuclear or radiological emergency.2. Understand key roles that medical health physicists can play in preparing for and responding to such emergencies.3. Learn what resources are available to assist medical health physicists and how these resources can be used.
TU‐B‐L100F‐01: Managing Patient Dose and Personnel Protection in Fluoroscopic Procedures
Authors: Balter S 
Published: July 2007

Fluoroscopically guided interventional procedures continue to grow both in numbers and in complexity. When individual procedures are clinically justified, their performance should be optimized to minimize the overall (radiogenic and non radiogenic) risks to both patients and staff. Medical physicists' contributions to this objective are in proportion to their knowledge and understanding of the interventional environment.This lecture will start with an overview of staff radiation safety. It will then emphasize patient radiation management, including the outline of an appropriate clinical program. It will conclude with a brief discussion on QA topics pertinent to interventional fluoroscopy.Educational Objectives:1. Understand the range of risks and benefits associated with interventional fluoroscopy.2. Establish appropriate staff and patient radiation management programs.3. Improve the routine physics QA process for interventional fluoroscopes.
TU‐B‐M100J‐01: Optimizing Mammography Image Quality and Dose: X‐Ray Spectrum and Exposure Parameter Selection
Authors: Williams M , Raghunathan P , Seibert JA , Kwan A , Lo J , Samei E , Ranger N , Fajardo L , McGruder A , Maxwell S , Maidment A , Yaffe M , Bloomquist A , Mawdsley G 
Published: July 2007

Optimization of exposure parameters (target, filter, and kVp) in digital mammography necessitates maximization of the image signal‐to‐noise ratio (SNR), while simultaneously minimizing patient dose. The goal of this talk is to compare, for each of the major commercially available full field mammography (FFDM) systems, the impact of the selection of technique factors on image SNR and radiation dose for a range of breast thickness and tissue types. The comparison will be based on the results of a multi‐center phantom study. The five commercial FFDM systems tested, the Senographe 2000D from GE Healthcare, the Mammomat Novation from Siemens, and the Selenia from Hologic, the Fischer Senoscan, and Fuji's 5000MA used with a Lorad M‐IV mammography unit, are located at five different university test sites. Performance was assessed using all available x‐ray target and filter combinations and nine different phantom types (three compressed thicknesses, and three tissue composition types). Each phantom type was also imaged using the automatic exposure control (AEC) of each system to identify the exposure parameters used under automated image acquisition. The figure of merit (FOM) used to compare technique factors is the ratio of the square of the image SNR to the mean glandular dose (MGD). The results show that, for a given target/filter combination, in general FOM is a slowly changing function of kVp, with stronger dependence on the choice of target/filter combination. In all cases the FOM was a decreasing function of kVp at the top of the available range of kVp settings, indicating that higher tube voltages would produce no further performance improvement. For a given phantom type, the exposure parameter set resulting in the highest FOM value was system‐specific, depending on both the set of available target/filter combinations, and on the receptor type. Noise performance differed noticeably among the FFDM systems and played an important role in determining relative FOM values. In most cases, the AECs of the FFDM systems successfully identified exposure parameters resulting in FOM values near the maximum ones, however there were several examples where AEC performance could be improved.Educational Objectives:1. become familiar with the effect of changing kVp, target material, and filtration on the mean glandular dose for a variety of breast.2. become familiar with the effect of changing kVp, target material, and filtration on image signal and noise for specific commercial FFDM systems.3. learn how the exposure technique factors selected for a variety of breast types by the AECs of current FFDM systems compare with the technique factors resulting in optimal FOM values.
TU‐B‐BRA‐01: CE: Functional/Molecular Imaging: PET for Planning/assessment
Authors: Bourland J , Jeraj R 
Published: July 2007

Purpose: Positron Emission Tomography (PET) images show physiological and biological information through the in vivo distribution of radioactive, positron‐emitting agents. PET imaging shows focal and distributed regions of cancer and its metastases. Initial PET uses in oncology include diagnosis and staging, which are important for determining treatment decisions. Current PET uses now include target definition for radiation planning followed by PET‐based assessment of treatment. Hybrid PET‐CT devices are beginning to be used as radiation treatment simulators. Method and Materials: F‐18‐labled Fluoro‐deoxyglucose (F‐18 FDG) is the most commonly used PET imaging agent. FDG shows regions of active glucose metabolism, such as local cancer, metastases, non‐cancer inflammation, and normal glucose use. Non‐FDG PET agents can be more specific in cell targeting (binding), and can image different aspects of tumor biology, like hypoxia (FMISO, CuATSM) and cell proliferation (FLT) Results: PET imaging has coarse spatial resolution compared to CT and MR. PET's clinical use is valued because of its great sensitivity for cancer detection. Voxel intensity and image fidelity depend on equipment design, patient size, anatomic site, and imaging study parameters. PET‐CT units enable CT‐based attenuation corrections and inclusion of CT information in a registered PET‐CT dataset. The Standardized Uptake Value (SUV) is a normalized intensity measure for quantitative indication of disease, and can be used to identify disease or possibly for target delineation, with certain limitations. While FDG remains the most promising agent for tumor detection, other, biologically more specific agents (e.g., FMISO, CuATSM for hypoxia imaging or FLT for cell proliferation imaging) might be more appropriate for target delineation and treatment assessment. Conclusion: This course reviews PET‐CT hybrid scanning devices, uses of FDG and non‐FDG PET for oncology imaging, and quantitative aspects for PET‐based radiation target definition and treatment assessment. Example images demonstrate the potential contributions and limitations of FDG and non‐ FDG PET oncology imaging. This review course is intended for both imaging and radiation oncology physicists.Educational Objectives1. Describe FDG PET imaging and oncologic indications.2. Review the uses and limitations of PET images in radiation treatment.3. Describe the SUV and other threshold parameters for target delineation.4. Review non‐FDG PET imaging of tumor biology.5. Discuss quantitative aspects of PET imaging for treatment assessment.Conflict of Interest: (JDB) Research sponsored in part by Varian Medical Systems.
TU‐B‐BRB‐02: Monte Carlo — II: Application of Monte Carlo to Clinical IMRT Treatment Planning
Authors: Siebers J 
Published: July 2007

The goal of this course is to familiarize participants with the clinical use of Monte Carlo (MC) dose calculation algorithms in IMRT photon‐beam treatment planning. Particular focus will be applied to the actual and potential clinical impact of MC dose calculation algorithms on patient treatments. Following a brief description of the integration of MC algorithms with commercial planning systems, MC dose re‐calculation results will be compared with plans computed using the conventional commercial treatment planning system algorithms. Specific patient examples where MC computed doses differ significantly from those computed with standard treatment planning system algorithms will be presented, with the causes of the dose discrepancies identified. With this background, the roles that MC has played in actual clinical practice will be described: as a QA tool to validate treatment planning system algorithms, as a QA tool to validate individual IMRT plans, and as a treatment planning tool to improve conformity between optimized and delivered IMRT plans. Strategies to minimize MC dose calculation time during IMRT optimization will be described.Educational Objectives:1. To instruct clinical physicists regarding roles of Monte Carlo dose calculations for clinical IMRT patient treatment planning.2. To describe the role of Monte Carlo in IMRT treatment planning system and patient specific quality assurance.3. To describe clinical cases where Monte Carlo dose calculation either resulted —or would have resulted— in a change in the clinical treatment.4. To describe the applications of and impact of Monte Carlo dose calculations for IMRT optimization.5. This work was sponsored in part by Philips Medical Systems and Varian Medical Systems.
TU‐C‐L100J‐03: Radiation Dose Reduction in Interventional Cardiology Using a Fixed Circular Collimator Attached to Cardiovascular Angiography System with Flat Panel Detector
Authors: Fukuda A , Yamaguchi I 
Published: July 2007

Purpose: Fixed Circular Collimator employed in cardiovascular angiography system with flat panel detector was developed to reduce radiation dose to both patient and cardiologist in coronary intervention. This study was designed to assess the radiation dose reduction using this new collimator. Method and Materials: This new collimator makes the radiation field circular and has tapered aluminum to reduce radiation dose at peripheral field.1. Entrance air kerma with backscatter (patient) and personnel dose equivalent (Hp) to cardiologist (scattered radiation dose) were measured to verify the radiation dose reduction using fixed circular collimator under a fixed geometric arrangement. The PMMA phantom was employed to simulate the patient thickness varying from 1.0 cm to 35.0 cm in increments of 1.0 cm. Upon completion of the data acquisition, entrance air kerma and Hp to cardiologist were plotted against the phantom thickness.2. Entrance skin regions (patient) were imaged to verify the overlap region reduction under ten routine angulations (RAO30, RAO10‐CAU30, RAO30‐CAU30, RAO30‐CRA30, LAO10‐CRA30, LAO20‐CRA30, LAO30‐CRA30, LAO45‐CRA30, LAO45, and LAO45‐CAU30). All tabletop position for every angulations were set up to image the heart center of chest phantom, subsequently, chest phantom was replaced by computed radiography and irradiated 1 sec. Results: Entrance air kerma and Hp to cardiologist were reduced by 8.0 % and 47.6 %, respectively. On the other hand, the overlapping region of skin was also reduced considerably. Conclusions: Due to the use of fixed circular collimator, entrance air kerma, the overlap region of exposed skin and Hp to cardiologist were decreased concurrently. It was considered that the use of fixed circular collimator makes the lower density of backscatter and region of interest optimize. Therefore, rectangular images should be reconsidered for safer coronary intervention. Although this study doesn't include image quality evaluation, cardiologists adopt this new collimator in clinical study currently.
TU‐C‐L100J‐08: Image Quality and Dose in Large Bore CT
Authors: Boedeker K , Mather R , MacLeod M 
Published: July 2007

Purpose: As large bore CT scanners are becoming more prevalent in the marketplace, so have questions about the image quality and dose associated with these scanners. The aim of this work is to compare the image quality and dose characteristics of a large bore 16‐slice CT scanner with a standard 16‐slice CT scanner. Methods: Two CT scanners, a large bore CT (Aquilion Large Bore, Toshiba) and a standard 16‐slice CT (Aquilion 16, Toshiba) were compared with respect to noise, spatial resolution, CT number accuracy, and low contrast. The technique factors on the large bore were adjusted to yield the same dose as a standard abdominal protocol on a standard 16‐slice scanner. Noise was measured on a 24cm water phantom, spatial resolution via the Fourier transform of bead, CT number via several known materials contained in a 32cm diameter phantom, and low contrast via a traditional low contrast phantom. Dose was measured via standard CTDI measurements. Results: The large bore required an increase in mAs of approximately 30% to yield the same dose as a standard 16‐slice scanner. After this adjustment was made, the image quality metrics for both scanners were identical. Conclusion: The large bore CT in this study yielded the same image quality in all four categories as the standard 16‐slice protocol.K. Boedeker, R. Mather, and M. MacLeod are employees of Toshiba America Medical Systems.