bluuebunny/crossref_metadata_2025_split huggingface dataset:
MO‐A‐352‐01: Fluoroscopic Imaging Equipment
Authors: Rauch P 
Published: July 2008

Modern fluoroscopy imaging equipment is designed to simultaneously monitor x‐ray beam attenuation, detector exposure rate, contrast‐to‐noise ratio, x‐ray generator parameters, and x‐ray tube loading. Knowledge of system design is essential to understanding equipment operation; and understanding equipment operation can facilitate optimization of performance. Under pre‐programmed control, fluoroscopy systems automatically make adjustments to the parameters controlling x‐ray production, beam filtration, detector signal output, digital image processing, and image presentation. The result is that reduction of patient dose does not necessarily require a loss of image quality.Optimizing performance begins with the determination of which system parameters are dynamically controlled, and the identification of the trigger points for changes in these parameters. Secondly, an understanding of how system parameters affect each other, affect image quality, and affect patient dose can lead to better choices in how the system should be set up for specific applications. This presentation will systematically describe the functions of the major system components including automatic exposure rate control, variable pulse‐rate fluoroscopy, generator operating curves, spectral beam filtration, and other factors that affect the ability of the imaging system to deliver optimum diagnostic images at moderate patient dose.Educational Objectives:1. Provide an understanding of modern fluoroscopic imaging system component design and functionality.2. Describe specific ways in which equipment settings can enhance or detract from optimum performance.
MO‐B‐350‐01: Functional/Molecular Imaging: PET for Treatment Planning and Response Assessment
Authors: Jeraj R , Machtay M 
Published: July 2008

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 Objectives:1. 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.
MO‐B‐AUD A‐01: Quality Assurance in Stereotactic Radiosurgery and Fractionated Stereotactic Radiotherapy
Authors: Shepard D , Solberg T 
Published: July 2008

In the 50‐plus years since it was first introduced, stereotactic radiosurgery, high‐dose irradiation of cranial neoplasms delivered in a single fraction, has become a standard of care in the treatment brain tumors, vascular malformations, functional disorders, and pain. Modern radiosurgery can be performed non‐invasively and on an outpatient basis, yet with an extremely high degree of accuracy. Within the past ten years, the field of radiosurgery has seen numerous technological enhancements, including: the development of dedicated devices for stereotactic delivery, the use of relocatable frames to facilitate fractionated delivery, the development of image guided and “frameless” approaches, and the application to extracranial tumor sites. Each of these developments is accompanied by its own challenges in assuring targeting and dosimetric accuracy. In this presentation we review the technologies for stereotactic localization and treatment of cranial targets with particular emphasis on the quality assurance aspects associated with establishing and maintaining a clinical radiosurgery program.Educational Objectives:1. Differentiate how radiation is delivered for Gamma Knife and Linac‐based (conventional and robotic) stereotactic radiosurgery.2. Define the treatment planning parameters for Gamma Knife and Linac‐based stereotactic radiosurgery.3. Discuss measures for assuring accuracy in stereotactic localization and dose delivery for Gamma Knife and Linac‐based stereotactic radiosurgery.
MO‐B‐351‐01: Dual Energy CT: Physics Principles
Authors: Pelc N 
Published: July 2008

Recent advances in CT scanner technologies have generated a great deal of interest in dual energy CT. The basic research on the fundamental principles, however, dates back to the 1970's, and that work in turn was based in part on even earlier work on x‐ray absorptiometry. The purpose of this presentation is to discuss the basic physics principles of multi‐energy x‐ray methods for material characterization, and the strengths and limitations of the techniques and the various implementations.A single energy CT image cannot possibly fully characterize materials. At best it is an image of the linear attenuation coefficient at one energy, and it is well‐known that this does not uniquely identify the tissue. The x‐ray attenuation of materials with different atomic numbers has different energy dependence, and the concept behind multi‐energy imaging is to measure the x‐ray attenuation properties at different energies to more fully characterize the material. At first glance one might assume that measurements at N energies would enable the separation of the object into N component materials. However, an important limitation to the ability of x‐ray attenuation measurements to fully characterize materials is the fact that in the diagnostic energy range the attenuation of all materials is dominated by Compton scattering and photoelectric absorption, and, unless there is an absorption edge in the energy range used, these x‐ray interaction mechanisms have the same energy dependence for all materials. Under these conditions, there are really only two “basis functions” and multi‐energy CT essentially measures the effective atomic number and the electron density of the material. This leaves us with considerable residual ambiguity as to what the material is. Also, measurement noise limits the ability to measure small changes in atomic number.The main requirement for dual energy CT is to measure projection data using two x‐ray spectra. There are several implementations available. These include systems that obtain measurements at multiple kVp and/or filtration. There are also methods in which the x‐ray energy discrimination is performed at the detector. These include layered detectors and photon counting systems with energy analysis. These various approaches to obtaining energy dependent measurements have different dose efficiency and different sensitivity to subject motion.There are two main ways to process the multi‐energy data. The simplest method reconstructs CT images from the data with each spectrum and performs the multi‐energy analysis on the values in the reconstructed images. The energy dependent processing can alternatively be applied to the measured projections prior to reconstruction. This latter method is somewhat more complicated but provides additional benefits, such as an implicit beam hardening correction.Research sponsored by GE Healthcare.
MO‐B‐351‐02: Dual‐Energy CT: Dual‐KV Techniques and Clinical Applications
Authors: McCollough C 
Published: July 2008

In CT imaging, materials having different chemical compositions can be represented by the same, or very similar, CT numbers, making the differentiation and classification of different types of tissues extremely challenging. In dual energy CT, an additional attenuation measurement is obtained at a second energy, allowing the differentiation of the two materials. Previously implemented in the 1980s, dual‐kV techniques are again available on clinical CT systems, accomplished with either slow or fast tube potential switching or dual‐source methods. The fundamental principles of dual‐kV techniques and their relative strengths and weaknesses will be reviewed. Clinical applications of dual‐kV CT imaging will be described, including: 1) automatic removal of bony anatomy, including calcified plaque, from a CT data set; 2) semi‐quantitative indication of the perfused blood volume in lung parenchyma or the myocardium; 3) removal of the iodine signal from contrast‐enhanced CT data, which may allow for the elimination of the non‐contrast scan phase in some exams; and 4) characterization of tissue by its chemical composition, as in the discrimination of uric acid from calcium‐containing renal stones.Educational Objectives:1. The technical approaches to dual‐kV, dual‐energy CT currently implemented or under investigation on commercial CT systems.2. The technical strengths and weaknesses of each approach.3. What clinical applications are currently in use or under investigation.
MO‐B‐352‐02: Multi‐Modality Imaging: Physics and Technology Considerations in Diagnostic and Image‐Guided Procedures
Authors: Siewerdsen J 
Published: July 2008

Medical imaging technologies that combine the capabilities of two or more imaging modalities are becoming increasingly important in the diagnosis, staging, treatment, and monitoring of disease. In particular, the combination of morphological imaging modalities (e.g., x‐ray, CT, ultrasound, and MR) with functional or molecular imaging modalities (e.g., optical, PET, SPECT, and functional MR) offers synergistic advances. This session provides an overview of technical and physical aspects of such developments, reviews the most prevalent technologies under consideration, addresses the challenges and limitations of such technologies, and discusses the opportunities for future research in multi‐modality imaging. Example multi‐modality approaches include x‐ray / ultrasound, CT / PET, MR / PET, and Optical / CT. Applications include pre‐clinical imaging, diagnosis and staging, image guidance, and treatment response monitoring.Educational Objectives:1. An understanding of the technical and physical factors of multi‐modality image quality, registration, and accuracy.2. An understanding of the challenges and potential opportunities associated with various multi‐modality imaging technologies.3. An understanding of the various clinical applications enabled by such technologies.
TU‐A‐351‐01: Small Animal Magnetic Resonance Imaging: Current Trends, Challenges and Perspectives for Pathological Imaging
Authors: Quarles C 
Published: July 2008

The utilization of magnetic resonance imaging (MRI) in the study of animal models of human pathology began more than 30 years ago. The continual advancement of imaging technology along with the increasing demand for tools to non‐invasively and serially assess disease progression and/or regression in small animals has driven this field forward since its inception. Standard clinical MRI scans primarily focus on disease detection and are based on anatomical and morphological abnormalities, whereas small animal MRI studies center on the serial characterization of the morphological, functional and molecular properties of diseased tissue. Small animal MRI studies often employ novel contrast mechanisms and exogenous chemical reagents, higher magnetic field strengths, higher spatial resolution and multi‐modality imaging but are complicated by issues such as low signal‐to‐noise ratios, enhanced sensitivity to respiratory and susceptibility artifacts, anesthesia‐induced alterations of disease physiology and demanding data processing requirements.This lecture will provide an overview of the role of small animal MRI in studying human disease, the technical and experimental challenges of such studies and how it could be used in the future to impact clinical treatment planning.Educational Objectives:1. Understand the role small animal MRI plays in understanding human disease and its impact on the development and validation of novel therapeutic strategies.2. Understand the issues and challenges related to a small animal MRI experiment including design, data acquisition and processing.3. Understand the future directions and potential advancements currently being pursued in small animal MRI.
TU‐A‐352‐01: Fluoroscopic Dose Measurement and Management
Authors: Balter S 
Published: July 2008

Radiation usage during fluoroscopically guided interventions can be high enough to warrant careful dosimetry and patient management. Basic compliance with the usual set of local regulatory requirements may not be sufficient for patient safety. Many of these rules date back to an era in which fluoroscopy was used for simple diagnostic procedures. The X‐ray tubes of this earlier era often overloaded and shut down before dangerous doses were delivered. Neither of these suppositions are currently valid. For example, modern systems meeting all regulatory dose restrictions are capable of delivering table top air kerma rates exceeding 200 mGy/min for normal mode fluoroscopy and 1,500 mGy/min for cinefluorography.Clinical dosimetry during each complex intervention is facilitated by dosimetric instrumentation built into the fluoroscopic system. The FDA now requires such instrumentation in all new fluoroscopes. The Society of Interventional Radiology has published a standard of practice recommending dosimetry for all interventional procedures. The DICOM‐DOSE project, a joint initiative of DICOM and the IEC will shortly provide tools for automated dose reporting. The Joint Commission has included fluoroscopic procedures with skin doses exceeding 15 Gy in its list of sentinel events; with the implicit challenge to facilities that they can prove the absence of such occurrences.This course reviews technical elements needed in a program of patient fluoroscopic radiation safety. Key concepts include: ICRU diagnostic dosimetric quantities and their fluoroscopic extensions FDA and IEC compliance measurements.Construction dosimetric features, and performance of modern fluoroscopes Extended QA protocols for compliance measurements, system characterization and clinical dosimetry. Dose recording and reporting, including DICOM‐DOSE. The Joint Commission fluoroscopy sentinel event.Educational Objectives:1. Understand dosimetric concepts relating to interventional fluoroscopy.2. Characterize the dosimetric features and performance of a modern fluoroscope.3. Be able to set up a clinical dose recording and reporting policy that will meet clinical and JC requirements.
TU‐B‐351‐01: Optimizing CT Examination Protocols with Respect to Image Quality and Radiation Dose
Authors: Kofler J , Cody D 
Published: July 2008

CT technology continues to develop at a rapid pace, offering imaging options and features that can dramatically improve image quality. Multichannel systems are now standard and the number of channels and image acquisition options continues to increase, allowing greater coverage per rotation, shorter scan times, and thinner images. Isotropic volumetric data acquisition permits retrospective reconstructions of many different image thicknesses and reformats can be created through multiple planes. These and many other advances have escalated and expanded the utility of CT imaging as a core diagnostic tool.However, coupled with the improved CT technology is the increased complexity of operating the scanners and the elevated potential of increasing the radiation dose. CT operators must choose from multiple options, many of which are interdependent, for the control of the multitude of available features. The impact of each of these options on image quality and radiation dose can range from subtle to substantial, and may not necessarily be obvious to the operator.This lecture will focus on the clinical implications of CT scan parameters and provide guidance on achieving an optimal compromise between image quality and radiation dose when constructing CT scan protocols.Educational Objectives:1. Understand the influence of primary CT scan parameters on image quality and radiation dose.2. Learn how to use imaging task‐specific priorities with consideration for radiation dose when determining scanner settings.
TU‐B‐352‐01: Quantification of 3‐D PET/CT Imaging
Authors: Saffer JR , Scheuermann JS , Karp JS , Perkins A 
Published: July 2008

In oncology, imaging studies play an increasingly important role in assessing patients' response to treatment. Serial CT scans of a patient are evaluated for changes in the number and size of tumors, while serial PET scans are assessed for changes in the metabolic activity of the lesions. The advent of combined CT and PET systems streamlines the fusion of these anatomic and functional images. However there are many confounding effects that complicate quantification in 3D PET/CT imaging.This lecture will review these sources of variability in the data, grouped into three broad categories: patient‐related factors (e.g. dose uptake time before imaging, blood glucose level, body habitus); instrument‐related factors (spatial and energy resolution, sensitivity, data acquisition mode (2D or 3D), attenuation and scatter correction method, image reconstruction algorithm, respiratory and cardiac motion‐correction method); and operator‐related factors such as acquisition and reconstruction protocols, instrument and image quality control, instrument calibrations, and method of image analysis. The impact of these variables on quantification will be discussed, with particular emphasis on how to minimize those that are controllable.The presentation will conclude with a review of current efforts by government agencies, professional organizations, academic institutions, and sponsors of multicenter trials to grapple with the additional complexities that arise from combining data from multiple patients at multiple sites. Research partially supported by the American College of Radiology Imaging Network (ACRIN).Educational Objectives:1. Understand the scope of the problems inherent in using PET/CT imaging to detect changes in patient response to treatment.2. Understand the factors that affect the variability and accuracy of PET/CT quantification.3. Understand the importance of minimizing variability in order to enhance the ability to identify non‐responders to treatment over ever‐shorter time intervals.4. Understand the efforts currently underway to standardize acquisition and processing protocols and to monitor equipment performance through credentialing and periodic quality control checks.
TU‐C‐350‐01: Review of Task Group Reports for Their Impacts On Clinical Practice
Authors: Chan M 
Published: July 2008

This review task was initiated under the direction of the Clinical Practice Committee of the Professional Council of the AAPM. Some of the Task Group (TG) reports published by the AAPM present a wide range of comprehensive performance tests or QA processes for a particular radiological modality or procedure. Limited by available resources and given the range of clinical uses, full‐time clinical physicists of many medium and small centers often find it difficult to determine the minimum subset of a complete TG report to follow to ensure consistent high quality of patient care and procedure maintenance. Furthermore, state regulators have, in some instances, unfortunately adopted entire sections of TG reports as regulatory requirements despite the clarification in all TG reports that such use would be inappropriate. Therefore, Minimum Practice Recommendations (MPR) should be established and be charged by the new Practice Guideline Subcommittee. The MPRs are intended to provide the AAPM members with a set of requirements for a basic standard of medical physics practice that AAPM would consider necessary in all sizes of clinical practice sites. These MPRs are not designed to replace extensive clinical practice guidelines, TG reports or review articles, but rather to describe minimum common standards. The establishment of MPRs is an important expression of AAPM's mission to disseminate knowledge, in order to maintain a high common standard in medical physics practice. The Subcommittee is charged with reviewing TG reports prior to publication, and determining which reports would benefit from an accompanying Implementation Guideline.Educational Objectives:1. Understand the benefits of reviewing TG reports by the Professional Council.2. Understand the concept of Minimum Practice Recommendation (MPR).3. Understand the guidelines and issues related to the establishment of MPR.
TU‐C‐AUD A‐01: Experience with IGRT Research, Development, and Clinical Implementation
Authors: Sharpe M 
Published: July 2008

At one point or another, almost everyone has recognized a problem and generated ideas they believe would improve clinical practice. In essence, this is what drives the desire to generate technical and clinical research, and translate findings into clinical practice. Some ideas become “practice changing” when the problem is important enough; the ideas compelling; and the right combination of skills, resources, and motivation are brought to bear. Geometric uncertainties in radiation therapy delivery represent an important problem and a fertile area of investigation that captures imaginations in clinical practice, academic research, and industry. This presentation will relate some experiences of participating in the development of image‐guided radiation therapy (IGRT) solutions.Educational Objectives:1. To demonstrate the importance of a team approach in making research ideas into clinical practice.2. To illustrate some essential lessons learned from IGRT research and development.3. To review some common institutional practices used to assess patient safety and the protection of ideas.