bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phantom Materials in Radiology
Authors: Watanabe Yoichi , Constantinou C. 
Published: April 2006

AbstractIn radiology, phantoms are utilized to estimate radiation dose delivered to patients and evaluate the quality of imaging systems. Hence, the material of the phantoms should closely mimic the human tissue; in particular, the radiological characteristics of the material must be similar to that of the tissue. This article reviews materials used to manufacture phantoms for radiology applications. In the first section, basic physics relevant to the phantom material and radiation interaction with matter is discussed. A brief history of the phantom material for radiology is offered. The second section gives extensive discussion on the materials mainly developed by D.R.White, C.Constantinou, and co‐workers in late 1970s to early 1980s. Their materials were made based on epoxy resin. They produced tissue‐equivalent materials mimicking 15 different tissue types. Detailed description on manufacturing methods and the results of evaluation is presented. Since their seminal work other investigators developed tissue‐equivalent materials by using polyethylene and polyurethane as base. Short discussion on those newer developments is given. The third section presents, how those materials are used for radiation dosimetry, radiation therapy, and diagnostic radiology. Our discussion on applications will be limited to the phantoms used with photons and electrons since most medical applications utilize those particles. The last section is devoted to speculative discussion on what types of phantom and material will be developed in the near future.
Piezoelectric Sensors
Authors: Li Yanbin , Su Xiao‐Li 
Published: April 2006

Abstract
Piezoelectric sensors have been developed based on very established theories in electricity, mass, and viscoelasticity and with commercially available instruments such as quartz crystal microbalance. Piezoelectric sensors have shown their advantages over other sensors in terms of sensitivity, versatility, label free, low cost, and simplicity. They have been applied to the biomedical area mainly in the forms of immunosensors and genosensors for rapid detection of bacteria, viruses and proteins, and DNA/RNA hybridization, respectively. However, the detection limit and reusable electrodes of piezoelectric sensors need to be improved for more applications in biomedical analyses.
Polymeric Materials
Authors: Liu Xiaohua , Shanmugasundaram Shobana , Arinzeh Treena Livingston 
Published: April 2006

AbstractThis article aims to provide basic and contemporary information on polymeric materials used in medical devices and instrumentation. The fundamental concepts and features of polymeric materials are introduced in the first section. In the second section, the major commodity polymers used in medicine are reviewed in terms of their basic chemical and physical properties. The main part of this article, however, is devoted to polymers in biomedical engineering applications, including tissue engineering and drug delivery systems.
Radiation Dose Planning, Computer‐Aided
Authors: Li Jonathan G. , Xing Lei 
Published: April 2006

Abstract
Radiation therapy aims at delivering a desired radiation dose to the intended volume while limiting the dose to surrounding healthy tissues as much as possible. The purpose of treatment planning is to design treatment strategies to best achieve such goals, and to estimate the radiation dose throughout the irradiated volume before the start of the treatment. Thanks to the rapid developments in computer and medical imaging technologies, treatment planning can now be done efficiently under the guidance of the patient’s internal anatomy in three dimensions, incorporating possibly functional and metabolic information with ever increasing resolution and clarity. This article reviews key components in the computer‐aided radiation dose planning, including virtual simulation, image registration, three‐dimensional dose calculation, treatment plan optimization, and treatment plan evaluation, emphasizing specifically the impact of computer technology on these recent developments. As we are ascending into an era of image‐guided radiation therapy with computer‐controlled delivery and real‐time image guidance and feedback, advanced computer technology will play an ever increasingly significant role in radiation oncology.
Radiation Protection Instrumentation
Authors: Glasgow Glenn P. 
Published: April 2006

Abstract
This article describes common radiation protection instruments used around or with radioactive materials and equipment in medical facilities. This article describes availability of instruments and sources of information about their use; instruments for specific tasks; types and sources of radiation; international definitions of radiation quantities and units; and common features of instruments. The detection principles of ionization chambers, gas proportional counters, Geiger–Müeller detectors, scintillation detectors (solid, liquid, and plastic), solid‐state detectors (semiconductors, thermally, and optically stimulated luminescence phosphors), and photographic detectors are described. Worldwide web Internet addresses are given for some major instrument manufacturers and vendors. The bibliography lists the latest editions of relevant textbooks. Common medical uses of these instruments include equipment surveys; personnel and area monitoring; contamination surveys; locating misplaced radioactive sources; air sampling; responding to emergencies; and spectroscopy. Using recent data (2002) from the Committee on Data for Science and Technology, this article describes electrons, beta particles, alpha particles, protons, neutrons, X rays, γ rays, and some radionuclides commonly used in medicine. Fundamental terms (exposure, kerma, absorbed dose), internationally recommended definitions of terms used for radiation protection (equivalent dose, committed equivalent dose, effective dose, committed effective dose), and units (roentgen, gray, sievert) are described. Currently used personnel radiation monitors are described. Instrument electronic circuitry is discussed only briefly.
Radiation Therapy Simulator
Authors: Low Daniel A. , Mutic Sasa 
Published: April 2006

Abstract

Radiation therapy is a medical specialty for treatment of malignancies (tumors or neoplasms) with high doses of radiation using X rays, γ rays, electrons, protons, and neutrons. This field is rapidly evolving because of recent advances in the technology used for diagnosis, treatment planning, treatment delivery, and verification of patient treatments. One of the cornerstones of modern radiation therapy practice are volumetric patient image datasets from computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and ultrasound (US). Devices that produce the
primary
images for use in radiation therapy treatment planning are called
Radiation Therapy Simulators
. Current devices include (1) Conventional Simulators (based on conventional X‐ray radiography planar imaging); (2) CT‐simulators (based on CT scanners); (3) PET/CT‐simulators (based on PET/CT scanners); (4) MR‐simulators (based on MR scanners).

The radiation therapy simulator has been an integral component of the treatment planning process since the 1960s. Conventional simulators are designed to mimic the linear accelerator geometry while providing a diagnostic‐quality X‐ray beam for anatomic imaging. Because of the increased use of three‐dimensional (3D) imaging for treatment planning, conventional simulators are less popular than in the past. Still, this technology continues to be developed and retains its presence in most radiation oncology departments. Shortly after the introduction of clinical CT scanners in the early 1970s, it was realized that this imaging modality had much to offer in a radiation oncology setting because they provided a volumetric view of the patient’s normal and tumor anatomy with excellent spatial accuracy. In response, CT simulators were developed during the 1980s, and 1990s and today CT simulator is the main imaging device in radiation therapy. The CT simulators have developed to a point where CT scanner manufacturers are designing scanners specifically for CT simulation purposes. PET imaging can also provide valuable information about tumors and PET–CT scanners have been implemented as radiation therapy simulators and can be found in many radiotherapy centers. Finally, MRI scanners have also been implemented and are used for treatment simulation in radiation therapy. The MRI scanners are less commonly found in radiotherapy departments, but because of the imaging advantages that MRI has to offer it is expected that the use of MRI scanner for radiotherapy simulation will experience significant growth.
This article describes the radiation therapy simulation process, design and features of conventional, CT, PET–CT, and MRI simulators, and their use for treatment planning.
Radionuclide Production and Radioactive Decay
Authors: Jurisson Silvia S. , Miller William , Robertson J. David 
Published: April 2006

Abstract

Radionuclide production and radioactive decay are two important factors for the development and use of radiopharmaceuticals for nuclear medicine imaging and radiotherapy applications. Sufficient quantities of the radionuclides used in medicine must be available on a routine basis at a reasonable cost. The radioactive ingredient must be sufficiently pure (both radiochemical and radionuclidic) and have enough activity to provide the therapeutic activity or the image information. The selection of a particular radionuclide for a specific application is determined by the radioactive decay properties (half‐lives, particle emission(s), particle energies, photon emissions, photon energies) and the behavior of the radionuclide in the body. Imaging applications require emission of penetrating radiations (gamma or positron annihilation photons), whereas radiotherapy applications require emission of short‐ range, high linear energy transfer (LET) radiations (alpha, beta, Auger electrons). Therapeutic radionuclides should not have significant emissions of penetrating radiations (gamma or positron annihilation photons), however, low abundance gamma emissions allow tracking of the
in vivo
therapeutic dose and dosimetry calculations. The factors of radioactive decay and radionuclide production are discussed, with examples and emphasis being on those radionuclides with applications to nuclear medicine.
Radiopharmaceutical Dosimetry
Authors: Thierens Hubert M.A. 
Published: April 2006

AbstractIn nuclear medicine, radiopharmaceuticals are administered to patients for diagnosis and therapeutic purposes. In diagnostic nuclear medicine, patient dosimetry aims predominantly to assess the risk for late effects of ionizing radiation (e.g., cancer and leukemia). To this end, the medical internal radiation dose (MIRD) dosimetry protocol is applied adopting standard biokinetics of the radiopharmaceutical and a standard anatomy of the reference male or female for the patient. For treatment purposes high activities of disease‐specific pharmaceuticals labeled with β‐emitters are given, necessitating an accurate patient‐specific dosimetry. In general patient‐specific biokinetics are derived from sequential images after administration of a tracer activity and combined with the MIRD methodology to calculate absorbed doses to target and critical tissues. In a complete patient‐specific dosimetry approach the individual patient anatomy is also taken into account and derived from computed tomography (CT) or magnetic resonance imaging (MRI) imaging. Three‐dimensional (3D) absorbed dose estimates are then determined from single single photon emission computed tomography (SPECT) or positron emission tomography (PET) activity data using dose‐point kernel convolution methods or by direct Monte Carlo calculation. A first part of the paper deals with the principles of the MIRD protocol and microdosimetric considerations, especially applicable to diagnostic nuclear medicine. The second part describes the methodology of dosimetry in metabolic radiotherapy with emphasis on the radioiodine therapy for treatment of benign and malignant thyroid diseases, meta‐iodo benzyl guanidine(131I‐MIBG) therapy for neuroblastoma and radioimmunotherapy. Finally, the dosimetric principles in the risk estimation of volunteers after administration of radiolabeled compounds in the framework of the development of new drugs are discussed.
Radiotherapy: Particle Beams
Authors: Becchetti F. D. 
Published: April 2006

AbstractAn overview, including historical developments, of various types of particle‐beam radiotherapies is given. This overview also includes electron, proton, neutron, and heavy‐ion radiotherapy. The types of particle accelerators and related apparatus for these are described together with the radiological aspects of each type of particle beam. Possible future developments in the field are outlined.
Radiotherapy Treatment Planning, Optimization of
Authors: Wolbarst Anthony B. , Chin Lee , Stavrev Pavel 
Published: April 2006

Abstract
Radiotherapy treatment planning is becoming ever more complex, driven largely by the growing use of intensity modulated radiotherapy (IMRT). There is a corresponding need to improve the computer‐based programs being designed to optimize the process of planning the spatial and temporal distributions of dose for such treatments. This article reviews the general objectives of treatment planning, and also the various physical and biological/statistical criteria that have been explored to serve as the bases for optimization objective functions.
Rehabilitation, Computers in Cognitive
Authors: Abreu Beatriz C. , Seale Gary , Temple Richard O. , Sangole Archana P. 
Published: April 2006

AbstractThis research is supported, in part, by the National Institute on Disability and Rehabilitation Research (NIDRR) grant no. H133P990001. The authors express their sincere gratitude to the Moody Foundation and the Moody Endowment for their support of this work.
Rehabilitation and Muscle Testing
Authors: Durfee W.K. , Iaizzo P.A. 
Published: April 2006

Abstract
Measurement of muscle function and strength is an essential component of many neurological and physical exams. Such evaluation of muscle strength is necessary for differential diagnosis, to determine the presence of disability, to plan potential treatments, and to track the effectiveness of treatments. As outcomes‐based medical practice bocomes more prevalent, the need for quantitative outcomes assessment of muscle strength will become even more critical. Several assessment techniques and tools are currently available. Manual muscle testing is the most widely used method to assess muscle function, however, its reliability and accuracy are questionable. when greater accuracy of results is needed, instruments are available that provide precise readouts of resistive force that muscle works against (i.e., hand dynamometers, pinch grips, and computer‐controlled dynamometers). More advanced muscle asessment methods include mathematical modeling of muscle activity and electromyogram recording of skeletal muscle contractions. Finally, stimulated muscle force assessment is discussed as a versatile approach for quantitative involuntary muscle torque.
Sexual Instrumentation
Authors: Brunswig Newring Kirk A. , Draper Crissa , O’Donohue William 
Published: April 2006

AbstractThe measurement of human sexuality has recently centered on the dysfunctional and disordered, while the early work was directed at understanding and assessing the human sexual response. This article reviews the development of medical devices and instruments for the assessment and treatment of female sexual function and dysfunction; then our attention is turned to the assessment and treatment of male sexual function and dysfunction, and lastly, we review phallometry and other assessments related deviant sexual interest and arousal in the human male.Tremendous gains have been made in the last 50 years of research and development in the measurement of human sexuality. Unfortunately, these gains have occurred within a context of varied approaches, methodologies, and instruments. Despite several reviews and recommendations, there remain differing instruments, methodologies, and procedures in the physiological assessment of human sexuality. Furthermore, with the advent of more easily administered self‐report questionnaires, many outcome studies now rely on these self‐report measures, often ignoring the physiological aspects of sexual interest, arousal, and functioning.Further complicating research in this area is the lack of representativeness of human sexuality research volunteers in comparison with “normals”. Thus, we are left with an indeterminate field; what research we have may be based in part on participant variables, a lack of standard instruments in methodologies and procedures, which impedes cross‐study comparisons, and on continuing advances in technology, leading to the promulgation of new devices and instruments. There are several reliable, valid, and useful devices and instruments for the psychophysiological assessment of human sexuality, and there is hope that with advances in technology, some of the concerns sounded by the scholars and pioneers in human sexuality research will be addressed.
Shock, Treatment of
Authors: Decau Sabin , Mackenzie Colin F. 
Published: April 2006

AbstractShock is a state of inadequate O2supply. It has many causes that include hypovolemia, maldistribution of perfusion, and cardiac pump failure. The common end‐point of all causes of shock is deficient capillary perfusion that triggers metabolic changes in organs and tissues. Acid–base and blood gas measurements are a common global measure of these metabolic changes. Mean blood pressure, heart rate, sublingual capnometry, capillary refill time, and mental status changes are noninvasive measures that have been used to quantitate shock. Invasive measurements include pulmonary artery or central venous pressure changes in response to fluid challenge, blood sampling, and cardiac output measurement to calculate O2consumption, O2extraction, and O2delivery. Brain function can be monitored continuously by near‐infrared spectroscopy and cerebral oximetry, cardiac function by transesophageal echocardiogram, and renal function by urinary flow and creatinine clearance. But all these measures have drawbacks because of their invasiveness, lack of validation, or sensitivity as markers of shock. The future holds promise of proteomic diagnostic tools and identification of shock factors and mediators that may reverse the multiorgan effects of prolonged shock and reduce mortality and morbidity.
Spinal Cord Stimulation
Authors: Trentman Terrence L. , Weinmeister Kent P. 
Published: April 2006

Abstract
Spinal cord stimulation (formally known as dorsal column stimulation) is a minimally invasive technique of applying an electric current in the vicinity of the spinal cord. It is used primarily to treat refractory neuropathic (nerve injury) pain. Patients typically considered for treatment with this modality include those suffering from the failed back surgery syndrome, chronic regional pain syndrome (RSD and causalgia), phantom limb pain, and other neuropathic pain in the lower extremity. Upper extremity neuropathic pain has also been treated successfully with spinal cord stimulation. After an initial successful trial, permanent spinal cord stimulation is accomplished via either a percutaneously inserted polyurethane lead or a surgically inserted “paddle” lead. To power the lead, an implanted pulse generator or radio frequency receiver is inserted in a subcutaneous pocket in the low abdomen or buttock. The patient then controls the stimulator with a hand‐held device. Animal and human studies have suggested that spinal cord stimulation has multiple effects on the spinal cord and pain transmission. Outcome studies show that long‐term success with this modality is ∼ 50%. In recent years, the potential role of stimulation has expanded to include treatment of peripheral neuropathic pain such as occipital neuralgia, ischemic pain (e.g., angina and lower extremity vascular insufficiency), and stress urinary incontinence.
Sterilization of Biologic Scaffold Materials
Authors: Freytes Donald O. , Badylak Stephen F. 
Published: April 2006

AbstractBiologic materials are currently used for tissue and organ repair and are typically regulated as medical devices and subjected to established sterilization guidelines. Sterilization of biologic materials involves unique considerations that may have an impact on their performance and clinical utility. This article discusses the advantages, disadvantages, and physical effects upon synthetic and naturally occurring materials of four commonly used methods of sterilization: heat, ethylene oxide, gamma irradiation, and electron beam irradiation. Alternative methods of sterilization and disinfection are briefly discussed, with emphasis on methods typically used for naturally occurring biomaterials. The majority of the biologic materials currently available for clinical use are sterilized by exposure to either ethylene oxide (ETO) or ionizing radiation (IR). Although there are dose‐dependent effects associated with both ETO and IR, effective doses can be used with minimal effects upon the structure and function of naturally occurring biologic materials.
Physiological Systems Modeling
Authors: Smith N. Ty , Starko Kenton R. 
Published: April 2006

AbstractThis article discusses modeling as a device that you might use in research, education, or the practice of medicine or engineering. The purpose of the article is to allow you to explore, examine, and perhaps even use models, just as you would a device. Physiological models are almost unique among equipment, because a major use is education. Through physiological models, one can learn about physiology, pharmacology, scientific concepts, and clinical situations. The main way to use a model is through simulation or a simulator. We distinguish between simulation and simulators, the former being much more common. We usually give enough detail about a model so that the reader can decide whether to make the effort to locate the reference(s), author(s), and/or a simulator.The article is divided by systems. Each section describes some characteristics and peculiarities of the system, followed by a description of the models available, highlighting some of the ones that can be easily and inexpensively used. We concentrate on the central nervous, cardiovascular and thermal regulatory systems, mainly in the area of classical, or macro, physiology.The body and its systems depend on control systems, and these are emphasized, including the fascinating phenomenon of autoregulation, which has its own section. Autoregulation can be astoundingly simple or amazingly complex, but never completely independent of other regulatory systems.The past, present, and future of physiological systems modeling are also explore. The future is particularly exciting. The physiome project is to physiology what the genome project has been to genetics.