No abstract available

No abstract available

[en] Custom-designed yttrium filters were installed on three General Electric CT/T 98000 CT scanners. Measurements were made before and after installation of the yttrium filters. The phantom test evaluations included: radiation exposure, high contrast spatial resolution, low contrast detectability, and CT number linearity/calibration. The reduction in exposure obtained for lucite head and body phantoms ranged from 22% to 27% on the surface and from 13% to 23% at the phantom center. The conclusion drawn is that no detrimental effect on image quality was observed through comparative analysis of the image parameters evaluated, nor were any differences in the quality of the pre- post-filter clinical images reported by the radiologists

[en] In this work, the care and testing of measurement and diagnostic instruments are described in detail. Difficulties encountered with therapeutic and diagnostic calibrations are explored and solutions are suggested. Volume I: Measurement of exposure and calibration of ion Chambers. Radiation Detectors in Radiotherapy. The Assay of Beta and Gamma Sources in Medicine and Biology. Statistical and Error Analysis in Medical Physics. Calibration of Low Energy X-Ray Units (10 to 100 KV). Calibration of Medium Energy X-Ray Units (10 to 300 KV). Calibration of Megavoltage X-Ray and Co-60 Units Used in Radiotherapy. Calibration of Megavoltage Electron Radiotherapy Beams. Routine Clinical Dosimetry. Brachytherapy Dosimetry. Neutrons and Heavy Charged Particles Used in Radiation Therapy. Time, Dose Fractionation and Volume Relationships in Radiotherapy. Index

[en] Bone scintigraphy and radiography were performed in seven children with back pain. Six of the children with radiographic evidence of a pars interarticularis defect also had abnormal scintigrams. Increased uptake of the bone imaging agent occurred at six of the ten sites of radiographic pars interarticularis defects, implying increased bone metabolic activity. However, the location of scintigraphic abnormalities did not correspond to the location of radiographic abnormalities in several cases. Possible explanations for the discordant findings are: (a) normal bone metabolism at the site of an old spondylolysis and (b) radiographically inapparent stress fractures. Measurements of absorbed radiation dose indicate that plain radiography, including oblique views where appropriate, has a lower absorbed radiation dose than scintigraphy or tomography and should be performed prior to these studies

[en] Bone scintigraphy and radiography were performed in seven children with back pain. Six of the children with radiographic evidence of a pars interarticularis defect also had abnormal scintigrams. Increased uptake of the bone imaging agent occurred at six of the ten sites of radiographic pars interarticularis defects, implying increased bone metabolic activity. However, the location of scintigraphic abnormalities did not correspond to the location of radiographic abnormalities in several cases. Measurements of absorbed radiation dose indicate that plain radiography, including oblique views where appropriate, has a lower absorbed radiation dose than scintigraphy or tomography and should be performed prior to these studies

[en] In this work, the care and testing of measurement and diagnostic instruments are described in detail. Difficulties encountered with therapeutic and diagnostic calibrations are explored and solutions are suggested. VOLUME III Physics Teaching for Radiologic Technologists, Physics Teaching for Diagnostic Radiology Residents, Physics Teaching for Nuclear Medicine Residents, Physics Teaching for Radiotherapy Residents, Degree Programs in Medical Physics, Radiobiology Teaching, Non-Degree Medical Physics Training and American Board of Radiology Certifications, Radioactivity and Production of Medical Isotopes, Practical Medical Physics Consulting, Radiologic Terminology, Nuclear Medicine Imaging Techniques, Description of Radiotherapy Procedures, Medical Applications of Ultrasonography and Thermography, Glossary of Medical and Anatomical Terms Used in Medical Physics, Equipment List for Medical Physics and Acquisition Priority. Bibliography of Reference Materials. Index

[en] A study was performed to determine the accuracy of 99Mo measurements using three commercial dose calibrators with their 99Mo assay shields. One 99Mo assay shield allowed excessive penetration by the lower energy 99mTc photons, resulting in the calibrator's falsely high interpretation of the activity of 99Mo present in the high-activity 99mTc eluates. All three calibrators performed adequately with a National Bureau of Standards 99Mo standard in equilibrium with 99mTc. By using low-activity aliquots of 99Mo and 99mTc, a low-level linearity test was performed. Two of the calibrators were found to have a threshold of approximately 10 microCi (370 kBq) for a nonzero 99Mo response, although one of these occasionally produced variable nonzero responses below its threshold. Only one of the calibrators was found to reflect accurately the activity of 99Mo present under all conditions tested

[en] In this work, the care and testing of measurement and diagnostic instruments are described in detail. Difficulties encountered with therapeutic and diagnostic calibrations are explored and solutions are suggested. VOLUME II: Nuclear Medicine Imaging Instrumentation. Physics Principles of Computer Tomography. Diagnostic Ultrasound-Physical Principles and Equipment. Electroradiography (Xeroradiography) - Equipment and Initial Acceptance Tests. Purchasing Diagnostic X-Ray Equipment and Initial Acceptance Tests. Measurement of Modulation Transfer Functions. Measurement of Image Noise. Practical Sensitometry in Medical Imaging. Quality Assurance in Diagnostic Radiology. Quality Control Procedures for Nuclear Medicine Instruments. Computers in Nuclear Medicine. Quality Assurance and Radiation Exposure Levels in Computer Tomography. Room Design and Radiation Protection Surveys for Radionuclides and Megavoltage Electron Accelerators. Room Design and Radiation Protection Surveys for Diagnostic and Orthovoltage X-ray Units. Effects of Ionizing Radiations on Humans. In Vivo Dosimetry of Beta and Gamma-Emitting Radiopharmaceuticals. Patient Dosimetry in Diagnostic Radiology. Index

No abstract available