Radiography in the Digital Age: Physics - Exposure - Radiation Biology - Third Edition

Long overdue, this new work provides just the right focus and scope for the practice of radiography in this digital age, covering four entire courses in a typical radiography program. The entire emphasis of foundational physics has been adjusted in order to properly support the specific information on digital imaging that will follow. The paradigm shift in imaging terminology is reflected by the careful phrasing of concepts, accurate descriptions and clear illustrations throughout the book. There are 713 illustrations, including meticulous color line drawings, numerous photographs and stark radiographs. The two chapters on digital image processing alone include 60 beautifully executed illustrations. Foundational chapters on math and basic physics maintain a focus on energy physics. Obsolete and extraneous material has been eliminated, while concepts supporting digital imaging are more thoroughly discussed. All discussion of electricity is limited to only those concepts which bear directly upon the production of x-rays in the x-ray tube. Following is a full discussion of the x-ray beam and its interactions within the patient, the production and characteristics of subject contrast, and an emphasis on the practical application of radiographic technique. This is conventional information, but the terminology and descriptions used have been adapted with great care to the digital environment. No fewer than ten chapters are devoted directly to digital imaging, providing extensive coverage of the physics of digital image capture, digital processing techniques, and the practical applications of both CR and DR. Image display systems are brought up to date with the physics of LCD screens and electronic images. PACS and medical imaging informatics are also covered. Chapters on Radiation Biology and Protection include an unflinching look at current issues and radiation protection in practice. The radiation biology is clearly presented with numerous lucid illustrations, and a balanced perspective on radiation and its medical use is developed. To reinforce mathematical concepts for the student, dozens of practice exercises are strategically dispersed throughout the chapters, with answer keys provided in the appendix. Extensive review questions at the end of each chapter give a thorough, comprehensive review of the material learned. The Instructor Resources for Radiography in the Digital Age, available on disc, includes the answer key for all chapter review questions and a bank of over 1500 multiple-choice questions for instructors use. It also includes 35 laboratory exercises, including 15 that demonstrate the applications of CR equipment.-- Provided by Publisher RADIOGRAPHY INTHE DIGITAL AGE: Physics—Exposure—Radiation Biology PREFACE New to This Edition Scope and Philosophical Approach Organization Feedback Instructional Resources INSTRUCTOR RESOURCES CD FOR RADIOGRAPHY IN THE DIGITAL AGE. POWERPOINT SLIDES ON DISC. STUDENT WORKBOOK FOR RADIOGRAPHY IN THE DIGITAL AGE. DVD MINI-LESSONS ACKNOWLEDGMENTS CONTENTS Part I: THE PHYSICS OF RADIOGRAPHY Chapter 1: INTRODUCTION TO RADIOGRAPHIC SCIENCE THE SCIENTIFIC APPROACH A BRIEF HISTORY OF X-RAYS THE DEVELOPMENT OF MODERN IMAGING TECHNOLOGY THE DEVELOPMENT OF DIGITAL IMAGING LIVING WITH RADIATION SUMMARY REVIEW QUESTIONS Chapter 2: BASIC PHYSICSFOR RADIOGRAPHY THE BASE QUANTITIES AND FORCES UNIT SYSTEMS THE PHYSICS OF ENERGY HEAT AND STATES OF MATTER SUMMARY REVIEW QUESTIONS Chapter 3: UNIT CONVERSIONS AND HELP WITH MATH MATHEMATICAL TERMINOLOGY BASIC OPERATIONS Converting Fractions to Decimals Converting Decimals and Percentages Extent of Rounding Order of Operations Algebraic Operations Rules for Exponents CONVERTING TO SCIENTIFIC NOTATION CALCULATING WITH SCIENTIFIC NOTATION CONVERTING UNITS WITH DIMENSIONAL ANALYSIS AREAS AND VOLUMES THE INVERSE SQUARE LAW GRAPHS Reading a Graph Understanding the X-Ray Beam Spectrum Curve Understanding the Digital Histogram SUMMARY REVIEW QUESTIONS: Chapter 4: THE ATOM MATTER PHYSICAL STRUCTURE OF ATOMS Electron Configuration CHEMICAL BONDING Covalent Bonding Ionic Bonding IONIZATION STRUCTURE OF THE NUCLEUS RADIOACTIVITY SUMMARY REVIEW QUESTIONS Chapter 5: ELECTROMAGNETIC WAVES WAVES Practice Exercise #1: Practice Exercise #2: THE ELECTROMAGNETIC WAVE FORMULA Practice Exercise #3: Practice Exercise #4: THE PLANK FORMULA Practice Exercise #5: Practice Exercise #6: THE NATURE OF ELECTROMAGNETIC WAVES THE ELECTROMAGNETIC SPECTRUM MEDICAL APPLICATIONS OF WAVES Magnetic Resonance Imaging (MRI) Ultrasound Lasers Computed Radiography (CR) Readers Laser Film Digitizers Laser Film Printers Optical Disc Reading and Writing CHARACTERISTICS OF VISIBLE LIGHTVS. X-RAYS DUAL NATURE OF ALL MATTERAND RADIATION SUMMARY REVIEW QUESTIONS Chapter 6: MAGNETISM AND ELECTROSTATICS MAGNETS MAGNETIC FIELDS ELECTROSTATICS The Five Laws of Electrostatics ELECTRIFICATION Using an Electroscope to Detect Radiation SUMMARY REVIEW QUESTIONS Chapter 7: ELECTRODYNAMICS ELECTRICAL CURRENT Practice Exercise #1 Practice Exercise #2 ELECTRICAL CIRCUITS CHARACTERISTICS OF ELECTRICITY Practice Exercise #3 Practice Exercise #4 Practice Exercise #5 ELECTRICAL POWER Practice Exercise #6 Practice Exercise #7 WAVE FORMS OF ELECTRICALCURRENT ELECTROMAGNETIC INDUCTION Practice Exercise #8 Practice Exercise #9 SUMMARY REVIEW QUESTIONS Chapter 8: X-RAY MACHINE CIRCUITSAND GENERATORS A BASIC X-RAY MACHINE CIRCUIT Rectification The Filament Circuit Meters X-RAY MACHINE GENERATORS EXPOSURE TIMERS Automatic Exposure Controls (AEC) SUMMARY REVIEW QUESTIONS Chapter 9: THE X-RAY TUBE X-RAY PRODUCTION COMPONENTS OF THE X-RAY TUBE The Cathode The Anode The Glass Envelope X-RAY TUBE FAILURE Rating Charts Practice Exercise #1 Extending X-Ray Tube Life SUMMARY REVIEW QUESTIONS Chapter 10: X-RAY PRODUCTION INTERACTIONS IN THE ANODE Bremsstrahlung Characteristic Radiation Anode Heat FACTORS AFFECTING THE X-RAYBEAM SPECTRUM Target Material Milliampere-Seconds (mAs) Added Filtration Kilovoltage-Peak (kVp) Generator Type SUMMARY REVIEW QUESTIONS Part II: PRODUCTION OF THE RADIOGRAPHIC IMAGE Chapter 11: CREATION OF THE RADIOGRAPHIC IMAGE THE X-RAY BEAM RADIOGRAPHIC VARIABLES Technical Variables Geometrical Variables Patient Status Image Receptor Systems Image Processing Viewing Conditions X-RAY INTERACTIONS WITHIN THE PATIENT The Photoelectric Effect Practice Exercise #1 The Compton Effect Practice Exercise #2 Coherent Scattering Characteristic Radiation Practice Exercise #3 ATTENUATION AND SUBJECT CONTRAST CAPTURING THE IMAGE SUMMARY REVIEW QUESTIONS Chapter 12: PRODUCTION OF SUBJECT CONTRAST GENERAL ATTENUATION AND SUBJECT CONTRAST Tissue Thickness Tissue Density Tissue Atomic Number SCATTERED X-RAYS AND SUBJECT CONTRAST PREDOMINANCE OF INTERACTIONS AND SUBJECT CONTRAST X-Ray Beam Energy (kVp) Types of Tissue and Contrast Agents Relative Importance of kVp in ControllingSubject Contrast SUMMARY REVIEW QUESTIONS Chapter 13: VISIBILITY QUALITIES OF THE IMAGE THE COMPONENTSOF VISIBILITY QUALITIES OF THERADIOGRAPHIC IMAGE Brightness and Density Contrast and Gray Scale Noise Signal-to-Noise Ratio Artifacts SUMMARY REVIEW QUESTIONS Chapter 14: GEOMETRICAL QUALITIES OF THE IMAGE RECOGNIZABILITY (GEOMETRICAL INTEGRITY) Sharpness (Spatial Resolution) Magnification (Size Distortion) Shape Distortion Measuring Unsharpness Practice Exercise #1 Radiographic Sharpness Practice Exercise #2 Radiographic Magnification Magnification Formula Practice Exercise #3 Practice Exercise #4 Practice Exercise #5 Radiographic Shape Distortion RESOLUTION HIERARCHY OF IMAGE QUALITIES SUMMARY REVIEW QUESTIONS Chapter 15: MILLIAMPERE-SECONDS (mAs) CONTROL OF X-RAY EXPOSURE Practice Exercise #1 Practice Exercise #2 Doing the Mental Math UNDEREXPOSURE AND QUANTUM MOTTLE SUBJECT CONTRAST AND OTHERIMAGE QUALITIES EXPOSURE TIME AND MOTION SUMMARY REVIEW QUESTIONS Chapter 16: KILOVOLTAGE-PEAK (kVp) SUFFICIENT PENETRATION AND SUBJECT CONTRAST THE FIFTEEN PERCENT RULE Doing the Mental Math OPTIMUM kVp Patient Exposure and the 15 Percent Rule Impact of Scatter Radiation on the Image Conclusion OTHER IMAGE QUALITIES SUMMARY REVIEW QUESTIONS Chapter 17: GENERATORS AND FILTRATION GENERATOR TYPE Effect of Rectification and Generatorson Exposure Other Image Qualities Battery-Operated Mobile Units BEAM FILTRATION Protective Filters Half-Value Layer Effects on Exposure and Beam Spectrum Compensating Filtration SUMMARY REVIEW QUESTIONS Chapter 18: FIELD SIZE LIMITATION COLLIMATION DEVICES Positive Beam Limitation OVERCOLLIMATION SCATTER RADIATION AND SUBJECT CONTRAST EFFECT ON EXPOSURE OTHER IMAGE QUALITIES CALCULATING FIELD SIZE COVERAGE Practice Exercise #1 Practice Exercise #2 SUMMARY REVIEW QUESTIONS Chapter 19: PATIENT CONDITION, PATHOLOGY, AND CONTRAST AGENTS GENERAL PATIENT CONDITION Thickness of the Part Thickness Ranges The Four Centimeter Rule Minimum Change Rule Body Habitus Sthenic Hyposthenic Asthenic Hypersthenic Large Muscular Influence of Age Anthropological Factors MOLECULAR COMPOSITIONOF TISSUES CONTRAST AGENTS STAGE OF RESPIRATION ANDPATIENT COOPERATION PATHOLOGY Additive Diseases Destructive Diseases TRAUMA Postmortem Radiography Soft-Tissue Technique Casts and Splints SUMMARY REVIEW QUESTIONS Chapter 20: SCATTERED RADIATION AND GRIDS THE CAUSES OF SCATTER High kVp Levels Large Soft-Tissue Part Thicknesses Conclusion SCATTER VERSUS BLUR REDUCING SCATTER WITH GRIDS Grid Ratio and Effectiveness Practice Exercise #1 Grid Frequency and Lead Content Effect on Subject Contrast Use of Grids with Digital Equipment Conventional Indications for Grid Use Part Thickness Field Size Kilovoltage Measuring Grid Effectiveness Bucky Factor Technique Compensation for Grids Other Image Qualities Grid Radius Alignment of the Beam and Grid SUMMARY REVIEW QUESTIONS Chapter 21: THE ANODE BEVEL AND FOCAL SPOT LINE-FOCUS PRINCIPLE ANODE HEEL EFFECT FOCAL SPOT SIZE Effect Upon Sharpness Penumbra Magnification Other Image Qualities Conclusion SUMMARY REVIEW QUESTIONS Chapter 22: SOURCE-TO-IMAGE RECEPTOR DISTANCE (SID) EFFECT ON SHARPNESS EFFECT ON MAGNIFICATION Increased Field-of-View at Longer SID Shape Distortion EFFECT ON EXPOSURE Radiographic Formula for the InverseSquare Law Practice Exercise #1 Practice Exercise #2 COMPENSATING TECHNIQUE:THE SQUARE LAW Practice Exercise #3 Practice Exercise #4 Practice Exercise #5 Practice Exercise #6 RULES OF THUMB FOR SID CHANGES OTHER IMAGE QUALITIES INCREASED SID TO REDUCE PATIENT DOSE SUMMARY REVIEW QUESTIONS Chapter 23: OID AND DISTANCE RATIOS OBJECT-IMAGE RECEPTOR DISTANCE Effect on Subject Contrast Effect on Exposure Effect on Sharpness Effect on Magnification Intentional Use of Long OID Shape Distortion DISTANCE RATIOS FOR MAGNIFICATION AND SHARPNESS Magnification: The SID/SOD Ratio Practice Exercise #1 Practice Exercise #2 Sharpness: The SOD/OID Ratio Practice Exercise #3 Visibility Functions and Distance Ratios SUMMARY REVIEW QUESTIONS Chapter 24: ALIGNMENT AND MOTION ALIGNMENT AND SHAPE DISTORTION Off-Centering Versus Angling Position, Shape, and Size ofthe Anatomical Part Objects with a Distinct Long Axis Ceiszynski’s Law of Isometry Objects without a DistinctLong Axis Off-Centering and Beam Divergence Rule for Beam Divergence SID as a Contributing Factor Maintaining Exposure: Compensating Tube-to-Tabletop Distance Other Image Qualities GEOMETRIC FUNCTIONS OFPOSITIONING MOTION Effect on Sharpness Effect on Image Contrast Other Image Qualities SUMMARY REVIEW QUESTIONS Chapter 25: ANALYZING THE LATENT RADIOGRAPHIC IMAGE Variables Affecting Exposureat the Image Receptor Variables Affecting Subject Contrast at the Image Receptor Variables Affecting Image Noise at the Image Receptor Variables Affecting Sharpness at the Image Receptor Variables Affecting Magnification at the Image Receptor Variables Affecting Shape Distortion at the Image Receptor Absorption Penumbra OVERALL RESOLUTION Resolution at the Microscopic Level Spatial Resolution: Spatial Frequency Practice Exercise #1 Contrast Resolution: MTF SUMMARY REVIEW QUESTIONS Chapter 26: SIMPLIFYING AND STANDARDIZING TECHNIQUE VARIABLE kVp VS. FIXED kVpAPPROACHES APPLYING THE VARIABLE kVpAPPROACH Practice Exercise #1 THE PROPORTIONAL ANATOMY APPROACH USING TECHNIQUE CHARTS DEVELOPING A CHART FROM SCRATCH VARIABLE TIME CHART VARIABLE MA/TIME CHART VARIABLE KVP CHART SUMMARY REVIEW QUESTIONS Chapter 27: USING AUTOMATIC EXPOSURE CONTROLS (AEC) MINIMUM RESPONSE TIME BACK-UP mAs OR TIME Preset Automatic Back-up mAs or Time THE AEC INTENSITY (DENSITY) CONTROL LIMITATIONS OF AEC DETECTOR CELL CONFIGURATION CHECKLIST OF AEC PRECAUTIONS AEC TECHNIQUE CHARTS PROGRAMMED EXPOSURECONTROLS SUMMARY REVIEW QUESTIONS Part III: DIGITAL RADIOGRAPHY Chapter 28: COMPUTER BASICS THE DEVELOPMENT OF COMPUTERS COMPUTER HARDWARE COMPONENTS The Central Processing Unit Secondary Storage Devices Types of Memory MANAGING DATA Analog vs. Digital Data Binary Code COMPUTER SOFTWARE PROCESSING METHODS COMMUNICATIONS SUMMARY REVIEW QUESTIONS Chapter 29: CREATING THE DIGITAL IMAGE THE NATURE OF DIGITAL IMAGES Practice Exercise #1 DIGITIZING AN ANALOG IMAGE ROLE OF X-RAY ATTENUATION IN FORMING THE DIGITAL IMAGE ENHANCEMENT OF CONTRAST RESOLUTION PROCEDURAL ALGORITHMS WINDOWING Workstations and Display Stations SUMMARY REVIEW QUESTIONS Chapter 30: DIGITAL IMAGE PREPROCESSING AND PROCESSING (RESCALING) INTRODUCTION PREPROCESSING I: FIELD UNIFORMITY Flat-Field Uniformity Corrections Electronic Response and Gain Offsets Variable Scintillator Thickness Light Guide Variations in CR PREPROCESSING II: NOISE REDUCTION FOR DEXEL DROP-OUT PREPROCESSING III: IMAGE ANALYSIS Segmentation and Exposure FieldRecognition Constructing the Histogram Types of Histogram Analysis Histogram Analysis Processing Errors MAINTAINING THE SPATIAL MATRIX RESCALING (PROCESSING) THE IMAGE Physicists’ Terminology SUMMARY REVIEW QUESTIONS Chapter 31: DIGITAL IMAGE POSTPROCESSING DIGITAL PROCESSING DOMAINS POSTPROCESSING I: GRADATION PROCESSING Initial Gradation Processing Parameters for Gradient Processing Data Clipping Dynamic Range Compression (DRC) or Equalization POSTPROCESSING II: DETAILPROCESSING Applying Kernels in the Spatial Domain Unsharp Mask Filtering Using Kernels for Noise Reduction and Smoothing Understanding the Frequency Domain Processing in the Frequency Domain Multiscale Processing and Band-PassFiltering Kernels as a Form of Band-Pass Processing Parameters for Frequency Processing POSTPROCESSING III: PREPARATIONFOR DISPLAY Noise Reduction Contrast-Noise Ratio Additional Gradation Processing Perceptual Tone Scaling Formatting for Display DIGITAL PROCESSING SUITES POSTPROCESSING IV: OPERATOR ADJUSTMENTS POSTPROCESSING V: SPECIAL POSTPROCESSING Dual-Energy Subtraction Grid Line Suppression CONCLUSION SUMMARY REVIEW QUESTIONS Chapter 32: POSTPROCESSING OPERATIONS IN PRACTICE NAVIGATING THE MENU SCREENS SPEED CLASS EXPOSURE INDICATORS Logarithmic Scales Proportional Scales Inversely Proportional Scales Limitations for Exposure Indicators ACCEPTABLE PARAMETERSFOR EXPOSURE Inappropriate Clinical Use ofthe Deviation Index (DI) EXPOSURE INDICATOR ERRORS USING ALTERNATIVE PROCESSING ALGORITHMS Examples of Alternative ProcessingAlgorithms WINDOWING SMOOTHING AND EDGEENHANCEMENT MISCELLANEOUS PROCESSING FEATURES Dark Masking Image Reversal (Black Bone) Resizing Image Stitching QUALITY CRITERIA FOR THE DISPLAYED DIGITAL RADIOGRAPHIC IMAGE GLOSSARY AND ARRT STANDARD DEFINITIONS “CONTROLLING” FACTORS FOR DISPLAYED IMAGE QUALITIES SUMMARY REVIEW QUESTIONS Chapter 33: APPLYING RADIOGRAPHIC TECHNIQUE TO DIGITAL IMAGING MINIMIZING PATIENT EXPOSURE High kVp and Scatter Radiation High kVp and Mottle Recommendation for Reducing Patient Exposure DOES kVp STILL CONTROL IMAGECONTRAST? EXPOSURE LATITUDE, OVEREXPOSURE, AND PUBLIC EXPOSURE SUFFICIENT PENETRATION AND SIGNAL-TO-NOISE RATIO EFFECTS OF kVp CHANGES ON THE IMAGE EFFECTS OF SCATTER RADIATION ON DIGITAL IMAGES FOG PATTERN CLEAN-UP BY FREQUENCY PROCESSING TECHNIQUE MYTHS PROPORTIONAL ANATOMY AND MANUAL TECHNIQUE RULES AUTOMATIC EXPOSURE CONTROLS (AECS) USE OF GRIDS WITH DIGITAL RADIOGRAPHY Aliasing (Moire Effect) On Reducing the Use of Grids Mottle or Scatter: Which is More Acceptable? Virtual Grid Software TARGETED AREA BRIGHTNESS CORRECTION MARKERS AND ANNOTATION ALIGNMENT ISSUES Centering of Anatomy Aligning Multiple Fields Overcollimation BILATERAL VIEWS IMAGE RETENTION IN PHOSPHOR PLATES SUMMARY REVIEW QUESTIONS Chapter 34: CAPTURING THE DIGITAL IMAGE: DR AND CR COMPARING CR AND DR FOR CLINICAL USE DIRECT-CAPTURE DIGITALRADIOGRAPHY (DR) The Dexel Direct Conversion Systems Indirect Conversion Systems COMPUTED RADIOGRAPHY (CR) The CR Cassette and Phosphor Plate The CR Reader (Processor) Recent Developments in CR Background and Scatter Radiation SPATIAL RESOLUTION OF DIGITAL SYSTEMS FIELD-OF-VIEW, MATRIX SIZE, AND SPATIAL RESOLUTION Formula Relating FOV to Pixel Size The DR Detector Hardware Matrix The Display Monitor Hardware Matrix The “Soft” Matrix of the Displayed Light Image: Summary EFFICIENCY OF IMAGE RECEPTORS CR Phosphor Plates K-Edge Effect DR Detector Panels Detective Quantum Efficiency (DQE) DIGITAL ARTIFACTS Digital Sampling and Aliasing SUMMARY REVIEW QUESTIONS Chapter 35: DISPLAY SYSTEMS AND ELECTRONIC IMAGES LIQUID CRYSTAL DISPLAY (LCD)MONITORS OTHER FLAT MONITOR SYSTEMS ADVANTAGES AND DISADVANTAGES OF LCDS NATURE OF PIXELS IN DISPLAY SYSTEMS SPATIAL RESOLUTION OF DISPLAY MONITORS CONCLUSION: THE WEAKEST LINK SUMMARY REVIEW QUESTIONS Chapter 36: PACS AND IMAGING INFORMATICS HARDWARE AND SOFTWARE FUNCTIONS IMAGE ACCESS MEDICAL IMAGING INFORMATICS HIS, RIS and PACS SUMMARY REVIEW QUESTIONS Chapter 37: QUALITY CONTROL RADIOGRAPHIC EQUIPMENT TESTING Radiographic Units Exposure Timer mA Linearity Exposure Reproducibility Half-Value Layer kVp Calibration Collimator and Distance Focal Spot Size and Condition Automatic Exposure Control (AEC) Fluoroscopic Units MONITORING OF DIGITALACQUISITION SYSTEMS Field Uniformity Erasure Thoroughness and “Ghosting” Intrinsic (Dark) Noise Spatial Resolution MONITORING OF ELECTRONIC IMAGE DISPLAY SYSTEMS Luminance Illuminance Luminance and Contrast Tests Ambient Lighting (Illuminance) and Reflectance Tests Noise Resolution Dead and Stuck Pixels Viewing Angle Dependence Stability of Self-Calibrating LCDs REPEAT ANALYSIS SUMMARY REVIEW QUESTIONS Chapter 38: MOBILE RADIOGRAPHY, FLUOROSCOPY AND DIGITAL FLUOROSCOPY MOBILE RADIOGRAPHY Mobile Generators Geometrical Factors Distance Considerations Alignment and Positioning Considerations Other Considerations DEVELOPMENT OF FLUOROSCOPY THE IMAGE INTENSIFIER TUBE Input Phosphor and Photocathode Electrostatic Focusing Lens Accelerating Anode Output Phosphor Brightness Gain Conversion Factor Multifield Image Intensifiers and Magnification Modes AUTOMATIC STABILIZATION OF BRIGHTNESS Signal Sensing Types of ABS Circuits FLUOROSCOPIC TECHNIQUE FLUOROSCOPIC IMAGE QUALITY Scintillation Contrast Distortion Veiling Glare Vignetting Processing the Image from the Intensifier Tube MOBILE IMAGE INTENSIFICATION (C-ARM) MINIMIZING PATIENT AND OPERATOR EXPOSURE Fluoroscopic Exposure Time DIGITAL FLUOROSCOPY (DF) Dynamic Flat-Panel Detectors Digital Subtraction Techniques Temporal Subtraction Energy Subtraction Roadmapping IMAGE RECORDING DEVICES: CCDS AND CMOSS SUMMARY REVIEW QUESTIONS Part IV: RADIATION BIOLOGY AND PROTECTION Chapter 39: RADIATION PERSPECTIVES PERCEPTIONS On the Radiographer’s Job On Environmental Radiation Developing a Frame of Reference SOURCES OF RADIATION Natural Background Radiation Manmade Sources of Radiation RADIOACTIVITY HALF-LIFE Practice Exercise #1 Practice Exercise #2 Practice Exercise #3 Practice Exercise #4 CONCLUSION SUMMARY REVIEW QUESTIONS Chapter 40: RADIATION UNITS AND MEASUREMENT RADIATION UNITS Radiation Exposure Air Kerma Exposure Area Product Surface Integral Exposure Absorbed Dose Dose Area Product Integral Dose Dose Equivalent Effective Dose Proper Use of Units DOSE EQUIVALENT LIMITS (DELS) The Cumulative Lifetime Limit The Prospective Limit The Retrospective Limit Current Limits Genetically Significant Dose (GSD) RADIATION DETECTION INSTRUMENTS Characteristics of RadiationDetection Devices Sensitivity Accuracy Resolving (Interrogation) Time Practice Exercise #3 Range Types of Radiation Detection Instruments Scintillation Detectors Optically Stimulated Luminescence (OSL) Dosimeters Thermoluminescent Dosimeter (TLDs) Film Badges Gas-Filled Detectors Pocket Dosimeters Ionization Chambers Proportional Counters Geiger-Mueller Tubes Personal Radiation Monitors Voltage-Dependence of Electronic Detection Instruments SUMMARY REVIEW QUESTIONS Chapter 41: RADIATION BIOLOGY: CELLULAR EFFECTS BIOLOGICAL REVIEW Tissues of the Human Body Human Cell Structure and Metabolism Transfer of Genetic Information Life Cycle of the Cell Mitosis Cell Life Cycle and Radiation Sensitivity Meiosis CELLULAR RADIATION EFFECTS Cell Sensitivity Law of Bergonie and Tribondeau Cellular Response to Radiation Theory of Cellular Damage Radiolysis of Water Damage to the Cell Membrane ypes of Cell Death from Radiation Exposure Types of Damage to Chromosomes Main Chain Scission Rung Damage Mutations and Chromosome Aberrations Visible Chromosome Aberrations Linear Energy Transfer (LET) Relative Biological Effectiveness (RBE) Dose Rate Protraction of Dose Fractionation Oxygen Enhancement Ratio (OER) Other Biological Factors Affecting Radiosensitivity Summary of Factors Affecting Radiosensitivity SUMMARY REVIEW QUESTIONS Chapter 42: RADIATION BIOLOGY: ORGANISM EFFECTS MEASURING RISK Stochastic Versus Deterministic Effects EARLY EFFECTS OF RADIATION Lethal Doses Acute Radiation Syndrome Other Early Effects LATE EFFECTS OF RADIATION Teratogenic Effects of Radiation Period #1: 0–2 Weeks Gestation Period #2: 2–8 Weeks Gestation Period #3: 8–12 Weeks Gestation Period #4: After 3 Months Gestation Mutagenic Effects of Radiation Life-Span Shortening Cataracts of the Eye Lens Cancers Leukemia Mammograms and Breast Cancer SUMMARY REVIEW QUESTIONS Chapter 43: RADIATION PROTECTION: PROCEDURES AND POLICIES DIAGNOSTIC EXPOSURE LEVELSTO PATIENTS Gonadal Exposure OPTIMIZING RADIOGRAPHICTECHNIQUE mAs and kVp Generators and Filtration Field Size Limitation Patient Status Grids and Image Receptors Increasing SID to Reduce Patient Dose Radiographic Positioning Radiographic Technique and AEC Quality Control and HVL Digital Processing Speed Class PROTECTING THE PATIENT Patient Shielding Policies for Patient Pregnancy Guidelines for Equipment Fluoroscope Technology Current Issues PROTECTING PERSONNEL Personnel Monitoring The Cardinal Principles: Time, Distance and Shielding Personnel Shielding Requirements Equipment Shielding Requirements Personnel Protection Policies Policies for Technologist Pregnancy Guidelines for Equipment STRUCTURAL BARRIER SHIELDING Factors for Adequacy of Barriers Types of Radiation Areas Posted Warnings ADVISORY AND REGULATORY AGENCIES A FINAL WORD SUMMARY REVIEW QUESTIONS Appendix #1: ANSWERS TO CHAPTER EXERCISES Appendix #2: ARRT STANDARD DEFINITIONS GLOSSARY OF RADIOGRAPHIC TERMS INDEX