Digital Radiography in Practice

DIGITAL RADIOGRAPHY IN PRACTICE
REVIEWERS
PREFACE
	Ancillary Resources
ACKNOWLEDGMENTS
CONTENTS
DIGITAL RADIOGRAPHY IN PRACTICE
	Chapter 1 NATURE OF THE DIGITAL RADIOGRAPH
		Objectives
		Development of Digital Radiography
		Nature of the Digital Image
		Digitizing the Analog Image
		Bit Depth, Dynamic Range, and Gray Scale
		What is a Pixel?
		Voxels, Dexels, and Pixels
		Chapter Review Questions
	Chapter 2 CREATING THE LATENT IMAGE
		Objectives
		Overview of Variables
			Technical Variables
			Geometrical Variables
			Patient Status
		Creating Subject Contrast
			X-Ray Interactions
			X-Ray Beam Energy
			Tissue Thickness
			Tissue Density
			Tissue Atomic Number
			Contrast Agents
			Summary of Variables Creating Subject Contrast
			Why mAs and SID Do Not Control Subject Contrast in the Latent Image
		Role of Radiographic Technique in the Digital Age
		Subject Contrast and Sharpness
		Variables Affecting the Quality of the Final Displayed Radiographic Image
		Chapter Review Questions
	Chapter 3 QUALITIES OF THE DIGITAL RADIOGRAPH
		Objectives
		Qualities of the Final Displayed Digital Image
			Brightness
			Contrast and Gray Scale
			Measuring Contrast
			Noise and SNR
			Sharpness (Spatial Resolution)
			Shape Distortion
			Geometric Magnification
			Display Magnification
		Qualities of the Latent Image Captured at the Image Receptor
		Resolution at the Microscopic Level
		Exposure Trace Diagrams
		Conclusion
		Chapter Review Questions
	Chapter 4 RADIOGRAPHIC TECHNIQUE FOR DIGITAL IMAGING
		Objectives
		Understanding X-Ray Beam Penetration
		Sensitivity of Digital Units to Subject Contrast
		Subject Contrast and Exposure Latitude
		Use of Grids
		Sufficient Input Gray Scale
		Minimizing Patient Exposure with the 15 Percent Rule
		Benefits of High kVp Radiography
		Chapter Review Questions
	Chapter 5 PREPROCESSING AND HISTOGRAM ANALYSIS
		Objectives
		The Generic Steps of Digital Image Processing
		Preprocessing
			Correcting for Dexel Dropout
			Correcting for Mottle
			Field Uniformity
			Constructing the Histogram
		Histogram Analysis
			Types of Histogram Analysis
			Errors in Histogram Analysis
		Chapter Review Questions
	Chapter 6 RESCALING (PROCESSING) THE DIGITAL RADIOGRAPH
		Objectives
		“Normalizing” the Image
		Q Values and the “Permanent” LUT
			Physicists’ Nomenclature
		Chapter Review Questions
	Chapter 7 DEFAULT POSTPROCESSING I: GRADATION PROCESSING
		Objectives
		Digital Processing Domains
			Spatial Domain Operations
			Intensity Domain Operations
			Frequency Domain Operations
		Gradation Processing
		Data Clipping
		Dynamic Range Compression
		Chapter Review Questions
	Chapter 8 DEFAULT POSTPROCESSING II: DETAIL PROCESSING
		Objectives
		Understanding the Frequency Domain
		Frequency Detail Processing
			Transition Between Image Domains
		Spatial Detail Processing (Kernels)
		Preparation for Display
		Chapter Review Questions
	Chapter 9 MANIPULATING THE DIGITAL IMAGE: OPERATOR ADJUSTMENTS
		Objectives
		Processing Algorithms
		Windowing
		Postprocessing Features
			Smoothing
			Edge Enhancement
			Background Suppression
			Targeted Area Brightness Correction
			Other Postprocessing Features
		Chapter Review Questions
	Chapter 10 MONITORING AND CONTROLLING EXPOSURE
		Objectives
		Speed Class
		A Brief History of Exposure Indicators
		The Deviation Index: Acceptable Parameters for Exposure
		Limitations of the DI
		A Note on “Controlling” Factors
		Chapter Review Questions
	Chapter 11 DIGITAL IMAGE ACQUISITION
		Objectives
		Direct-Conversion DR Detectors
		Indirect-Conversion DR Detectors
		Computed Radiography (CR)
			The CR Reader (Processor)
		Background and Scatter Radiation
		Sharpness of Digital Systems
			Hardware Matrices
			The Soft Matrix of a Light Image
			The Pixel Size Formula
		Efficiency of Image Receptors
			Detective Quantum Efficiency
			Fill Factor
		Digital Sampling and Aliasing
			Aliasing from Grids
		Other Digital Artifacts
		Chapter Review Questions
	Chapter 12 DISPLAYING THE DIGITAL IMAGE
		Objectives
		The Liquid Crystal Display (LCD) Monitor
		LCD Image Quality
			Spatial Resolution (Sharpness)
			Luminance and Contrast
		Nature of Display Pixels
		Chapter Review Questions
	Chapter 13 ARCHIVING PATIENT IMAGES AND INFORMATION
		Objectives
		Picture Archiving and Communication Systems (PACS)
		Medical Imaging Informatics
		Chapter Review Questions
	Chapter 14 DIGITAL FLUOROSCOPY
		Objectives
		Image Recording from an Image Intensifier Tube
		Dynamic Flat-Panel Detectors
		Reducing Patient Dose
		Chapter Review Questions
	Chapter 15 QUALITY CONTROL FOR DIGITAL EQUIPMENT
		Objectives
		Monitoring of Digital X-Ray Units
			Field Uniformity
			Intrinisic (Dark) Noise
			Erasure Thoroughness and “Ghosting”
			Sharpness
		Monitoring of Electronic Image Display Systems
			Maximum Luminance
			Luminance Response
			Luminance Ratio
			Luminance Uniformity
			Reflectance and Ambient Lighting
			Noise
			Resolution
			Dead and Stuck Pixels
			Other QC Tests
		Chapter Review Questions
	GLOSSARY OF DIGITAL RADIOGRAPHIC TERMS
	REFERENCES
	INDEX