Dose Optimization in Digital Radiography and Computed Tomography

Description:

This book addresses radiation protection of patients having digital radiography and computed tomography (CT) examinations. The literature on radiation doses to patients from these two modalities have reported that the doses to patients are high. As a result, the radiology community has focused on methods and procedures to keep these doses as low as reasonably achievable (ALARA) without compromising the diagnostic image quality. This book outlines the motivation for dose optimization in radiology, identifies and describes the ICRP principle of optimization, outlines the factors affecting the dose in digital radiography and in CT, and identifies and describes strategies used in digital radiography and in CT for dose optimization.

This book is intended for all those working in digital radiography and CT environments including radiological technologists, and radiographers, radiologists, biomedical engineering technologists, and student medical physicists.

It is best used as a supplement to radiologic science textbooks, and in particular, radiation protection textbooks. Furthermore, this book lays the foundations for students and practitioners engaged in research on dose reduction and dose optimization in radiology.

·         Provides practical and useful methods for optimization of doses from digital radiography and CT

·         Describes the International Commission on Radiological Protection (ICRP) principle of optimization

·         Outlines the factors affecting the dose in digital radiography and in computed tomography

Table of contents :

Preface
Acknowledgments
Contents
Chapter 1: Dose Optimization: A Major Principle of Optimization
1.1 Biological Effects of Radiation Exposure
1.2 Fundamental Principles of Radiation Protection
1.2.1 The Principle of Justification
1.2.2 The Principle of Optimization
Digital Radiography and Computed Tomography: System Components at a Glance
1.3 Motivation for Dose Optimization in Digital Radiography and Computed Tomography
1.3.1 Radiation Risks
1.3.2 Dose Creep in Digital Radiography
1.3.3 Dose in Computed Tomography
1.4 Optimization Strategies: An Overview
References
Chapter 2: Digital Radiography: A Technical Review
2.1 Digital Radiography: Two Notable Facts Related to Dose Management
2.2 Digital Radiography Systems: A Technical Review
2.2.1 Computed Radiography: Physical Principles and Technology
2.2.2 Flat-Panel Digital Radiography: Physical Principles and Technology
Indirect Conversion Digital Radiography
Direct Conversion Digital Radiography
2.3 Other Considerations Related to CR and FPDR Systems
2.3.1 Image Processing
2.3.2 The Standardized Exposure Indicator and the Deviation Index
2.4 Factors Affecting the Dose in Digital Radiography: An Essential Review
2.5 Diagnostic Reference Levels
2.5.1 Definitions and Major Guidelines
References
Chapter 3: Optimization Strategies in Digital Radiography
3.1 Introduction
3.2 Optimization of Exposure Technique Factors
3.2.1 Optimization of kV and mAs
3.3 Optimization of the Exposure Indicator
3.4 Optimization of the Deviation Index
3.5 Optimization Using Image Postprocessing Algorithms
3.5.1 Optimization Studies Using Multifrequency Processing and Noise Reduction Algorithms
3.6 Diagnostic Reference Levels: A Useful Tool in Dose Optimization
References
Chapter 4: Computed Tomography: A Technical Review
4.1 Introduction
4.2 The CT Scanner: Fundamental Physics and Major System Components
4.2.1 Attenuation Physics: An Essential Overview
4.2.2 Attenuation and CT Numbers
4.2.3 Data Acquisition: System Components and Principles
4.2.4 Image Reconstruction
Iterative Reconstruction Algorithms
Artificial Intelligence in CT Image Reconstruction
Deep Learning CT Image Reconstruction Algorithms
4.2.5 Image Display/Storage/Communication
4.3 Multi-slice CT Principles at a Glance
4.3.1 MSCT Detectors: An Overview
Scintillation Detectors and Photon Counting Detectors
MSCT Detector Designs
4.3.2 Selectable Scan Parameters
4.4 Radiation Protection
References
Chapter 5: Dose Reduction and Optimization Strategies in Computed Tomography
5.1 Introduction
5.2 Motivation for Dose Optimization in CT
5.2.1 Literature on Cancer Risks from CT
5.2.2 Effects of Low-Dose Chest CT on Chromosomal DNA
5.2.3 In Summary
5.3 Radiation Protection Principles
5.4 Elements of CT Dosimetry at a Glance
5.5 Factors Affecting the Dose in CT: An Overview
5.5.1 Image Quality Considerations
5.5.2 Significant Dose Parameters
5.6 Dose Optimization Strategies in CT
5.7 Other Useful Tools for Dose Reduction and Optimization in CT
5.7.1 The Use of DRLs
5.7.2 The Use of AI-Based Image Reconstruction
5.7.3 The Use of PCDs
5.8 The Role of the Technologist in CT Dose Reduction and Optimization
References
Chapter 6: Optimization Research in Medical Imaging
6.1 Introduction
6.1.1 Strategies Used in Dose/Image Quality Optimization Research
Additional Considerations
6.1.2 The Nature of Image Quality
Image Quality Descriptors
6.1.3 Image Quality Assessment Tools for Clinical CT Images: An Overview
Objective Physical Measures
Observer Performance Methods
6.1.4 Receiver Operating Characteristics: A Brief Overview
6.1.5 Visual Grading Analysis: An Overview
VGA Methods
6.1.6 Example of a Dose Optimization Study in Digital Radiography
References
Chapter 7: Review Questions
Index