Computed Tomography: Approaches, Applications, and Operations

✍ Scribed by Ehsan Samei (editor), Norbert J. Pelc (editor)

• Publisher: Springer
• Year: 2019
• Tongue: English
• Leaves: 469
• Edition: 1st ed. 2020
• Category: Library

✦ Synopsis

This book offers a comprehensive and topical depiction of advances in CT imaging. CT has become a leading medical imaging modality, thanks to its superb spatial and temporal resolution to depict anatomical details. New advances have further extended the technology to provide physiological information, enabling a wide and expanding range of clinical applications. The text covers the latest advancements in CT technology and clinical applications for a variety of CT types and imaging methods. The content is presented in seven parts to offer a structure across a board coverage of CT: CT Systems, CT Performance, CT Practice, Spectral CT, Quantitative CT, Functional CT, and Special Purpose CT. Each contain chapters written by leading experts in the field, covering CT hardware and software innovations, CT operation, CT performance characterization, functional and quantitative applications, and CT systems devised for specific anatomical applications. This book is an ideal resource for practitioners of CT applications in medicine, including physicians, trainees, engineers, and scientists.

✦ Table of Contents

Foreword
Preface
Contents
Contributors
Part I: CT Systems
1: Fan-Beam CT Systems
Introduction
X-Ray Sources
X-Ray Detectors
Summary
References
2: Cone-Beam CT Systems
Basic Principles of Cone-Beam CT
Introduction
Physical Configurations
Image Reconstruction
Image Quality
Applications
Overview of This Chapter
Cone-Beam CT Systems
Genesis
System Geometry and the (Inaccurately Named) “Cone” Beam
The X-Ray Source
The Detector
Post-Patient Collimator/Anti-scatter Grid
Field of View (FOV)
Table Motion
Scan Speed
The Imaging Platform and Scan Trajectory
Power
Portability
Imaging Modes
4D Imaging
Imaging Performance: Spatial Resolution
Imaging Performance: Contrast and Noise
Imaging Performance: Artifacts Associated with the X-Ray Beam
Imaging Performance: Artifacts Associated with the Detector
Imaging Performance: Artifacts Associated with the System Geometry
Imaging Performance: Artifacts Associated with the Subject
Dosimetry
Clinical Applications
Regulations and Accreditation
Emerging Topics and Ongoing Research
Conclusions
References
3: Novel CT Acquisition
Introduction
Basic CT Acquisition Modes
Advanced CT Acquisition Modes
Axial Scan with a Large Area Detector
Dynamic or Perfusion Scan with Shuttle Mode
Helical Fast Pitch Scan on Dual-Source Scanners
Helical Scan with Variable Pitch
Organ-Based Tube Current Modulation
Automatic Selection of Optimal Tube Potential
Added Beam Filter to Optimize Beam Quality
Electrocardiogram (ECG)-Gated Cardiac Scan
Dual-Energy CT
Multi-energy CT
Dynamic Bowtie Filter
Conclusion
References
4: CT Statistical and Iterative Reconstructions and Post Processing
Introduction
Iterative Reconstruction
Examples
Statistical Reconstruction
Image Quality Metrics
Outlook
Conclusions
References
Part II: CT Performance
5: Dose and Risk Characterization in CT
Introduction
Computational Anatomic Models of Patients
Computational Phantom Format Types
Computational Phantom Morphometric Categories
Organ Dosimetry in CT Imaging
Modeling of the X-Ray Source Term
Normalization of the Monte Carlo Reported Organ Dose
Generic Axial Dose Libraries Versus Helical Protocol-Specific Dose Libraries
Considerations of Starting Angle and Over-Ranging
Modeling of Tube Current Modulation: Generic Versus Explicit
Risk Modeling in CT Imaging
Effective Dose and Radiation Detriment
Age- and Sex-Dependent Models of Lifetime Attributable Risk (LAR) of Cancer
Example Dose and Risk Assessment: Pediatric 18FDG PET/CT
Methods of Organ Dose and Risk Modeling in 18FDG PET/CT
Resulting Organ Doses and Cancer Risks Associated with 18FDG PET/CT
Conclusions
References
6: CT Image Quality Characterization
Introduction
Idealized Linear CT Systems
Noise Properties of Raw Detector Outputs
Noise Properties of Post-log Projection Data
Noise Properties of CT Images
Brief Review of Filtered Backprojection Reconstruction Algorithm
CT Noise Variance
CT Noise Power Spectrum
CT Spatial Resolution
CT Number Accuracy
Realistic Quasi-linear CT Systems
Noise Properties of Realistic Systems
Impacts of Bowtie Filter and Patient Position
Impacts of Polychromatic Source and Energy-Integrating Detector
Impacts of Discrete Sampling
Other Considerations
Spatial Resolution Properties of Realistic Systems
Summary of Realistic Quasi-linear CT Systems
Nonlinear CT Systems with Model-Based Iterative Reconstruction
Challenges Introduced by MBIR
Unconventional Noise Characteristics
Unconventional Spatial Resolution Characteristics
Image Quality Estimation for MBIR-Based CT Systems
Estimation of Noise Performance
Task-Based Estimation of Spatial Resolution Performance
CT Number Accuracy in MBIR-Based Systems
Summary
Appendix I: Autocovariance of Post-log Projection Data
Appendix II: CT Autocovariance
Appendix III: CT Image of a Point-Like Object Generated from an Idealized Linear System
References
7: Clinical CT Performance Evaluation
Performance Evaluation Preparation
Safety and Operational Inspection
Pretest Inspection
Quality Control Program
Display Monitor
System Geometry
Laser Alignment Accuracy
Scout Prescription Accuracy
Table Movement
Gantry Tilt
Axial Slice Thickness
Helical Slice Thickness
Radiation Beam Width
Radiation Output Performance
Exposure and Timer Characterization
Bow-Tie Filter Characterization
Displayed CTDIvol Accuracy for Clinical Protocols
Half-Value Layer and kVp
Localizer Dose
Tube Current Modulation
Image Quality
CT Number Accuracy
CT Number Uniformity
Spatial Resolution
Image Noise
Low-Contrast Resolution
Artifact Evaluation
Task-Based Performance
Dual Energy
Posttest Responsibilities
References
8: CT Performance Optimization
Introduction
Framework for CT Optimization
Radiation Risk Quantification
Clinical Risk Quantification
Optimization Dependency and Operating Points
The CT Protocol Review Process
What Is a CT Imaging Protocol?
Review Process
Standard Checklists
Achieving Consistency
Retrospective Radiation Dose Data
Retrospective Image Quality
Prospective Image Quality Data from Phantoms
Adjust Protocols for Consistency
Expected Dose and Image Quality Ranges for Revised Protocol
Feedback from Technologists and Radiologists
Monitor and Adjust if Needed
Relating Consistency to Optimization
Summary
References
Part III: CT Practice
9: CT Practice Management
Introduction: Motivation for Protocol Uniformity
Definition of a Protocol
CT Protocol Optimization Team
Lead CT Radiologist
Section Lead CT Radiologist
CT Physicist
Lead CT Technologist
IT Support
Applications Specialist
Management Solutions
Protocol Editing/Disseminating/Reviewing
Access to Protocol Information
References
10: CT Practice Optimization
Introduction: Defining the Scope
Proper Indication for CT Equals Justification
CT Protocols: Why, How, Who, and What?
The Why?
The Who and How?
The What?
Scan Parameters
Head CT
Chest CT
Abdomen-Pelvis CT
Pediatric CT
Quality Concerns
Dose Monitoring
Conclusions
References
11: CT Practice Monitoring
Introduction
Benefits of CT Performance Monitoring: Towards a Value-Based Care
Regulatory
Healthcare Providers
Researchers
Patients
Consistency of Care
Sources of Variability
Key Components of an Effective CT Practice Monitoring System
Access: Get Connection and Collection of Exam-Relevant Data
Metrology: Meaningful Quantities to Monitor
Dose Monitoring
Image Quality Monitoring
Scanner Parameters, Operations, and Patient Monitoring
Contrast Media Administration Monitoring
Analytics: From Data to Knowledge
Informatics: Dose and Quality Monitoring as a Secure, Integrated Solution
Metis: A New Next–Generation CT Practice Monitoring System
Patient-Specific Organ Dose Estimation
Patient-Specific Image Quality Metric
Automated Patient-Specific Noise Estimation
Automated Patient-Specific Spatial Resolution Estimation
Automated Patient-Specific HU Contrast Estimation
Predictive Analytic Models on Captured Dose, Image Quality, and Associated CT Examination Data
Ascertain Protocol- and Size-Specific Radiation Dose and Quality Reference Levels
Identify and Investigate Over- and Underexposure Cases
Ascertain Intra- and Intersystem Variability
Web-Based Graphical User Interface
Conclusion
References
Part IV: Spectral CT
12: Methods for Spectral CT Imaging
Introduction
Clinical Motivation
History of Dual-Energy CT
Importance of Spectral Separation
Multi-energy CT Data Acquisition Methods
Split-Beam Filtration
Dual-Layer Detectors
Photon-Counting Detectors (PCDs)
Slow Tube Potential Switching
Rapid Tube Potential Switching
Dual-Source Geometry
Image Rendition Methods
Low- or High-Energy Source Images
Mixed or Blended Images
Material-Selective Images
Classification vs. Quantification
Material Classification
Material Quantitation
Virtual Non-contrast Images
Energy-Selective Images
Discussion and Conclusion
References
13: Clinical Applications of Spectral CT
Neuroradiology
Stroke Imaging
Emergency Imaging
Further Applications
Thoracic Imaging
Lung Perfusion and Pulmonary Embolism
Cardiovascular Imaging
Cardiac Imaging
Vascular Imaging
Abdominal Imaging
Radiation Dose Reduction with Virtual Non-contrast Imaging
Characterization of Incidental Adrenal Nodules
Characterization of Urinary Stones
Evaluation of Bowel Disease
Quantification of Liver Fat
Oncologic Imaging
Tumor Detection and Characterization
Treatment Response Assessment
Iodine Quantification as a Predictive Biomarker
Musculoskeletal Imaging
Detection of Bone Marrow Edema
Detection of Gout
Reduction of Metal Artifacts
Pitfalls in Dual-Energy Imaging
Accuracy of Virtual Non-contrast Imaging
Reliability and Reproducibility of DECT Parameters
Artifacts in VNC and Iodine Imaging
References
14: Future Prospects of Spectral CT: Photon Counting
How Photon-Counting Detectors Differ from Conventional CT Detectors
Conventional CT Detectors: Indirect Conversion and Energy Integration
Photon-Counting CT (PCCT): Direct Conversion and Pulse-Height Analysis
Advantages of Photon-Counting CT Compared to Conventional Spectral CT Approaches
Challenges and Limitations of Photon-Counting CT
Flux-Independent Spectral Degradations
Flux-Dependent Spectral Degradations (Pulse Pileup)
Overcoming the Challenges of PCCT
Detector Hardware Solutions: Charge Summing and Layered Detectors
CT System Solutions: Improved Beam-Shaping Filters and Interior PCCT Imaging
Algorithmic Solutions: Detector Modeling and Empirical Decomposition
The Demonstrated and Future Impact of Photon-Counting CT
Improved Conventional (Nonspectral) CT Images
Improved Material Decomposition Imaging
Summary
References
Part V: Quantitative CT
15: CT-Based Quantification
Introduction
Relevance
Objectivity
Robustness
Implementation
Interactions
Conclusions
References
16: CT Material Identification
Introduction
Material Identification: General Principles
Dual-Energy CT: Material Identification with Single- and Dual-Source Systems
Photon-Counting CT: An Emerging Approach for Material Identification
Clinical Applications of Material Identification with DECT
Material Identification with DECT: Hepatic Applications
Material Identification with DECT: Pancreatic Applications
Material Identification with DECT: Genitourinary Applications
Material Identification with DECT: Other Abdominal Applications
Material Identification with DECT: Chest Applications
Material Identification with DECT: Musculoskeletal Applications
Material Identification with DECT: Head and Neck Applications
Clinical Applications of Material Identification with PCCT
Discussion and Conclusion
References
17: CT Texture Characterization
Introduction
Image Texture
Histogram Analysis
Gray-Level Co-occurrence Matrix
Fourier Analysis
1.4 Laws’ Textures Analysis
Fractal Analysis
Practical Considerations
Regions of Interest
Image Acquisition
Image Manipulation
Texture Software Packages
Applications of Image Texture in CT Scans
Bladder Lesion Response
Lung Lesion Classification
Normal Tissue Complications
Conclusions
References
Part VI: Functional CT
18: CT as a Functional Imaging Technique
Introduction
PET/CT
CT Texture Analysis
CT Perfusion in the Oncologic Setting
CT Functional Assessment in Cardiac Imaging
Volumetric CT Measurements
Material Decomposition
Conclusion
References
19: CT Perfusion Techniques and Applications in Stroke and Cancer
Introduction
Theory of Contrast Transport
Model-Independent Approach
Modeling Approaches
Blood Vessels as a Compartment: Two-Compartment Model
Plug (Non-dispersive) Flow in Blood Vessels: Johnson-Wilson-Lee Model
No Contrast Efflux from Interstitial Space: Patlak Model
Numerical Deconvolution Techniques
Model-Independent (Black Box) Deconvolution
Model-Based Deconvolution
Comparison of Deconvolution Methods for CTP
CTP Scanning Protocols, Effective Dose, and Image Reconstruction
Applications in Stroke and Cancer
Hemorrhage Transformation in Stroke
Segmentation of Penumbra and Infarct in Stroke
Monitoring Response to Transarterial Chemoembolization of Liver Tumor
Conclusion
References
20: CT Myocardial Perfusion Imaging
Introduction
Fundamental Physiological Parameters
Indicator-Dilution Method
Maximum Slope Method
Deconvolution Method
Tracer Kinetic Models
Two-Compartment Exchange Model
Patlak Model
Tissue Homogeneity Model
Model-Based Maximum Slope Analysis
Practical Issues of Tracer Kinetic Modeling
Recirculation of Contrast Medium
Dispersion in True Arterial TEC Relative to Measured Arterial TEC
Delay of Tissue TEC Relative to Measured Arterial TEC
Implementations
Contrast Administration
Contrast Materials
Contrast Injection Rate
Contrast Concentration
Contrast Volume
Acquisition Settings
Tube Voltage
Tube Current
Gantry Rotation Speed
Total Acquisition Time
Sampling Frequency
Image Reconstruction
Reconstruction Filter
Statistical-Based Iterative Reconstruction
Sparse-View Reconstruction
Clinical Applications
Conclusion
References
Part VII: Special Purpose CT
21: CT in Musculoskeletal Applications
Role of Radiography and CT in Musculoskeletal Radiology
Development of Specialized Cone-Beam CT for Musculoskeletal Extremities
Artifacts and Corrections in Extremity CBCT
Current and Emerging Clinical Applications of Extremity CBCT
New Directions in Musculoskeletal CT
References
22: Utility of CBCT in Neurovascular Diagnosis and Interventions
Introduction
Treatment Planning and Guidance
Acute Ischemic Stroke
Flat Detector Digital Subtraction Angiography
Parametric Color-Coded 2D-DSA
3D-DSA and Time-Resolved 3D-DSA (4D-DSA)
Acquisition and Contrast Injection Protocols
References
23: CT in Cardiac Applications
The Heart
Anatomy
Aorta and Coronary Artery Origins
Coronary Arteries
Coronary Veins
Pericardium
Physiology
Cardiac Cycle
The Electrocardiogram and Cardiac Rhythms
Evolution of Cardiac CT
Early Designs
Electron Beam CT
Multidetector Row CT
Detector Width and Row Number
Multiple Radiation Sources
Gantry Rotation Time
Cardiac-Specific Considerations for CT Acquisition and Reconstruction
Spatial Resolution
Temporal Resolution
Contrast Considerations
Image Artifacts
Display Planes
Cardiac-Specific Strategies for Patient Preparation, CT Acquisition, and CT Reconstruction
Managing Heart Rate for Improved Scan Quality
Potential Causes of Heart Rate Elevation or Lability
Beta Blockade to Lower and Stabilize Heart Rate
Acquisition Modes for Cardiac CT
Multi-beat Acquisition Modes
Prospective Triggering
Retrospective Gating
Single-Beat Acquisition Modes
Temporal Resolution of CT Sections
Half-Scan Reconstruction
Multi-segment Reconstruction
Dual-Source CT
Anatomically Directed Motion Correction
Radiation Exposure
Low kV Imaging
Scan Mode
Iterative Reconstruction
Clinical Applications
Coronary Arteries
Coronary Calcium Measurement
Coronary CT Angiography
Image Analysis
Application to Assessing Coronary Artery Disease
Anomalous Coronary Artery Course
Surgical Planning
Pulmonary Vein Evaluation
Resynchronization
Transcatheter Valve Replacement
Re-operative Cardiac Surgery
Structural Heart Disease
Congenital Heart Disease
Tumors/Masses
Valves
Emerging and Future Applications
Infarction and Viability
Myocardial Perfusion Imaging
Summary
References
Index