Outline and Guide for Learning

1.      Introduction and Overview

1.1.   Image Quality Characteristics and Clinical Significance

1.2.   Radiation Dose Significance and Management

2.      Image Quality Characteristics

2.1.   Contrast Sensitivity

2.2.   Blurring and Visibility of Detail

2.3.   Visual Noise

2.4.   Spatial Characteristics

2.5.   Artifacts

3.      Blurring and Visibility of Detail

3.1.   Clinical Significance

3.2.   Sources of Blurring in CT

3.2.1.      Ray Dimensions

3.2.2.      Pitch

3.2.3.      Voxel Size

3.2.4.      Reconstruction Filter Algorithm

3.3.   Ray Dimensions

3.3.1.      Detector Size

3.3.2.      Focal Spot Size

3.3.3.      X-ray Beam Width

3.4.   Pitch

3.4.1.      Concept

3.4.2.      Effect on Detail

3.5.   Voxel Size

3.5.1.      Concept and effect on blurring

3.5.2.      Matrix Size

3.5.3.      Field of View

3.5.4.      Slice Thickness

3.6.   Reconstruction Filter Algorithms

3.6.1.      Concept

3.6.2.      Effect on Blurring and Detail

3.6.3.      Algorithm Selection

3.7.   Measuring the Effects of Blurring

3.7.1.      Spatial Resolution as a Measure of Blurring

3.7.2.      Test Objects, Phantoms, and Methods
 

4.      Image Visual Noise

4.1.   Concept and Visual Characteristics

4.1.1.      General Appearance

4.1.2.      Relationship to CT Numbers

4.2.   Effects on Image Quality and Visibility

4.2.1.      General Effects

4.2.2.      Effects on Visibility of Low-Contrast Objects

4.3.   Quantum Noise

4.3.1.      Concept

4.3.2.      Effect of Voxel Size

4.3.3.      Effect of X-ray Exposure and Dose

4.3.4.      Effect of Reconstruction Filter Algorithm

4.4.   Measurement of Noise in CT Image

4.4.1.      Concept

4.4.2.      Noise Statistics and Standard Deviation

4.4.3.      Water Phantom

4.4.4.      Region of Interest (ROI) and Standard Deviation
 

5.      Radiation Dose in CT

5.1.   Special Dose Quantities for CT

5.1.1.      Computed Tomography Dose Index (CTDI)

5.1.2.      Dose Length Product (DLP)

5.2.   Determining Dose Values

5.2.1.      Measurement in Phantoms

5.2.2.      Calculation From Scan Factors

5.2.3.      Values Displayed by the CT Equipment

5.3.   Factors Directly Affecting Dose

5.3.1.      MAS

5.3.2.      Pitch

5.3.3.      Length of Scanned Area

5.4.   Relationship of Dose to Image Noise

5.4.1.      Concept

5.4.2.      Level of Noise in CT Images

5.4.3.      Selecting the Optimum Noise Level

5.5.   Relationship of Dose to Image Detail

5.5.1.      Concept

5.5.2.      The Detail-Noise Relationship

5.5.3.      Selecting Optimum Image Detail
 

6.      Image Quality Optimization and Dose Management

6.1.   Concept

6.2.   Clinical Requirements for Detail

6.3.   Adjusting the Noise Level

6.4.   Monitor Dose Values
 

7.      Image Artifacts

7.1.   Concept

7.2.   Partial Volume

7.3.   Beam Hardening

7.4.   Motion

7.5.   Metal

8.      Image Quality Assurance

8.1.   Evaluations and Preventative Maintenance by Equipment Engineers

8.2.   Evaluations by Physicists

8.3.   Evaluations and Observations by Technologists

8.4.   Observations and Requirements by Radiologists