ABSTRACT
CONTENTS 5.1 Methods and Measurement in Nuclear Medicine . . . . . . . . . . . . . . 134
5.1.1 The Physics of Detection: Basic Concepts . . . . . . . . . . . . . . . 137 5.1.1.1 Interaction of Radiation with Matter . . . . . . . . . . . . 140
5.1.2 Gamma Radiation Detectors . . . . . . . . . . . . . . . . . . . . . . . . 144 5.1.2.1 Gas-Filled Detectors . . . . . . . . . . . . . . . . . . . . . . . . 144 5.1.2.2 Semiconductor Detectors . . . . . . . . . . . . . . . . . . . . 145 5.1.2.3 Scintillation Detectors . . . . . . . . . . . . . . . . . . . . . . . 147 5.1.2.4 Photomultipliers . . . . . . . . . . . . . . . . . . . . . . . . . . 152 5.1.2.5 Variants and Alternatives . . . . . . . . . . . . . . . . . . . . 154
5.1.3 Signal Acquisition Electronics . . . . . . . . . . . . . . . . . . . . . . . 155 5.2 Properties of Image Detection Systems . . . . . . . . . . . . . . . . . . . . . . 158
5.2.1 Distance of Resolution: PSF . . . . . . . . . . . . . . . . . . . . . . . . . 158 5.2.2 Modulation Transfer Function . . . . . . . . . . . . . . . . . . . . . . 160 5.2.3 Detection Efficiency or Sensitivity . . . . . . . . . . . . . . . . . . . . 163
5.2.3.1 Geometric Efficiency . . . . . . . . . . . . . . . . . . . . . . . . 163 5.2.3.2 Quantum Efficiency . . . . . . . . . . . . . . . . . . . . . . . . 163 5.2.3.3 Conversion Efficiency . . . . . . . . . . . . . . . . . . . . . . . 164 5.2.3.4 Total Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
5.2.4 Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 5.3 Methods of Image Production in Nuclear Medicine . . . . . . . . . . . . 165
5.3.1 Gamma Camera and SPECT . . . . . . . . . . . . . . . . . . . . . . . . 167 5.3.1.1 Collimators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 5.3.1.2 Data Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . 174 5.3.1.3 Data Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 5.3.1.4 Preprocessing of Data . . . . . . . . . . . . . . . . . . . . . . . 177 5.3.1.5 Image Reconstruction . . . . . . . . . . . . . . . . . . . . . . . 177
5.3.2 PET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 5.3.2.1 Physical Principles and Limits . . . . . . . . . . . . . . . . 178 5.3.2.2 Data Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . 182 5.3.2.3 Data Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 5.3.2.4 Preprocessing of Data . . . . . . . . . . . . . . . . . . . . . . . 190 5.3.2.5 Image Reconstruction . . . . . . . . . . . . . . . . . . . . . . . 196
5.3.3 Multimodal and Dedicated Systems . . . . . . . . . . . . . . . . . . 197 5.3.3.1 Systems for Specific Applications . . . . . . . . . . . . . . 197 5.3.3.2 PET/CT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 5.3.3.3 PET/MRI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Imaging is becoming increasingly important in modern medicine, either as a means of diagnosis or as additional support for planning and controlling clinical procedures. One of the factors that has contributed to this has been the improved quality of medical images. Enhanced contrast and resolution, reduced noise, distortion and artifacts, as well as the possibility of quantification have become key objectives in several areas such as the physics of detectors or image reconstruction mathematics.
