Computed Radiography Technology 2004
نویسنده
چکیده
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 The CR System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 Image Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 Point-Scan CR Readers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 Line-Scan CR Readers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Image Data Pre-Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Shading Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Identification and Scaling of “Pertinent” Data . . . . . . . . . . . . . . . . . . . . . . . . 161 Image Data Post-Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 Contrast Enhancement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 Spatial Frequency Enhancement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 Multi-Scale, Multi-Frequency Enhancement . . . . . . . . . . . . . . . . . . . . . . . . . 164 Disease-Specific and Dual-Energy Processing . . . . . . . . . . . . . . . . . . . . . . . . 165 The Physicist’s Role in CR Implementation . . . . . . . . . . . . . . . . . . . . . . . 166 Clinical Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 CR Reader Throughput . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 Phosphor Plates, Cassettes, Grids, Identification Terminals . . . . . . . . . . . . . 166 Incident Exposure Estimation and Other Data Fields . . . . . . . . . . . . . . . . . . 167 Image-Processing Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 CR Interfaces to RIS, HIS, Imaging Networks, and PACS . . . . . . . . . . . . . . 167 Quality Control Phantom Set and Software . . . . . . . . . . . . . . . . . . . . . . . . . . 168 Service Contracts, Preventive Maintenance, Warranty, and Siting Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 Exposure Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 Fuji CR: Sensitivity Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 Kodak CR: Exposure Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Agfa CR: lgM Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 CR Exposure Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 Spatial Resolution, Contrast Resolution, and Detective Quantum Efficiency (DQE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Spatial Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Contrast Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 Detective Quantum Efficiency (DQE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 CR Manufacturers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
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