2. Vidicor 3. Anacor 4. Digicor 5. Magnetic Recording of the Videosignal VI. GEOMETRIC MODEL I. Introduction 2. Survey of Models 3. Preparation of Casts 4. Index of Irregularity 5. In Vitro Tests VII. DETECTION OF THE VENTRICULAR CONTOUR I. Introduction 2. Semi-automatic Methods 3. The Influence of the Trained Operator 4. Conclusions VIII. DATA CONVERSION 1. Introduction 2. Light-pen System and Contour Memory 3. Digicor 4. Evaluation Procedure 5. Data Presentation IX. SOFTWARE SYSTEM 1. Introduction 2. Modular Structure 3. Data Conversion 4. Volume Calculation 5. Data Presentation 6. Special Programs X. IN VIVO TESTS 1. Introduction 2. Materials and Methods 3. Results XI. UNCERTAINTY ANALYSIS I. Introduction 2. Uncertainty Intervals for Relevant Variables Propagation 3. of Uncertainty 4. Uncertainty Interval in the Result XII. DISCUSSION XIII. APPENDIX 1. Glossary 2. Dedvations 3. Results XIV. REFERENCES 1. Literature 2. Internal Reports ACKNOWLEDGEMENTS VIII Illustrations Figure Block-diagram of Instrumentation 12 1. 1 Central Synchronization 17 2. 1 2. 2 Effect of Scattered Radiation (Biplane) 18 Block-diagram of X-ray/TV-system 2. 3 21 2. 4 Test-object for OTF-measurement 25 Spatial Responses and Optical Transfer Functions 2. 5 26 Deviation from Isoplanasy and Influence of Additional Equipment 2. 6 28 2. 7 Temporal Modulation Transfer Function Curves 31 2. 8 Biplane Projections 33 2. 9 X-ray Aiming Device 36 2. 10 Calibration Curve 37 3. 1 Concentration vs. Tube Voltage Curves 45 3. 2 Markers and Applicators 48 3. 3.