17 Image Post-Processing and Interpretation

Image post-processing is defined as the process of integrating a series of axial images into a form that is often easier to interpret than the sections themselves. The source transverse section is a fundamental image for interpretation. However, because of the complexity of coronary anatomy, interpreters must review coronary CT angiography interactively on workstations capable of 3-dimensional (3D) displays. The 3D data set can be reformatted according to the needs of the investigator using several types of post-processing algorithms. Coronary artery interpretation includes assessment of calcium scoring on non-contrast image and coronary angiography on enhanced image. Non-coronary cardiovascular findings and extra-cardiac findings should be reviewed in addition to recognize primary and secondary comorbid pathology and to identify findings that lead to alternative non-cardiovascular diagnoses. The ultimate objective of post-processing and interpretation is to convey diagnostic information to the treating physician with as much clarity and accuracy as possible. Interpretation times vary, usually depending on the image quality and the user’s experience and knowledge of cardiac CT and the individual workstation. Normally, experienced users usually spend no more than 10 minutes segmenting and interpreting cardiac CT studies.