Book excerpt: It was our aim to place at the disposal of radiologists within a short time an atlas of high-quality, valuable pictures of abdominal CT without We felt that, the image degradation inherent to slower scanning apparatus. notwithstanding rapid evolution in CT scanning apparatus and the resulting rapid advances in our clinical knowledge about the value, limitations and applications of this new diagnostic imaging modality, an effort should be made to realize an atlas of reference. From more than 7,000 patients studied with abdominal CT, we tried to assemble images with maximal anatomical detail, which implies the use of large window settings, being well aware that in daily routine practice basic CT methodology includes the use of different window settings for optimal information. It was, however, a conscious decision not to use comparative images with large and small window settings in order to stay within a reasonable total number of figures. Much emphasis has been placed upon the use of contrast enhancement by intravenous contrast media. This is based on the conviction that essen tially new and better morphological information about normal and pathological processes within the abdomen can be obtained because short exposure times now allow one to capture the rapidly changing aspect and degree of contrast enhancement of the lesions as a function of their vascu larity.