The purpose of the DICOM Structured Reporting (SR)) specification is to improve the documentation of diagnostic images and waveforms. The specification supports the interchange of expressive compound reports in which the critical features shown by images and waveforms can be denoted unambiguously by the observer, indexed, and retrieved selectively by subsequent reviewers. Findings may be expressed by the observer as: 1)) text, codes, numeric measurements; 2)) computer-generated coordinates of specific regions of interest within images or waveforms; or 3)) references to comparison images, sound, waveforms, curves, and previous report information. The observational and historical findings recorded by the observer may include any evidence referenced as part of an interpretation procedure. Thus, DICOM SR supports not only the reporting of diagnostic observations, but the capability to document fully the evidence that evoked the observations. This capability provides significant new opportunities for large-scale collection of structured data for clinical research, training, and outcomes assessment as a routine by-product of diagnostic image and waveform interpretation and facilitates the pooling of structured data for multi-center clinical trials and evaluations.