Image processing for indexing of cineangiograms

Video is the primary media used for cardiology diagnosis. Video data is currently stored on either cinefilm or videotape and provides no means of integration with other information such as patient's history, x-ray images, and test results. Maintaining and searching this data is also difficult. A multimedia database system would significantly enhance the diagnosis process by facilitating these integration, maintenance, and searching processes. One of the challenges in designing such a database is indexing the sequential video streams. The required storage space and the retrieval time to one specific video frame are two crucial issues in the design of a video database system. This paper presents two novel and fast image processing techniques for use in the selection of video frames. These selected frames can then be stored in the database. The first type of analysis is based on the analysis of spatial transitions and the second is based on the spectral components in the discrete cosine domain. The proposed techniques extract the length of the total edges in every frame of the cineangiogram. The extracted parameter is directly related to the amount of radio opaque dye injected in the coronary arteries. Those frames in the cineangiogram with a significant level of dye are then identified and indexed for evaluation. The extracted parameter index is used to select these frames for physician review. The same techniques are applied to the centered window of every frame to extract the cardiac cycles in the cineangiogram. This information can be used to index the stored cineangiogram for fast retrieval. It can also be used to synchronize two cineangiograms playing at the same time for clinical comparison and evaluation. Both techniques have been applied to twenty-one sets of cineangiograms. The results are very consistent with physician observation. Since both techniques produce comparable result, the selection between them is dependent on the format of the video. The second technique is effective when the compression standard JPEG or MPEG is used to encode the cineangiogram while the first one can be used for uncompressed or lossless compressed cineangiograms.