Separation of metadata and bulkdata to speed DICOM tag morphing

Most medical images are archived and transmitted using the DICOM format. The DICOM information model combines image pixel data and associated metadata into a single object. It is not possible to access the metadata separately from the pixel data. However, there are important use cases that only need access to metadata, and the DICOM format increases the running time of those use cases. Tag morphing is an example of one such use case. Tag or attribute morphing includes insertion, deletion, or modification of one or more of the metadata attributes in a study. It is typically used for order reconciliation on study acquisition or to localize the Issuer of Patient ID and the Patient ID attributes when data from one Medical Record Number (MRN) domain is transferred to or displayed in a different domain. This work uses the Multi-Series DICOM (MSD) format to reduce the time required for tag morphing. The MSD format separates metadata from pixel data, and at the same time eliminates duplicate attributes. MSD stores studies using two files rather than in many single frame files typical of DICOM. The first file contains the de-duplicated study metadata, and the second contains pixel data and other bulkdata. A set of experiments were performed where metadata updates were applied to a set of DICOM studies stored in both the traditional Single Frame DICOM (SFD) format and the MSD format. The time required to perform the updates was recorded for each format. The results show that tag morphing is, on average, more than eight times faster in MSD format.