A Data Model for Handling Whole Slide Microscopy Images in Picture Archiving and Communications Systems

Extremely large medical images, like ones of virtual slide microscopy, are beyond some limitations of the DICOM standard (e.g., a 4 Gbyte barrier, caused by 32-bit architecture). Some solutions and trade-offs have been already proposed and included in the DICOM standard (e.g., usage of JPEG2000 image compression standard, JPEG2000 interactive protocol [JPIP] and division of the images into smaller parts for placing them in the PACS). These new features lead to implementation of alternative interaction solutions simultaneously in the same PACS to serve both images of typical size (e.g., radiological) and large size virtual slide microscopy images. The paper deals with problems of (a) constructing a data and interaction model of images within PACS, (b) searching for criteria to assess image content complexity and to reach an efficient division of virtual slide microscopy images into tiles; (c) providing both the conventional DICOM services and the image interchange using JPIP.