Enhancement of medical device interoperability by defining custom extensions to DICOM standards: User-defined DICOM SR

Ultrasound as an imaging modality uses sound waves to scan soft tissues. Ultrasound systems provide users a way to quantify anatomical structures by providing well defined (standard) measurements. Systems also compute certain results; referred to as standard calculations, based on the measurements that user performs on the image. This quantified information is sent using DICOM (Digital Imaging and Communications in Medicine) Structured Report (SR) to PACS (Picture Archiving and Communication System). However, as clinical science is a continuously emerging field, the needs to quantify the anatomy using different measurements and different computations than what is defined in DICOM standards must be met by the Ultrasound systems. This requires Ultrasound systems to provide users a way to create user-defined measurements, calculations and authors(clinical scientists that define mathematical equations for measurements or calculations). This definition of custom data poses a problem from the standpoint of interoperability with devices such as PACS. The most common way to address this problem is to define a private DICOM SR template. But this can address the issue only for those configurations where the connected systems are from the same manufacturer. The purpose of this paper is to define a way to standardize the definition of user-defined objects such as user-defined measurements, calculations and authors by using the existing DICOM Structured Report templates. This ensures that user-defined objects can be interpreted by all PACS vendors with their existing software in the same way as they interpret the standard objects. The paper further discusses usage of a mapping tool that can be used on PACS to associate user-defined objects with the known objects on the PACS.