Now that the dust has settled from HIMSS 2018, interoperability was a hot topic that has promise for improving interaction between systems and entities.  Many are jumping on the FHIR (Fast Healthcare Interoperability Resources) bandwagon as a methodology for improving interoperability.  This is great news for IDN’s, and for data accessibility across entities, but hopefully, the marketplace will consider lessons learned from the imaging space.

Many years ago, there was great enthusiasm for another industry standard, and what it was going to mean for image exchange – that being the DICOM (Digital Imaging Communications) Standard.  DICOM was purported to be the answer to how disparate imaging systems and PACS (Picture Archive and Communications System) could interoperate. 

What those involved in the early DICOM efforts discovered was that it requires more than simply defining a protocol or means for sharing information.  For example, there needs to be a common definition of nomenclature so that information can be reliably passed between systems. 

I recall an early issue that cropped up between a certain vendor’s CT scanner and different vendor’s PACS. CT images are composed of pixels that are quantified by a measurement known as Hounsfield Units. Tissue densities are represented by numerical values that range from -1000 (air) to +1000 (bone).  To simplify things, this particular CT vendor stored values by adding 1000 units to make everything positive (0-2000).  Since the PACS was expecting images with the standard Hounsfield units, images displayed on the PACS were blank (black) screens, as normal tissue with a value of zero would now be 1000.