Concepts to support users of the Diagnostic Imaging Dataset (DIDS) data product

The DIDS collects information relating to the examination through submitted codes. There are two types of exam code that trusts are required to submit:

• National Interim Clinical Imaging Procedure codes (NICIP codes) 
• Systematized Nomenclature of Medicine Clinical Terms codes (SNOMED CT codes)

The system is enabled for submissions of both NICIP and SNOMED CT codes and trusts can submit either or both codes. The system maps all submitted NICIP codes to their equivalent SNOMED CT code to enable derivation of examination categories such as modality, body site, body region.

Each record relates to a single examination. In some cases, examinations will include multiple elements, each of which is covered by its own NICIP or SNOMED CT code. In these cases, the most complex code is submitted as part a single submission for the examination. The records within the DIDS do not represent the number of scans or tests which have taken place.

The DIDS is a central collection of detailed information about diagnostic imaging tests carried out on NHS patients, which is extracted and submitted monthly.

Data submitted to the collection has been extracted from local Radiological Information Systems (RISs). Data not captured on the provider’s RIS such as for breast screening or cardiac ultrasound activity is not included in the collection. The images that are produced from the tests or post mortem imaging are not included. 

The DIDS collection includes activity undertaken since April 2012.

Each record within the DIDS represents an examination. Where the examination has involved multiple elements, a single record is submitted with the most complex NICIP or SNOMED CT code used to represent the activity undertaken. 

Care should be taken to understand the status of the DIDS data that is being utilised from the DIDS data product at any given time and whether this is considered either provisional or finalised in nature.

Whilst the submission timeline for the DIDS collection expects that data will be submitted by providers in the month after the examination took place. Data can be submitted or changes to a record made by the provider for up to 3 months following the month the activity took place. In addition, to accommodate exceptional circumstances where providers maybe experiencing challenges in achieving this, a DIDS submission be enabled to occur outside of the 3 month window. No submission or amendment to a record is possible after 6 months following the month the activity took place and it is after this point that the data maybe considered to be finalised in nature.

Data of both a provisional and finalised nature is provided within the DIDS data product to accommodate use cases where timeliness rather than completion may be more desirable.

Each submitted record includes a radiological accession number. The combination of site code and radiological accession number uniquely define an examination.

The radiological accession number can be used by a site to make updates to the examination record, the previous record is then archived from the collection.