Accession Number

In the DICOM framework, Accession Numbers play a critical role in maintaining the connection between patient diagnostic information, order details, and related scheduling data, which is made available at a given medical imaging modality through the DICOM Modality Worklist (MWL) from a Radiology Information System (RIS). This system helps avoid redundant data entry and ensure data accuracy.

The Accession Number, rather than order placer number or order filler number, serves as the key identifier for the order, copied from the MWL into the image header. This enables radiologists to identify the corresponding diagnostic report accurately.

In scenarios where a patient has multiple scheduled exams, the Accession Number becomes an essential link connecting the specific radiology order with the completed exam. It is common for medical institutions to necessitate the Accession Number at a radiology workstation, fostering precise correlation between the diagnostic report and the performed examination.

Although the DICOM standard mandates the Accession Number’s provision with the images, it may not always be readily available. Some equipment manufacturers may not even facilitate its entry at the modality. However, implementing an Information System (IS) interface can resolve this issue, enabling the retrieval and transmission of the Accession Number with the images.

The MWL retrieves scheduling information from the RIS, allowing images to be distinctly identified through key values that pair them with the respective radiology order and diagnostic reports. This retrieval process necessitates, at the very least, the following keys: Accession Number, Patient Name, and Patient ID.