MIsmatich or orphan studies are those studies which does not have a matching accession number with the RIS order.As per IHE RIS generates the Accession number when the case is scheduled or registered and then it gives command to PACS to create the empty study folder with Accession number.After images are acquired if the modality is aware of the accession number then it send those images to the created folder with the same accession number. What are the scenarios when there is mismatch occur 1) If there is no DICOM Modality worklist option configured on the Modality and the RIS then this can cause many mismatch issue as tech will need to enter the registration data on the modality manually and manual entry always has more erro rate. 2) If the RIS is not working and then patient is scanned with manual registration of the patient on the Modality 3) Many times complementary studies are done and need to send to the existing study folder in the PACS as a different series. This above sceanrio may cause mismatch study.

MIsmatich or orphan studies are those studies which does not have a matching accession number with the RIS order.As per IHE RIS generates the Accession number when the case is scheduled or registered and then it gives command to PACS to create the empty study folder with Accession number.After images are acquired if the modality is aware of the accession number then it send those images to the created folder with the same accession number. What are the scenarios when there is mismatch occur 1) If there is no DICOM Modality worklist option configured on the Modality and the RIS then this can cause many mismatch issue as tech will need to enter the registration data on the modality manually and manual entry always has more erro rate. 2) If the RIS is not working and then patient is scanned with manual registration of the patient on the Modality 3) Many times complementary studies are done and need to send to the existing study folder in the PACS as a different series. This above sceanrio may cause mismatch study.