Yes and no. I spoke with an Epic engineer recently and he confirmed that Epic is still a front-end to HL7 databases. With that said, many PACS are adopting the WADO standard (https://www.research.ibm.com/haifa/projects/software/wado/), which provides a REST interface to radiology images. It makes it a lot easier to retrieve images for analysis, albeit you'd still have to implement DICOM/HL7 if you want to make a usable product.