A Short Introduction to DICOM or Where's My Data?

From Bangor Imaging Unit

The DICOM standard specifies data structures, file formats and communications protocols. DICOM is both file format and a transfer protocol. DICOM is commonly used with medical data, especially images. The National Electrical Manufacturers Association (NEMA) holds the copyright to the standard.[1]

On The Scanner

The scanner console computer stores exams (studies) in the Local Patient Database. The scanner automatically transfers studies from the local patient database to our PACS but only if the study is set to automatically push to PACS. Studies should appear on the PACS within a few hours.

You can see the contents of the local patient database on the scanner console by selecting Administration from the Patients menu.

Clicking on a patient name will open up that patient and show information about each exam.

The scanner only has space for a month's worth of scans. If your data did not transfer correctly, ask for help or Push Data to PACS manually. Studies over two weeks old in the Local Patent Database are subject to deletion.

Getting Your Data the Easy Way

Dcmdb automates retrieving data from the PACS. At 1AM every morning, dcmdb retrieves the previous day's studies to the shared volume dcmdb on Odin and Saga then converts any DICOM files to NifTI. Studies are sorted into folders by Referring Physician Name. Studies without a referring physician name are put in the unknown folder.

To get your data, connect to smb://odin.ad.bangor.ac.uk or smb://saga.ad.bangor.ac.uk (Finder, Go, Connect to Server...) and mount the volume dcmdb. Open your folder and copy the studies you want. Implementation details are on the dcmdb wiki page. Dcmdb is not a archival backup. Very old studies may be deleted if we run low on space.

Getting Your Data from the PACS

To find retrieve your study is on the PACS you need to run a DICOM query followed by a move. Our PACS will only move data to AE Titles and IP addresses it recognises and only to computers on the wired university network. Ask Andrew to add an AETitle for your desktop computer to the PACS. Once that is done you can configure a tool to run a query.

Weasis, DicomQueryTool, Horos and OsiriX are tools that can query a PACS and retrieve studies. We recommend Weasis.
Scans on PACS use transfer syntax 1.2.840.10008.1.2.4.90, JPEG-2000 Lossless compression. Most work flows require a transcode to uncompressed. See Image Data Formats and Conversions.

  1. DICOM brochure, nema.org.