High throughput tools to access images from clinical archives for research

Abstract

Historically, medical images collected in the course of clinical care have been difficult to access for secondary research studies. While there is a tremendous potential value in the large volume of studies contained in clinical image archives, Picture Archiving and Communication Systems (PACS) are designed to optimize clinical operations and workflow. Search capabilities in PACS are basic, limiting their use for population studies, and duplication of archives for research is costly. To address this need, we augment the Informatics for Integrating Biology and the Bedside (i2b2) open source software, providing investigators with the tools necessary to query and integrate medical record and clinical research data. Over 100 healthcare institutions have installed this suite of software tools that allows investigators to search medical record metadata including images for specific types of patients. In this report, we describe a new Medical Imaging Informatics Bench to Bedside (mi2b2) module ( www.mi2b2.org ), available now as an open source addition to the i2b2 software platform that allows medical imaging examinations collected during routine clinical care to be made available to translational investigators directly from their institution's clinical PACS for research and educational use in compliance with the Health Insurance Portability and Accountability Act (HIPAA) Omnibus Rule. Access governance within the mi2b2 module is customizable per institution and PACS minimizing impact on clinical systems. Currently in active use at our institutions, this new technology has already been used to facilitate access to thousands of clinical MRI brain studies representing specific patient phenotypes for use in research.

Fig. 1

This schematic diagram shows how the mi2b2 software communicates with multiple institutional PACSs. In part A, we show the user initiating a query from the mi2b2 client for patient or study information (1). The mi2b2 server cell translates this query into a C-FIND request across the appropriate institution(s) and PACSs (2). The PACSs return information to the mi2b2 server cell (3) and the server cell formats and returns this information back to the mi2b2 client (4) for viewing. In part B, we show the user initiating an image request from the mi2b2 client (1). The mi2b2 server cell queues that request and then issues C-MOVE commands to the appropriate PACSs in accordance with the governance settings (2). The PACSs move the image data into a secure, central cache within the mi2b2 server cell (3). The user is notified that the images are available in the cache and he/she initiates the transfer of the image data through the mi2b2 client to the user specified local storage (4). Note that all steps must be specifically covered by an Institutional Review Board approved protocol

Fig. 2

This is a screen shot of Tab 1 (Search for Patients). It shows a list of MRNs (1a) that are searched against the connected PACS. Search results (patients) are shown in the table below (1b). Controls on right allow users to further filter results (1c). Users initiate finding studies by clicking on “Find Studies for Selected Patients” button on the bottom right (1d). The formats of the MRNs vary because these are “TEST” MRNs, not truly linked to real patients

Fig. 3

This is a screen shot of Tab 2 (Search for Studies). It illustrates how the patients previously selected in Tab 1 are used to search for studies (2a). Resultant studies are shown in the main panel (2b). Users can select desired studies and press “Move to Repository” to initiate a C-MOVE to move studies from the PACS to mi2b2’s cache (2c). The formats of the accession numbers vary because these are “TEST” accession numbers, not truly linked to real patients

Fig. 4

This is a screen shot of Tab 3 (Image Repository) showing all studies moved to the mi2b2 cache (see Fig. 3). The used and available capacity of the cache is displayed on top (3a), and the list of available studies is shown in the main panel (3b). Users can manage their cache usage by deleting studies. Selected studies can then be copied to other connected services such as XNAT, OsiriX, or to a local machine by selecting from the drop down box “Choose a Request Type…” on the bottom right (3c)

Fig. 5

The simple DICOM image viewer in Tab 4 of the client lets users view downloaded studies. Selected studies are organized on top left by patient ID, study UID, series UID, and image ID (4a). The bottom left panel shows a list of studies already downloaded to local machine (4b)

Fig. 6

Tab 5: All requests, such as a C-MOVE, made to mi2b2 are placed in the Request Log in Tab 5. Users can track whether a request is scheduled, processing, completed, or has failed (5a)