A new technique for measuring lumbar segmental motion in vivo. Method, accuracy, and preliminary results.

STUDY DESIGN: A direct method for three-dimensional in vivo spine kinematic studies was developed and used to measure segmental motion patterns in healthy subjects. OBJECTIVES: To validate the new method, and to study the L3-L4 segmental motion patterns for complex dynamic movements. SUMMARY OF BACKGROUND DATA: Conventional two-dimensional and three-dimensional radiographic methods have been used in the past to study spine kinematics. Few studies provided a direct approach to study segmental kinematics. No dynamic recordings of three-dimensional segmental motion patterns have been reported previously. METHODS: In 16 healthy men, Kirschner wires were inserted in the spinous processes of L3 and L4. Electromagnetic tracking sensors were attached to the pins. Motion data recorded during ranging exercises were used with biplanar radiographs to calculate L3-L4 segmental motion patterns. Errors resulting from pin deformation and the dynamic accuracy of the tracking system were investigated thoroughly. RESULTS: The average range of motion for flexion-extension was 16.9 degrees, for one side lateral bending 6.3 degrees and for one side axial rotation 1.1 degrees. Large intersubject variation was found in flexion-extension with values ranging from 7.1 to 29.9 degrees. Coupled motion patterns were found to be consistent among subjects in active lateral bending and inconsistent for active axial rotation. CONCLUSIONS: This new method offers dynamic recording capabilities and a measurement error comparable with stereo radiographic methods. Repetitive ranging experiments are highly reproducible. The range of motion for axial rotation seems overestimated in previous cadaveric studies. Coupling patterns show large variations between individuals.

Bridging the gap: linking a legacy hospital information system with a filmless radiology picture archiving and communications system within a nonhomogeneous environment.

A health level 7 (HL7)-conformant data link to exchange information between the mainframe hospital information system (HIS) of our hospital and our home-grown picture archiving and communications system (PACS) is a result of a collaborative effort between the HIS department and the PACS development team. Based of the ability to link examination requisitions and image studies, applications have been generated to optimise workflow and to improve the reliability and distribution of radiology information. Now, images can be routed to individual radiologists and clinicians; worklists facilitate radiology reporting; applications exist to create, edit, and view reports and images via the internet; and automated quality control now limits the incidence of "lost" cases and errors in image routing. By following the HL7 standard to develop the gateway to the legacy system, the development of a radiology information system for booking, reading, reporting, and billing remains universal and does not preclude the option to integrate off-the-shelf commercial products.

Transparent image access in a distributed picture archiving and communications system: the Master Database broker.

A distributed design is the most cost-effective system for small-to medium-scale picture archiving and communications systems (PACS) implementations. However, the design presents an interesting challenge to developers and implementers: to make stored image data, distributed throughout the PACS network, appear to be centralized with a single access point for users. A key component for the distributed system is a central or master database, containing all the studies that have been scanned into the PACS. Each study includes a list of one or more locations for that particular dataset so that applications can easily find it. Non-Digital Imaging and Communications in Medicine (DICOM) clients, such as our worldwide web (WWW)-based PACS browser, query the master database directly to find the images, then jump to the most appropriate location via a distributed web-based viewing system. The Master Database Broker provides DICOM clients with the same functionality by translating DICOM queries to master database searches and distributing retrieval requests transparently to the appropriate source. The Broker also acts as a storage service class provider, allowing users to store selected image subsets and reformatted images with the original study, without having to know on which server the original data are stored.

Design and implementation of World Wide Web-based tools for image management in computed tomography, magnetic resonance imaging, and ultrasonography.

This article describes our experience in developing and using several web-based tools to facilitate access to and management of images from inside and outside of our department. Having recently eliminated film in ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI), a simple method was required to access imaging from computers already existing throughout the hospital. The success of the World Wide Web (WWW), the familiarity of endusers with web browsers, and the relative ease of developing user interfaces virtually dictated that such an approach be pursued in our case. The resulting web-based tools allow validated users to search our Digital Imaging and Communications in Medicine (DICOM)-compliant archive servers for specific exams; to download image data from a remote site; to request the retrieval of data from long-term storage; to view images, and to perform certain DICOM routing operations. The existing infrastructure of the internet has allowed us to develop a low-cost system capable of being used for teleradiology. Since low-level, machine-specific interface programming was avoided, these tools were developed rapidly and are easily adapted. The familiarity of browser-based interfaces has facilitated user acceptance, and the benefit of platform independence minimizes software portability concerns.