DICOM networks accelerate medical-image distribution
In many life-threatening medical examinations, diagnostic decisions must be made almost immediately. No matter where or which imaging technology has been used, such as ultrasound, computed tomography, nuclear magnetic resonance, or digital angiography, the images often need to be distributed rapidly among cardiologists, surgeons, and specialists for fast decision analysis. To speed up distribution, most teleradiology systems now transmit images across networks using the Digital Imaging and Communications in Medicine (DICOM) standard.
Developed in 1985 by the American College of Radiology and the National Electrical Manufacturers Association, the DICOM standard determines how vendor-independent digital medical images can be transferred across networks. Because DICOM relies on industry standard network connections (TCP/IP), it is an efficient method for communicating digital images from diagnostic devices to display systems.
By accessing images over such networks, physicians can remotely review cases while on-call or preparing for rounds. Alternatively, doctors can view images in their offices while consulting with another physician or with a patient. For proper analysis, however, DICOM viewers must allow medical images and data to be correctly interpreted between systems.
Because many of these systems are PC-based, several software vendors have tailored their image-processing toolkits to address this medical market. For example, Pegasus Imaging (Tampa, FL) offers a PICTools medical-compression software development toolkit. This software decompresses and displays digital ultrasound, angiogram, and cardiogram DICOM cine loops in real time using PICTools 8-bit lossless and 24-bit lossy JPEG implementations.
In another approach, some vendors have developed "add-on" packages for well-known image viewers that are capable of viewing medical images. The DICOMaccess, an Adobe PhotoShop plug-in from DesAcc (Chicago, IL), for example, enables Adobe PhotoShop to transparently read and write DICOM 3.0 and ACR-NEMA 2.0 files. Running this plug-in program, any DICOM file can be opened in PhotoShop or saved in any non-DICOM file format.
Stand-alone DICOM viewers are also available from a number of vendors, including Medcon (Livingston, NJ) and Rubo Medical Imaging (Uithoorn, The Netherlands). Supporting x-ray angiography, echocardiography, and magnetic-resonance-imaging modalities, the Medcon Universal MDView software operates under Windows 95/98/NT and features real-time playback, image enhancement, zooming, and data-export capabilities. Also running on a PC, the Rubo DICOM Viewer can display DICOM images of any color, compression, size, depth, or modality.
Free demos
By integrating these viewers into PC-based imaging systems and workstations, medical-system vendors can provide immediate access to diagnostic images for remote viewing. To demonstrate the effectiveness of their software, many DICOM viewer-vendors offer free viewer downloads from their Web sites. Others offer demo code that, although not fully functional, provides systems integrators with a capability sampler of their viewers.