DICOM and DICOM Browsers
The digital imaging and communications in medicine (DICOM) standard was created by
the National Electrical Manufacturers' Association (NEMA) in order to improve compatibility
and workflow efficiency between imaging systems, medical devices, and other information
systems used in a hospital environment. This has become the principal standard for
the communication of medical images and is now implemented by virtually all medical
imaging equipment manufacturers.
Image files that conform to the DICOM standards are commonly referred to as DICOM-format
images. The basic difference between a DICOM image and an image in other formats like
JPEG, TIFF, or GIF is that the DICOM image contains a ‘header’ with information (such
as patient demographics, machine, scan parameters, and a host of other non-image data)
in addition to the image data. Thus it is possible to identify the origin of the image,
the patient, data acquisition parameters of the study and so on, even if a single
image is analyzed in isolation. The adoption of DICOM standards by medical imaging
equipment vendors has helped in effective cross-machine communications and made possible
integration of imaging equipment from different manufacturers.[1]
Although DICOM is the accepted standard for the storage and networking of medical
images, the image is encoded in a format that cannot readily be viewed on an average
personal computer (PC). Viewing these images outside the radiology network still requires
printing of the images on hardcopy films. With the fall in prices of hardware and
peripheral devices, computers with high-end hardware specifications are available
at affordable prices. To view DICOM images on PCs, dedicated DICOM browsers are needed.
Though these softwares are available from several vendors, they are expensive and
beyond the reach of the average radiologist.
Several freely downloadable DICOM browsers, which can be easily integrated into a
radiologist's practice, are available via the Internet.[2–4] This article describes
the applications of a few DICOM browsers in clinical radiology and imaging research
and evaluates their merits and demerits in common radiology applications (Appendix
1).
Free DICOM Browsers Available Online: A Functional Classification
The DICOM browsers can be broadly and functionally segregated into four groups: for
viewing DICOM images, for teaching, for use as mini-PACS servers, and for research
purposes. Let us examine each of these individually.
DICOM browsers for basic viewing of DICOM images
The simplest and most intuitive application of DICOM browsers is to view images on
stand-alone systems that are not a part of a radiology network. Most equipment manufacturers
offer the option of archiving imaging data on compact discs (CDs) which can be transported,
stored, and reviewed easily. Though a proprietary DICOM viewer is written into the
CD along with the image data, it is often limited in its functionality. Using a DICOM
browser of one's own choice permits the use of a set of tools suited to one's needs,
irrespective of the source of the imaging data. It must be remembered that most freely
downloadable software is intended for educational purposes and is not custom built
for medical diagnosis or commercial purposes.
Most browsers in this category [Table 1] provide basic image-processing functions,
such as the ability to adjust image contrast and brightness, to magnify, to perform
measurements (distances, angles, areas, pixel values, etc.), to change image orientation,
and the ability to annotate. Studies containing a time series of image data need a
‘cine’ viewer with the ability to change the frame rate. Another useful tool is the
ability to simultaneously load and compare two sets of images (available with Jivex
[dv] viewer and Sante DICOM viewer); this is usually necessary when looking for enhancement
on post-contrast studies and to check for response to therapy. The ability to view
the localizer/scout view, along with a specific image, is a feature of Sante DICOM
and Jivex [dv] viewers as well.
Table 1
Free DICOM browsers - basic viewing software
Free DICOM software
Web address
Free/limits
DICOM query
Thumbnail view
Display layout
Flip/rotation
Invert b/w
Linear measure
Angle measure
Cine viewer
Compare view
Scout localizer support
Software required
Additional features
3D-Doctor Viewer v 4.0.070803
http://www.ablesw.com/3d-doctor/get3dview.html
Free
No
No
1 × 1
No
No
No
No
Yes
No
No
None
Full version is an advanced 3D visualization and processing tool
CarDiCon v 1.53B
http://fhs-consulting.com/cardicon/E_cardicon.html
Free
No
Yes
1 × 1
No
No
No
No
Yes
Yes
No
None
Primarily a browser for angiographic studies
DCM View
http://www.rmrsystems.co.uk/dcmview.htm
Free
No
Yes
1 × 1 to all-in-one
No
No
No
No
No
No
No
None
No installation. Small program
DCM Vista v 3.2
http://www.charruasoft.com/downen.php
Free
Yes and data import function
Yes
1 × 1 to 4 × 5
Yes
Yes
Yes
No
Yes
No
No
None
No installation. Small program
Dicomlight v 5.4
http://www.charruasoft.com/downen.php
Free
No
No
1 × 1 to 4 × 5
No
Yes
No
No
No
No
No
None
No installation. Small program
DICOM Scope v 3.5.1
http://dicom.offis.de/dscope.php.en
Free
No
No
1 × 1
Yes
Yes
Yes
Yes
No
No
No
Java
Offers structured reporting
ImRead DICOM Viewer
http://www.uchsc.edu/sm/neuroimaging/download/imread/imread1.htm
Free
No
No
1 × 1
Yes
No
No
No
No
No
No
Tomovision
http://www.tomovision.com/
Can open only five images at a time
No
No
1 × 1
No
No
No
No
Yes
No
No
DICOM browsers useful for teaching
Of late, more and more departments are beginning to use electronic media for teaching.
The rising cost of x-ray films and the ease with which digital images can be archived,
queried, retrieved, and presented, have seen the gradual replacement of the ‘departmental
film library’ by a ‘virtual library’ of ‘teaching collections.’ The greatest advantage
of creating digital teaching files is the ease with which they can be stored and distributed.
The database of a single server can hold much more image data than several rooms containing
shelves and shelves of ageing and disintegrating radiographs and this data can be
accessed simultaneously by several users across a network or over the World Wide Web.
The addition of non-radiological medical images, such as clinical photographs, endoscopic
views, and photomicrographs, enables the creation of a comprehensive multimodality
teaching file.
Images in DICOM format are usually converted to other image formats such as JPEG,
GIF, or TIFF prior to creation of the teaching file. These formats are more compact
than the original image and are recognized by most non-medical image management software
that can be used to create teaching files and albums. Software for this purpose must
have the capability to adjust image quality, size, and resolution [Table 2]. Batch
conversion of a series of images saves the operator from having to vary the window
level and width in individual images; (this feature is available with DicomWorks.)
The ability to produce movie files from a series of individual images (a feature available
with CarDiCon and DicomWorks) and to visualize 3D data (which is possible with 3D
Doctor Viewer and FP Image Viewer) are an added advantage.[5]
Table 2
Free DICOM browsers useful for teaching
Free DICOM Software
Web address
Input format
Thumbnail view
Display layout
Flip/rotate
Invert b/w
Text annotations
Measurements
Cine viewer
Export Formats
Annotations Off
Additional software required
Additional features
Radfiler DICOM for PowerPoint
http://www.radfiler.com/
DICOM
No
1 × 1
No
No
No
No
No
No
No
Microsoft PowerPoint
Provides DICOM functionality within a presentation
DicomLitev1.01
http://www.3d-head.com
DICOM
No
1 × 1
No
No
No
No
No
TIFF
No
None
No installation. Small program
DCM2JPG
http://www.sph.sc.edu/comd/rorden/ezdicom.html
DICOM
No
No
No
No
No
No
No
BMP, JPEG
No
None
Command line conversion to JPG/BMP formats
DICOM Browser from FP Image
http://www.fpimage.com/info.html
DICOM
No
1 × 1
No
No
No
No
No
JPEG
Yes
DicomWorks v 1.3.5
http://dicom.online.fr/
DICOM
No
1 × 1
No
No
No
No
Yes
JPEG, AVI
Yes
MPR and CMPR Recon of 3D data, Direct e-mail of images
Eviewbox
http://eviewbox.sourceforge.net/
DICOM
Yes
Auto
No
No
No
No
Slideshow
GIF
No
Java
MPR and CMPR Recon of 3D data, Direct e-mail of images
ezDICOMv1.0
http://www.sph.sc.edu/comd/rorden/ezdicom.html
DICOM, Medical image formats
No
1 × 1
No
Yes
No
No
No
BMP, JPEG Medical image formats
Yes
None
Primarily aimed at converting data into other medical image formats
ImageJ v 1.38x
http://rsb.info.nih.gov/ij/
DICOM
No
1 × 1
Yes
No
Yes
Yes
Yes
JPEG, GIF, TIFF, BMP, PNG, AVI
No
Java
Image Stacking, reslicing, Z-project, 3D Project,
ImRead DICOM Processor
http://www.uchsc.edu/sm/neuroimaging/download/imread/imread1.htm
DICOM
No
1 × 1
Yes
No
No
No
No
JPEG, TIFF
No
Java
Small program
IrfanView v 4.1
http://www.irfanview.com/
DICOM
No
1 × 1
Yes
Yes
No
No
Slide-show
Can be converted into a large number of image formats
No
Additional plugin
Image management software with DICOM image support
JiveX [dv] Viewer v 4.2.1
http://www.visus-tt.com/DICOM_Viewer.59.0.html
DICOM images
Yes
1 × 1 to 4 × 4
Yes
Yes
Yes
Yes
Yes
image, matrix, series disabled
Yes
Java version 1.4
Save presentation state to unique format; needs key
MEDISP v 1.0.2
http://medisp.bme.teiath. gr/downloadMEDISPDI-COMViewer.htm
DICOM
Yes
1 × 1 to 4 × 4
Yes
Yes
Yes
Yes
Yes
JPEG, TIFF, BMP, PNG, AVI
Yes
None
Osiris v 4.19
http://www.sim.hcuge. ch/osiris/01 _Osiris_Presentation_EN.htm
DICOM
No
1 × 1
Yes
Yes
Yes
Yes
Yes
JPEG, BMP, TIFF, AVI
Yes
Yes
No
An earlier publication has described the integration of DICOM viewer functions into
Microsoft PowerPoint presentations by the installation of ActiveX components and add-ins.[6]
A freely available software - Iconotech[7] - is now available to help compile a database
of teaching files, incorporating patient demographic information, clinical details,
imaging findings, diagnosis, as well as bibliographic references, along with DICOM
images. Presentation as teaching cases as well as in the form of quizzes, is enabled
in this software.
It must always be remembered that when an image is being stored for teaching purposes
or for publication, it is essential to hide the demographic information on the image.
In most browsers it is possible to turn annotations off while the image is being exported
into a different format, to maintain patient confidentiality. Some browsers also have
the ability to alter certain tags in the DICOM header so as to introduce information
into the image to help in organizing the teaching file.
DICOM browsers for mini-PACS servers
A direct extension of the capabilities of a DICOM browser would be the ability to
access, store and retrieve, transmit, display, and process images that were generated
by DICOM-compatible equipment. Softwares in this category range from simple solutions
called mini-PACS to extremely complex systems that interact with the hospital information
system/radiology information system (HIS/RIS), electronic medical record systems,
and web servers. Essential features of such softwares include the ability to access
DICOM data available on a local or network drive and to search for DICOM data within
hard disks, folders, and CDs, using patient name, study number, study date, or other
queries. Examples of software available on the web that can be used for such applications
include CharuaPACS,[8] Dicomscope,[9] KPACS,[10] Tudor DICOM Viewer,[11] and Sante
DICOM Viewer.[12]
The setting up of such a system and its integration with the imaging equipment usually
requires the help of a network administrator. Such software can also be of use for
arranging viewing stations for monitoring imaging studies from the radiologist's office,
for printing images using DICOM printers or paper printers, and for teleradiology.
DICOM Browsers for Research Applications
Anonymization of the DICOM header is of vital importance in medical research, where
the identity of the patient and the participating institution needs to be removed
from the DICOM header [Table 3]. There are several software programs that can be used
for extraction and analysis of structural and functional imaging data. These programs
have been developed for applications such as image segmentation, registration with
atlases, contour generation, texture analysis, computer-aided diagnosis, volumetric
studies, and relaxometric studies. As some of these programs are designed to run on
image data in non-DICOM formats (such as Analyze and NIFTI), DICOM data needs to be
converted using applications such as MRIcro. A review on freely downloadable software
for offline analysis of structural and functional neuroimaging data can be found in
a future issue of this journal.
Table 3
Free DICOM browsers useful for research
Free DICOM Software
Web address
Free/limits
Input format
DICOM query
View DICOM Info
Edit DICOM Info
Anonymize
Export function
DICOM Browser FP Image
http://www.fpimage.com/info.html
Free
DICOM
No
Yes
No
Yes
JPEG
DicomWorks v 1.3.5
http://dicom.online.fr/
Free
DICOM
Yes
Yes
No
Yes
JPEG, AVI
MEDISPv 1.0.2
http://medisp.bme.teiath.gr/downloadMEDISPDICOMViewer.htm
Free
DICOM
Yes
Yes
No
Yes
JPEG, TIFF, BMP, PNG, AVI
MRIcro v 1.4
http://www.mricro.com
Free
DICOM and other formats
Yes
Yes
No
Yes
Conversion into a wide variety of medical image formats for functional analysis
Same DICOM Viewer 6 (Demo mode)
http://users.forthnet.gr/ath/mkanell/
Unlimited time with watermarks and options disabled
DICOM and DICOMDIR
Yes
Yes
No
Yes
Watermarked JPEG, TIFF, BMP, PNG, HTML, AVI
Summary
There is a large array of DICOM browsers that can be downloaded from the Net free
of cost. These can prove to be effective alternatives to commercially available programs
and radiologists can implement these solutions to augment their clinical practice,
taking into consideration their individual requirements as well as the software's
functional capabilities and limitations.