Indian Journal of Radiology and Imaging Indian Journal of Radiology and Imaging

COMPUTERS IN RADIOLOGY
Year
: 2008  |  Volume : 18  |  Issue : 1  |  Page : 12--16

Free DICOM browsers


Dandu Ravi Varma 
 Department of Radiology, Krishna Institute of Medical Sciences, 1-8-31/1, Minister Road, Secunderabad - 500 003, Andhra Pradesh, India

Correspondence Address:
Dandu Ravi Varma
Department of Radiology, Krishna Institute of Medical Sciences, 1-8-31/1, Minister Road, Secunderabad - 500 003, Andhra Pradesh
India




How to cite this article:
Varma DR. Free DICOM browsers.Indian J Radiol Imaging 2008;18:12-16


How to cite this URL:
Varma DR. Free DICOM browsers. Indian J Radiol Imaging [serial online] 2008 [cited 2019 Nov 12 ];18:12-16
Available from: http://www.ijri.org/text.asp?2008/18/1/12/38503


Full Text

 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],[3],[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.

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]

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.

 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.

References

1Indrajit IK. Digital imaging and communications in medicine: A basic review. Indian J Radiol Imaging 2007;17:5-7.
2The DICOM standard. In : Rorden C, editors. Available from: http://www.sph.sc.edu/comd/rorden/dicom.html. [Last accessed on 2007 Oct 25].
3Free DICOM viewer links. In : Crabb A, editors. Available from: http://www.idoimaging.com/index.shtml. [Last accessed on 2007 Oct 25].
4Escott EJ, Rubinstein D. Free DICOM image viewing and processing software for your desktop computer: What's available and what it can do for you. Radiographics 2003;23:1341-57.
5Ernst RD, Baumgartner BR, Tamm EP, Torres WE. Development of a teaching file by using a DICOM database. Radiographics 2002;22:217-21.
6Haider MA. Extending PowerPoint with DICOM image support. Radiographics 2003;23:1683-7.
7Iconotech software. Available from: http://www.iconotech.net. [Last accessed on 2007 Oct 25].
8CharuaPACS Software. Available from: http://www.charruasoft.com. [Last accessed on 2007 Oct 25].
9Dicomscope Software. Available from: http://dicom.offis.de/dscope.php.en. [Last accessed on 2007 Oct 25].
10KPACS Software. Available from: http://www.k-pacs.de/. [Last accessed on 2007 Oct 25].
11Tudor DICOM Viewer Software. Available from: http://www.santec.lu/projects/optimage/dicomtools. [Last accessed on 2007 Oct 25].
12Sante DICOM Viewer Software. Available from: http://users.forthnet.gr/ath/mkanell. [Last accessed on 2007 Oct 25].