Sunday, November 11, 2007

Comparing different DICOM viewers

Digital Imaging and Communication in Medicine (DICOM) is a standard format for encoding and transmitting medical CT and MRI data. This format stores the image information along with other data like patient details, acquisition parameters etc. Since DICOM standards have become popular, many image processing readers and viewers have been created to read, process and write images. There are so many such software and its details can be seen here.

Since the details of the various software can be obtained using the previous website, in this blog we will classify some of these softwares based on the user requirement and discuss accordingly.

The users might need
1. A simple viewer with limited manipulation like ezDICOM
2. A viewer with ability to manipulate images and perform rendering like Osirix
3. A viewer with image manipulation capability and also extensible with plugins like ImageJ
4. A command line reader and viewer that allows batch processing like ImageMagick

There are more softwares that can be classified under the four categories but we will limit to these software for this blog. This does not limit the number of software available for viewing and manipulating dicom image, rather helps users choose the software right for them.

ezDICOM
It is a viewer that provides sufficient functionality that allows users to view and save dicom files without installing any software in their system. It is available only for Windows OS. It can read dicom files and save them in other file formats. It can also convert image files to Analyze format.

Osirix
It is a viewer with functionality that you might generally find in expensive workstation. It works great and it is free! But unfortunately, it is available only in MacOSX.
Like other dicom viewer, it can read and store files in different file formats and as movies. It can performs Multi-planar Reconstruction (MPR), 3D surface rendering, 3D volume rendering, endoscopy. It can also view 4D dicom data. The surface rendered data can also be stored as VRML, STL files etc. In short, I would highly recommend it if you have a Mac system.

ImageJ
ImageJ was funded by National Institute of Health (NIH) and is available as open source. It was written in Java and users can add their own Java class or plugins. It is available in all major operating system like Windows, Linux, UNIX, Mac etc. It can read all dicom formats and can store the data in various common file formats and also as movies. The plugins allow various image processing operation. Since the plugins can be easily added, the complexity of the image processing operation is just limited by the users knowledge of Java.

ImageMagick
If the various operations in image processing can be classified in to input, processing and output, ImageMagick provides functionalities that perform all these three operations. ImageMagick can be used in command line in almost all the common operating systems like Windows, Linux, UNIX, Mac etc by combining the read, write and image processing operations. Since ImageMagick is a command line tool, it can be used in any scripting language like perl, PHP, shell script etc. For users who are more adventurous, ImageMagick also provides APIs that allow programming low level image processing operation.

If you want to be even more adventurous and would like to program in C and C++, check out dicom toolkit.

1 comment:

AnnaGoesToJapan said...

Hello,

I know this was posted in 2007 but I came across the information in a Google search. I am currently working with MRI scans and segmentation & volume rendering. I am interested in exporting my data as STL and VRML. This may seem a simple question but where can I find these options on OsiriX? In other words, how do I do this with OsiriX?

Also, you seem familiar with OsiriX -is there a way to custom set the parameters of the "Compute Volume" tool to generate a mesh?

Thank you,
Anna