如何从DICOM图像的原始数据创建图像

Question

I have a raw pixel data in a byte[] from a DICOM image. Now I would like to convert this byte[] to an Image object.

I tried:

Image img = Image.FromStream(new MemoryStream(byteArray));

but this is not working for me. What else should I be using ?

Answer 1

One thing to be aware of is that a dicom "image" is not necessarily just image data. The dicom file format contains much more than raw image data. This may be where you're getting hung up. Consider checking out the dicom file standard which you should be able to find linked on the wikipedia article for dicom. This should help you figure out how to parse out the information you're actually interested in.

Answer 2

You should use GDCM.

Grassroots DiCoM is a C++ library for DICOM medical files. It is automatically wrapped to python/C#/Java (using swig). It supports RAW, JPEG 8/12/16bits (lossy/lossless), JPEG 2000, JPEG-LS, RLE and deflated (zlib).

It is portable and is known to run on most system (Win32, linux, MacOSX).

• http://gdcm.sourceforge.net/wiki/index.php/GDCM_Release_2.4

See for example:

• http://gdcm.sourceforge.net/html/DecompressImage_8cs-example.html

Answer 3

The pixel data usually (if not always) ends up at the end of the DICOM data. If you can figure out width, height, stride and color depth, it should be doable to skip to the (7FE0,0010) data element value and just grab the succeeding bytes. This is the trick that most normal image viewers use when they show DICOM images.

Answer 4

There is a C# library called EvilDicom ( http://rexcardan.com/evildicom/ ) that can be used to pull the image out of a DICOM file. It has a tutorial on how to do it on the website.

Answer 5

You have to do the following

1. Identify the PIXEL DATA tag from the file. You may use FileStream to read byte by byte.
2. Read the pixel data
3. Convert it to RGB
4. Create a BitMap object from the RGB
5. Use Graphics class to draw the BitMap on a panel.

Answer 6

DICOM is a ridiculous specification and I sincerely hope it gets overhauled in the near future. That said Offis has a software suite "DCMTK" which is fairly good at converting dicoms with the various popular encodings. Just trying to skip ahead in the file x-bytes will probably be fine for a single file but if you have a volume or several volumes a more robust strategy is in order. I used DCMTK's conversion code and just grabbed the image bits before they went into a pnm. The file you'll be looking for in DCMTK is dcm2pnm or possibly dcmj2pnm depending on the encoding scheme.

I had a problem with the scale window that I fixed with one of the runtime flags. DCMTK is open source and comes with fairly simple build instructions.

Answer 7

Are you working with a pure standard DICOM File? I've been maintainning a DICOM parser for over a two years and I came across some realy strange DICOM files that didn't completely fulfill the standard (companies implementing their "own" twisted standard DICOM files) . flush you byte array into a file and test whether your image viewer(irfanview, picassa or whatever) can show it. If your code is working with a normal JPEG stream then from my experience , 99.9999% chance that this simply because the file voilate the standard in some strange way ( and believe me , medical companies does that a lot)

Also note that DICOM standard support several variants of the JPEG standard . could be that the Bitmap class doesn't support the data you get from the DICOM file. Can you please write down the transfer syntax?

You are welcome to send me the file (if it's not big) yossi1981@gmail.com , I can check it out , There was a time I've been hex-editing DICOM file for a half a year.