It's easy to take compression for granted with the availability of cheap storage. Many of the common file formats used in many applications are intrinsically compressed as well, like JPEGs and PNGs. However, when you get into the Medical Imaging market and the prevalent DICOM file format, it is a very different ballgame. Like any good preschooler, you might be asking, "Why?".

More often than not, DICOM files are loaded from a location on disk due to the size and complexity of the files. However, no environment and scenario is the same and we periodically get requests regarding how to load DICOM files from memory, more specifically a byte[] rather than a Stream. Due to the way that .NET garbage collection works we must use a .NET GCHandle object when passing an IntPtr to the overloaded DicomDataSet.Load function.

private byte[] loadedFile; // byte array for DICOM file from database, server, etc.
private DicomDataSet dicomDS;
private DicomElement element;

// Pin object so it is not garbage collected before work is done.
GCHandle gch = GCHandle.Alloc(loadedFile);

// Load DicomDS from byte[] using IntPtr of array.
dicomDS.Load(Marshal.UnsafeAddrOfPinnedArrayElement(loadedFile, 0),
   loadedFile.Length, DicomDataSetFlags.None);

// Unpin object.
gch.Free();

// Get image from DicomDS.
element = dicomDS.FindFirstElement(null, DicomTag.PixelData, true);
rasterImageViewer1.Image = dicomDS.GetImage(element, 0, 0,
   Leadtools.RasterByteOrder.Gray, DicomGetImageFlags.None);

To download the entire C# example project for versions 17.5 and 18, check out this forum post.

We have received several requests regarding PACS and DICOM Communication within our Android imaging SDK. One way of accomplishing this is by using JSON to communicate with the RESTful web services included with the HTML5 Zero Footprint DICOM Viewer.

The snippet below shows a portion of the asynchronous code that calls the RESTful Medical Viewer Service and then parses the JSON response to get the SOP Instance UID. After that, the SOP Instance UID is used to get the image data and put it into an InputStream.