Display DICOM monochrome2 having bits stored less than bits allocated

I want to display DICOM file having photometric interpretation MONOCHROME2.

some of the specifications of image are-

Rows:           1024
Columns:        1024
No of Frames:   622
Bits Allocated: 16
Bits Stored:    10
High Bit:       9
Pixel Representation: 0
Sample per pixel: 1

I am using gdcmRegionReader to extract single frames byte array in the following way.

 gdcm.ImageRegionReader _regionReader = new gdcm.ImageRegionReader();
 _regionReader.SetRegion(_boxRegion);  // _boxRegion is some region
 _regionReader.ReadIntoBuffer(Result, (uint)Result.Length);
 Marshal.Copy(Result.ToArray(), 0, _imageData.GetScalarPointer(), 
 Result.ToArray().Length);
 _viewer.SetInput(_imageData);  // _viewer = vtkImageViewer

But when i display that file it is displaying like this..

but the original image is like this..

So can someone help me on how to load and display MONOCHROME2 dicom images.