DicomDataSet ds = new DicomDataSet();
byte[] data;
                    
string transferSyntax = TransferSyntaxes.ExplicitVRLittleEndian;
ds.Add(Keyword.SamplesPerPixel, 1);
ds.Add(Keyword.PhotometricInterpretation, "MONOCHROME2");
ds.Add(Keyword.Rows, 512);
ds.Add(Keyword.Columns, 512);
ds.Add(Keyword.PixelSpacing, new float[] { 0.684f, 0.684f });
ds.Add(Keyword.BitsAllocated, 16);
ds.Add(Keyword.BitsStored, 12);
ds.Add(Keyword.HighBit, 11);
ds.Add(Keyword.PixelRepresentation, 0);
ds.Add(Keyword.WindowCenter, new int[] { 35, 50 });
ds.Add(Keyword.WindowWidth, new int[] { 350, 150 });
ds.Add(Keyword.RescaleIntercept, -1200);
ds.Add(Keyword.RescaleSlope, 1);
ds.SetPixelData(transferSyntax, getData);  
                    
ds.Write(out data);
                    
using (FileStream fs = new FileStream("Output_Dataset.dcm", FileMode.Create, FileAccess.Write))
{
    fs.Write(data, 0, data.Length);
}
                    
// Method
private Stream getData(int arg)
{
    return new FileStream("pixel.data", FileMode.Open, FileAccess.Read, FileShare.Read);
}