【转】DELPHI 对DICOM中的窗宽、窗位调整

傷城~ 2022-11-07 04:19 182阅读 0赞

在写这篇文章前72小时，我的多窗显示组件对于个别大W/C值的16位影像显示还是个问题，也发了帖子到PACS站询问过，更是在Google上猫刨了很久，终归一无所获，今天静下心来，用了2小时反复查看程序处理过程，对比数据，居然就这么搞定了，原来如此简单，哎，困惑了3天，把答案公布了，也算是助人为乐（中国地大物博，人心应宽广无量）

对16位的影像，要判断DICOM中最大像素值(0028,0107)大于65534，是则将16位影像数据的像素值大于等于0的全部减去65535，小于0的全部加上65535，然后在window-level的方法中将pixel\_val按word取值（word是无符号类型，相当于取绝对值）进行判断，然后赋值即可（CT影像不能用word类型取值和赋值），就这么简单，以下是关键代码，祝你愉快！！！

procedure DCM\_GetWidAndCenBySmallint(var DICOMDATA: TDICOMDATA; var Buffer: SMallIntp0);  
var  
  Value, Size, i: integer;  
  min16, max16: integer;  
begin  
  Size := DICOMDATA.ImageColumns \* DICOMDATA.ImageRows;

Value := Buffer\[0\];  
  max16 := Value;  
  min16 := Value;  
  i := 0;  
  while i < Size do begin  
    Value := Buffer;  
    if Value < min16 then min16 := Value;  
    if Value > max16 then max16 := Value;  
    i := i + 1;  
  end;

if DICOMDATA.MaxIntensity = 0 then DICOMDATA.MaxIntensity := max16;

if (DICOMDATA.MaxIntensity > 65534) then begin//这里对高CT值的数据进行处理  
    i := 0;  
    while i < (Size) do begin  
      if Buffer >= 0 then  
        Buffer := Buffer - 65535  
      else  
        Buffer := 65535 + Buffer;  
      i := i + 1;  
    end;  
  end;

DICOMDATA.WinCen := round(DICOMDATA.WindowCenter);  
  DICOMDATA.WinWid := round(DICOMDATA.WindowWidth);  
  DICOMDATA.ImgMin := min16;  
  DICOMDATA.ImgMax := max16;  
  DICOMDATA.ImgWid := DICOMDATA.ImgMax - DICOMDATA.ImgMin;  
  DICOMDATA.ImgCen := DICOMDATA.ImgMin + ((DICOMDATA.ImgWid) shr 1);  
  if DICOMDATA.WindowWidth <= 0 then begin  
    DICOMDATA.WinCen := DICOMDATA.ImgCen;  
    DICOMDATA.WinWid := DICOMDATA.ImgWid;  
    DICOMDATA.WindowCenter := DICOMDATA.ImgCen;  
    DICOMDATA.WindowWidth := DICOMDATA.ImgWid;  
  end;  
end;

procedure DCM\_Scale16to8bit(var DICOMDATA: TDICOMDATA; var Buffer: SMallIntp0; var lOutBuff: pByteArray; DataLen: integer);  
var  
  Value, i, lScaleShl10, Size, lWid, lcen: integer;  
  min16, max16: integer;  
  PixelVal: integer;  
  Modality\_CT: boolean;  
begin  
  if Buffer = nil then exit;  
  //影像是否是CT  
  if (DICOMDATA.TransferSyntax = '1.2.840.10008.5.1.4.1.1.2') or (trim(DICOMDATA.Modality) = 'CT') then  
    Modality\_CT := true  
  else  
    Modality\_CT := false;  
  DICOMDATA.WinCen := round(DICOMDATA.WindowCenter);  
  DICOMDATA.WinWid := round(DICOMDATA.WindowWidth);  
  Size := DICOMDATA.ImageColumns \* DICOMDATA.ImageRows;  
  lcen := round((round(DICOMDATA.WindowCenter) - DICOMDATA.IntenIntercept) / DICOMDATA.IntenScale); // 截距/斜率  
  lWid := (trunc((round(DICOMDATA.WindowWidth) / DICOMDATA.IntenScale) / 2));

min16 := lcen - lWid; //15za  
  max16 := lcen + lWid; //15za

getmem(lOutBuff, Size);  
  Size := Size - 1;  
  Value := (max16 - min16);  
  if (Value = 0) or (trunc((1024 / Value) \* 255) = 0) then begin  
    if DICOMDATA.WinWid > 1024 then begin  
      for i := 0 to Size do  
        lOutBuff := 128;  
    end else begin  
      for i := 0 to Size do  
        if Buffer < DICOMDATA.WinCen then  
          lOutBuff := 0  
        else  
          lOutBuff := 255;  
    end;  
  end else begin  
    if Value = 0 then Value := 1;  
    lScaleShl10 := trunc((1024 / Value) \* 255); //value = range,Scale = 255/range  
    for i := 0 to Size do begin  
      //除CT外，其余的全部取正值  
      if Modality\_CT then begin  
        if (Buffer) < min16 then  
          lOutBuff := 0  
        else if (Buffer) > max16 then  
          lOutBuff := 255  
        else  
          lOutBuff := (((Buffer) - min16) \* lScaleShl10) shr 10;  
      end else begin //非CT  
        if word(Buffer) < min16 then  
          lOutBuff := 0  
        else if word(Buffer) > max16 then  
          lOutBuff := 255  
        else  
          lOutBuff := ((word(Buffer) - min16) \* lScaleShl10) shr 10;  
      end;   
    end;  
  end;  
  DICOMDATA.BitsStored := 8; //转换为8位  
end;