// Word.Application-Objekt erzeugen
            ComObject word = new ComObject("Word.Application");

            // Sichtbar machen
            word.SetProperty("Visible", true);

            // Dokument-Auflistung abrufen
            ComObject documents = word.GetObjectReturningProperty("Documents");

            //  Dokument öffnen
                      ComObject document = documents.InvokeObjectReturningFunction("Open", @"D:\xy.doc");

            ComObject Shapes = document.GetObjectReturningProperty("Shapes");

            int PicCount = (int)Shapes.GetProperty("Count");


            for (int i = PicCount; i > 0; i--)
            {
                  if (Shapes[i].Type == Microsoft.Office.Core.MsoShapeType.msoPicture) // <------------

                        {
                             Shapes[i].Delete();   // <------------
                        }             }  

ComObject shapeObject = Shapes.InvokeObjectReturningFunction("Item", i);
int shapeType = (int)shapeObject.GetProperty("Type");

// do whatever you want

shapeObject .Dispose();

 
public object GetProperty(string propertyName, params object[] parameters)
{
    // Methode aufrufen und Rückgabewert zurückgeben
    return _realComObject.GetType().InvokeMember(propertyName, BindingFlags.GetProperty | BindingFlags.OptionalParamBinding, null, _realComObject, parameters);
}

           // Word.Application-Objekt erzeugen
            ComObject word = new ComObject("Word.Application");

            // Sichtbar machen
            word.SetProperty("Visible", true);

            // Dokument-Auflistung abrufen
            ComObject documents = word.GetObjectReturningProperty("Documents");

            // Neues Dokument erzeugen
            ComObject document = documents.InvokeObjectReturningFunction("Open", @"D:\xy.doc");

            ComObject Shapes = document.GetObjectReturningProperty("Shapes");
  
            int PicCount = (int)Shapes.GetProperty("Count");
            
 
            for (int i = PicCount; i > 0; i--)
            {

               ComObject shapeObject = Shapes.InvokeObjectReturningFunction("Item", i);
                int shapeType = (int)shapeObject.GetProperty("Type");
                 
                // Microsoft.Office.Core.MsoShapeType.msoPicture
                if(shapeType == 13)
                {
                    shapeObject.InvokeFunction("Delete");
                }

                shapeObject.Dispose();
            }


                  // Verweise auf Dokument und Dokumentauflistung entsorgen
            document.Dispose();
            documents.Dispose();

            

            // Word beenden ohne zu speichern
            word.InvokeProcedure("Quit", 0);

            // Word-Instanz entsoregn
            word.Dispose();