/// <summary>
/// This splits a structure into two. It creates a margin around the target,
/// so that it approximately crosses the mass center of the structure, and then
/// uses boolean operators to create two new structures. Note: due to the nature
/// of the segment model in Eclipse, the new structures do not always perfectly cover
/// the whole volume of the original structure.
/// </summary>
/// <param name="s"></param>
/// <param name="ss"></param>
/// <returns></returns>
bool SplitStructure(StructureSet ss, Structure target, Structure roi)
{
if (ss.CanAddStructure(roi.DicomType, roi.Id + "_spl1"))
{
Structure newStr1 = ss.AddStructure(roi.DicomType, roi.Id + "_spl1");
Structure newStr2 = ss.AddStructure(roi.DicomType, roi.Id + "_spl2");
VVector targetCenter = target.CenterPoint;
VVector roiCenter = roi.CenterPoint;
double dist = (targetCenter - roiCenter).Length;
//figure out distance from target center to target surface
System.Collections.BitArray buffer = new System.Collections.BitArray(100);
SegmentProfile profile = target.GetSegmentProfile(targetCenter, roiCenter, buffer);
double distToTargetSurface = 0;
foreach (SegmentProfilePoint point in profile)
{
if (point.Value == false)
{
//first point outside structure
distToTargetSurface = (point.Position - targetCenter).Length;
break;
}
}
//SegmentVolume seg = target.Margin(dist - distToTargetSurface);
SegmentVolume seg = target.LargeMargin(dist - distToTargetSurface);
newStr1.SegmentVolume = seg.And(roi);
newStr2.SegmentVolume = roi.Sub(newStr1);
return(true);
}
return(false);
}
public static double Structure_Distance(ROI roi, ROI ptv, ScriptContext context)
{
//Get the minimum distance between two rois.
double min_distance = 1000;
double total_distance = 0;
List <Structure> temp_structures = new List <Structure>();
List <Structure> roi_structures = roi.MatchingStructures;
List <Structure> ptv_structures = ptv.MatchingStructures;
for (int r = 0; r < roi_structures.Count; r++)
{
for (int p = 0; p < ptv_structures.Count; p++)
{
Structure roi_structure = roi_structures[r];
Structure ptv_structure = ptv_structures[p];
//First see if they overlap, and if they do, min distance = 0.
//Now keep margining the ptv and finding out when an intersection occurs (to get the minimum distance). This minimum distance will be the margin amount.
double margin = 0;
SegmentVolume margin_seg_vol = ptv_structure.Margin(margin);
SegmentVolume overlap_volume = margin_seg_vol.And(roi_structure);
Structure overlap_structure = context.StructureSet.AddStructure("CONTROL", "overlap_struc");
Structure margin_structure = context.StructureSet.AddStructure("CONTROL", "margin_struct");
overlap_structure.SegmentVolume = overlap_volume;
margin_structure.SegmentVolume = margin_seg_vol;
double overlap = overlap_structure.Volume;
if (overlap > 0)
{
System.Windows.MessageBox.Show(roi_structure.Name + " overlaps with " + ptv_structure.Name);
return(0);
}
double last_no = 0;
double last_yes = 1000;
//these doubles are the last margins used for which there was not an overlap, and for which there was an overlap
while (last_yes == 1000)
{
margin = 50;
total_distance += 50;
margin_seg_vol = margin_structure.Margin(margin);
overlap_volume = margin_seg_vol.And(roi_structure);
overlap_structure.SegmentVolume = overlap_volume;
margin_structure.SegmentVolume = margin_seg_vol;
overlap = overlap_structure.Volume;
if (overlap > 0)
{
last_yes = total_distance;
}
else
{
last_no = total_distance;
}
}
//Now get the last_no margin ptv again to start the final iteration.
total_distance -= 50;
margin_seg_vol = margin_structure.Margin(-50);
margin_structure.SegmentVolume = margin_seg_vol;
last_yes = 50;
last_no = 0;
//Do a maximum of 30 iterations
int loop_count = 0;
do
{
loop_count++;
margin = 0.5 * (last_yes - last_no);
margin_seg_vol = margin_structure.Margin(margin);
overlap_volume = margin_seg_vol.And(roi_structure);
overlap_structure.SegmentVolume = overlap_volume;
margin_structure.SegmentVolume = margin_seg_vol;
overlap = overlap_structure.Volume;
if (overlap > 0)
{
last_yes = margin;
}
else
{
last_no = margin;
}
context.StructureSet.RemoveStructure(margin_structure);
margin_structure = context.StructureSet.AddStructure("CONTROL", "margin_struc");
if (loop_count > 30)
{
System.Windows.MessageBox.Show("Maxed out with 30 iterations of overlap checking for " + roi.Name);
break;
}
} while (last_yes - last_no > 1); //look until within 1mm of distance
total_distance += margin;
if (total_distance < min_distance)
{
total_distance = margin;
}
context.StructureSet.RemoveStructure(overlap_structure);
}
}
System.Windows.MessageBox.Show(roi.Name + " distance: " + min_distance);
return(min_distance);
}