diff --git a/code/io/itk/files.cmake b/code/io/itk/files.cmake
index 9c20e7c..ff05187 100644
--- a/code/io/itk/files.cmake
+++ b/code/io/itk/files.cmake
@@ -1,39 +1,41 @@
 SET(CPP_FILES 
 	rttbFileDispatch.cpp
 	rttbGenericImageReader.cpp
 	rttbImageWriter.cpp
 	rttbITKException.cpp
 	rttbITKImageAccessor.cpp
 	rttbITKImageAccessorConverter.cpp
 	rttbITKImageAccessorGenerator.cpp
 	rttbITKImageFileAccessorGenerator.cpp
 	rttbITKImageFileMaskAccessorGenerator.cpp
 	rttbITKImageMaskAccessor.cpp
 	rttbITKImageMaskAccessorGenerator.cpp
 	rttbITKImageMaskAccessorConverter.cpp
 	rttbITKIOHelper.cpp
 	itkDoseAccessorImageFilter.cpp
+	itkMaskAccessorImageSource.cpp
   )
 
 SET(H_FILES 
 	rttbDoseAccessorConversionSettingInterface.h
 	rttbDoseAccessorProcessorBase.h
 	rttbDoseAccessorProcessorInterface.h
 	rttbFileDispatch.h
 	rttbGenericImageReader.h
 	rttbImageReader.h
 	rttbImageReader.tpp
 	rttbImageWriter.h
 	rttbITKException.h
 	rttbITKImageAccessor.h
 	rttbITKImageAccessorConverter.h
 	rttbITKImageAccessorGenerator.h
 	rttbITKImageFileAccessorGenerator.h
 	rttbITKImageFileMaskAccessorGenerator.h
 	rttbITKImageMaskAccessor.h
 	rttbITKImageMaskAccessorConverter.h
 	rttbITKImageMaskAccessorGenerator.h
 	rttbITKIOHelper.h
 	rttbITKIOHelper.tpp
 	itkDoseAccessorImageFilter.h
+	itkMaskAccessorImageSource.h
 )
diff --git a/code/io/itk/rttbITKImageMaskAccessorConverter.cpp b/code/io/itk/rttbITKImageMaskAccessorConverter.cpp
index 4f0e80a..c777f42 100644
--- a/code/io/itk/rttbITKImageMaskAccessorConverter.cpp
+++ b/code/io/itk/rttbITKImageMaskAccessorConverter.cpp
@@ -1,126 +1,95 @@
 // -----------------------------------------------------------------------
 // RTToolbox - DKFZ radiotherapy quantitative evaluation library
 //
 // Copyright (c) German Cancer Research Center (DKFZ),
 // Software development for Integrated Diagnostics and Therapy (SIDT).
 // ALL RIGHTS RESERVED.
 // See rttbCopyright.txt or
 // http://www.dkfz.de/en/sidt/projects/rttb/copyright.html
 //
 // This software is distributed WITHOUT ANY WARRANTY; without even
 // the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 // PURPOSE.  See the above copyright notices for more information.
 //
 //------------------------------------------------------------------------
 /*!
 // @file
 // @version $Revision$ (last changed revision)
 // @date    $Date$ (last change date)
 // @author  $Author$ (last changed by)
 */
 
 
 #include <boost/shared_ptr.hpp>
 
 #include "rttbITKImageMaskAccessorConverter.h"
 #include "rttbInvalidDoseException.h"
 #include "rttbGeometricInfo.h"
 #include "itkImageRegionIterator.h"
 #include "rttbITKImageMaskAccessor.h"
+#include "itkMaskAccessorImageSource.h"
 
 namespace rttb
 {
 	namespace io
 	{
 		namespace itk
 		{
 			ITKImageMaskAccessorConverter::ITKImageMaskAccessorConverter(MaskAccessorPointer accessor)
 			{
 				setMaskAccessor(accessor);
 			}
 
 			bool ITKImageMaskAccessorConverter::process()
 			{
 				//Transfer GeometricInfo to ITK Properties
 				core::GeometricInfo geoInfo = _maskAccessor->getGeometricInfo();
 
-				ITKImageMaskAccessor::ITKMaskImageType::RegionType region;
-
 				ITKImageMaskAccessor::ITKMaskImageType::IndexType start = {{0, 0, 0}};
 
 				ITKImageMaskAccessor::ITKMaskImageType::SizeType size = {{geoInfo.getNumColumns(), geoInfo.getNumRows(), geoInfo.getNumSlices()}};
 
 				ITKImageMaskAccessor::ITKMaskImageType::SpacingType spacing;
 				for (unsigned int i = 0; i < 3; ++i)
 				{
 					spacing[i] = geoInfo.getSpacing()[i];
 				}
 
 				ITKImageMaskAccessor::ITKMaskImageType::PointType origin;
 
 				for (unsigned int i = 0; i < 3; ++i)
 				{
 					origin[i] = geoInfo.getImagePositionPatient()[i];
 				}
 
 				ITKImageMaskAccessor::ITKMaskImageType::DirectionType direction;
 				OrientationMatrix OM = geoInfo.getOrientationMatrix();
 
 				for (unsigned int col = 0; col < 3; ++col)
 				{
 					for (unsigned int row = 0; row < 3; ++row)
 					{
 						direction(col, row) = OM(col, row);
 					}
 				}
-				//Create image, assign properties
-				region.SetSize(size);
-				region.SetIndex(start);
-
-				_itkImage = ITKImageMaskAccessor::ITKMaskImageType::New();
-				_itkImage->SetRegions(region);
-				_itkImage->SetSpacing(spacing);
-				_itkImage->SetDirection(direction);
-				_itkImage->SetOrigin(origin);
-				_itkImage->Allocate();
-
-				::itk::ImageRegionIterator<ITKImageMaskAccessor::ITKMaskImageType> imageIterator(_itkImage, region);
-				VoxelGridID id = 0;
-
-				//Transfer Mask values to itk image
-				//Large advantage: rttbVoxelGridId ordering is the same as itk ordering
-				while (!imageIterator.IsAtEnd())
-				{
-					VoxelGridIndex3D aIndex;
 
-					if (_maskAccessor->getGeometricInfo().validID(id))
-					{
-						rttb::core::MaskVoxel maskVoxel = core::MaskVoxel(id);;
-						_maskAccessor->getMaskAt(id, maskVoxel);
-						// Set the current pixel
-						imageIterator.Set(maskVoxel.getRelevantVolumeFraction());
-					}
-					else
-					{
-						if (failsOnInvalidIDs())
-						{
-							throw core::InvalidDoseException("invalid Mask id!");
-							return false;
-						}
-						else
-						{
-							imageIterator.Set(_invalidDoseValue);
-						}
-					}
+        ::itk::MaskAccessorImageSource::Pointer imagesource = ::itk::MaskAccessorImageSource::New();
+
+        imagesource->SetSize(size);
+        imagesource->SetSpacing(spacing);
+        imagesource->SetDirection(direction);
+        imagesource->SetOrigin(origin);
+        imagesource->SetAccessor(_maskAccessor);
+        imagesource->SetFailsOnInvalidIDs(failsOnInvalidIDs());
+        imagesource->SetInvalidMaskValue(_invalidDoseValue);
+        imagesource->Update();
+        _itkImage = imagesource->GetOutput();
 
-					++imageIterator;
-					++id;
-				}
 				return true;
 			}
 
 
 		}//end namespace mask
 	}//end namespace io
 }//end namespace rttb