diff --git a/code/io/itk/itkMaskAccessorImageSource.cpp b/code/io/itk/itkMaskAccessorImageSource.cpp
new file mode 100644
index 0000000..0ab61c9
--- /dev/null
+++ b/code/io/itk/itkMaskAccessorImageSource.cpp
@@ -0,0 +1,107 @@
+// -----------------------------------------------------------------------
+// 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: 1233 $ (last changed revision)
+// @date    $Date: 2016-01-20 15:47:47 +0100 (Mi, 20 Jan 2016) $ (last change date)
+// @author  $Author: hentsch $ (last changed by)
+*/
+
+
+#include "itkMaskAccessorImageSource.h"
+#include "itkImageRegionIterator.h"
+#include "itkImageRegionConstIteratorWithIndex.h"
+#include "itkProgressReporter.h"
+#include "itkExceptionObject.h"
+
+namespace itk
+{
+	/**
+	* Constructor
+	*/
+	MaskAccessorImageSource
+    ::MaskAccessorImageSource() : m_FailsOnInvalidIDs(true), m_InvalidMaskValue(0)
+	{
+	}
+
+	void
+	MaskAccessorImageSource
+	::ThreadedGenerateData(const OutputImageRegionType& outputRegionForThread,
+	                       ThreadIdType threadId)
+	{
+		ProgressReporter progress(this, threadId,
+		                          outputRegionForThread.GetNumberOfPixels());
+
+		typedef ImageRegionIterator< OutputImageType > OutputImageRegionIteratorType;
+
+		OutputImagePointer outputPtr = dynamic_cast< OutputImageType* >(ProcessObject::GetOutput(0));
+		OutputImageRegionIteratorType outputItr;
+
+		if (outputPtr)
+		{
+			outputItr = OutputImageRegionIteratorType(outputPtr, outputRegionForThread);
+
+      for (; !(outputItr.IsAtEnd()); ++outputItr)
+			{
+        OutputImageType::IndexType index = outputItr.GetIndex();
+        rttb::VoxelGridIndex3D maskIndex(index[0], index[1], index[2]);
+        rttb::VoxelGridID id = 0;
+
+        if (m_Accessor->getGeometricInfo().convert(maskIndex, id))
+        {
+          auto finding = m_idMap.find(id);
+          if (finding != m_idMap.end())
+          {
+            // Set the current pixel
+            outputItr.Set(m_MaskedVoxels->at(finding->second).getRelevantVolumeFraction());
+          }
+        }
+        else
+        {
+          if (m_FailsOnInvalidIDs)
+          {
+            itkExceptionMacro(<<"invalid Mask index. Index:"<<index);
+          }
+          else
+          {
+            outputItr.Set(m_InvalidMaskValue);
+          }
+        }
+
+				progress.CompletedPixel();
+			}
+		}
+	}
+
+  void
+    MaskAccessorImageSource
+    ::BeforeThreadedGenerateData()
+  {
+
+    OutputImagePointer outputPtr = dynamic_cast< OutputImageType* >(ProcessObject::GetOutput(0));
+    outputPtr->FillBuffer(0.0);
+
+    //The id map approach and working with relevant voxel vector is a workarround till task T22067 is solved and and can be used again.
+    m_MaskedVoxels = m_Accessor->getRelevantVoxelVector();
+
+    m_idMap.clear();
+
+    for (rttb::core::MaskAccessorInterface::MaskVoxelList::size_type pos = 0; pos < m_MaskedVoxels->size(); ++pos)
+    {
+      m_idMap.insert(std::make_pair((*m_MaskedVoxels)[pos].getVoxelGridID(), pos));
+    }
+  }
+} // end namespace itk
+
diff --git a/code/io/itk/itkMaskAccessorImageSource.h b/code/io/itk/itkMaskAccessorImageSource.h
new file mode 100644
index 0000000..59b6235
--- /dev/null
+++ b/code/io/itk/itkMaskAccessorImageSource.h
@@ -0,0 +1,115 @@
+// -----------------------------------------------------------------------
+// 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: 1221 $ (last changed revision)
+// @date    $Date: 2015-12-01 13:43:31 +0100 (Di, 01 Dez 2015) $ (last change date)
+// @author  $Author: hentsch $ (last changed by)
+*/
+
+#ifndef __itkMaskAccessorImageSource_h
+#define __itkMaskAccessorImageSource_h
+
+#include "itkGenerateImageSource.h"
+#include "itkImageIterator.h"
+
+#include "rttbMaskAccessorInterface.h"
+#include "rttbITKImageMaskAccessor.h"
+
+namespace itk
+{
+	/** \class MaskAccessorImageSource
+	 * \brief Converts a given mask accessor into an itk image.
+	 *
+	 */
+
+  typedef rttb::io::itk::ITKImageMaskAccessor::ITKMaskImageType RTTBMaskImageType;
+
+	class ITK_EXPORT MaskAccessorImageSource:
+    public GenerateImageSource< RTTBMaskImageType>
+
+	{
+	public:
+		/** Standard class typedefs. */
+		typedef MaskAccessorImageSource                          Self;
+    typedef GenerateImageSource< RTTBMaskImageType > Superclass;
+		typedef SmartPointer< Self >                            Pointer;
+		typedef SmartPointer< const Self >                      ConstPointer;
+		/** Method for creation through the object factory. */
+		itkNewMacro(Self);
+
+		/** Run-time type information (and related methods). */
+		itkTypeMacro(MaskAccessorImageSource, ImageToImageFilter);
+
+		/** Some typedefs. */
+    typedef RTTBMaskImageType           OutputImageType;
+		typedef OutputImageType::Pointer    OutputImagePointer;
+		typedef OutputImageType::RegionType OutputImageRegionType;
+		typedef OutputImageType::PixelType  OutputImagePixelType;
+
+		typedef rttb::core::MaskAccessorInterface AccessorType;
+    typedef rttb::core::MaskAccessorInterface::MaskAccessorPointer AccessorPointer;
+
+		/** Get the accessor pointer. */
+    AccessorPointer GetAccessor()
+		{
+			return m_Accessor;
+		}
+
+		/** Set the accessor pointer. */
+    void SetAccessor(AccessorPointer accessor)
+		{
+			if (m_Accessor != accessor)
+			{
+				m_Accessor = accessor;
+				this->Modified();
+			}
+		}
+
+    itkSetMacro(FailsOnInvalidIDs, bool);
+    itkGetConstMacro(FailsOnInvalidIDs, bool);
+
+    itkSetMacro(InvalidMaskValue, OutputImageType::ValueType);
+    itkGetConstMacro(InvalidMaskValue, OutputImageType::ValueType);
+
+		/** ImageDimension constants */
+		itkStaticConstMacro(
+		    OutputImageDimension, unsigned int, OutputImageType::ImageDimension);
+
+	protected:
+		MaskAccessorImageSource();
+		virtual ~MaskAccessorImageSource() {}
+
+		void ThreadedGenerateData(const OutputImageRegionType& outputRegionForThread,
+		                          ThreadIdType threadId);
+
+    virtual void BeforeThreadedGenerateData();
+
+	private:
+		MaskAccessorImageSource(const Self&);  //purposely not implemented
+		void operator=(const Self&);          //purposely not implemented
+
+    typedef std::map <rttb::VoxelGridID, rttb::core::MaskAccessorInterface::MaskVoxelList::size_type> VoxelMapType;
+    VoxelMapType m_idMap;
+    rttb::core::MaskAccessorInterface::MaskVoxelListPointer m_MaskedVoxels;
+
+    AccessorPointer m_Accessor;
+    bool m_FailsOnInvalidIDs;
+    OutputImageType::ValueType m_InvalidMaskValue;
+	};
+} // end namespace itk
+
+
+#endif