diff --git a/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkAcquisitionType.h b/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkAcquisitionType.h
index 93621848a5..24a7002828 100644
--- a/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkAcquisitionType.h
+++ b/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkAcquisitionType.h
@@ -1,68 +1,68 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #ifndef _MITK_KspaceReadout_H
 #define _MITK_KspaceReadout_H
 
 #include <mitkFiberfoxParameters.h>
 #include <itkSize.h>
 
 namespace mitk {
 
 /**
   * \brief Abstract class for k-space acquisiton type (k-space trajectory and echo placement)
   *
   */
 class AcquisitionType
 {
 public:
 
   AcquisitionType(FiberfoxParameters* parameters)
   {
     m_Parameters = parameters;
     kxMax = static_cast<int>(m_Parameters->m_SignalGen.m_CroppedRegion.GetSize(0));
     kyMax = static_cast<int>(m_Parameters->m_SignalGen.m_CroppedRegion.GetSize(1));
   }
   virtual ~AcquisitionType(){}
 
-  virtual float GetTimeFromMaxEcho(itk::Index< 2 > index) = 0;               ///< Time from maximum echo intensity in milliseconds
-  virtual float GetRedoutTime(itk::Index< 2 > index) = 0;                    ///< Time passed since readout started in milliseconds
-  virtual float GetTimeFromRf(itk::Index< 2 > index) = 0;                    ///< Time passed since RF pulse was applied in milliseconds
-  virtual itk::Index< 2 > GetActualKspaceIndex(itk::Index< 2 > index) = 0;    ///< Transfer simple image iterator index to desired k-space index (depends on k-space readout scheme)
+  virtual float GetTimeFromMaxEcho(const itk::Index< 2 >& index) = 0;               ///< Time from maximum echo intensity in milliseconds
+  virtual float GetRedoutTime(const itk::Index< 2 >& index) = 0;                    ///< Time passed since readout started in milliseconds
+  virtual float GetTimeFromRf(const itk::Index< 2 >& index) = 0;                    ///< Time passed since RF pulse was applied in milliseconds
+  virtual itk::Index< 2 > GetActualKspaceIndex(const itk::Index< 2 >& index) = 0;    ///< Transfer simple image iterator index to desired k-space index (depends on k-space readout scheme)
   virtual void AdjustEchoTime() = 0;                                          ///< Depending on the k-space readout scheme and acquisition parameters the minimum TE varies. This has to be checked and adjusted in this method.
-  itk::Index< 2 > GetSymmetricIndex(itk::Index< 2 >& index) const
+  itk::Index< 2 > GetSymmetricIndex(const itk::Index< 2 >& index)
   {
     itk::Index< 2 > sym;
     sym[0] = kxMax-index[0]-1;
     sym[1] = kyMax-index[1]-1;
     return sym;
   }
 
 protected:
 
   float                       m_NegTEhalf;  ///< negative time to read half the k-space (needed to calculate the ms from the maximum echo); THIS IS NOT THE WELL KNOWN TE/2 SCANNER PARAMETER
   FiberfoxParameters*         m_Parameters;
   itk::Size< 2 >              m_Size;
 
   float dt;   // time to read one k-space voxe
   int kxMax;
   int kyMax;
 };
 
 }
 
 #endif
 
diff --git a/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkConventionalSpinEcho.h b/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkConventionalSpinEcho.h
index 5e1a176ea4..2586dfd695 100644
--- a/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkConventionalSpinEcho.h
+++ b/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkConventionalSpinEcho.h
@@ -1,88 +1,89 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #ifndef _MITK_ConventionalSpinEcho_H
 #define _MITK_ConventionalSpinEcho_H
 
 #include <mitkAcquisitionType.h>
 
 namespace mitk {
 
 /**
   * \brief Conventional spin echo sequence. Cartesian readout. One echo and one excitation per k-space line.
   *
   */
 class ConventionalSpinEcho : public AcquisitionType
 {
 public:
 
   ConventionalSpinEcho(FiberfoxParameters* parameters) : AcquisitionType(parameters)
   {
     dt =  m_Parameters->m_SignalGen.m_tLine/kxMax;  // time to read one k-space voxel
 
     // maximum echo at center of each line
     m_NegTEhalf = -dt*(kxMax-kxMax%2)/2;
   }
   ~ConventionalSpinEcho() override
   {}
 
   // one echo per k-space line
-  float GetTimeFromMaxEcho(itk::Index< 2 > index) override
+  float GetTimeFromMaxEcho(const itk::Index< 2 >& index) override
   {
     float t = 0;
     t = m_NegTEhalf + static_cast<float>(index[0])*dt;
     return t;
   }
 
   // time since current readout pulse started
-  float GetRedoutTime(itk::Index< 2 > index) override
+  float GetRedoutTime(const itk::Index< 2 >& index) override
   {
     return static_cast<float>(index[0])*dt;
   }
 
   // time from max-echo + TE
-  float GetTimeFromRf(itk::Index< 2 > index) override
+  float GetTimeFromRf(const itk::Index< 2 >& index) override
   {
     return m_Parameters->m_SignalGen.m_tEcho + GetTimeFromMaxEcho(index);
   }
 
-  itk::Index< 2 > GetActualKspaceIndex(itk::Index< 2 > index) override
+  itk::Index< 2 > GetActualKspaceIndex(const itk::Index< 2 >& index) override
   {
+    itk::Index< 2 > out_idx = index;
     // reverse phase
     if (!m_Parameters->m_SignalGen.m_ReversePhase)
-      index[1] = kyMax-1-index[1];
+      out_idx[1] = kyMax-1-out_idx[1];
 
-    return index;
+    return out_idx;
   }
 
   void AdjustEchoTime() override
   {
     if ( m_Parameters->m_SignalGen.m_tEcho < m_Parameters->m_SignalGen.m_tLine )
     {
       m_Parameters->m_SignalGen.m_tEcho = m_Parameters->m_SignalGen.m_tLine;
       MITK_WARN << "Echo time is too short! Time not sufficient to read slice. Automatically adjusted to " << m_Parameters->m_SignalGen.m_tEcho << " ms";
       m_Parameters->m_Misc.m_AfterSimulationMessage += "Echo time was chosen too short! Time not sufficient to read slice. Internally adjusted to " + boost::lexical_cast<std::string>(m_Parameters->m_SignalGen.m_tEcho) + " ms\n";
     }
   }
 
 protected:
 
 };
 
 }
 
 #endif
 
diff --git a/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkFastSpinEcho.h b/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkFastSpinEcho.h
index 0d8aa8131b..a70aa0ab01 100644
--- a/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkFastSpinEcho.h
+++ b/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkFastSpinEcho.h
@@ -1,91 +1,92 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #ifndef _MITK_FastSpinEcho_H
 #define _MITK_FastSpinEcho_H
 
 #include <mitkAcquisitionType.h>
 
 namespace mitk {
 
 /**
   * \brief Fast spin echo sequence. Cartesian readout.
   * Echo spacing = TE
   */
 class FastSpinEcho : public AcquisitionType
 {
 public:
 
   FastSpinEcho(FiberfoxParameters* parameters)
     : AcquisitionType(parameters)
   {
     m_LinesWithSameTime = static_cast<unsigned int>(std::ceil(static_cast<float>(kyMax)/m_Parameters->m_SignalGen.m_EchoTrainLength));
 
     dt =  m_Parameters->m_SignalGen.m_tLine/kxMax;  // time to read one k-space voxel
 
     // maximum echo at center of each line
     m_NegTEhalf = -dt*(kxMax-kxMax%2)/2;
   }
   ~FastSpinEcho() override
   {}
 
   // one echo per k-space line
-  float GetTimeFromMaxEcho(itk::Index< 2 > index) override
+  float GetTimeFromMaxEcho(const itk::Index< 2 >& index) override
   {
     return m_NegTEhalf + static_cast<float>(index[0])*dt;
   }
 
   // time since current readout pulse started
-  float GetRedoutTime(itk::Index< 2 > index) override
+  float GetRedoutTime(const itk::Index< 2 >& index) override
   {
     return static_cast<float>(index[0])*dt;
   }
 
   // depends on ETL
-  float GetTimeFromRf(itk::Index< 2 > index) override
+  float GetTimeFromRf(const itk::Index< 2 >& index) override
   {
     return m_Parameters->m_SignalGen.m_tEcho*std::ceil(static_cast<float>(index[1]+1)/m_LinesWithSameTime) + GetTimeFromMaxEcho(index);
   }
 
-  itk::Index< 2 > GetActualKspaceIndex(itk::Index< 2 > index) override
+  itk::Index< 2 > GetActualKspaceIndex(const itk::Index< 2 >& index) override
   {
+    itk::Index< 2 > out_idx = index;
     // reverse phase
     if (!m_Parameters->m_SignalGen.m_ReversePhase)
-      index[1] = kyMax-1-index[1];
+      out_idx[1] = kyMax-1-out_idx[1];
 
     return index;
   }
 
   void AdjustEchoTime() override
   {
     if ( m_Parameters->m_SignalGen.m_tEcho < m_Parameters->m_SignalGen.m_tLine )
     {
       m_Parameters->m_SignalGen.m_tEcho = m_Parameters->m_SignalGen.m_tLine;
       MITK_WARN << "Echo time is too short! Time not sufficient to read slice. Automatically adjusted to " << m_Parameters->m_SignalGen.m_tEcho << " ms";
       m_Parameters->m_Misc.m_AfterSimulationMessage += "Echo time was chosen too short! Time not sufficient to read slice. Internally adjusted to " + boost::lexical_cast<std::string>(m_Parameters->m_SignalGen.m_tEcho) + " ms\n";
     }
   }
 
 protected:
 
   unsigned int m_LinesWithSameTime;
 
 };
 
 }
 
 #endif
 
diff --git a/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkSingleShotEpi.h b/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkSingleShotEpi.h
index b5629ab8d5..bab5ef167a 100644
--- a/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkSingleShotEpi.h
+++ b/Modules/DiffusionImaging/FiberTracking/Fiberfox/Sequences/mitkSingleShotEpi.h
@@ -1,99 +1,100 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #ifndef _MITK_SingleShotEpi_H
 #define _MITK_SingleShotEpi_H
 
 #include <mitkAcquisitionType.h>
 
 namespace mitk {
 
 /**
   * \brief Realizes EPI readout: one echo, maximum intensity in the k-space center, zig-zag trajectory
   *
   */
 class SingleShotEpi : public AcquisitionType
 {
 public:
 
   SingleShotEpi(FiberfoxParameters* parameters) : AcquisitionType(parameters)
   {
     dt =  m_Parameters->m_SignalGen.m_tLine/kxMax;  // time to read one k-space voxel
 
     // k-space center at maximum echo
     if ( kyMax%2==0 )
     {
       m_NegTEhalf = -m_Parameters->m_SignalGen.m_tLine*(kyMax-1)/2 + dt*(kxMax-kxMax%2)/2;
     }
     else
       m_NegTEhalf = -m_Parameters->m_SignalGen.m_tLine*(kyMax-1)/2 - dt*(kxMax-kxMax%2)/2;
   }
   ~SingleShotEpi() override
   {}
 
   // one echo per slice
-  float GetTimeFromMaxEcho(itk::Index< 2 > index) override
+  float GetTimeFromMaxEcho(const itk::Index< 2 >& index) override
   {
     float t = 0;
     t = m_NegTEhalf + (static_cast<float>(index[1])*kxMax+static_cast<float>(index[0]))*dt;
     return t;
   }
 
-  float GetRedoutTime(itk::Index< 2 > index) override
+  float GetRedoutTime(const itk::Index< 2 >& index) override
   {
     float t = 0;
     t = (static_cast<float>(index[1])*kxMax+static_cast<float>(index[0]))*dt;
     return t;
   }
 
-  float GetTimeFromRf(itk::Index< 2 > index) override
+  float GetTimeFromRf(const itk::Index< 2 >& index) override
   {
     return m_Parameters->m_SignalGen.m_tEcho + GetTimeFromMaxEcho(index);
   }
 
-  itk::Index< 2 > GetActualKspaceIndex(itk::Index< 2 > index) override
+  itk::Index< 2 > GetActualKspaceIndex(const itk::Index< 2 >& index) override
   {
+    itk::Index< 2 > out_idx = index;
     // reverse phase
     if (!m_Parameters->m_SignalGen.m_ReversePhase)
-      index[1] = kyMax-1-index[1];
+      out_idx[1] = kyMax-1-out_idx[1];
 
     // reverse readout direction
-    if (index[1]%2 == 1)
-      index[0] = kxMax-index[0]-1;
+    if (out_idx[1]%2 == 1)
+      out_idx[0] = kxMax-out_idx[0]-1;
 
-    return index;
+    return out_idx;
   }
 
   void AdjustEchoTime() override
   {
     auto temp = m_Parameters->m_SignalGen.m_CroppedRegion.GetSize(1)*m_Parameters->m_SignalGen.m_PartialFourier - (m_Parameters->m_SignalGen.m_CroppedRegion.GetSize(1)+m_Parameters->m_SignalGen.m_CroppedRegion.GetSize(1)%2)/2;
 
     if ( m_Parameters->m_SignalGen.m_tEcho/2 < temp*m_Parameters->m_SignalGen.m_tLine )
     {
       m_Parameters->m_SignalGen.m_tEcho = 2*temp*m_Parameters->m_SignalGen.m_tLine;
       MITK_WARN << "Echo time is too short! Time not sufficient to read slice. Automatically adjusted to " << m_Parameters->m_SignalGen.m_tEcho << " ms";
       m_Parameters->m_Misc.m_AfterSimulationMessage += "Echo time was chosen too short! Time not sufficient to read slice. Internally adjusted to " + boost::lexical_cast<std::string>(m_Parameters->m_SignalGen.m_tEcho) + " ms\n";
     }
   }
 
 protected:
 
 };
 
 }
 
 #endif