diff --git a/Plugins/org.mitk.gui.qt.diffusionimaging/src/QmitkIVIMWidget.cpp b/Plugins/org.mitk.gui.qt.diffusionimaging/src/QmitkIVIMWidget.cpp
index 4cc6e9a0b6..cd3f7aa0b5 100644
--- a/Plugins/org.mitk.gui.qt.diffusionimaging/src/QmitkIVIMWidget.cpp
+++ b/Plugins/org.mitk.gui.qt.diffusionimaging/src/QmitkIVIMWidget.cpp
@@ -1,150 +1,150 @@
 /*===================================================================
 
 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.
 
 ===================================================================*/
 
 #include "QmitkIVIMWidget.h"
 
 #include "mitkHistogramGenerator.h"
 
 
 #include <qwt_scale_engine.h>
 #include <qwt_legend.h>
 
 
 QmitkIVIMWidget::QmitkIVIMWidget( QWidget * parent )
   : QmitkPlotWidget(parent)
 {
   //  this->SetAxisTitle( QwtPlot::xBottom, "Grayvalue" );
   //  this->SetAxisTitle( QwtPlot::yLeft, "Probability" );
   //  this->Replot();
   QFrame* canvas = qobject_cast<QFrame*>(m_Plot->canvas());
   if (canvas)
   {
     canvas->setLineWidth(0);
     canvas->setContentsMargins(0,0,0,0);
   }
 
   QwtLogScaleEngine* logScale = new QwtLogScaleEngine();
   m_Plot->setAxisScaleEngine(0, logScale);
 
   m_Plot->setAxisScale( 0, 0.15, 1.0 );
 }
 
 
 
 QmitkIVIMWidget::~QmitkIVIMWidget()
 {
 }
 
 
 void QmitkIVIMWidget::DrawGauss()
 {
 
 }
 
 
 void QmitkIVIMWidget::ClearItemModel()
 {
 
 }
 
-std::vector<double> QmitkIVIMWidget::vec(vnl_vector<double> vector)
+std::vector<double> QmitkIVIMWidget::vec(const vnl_vector<double>& vector)
 {
   std::vector<double> retval(vector.size());
   for(unsigned int i=0; i<vector.size(); i++)
   {
     retval.at(i) = vector[i];
   }
   return retval;
 }
 
 void QmitkIVIMWidget::SetParameters( IVIMFilterType::IVIMSnapshot snap )
 {
   this->Clear();
   if (snap.bvalues.empty())
       return;
 
   QString s("f=%1, D=%2, D*=%3");
   s = s.arg(snap.currentF,4);
   s = s.arg(snap.currentD,4);
   s = s.arg(snap.currentDStar,4);
   int curveId = this->InsertCurve( s.toAscii() );
   this->SetCurvePen( curveId, QPen( Qt::NoPen ) );
 
   curveId = this->InsertCurve( "ignored measurement points" );
   this->SetCurveData( curveId, vec(snap.bvalues), vec(snap.allmeas) );
-  this->SetCurvePen( curveId, QPen( Qt::NoPen ) );
-  QwtSymbol whiteSymbol(QwtSymbol::Diamond, QColor(Qt::white), QColor(Qt::black), QSize(10,10));
-  this->SetCurveSymbol(curveId, &whiteSymbol);
+  this->SetCurvePen( curveId, QPen(Qt::NoPen) );
+  QwtSymbol* whiteSymbol = new QwtSymbol(QwtSymbol::Diamond, QColor(Qt::white), QColor(Qt::black), QSize(10,10));
+  this->SetCurveSymbol(curveId, whiteSymbol);
 
   if(snap.currentDStar != 0)
   {
     curveId = this->InsertCurve( "additional points second fit" );
     this->SetCurveData( curveId, vec(snap.bvals2), vec(snap.meas2) );
     this->SetCurvePen( curveId, QPen( Qt::NoPen ) );
-    QwtSymbol blackSymbol(QwtSymbol::Diamond, QColor(Qt::black), QColor(Qt::black), QSize(10,10));
-    this->SetCurveSymbol(curveId, &blackSymbol);
+    QwtSymbol* blackSymbol = new QwtSymbol(QwtSymbol::Diamond, QColor(Qt::black), QColor(Qt::black), QSize(10,10));
+    this->SetCurveSymbol(curveId, blackSymbol);
   }
 
   curveId = this->InsertCurve( "points first fit" );
   this->SetCurveData( curveId, vec(snap.bvals1), vec(snap.meas1) );
   this->SetCurvePen( curveId, QPen( Qt::NoPen ) );
-  QwtSymbol redSymbol(QwtSymbol::Diamond, QColor(Qt::red), QColor(Qt::red), QSize(10,10));
-  this->SetCurveSymbol(curveId, &redSymbol);
+  QwtSymbol* redSymbol = new QwtSymbol(QwtSymbol::Diamond, QColor(Qt::red), QColor(Qt::red), QSize(10,10));
+  this->SetCurveSymbol(curveId, redSymbol);
 
   QPen pen;
   pen.setColor( QColor(Qt::red) );
   pen.setWidth(2);
   double maxb = snap.bvalues.max_value();
   vnl_vector<double> xvals(2);
   vnl_vector<double> yvals(2);
   xvals[0] = 0;
   xvals[1] = maxb;
   yvals[0] = 1-snap.currentFunceiled;
   yvals[1] = yvals[0]*exp(-maxb * snap.currentD);
   curveId = this->InsertCurve( "contribution of D to the signal" );
   this->SetCurveData( curveId, vec(xvals), vec(yvals) );
   this->SetCurvePen( curveId, pen );
 
   if(snap.currentDStar != 0)
   {
     pen.setColor(Qt::black);
     int nsampling = 50;
     xvals.set_size(nsampling);
     yvals.set_size(nsampling);
     double f = 1-snap.currentFunceiled;
     for(int i=0; i<nsampling; i++)
     {
       xvals[i] = (((1.0)*i)/(1.0*nsampling))*maxb;
       yvals[i] = f*exp(- xvals[i] * snap.currentD) + (1-f)*exp(- xvals[i] * (snap.currentD+snap.currentDStar));
     }
     curveId = this->InsertCurve( "resulting fit of the model" );
     this->SetCurveData( curveId, vec(xvals), vec(yvals) );
     this->SetCurvePen( curveId, pen );
   }
 
 //  QMargins margins;
 //  margins.setBottom(0);
 //  margins.setLeft(0);
 //  margins.setRight(0);
 //  margins.setTop(0);
 
   QwtLegend* legend = new QwtLegend();
 //  legend->setContentsMargins(margins);
   m_Plot->insertLegend(legend, QwtPlot::BottomLegend);
 
   this->Replot();
 
 }
diff --git a/Plugins/org.mitk.gui.qt.diffusionimaging/src/QmitkIVIMWidget.h b/Plugins/org.mitk.gui.qt.diffusionimaging/src/QmitkIVIMWidget.h
index 144b6bd34d..f3da316d1c 100644
--- a/Plugins/org.mitk.gui.qt.diffusionimaging/src/QmitkIVIMWidget.h
+++ b/Plugins/org.mitk.gui.qt.diffusionimaging/src/QmitkIVIMWidget.h
@@ -1,58 +1,58 @@
 /*===================================================================
 
 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 QmitkIVIMWidget_H_
 #define QmitkIVIMWidget_H_
 
 #include "QmitkPlotWidget.h"
 
 #include "mitkImage.h"
 
 #include "itkDiffusionIntravoxelIncoherentMotionReconstructionImageFilter.h"
 
 
 /**
  * \brief Widget for displaying image histograms based on the vtkQtChart
  * framework
  */
 class QmitkIVIMWidget : public QmitkPlotWidget
 {
 
 public:
 
   typedef itk::DiffusionIntravoxelIncoherentMotionReconstructionImageFilter<short, float> IVIMFilterType;
 
   typedef mitk::Image::HistogramType HistogramType;
   typedef mitk::Image::HistogramType::ConstIterator HistogramConstIteratorType;
 
   void SetParameters( IVIMFilterType::IVIMSnapshot snap );
 
   QmitkIVIMWidget( QWidget * /*parent = 0 */);
   virtual ~QmitkIVIMWidget();
 
   void DrawGauss();
 
   void ClearItemModel();
 
   std::vector< std::vector<double>* > m_Vals;
 
 private:
 
-  std::vector<double> vec(vnl_vector<double> vector);
+  std::vector<double> vec(const vnl_vector<double>& vector);
 
 };
 
 #endif /* QmitkIVIMWidget_H_ */