diff --git a/Modules/SemanticRelationsUI/include/QmitkLesionTreeModel.h b/Modules/SemanticRelationsUI/include/QmitkLesionTreeModel.h
index ff80a1b00e..cafc181553 100644
--- a/Modules/SemanticRelationsUI/include/QmitkLesionTreeModel.h
+++ b/Modules/SemanticRelationsUI/include/QmitkLesionTreeModel.h
@@ -1,87 +1,86 @@
 /*===================================================================
 
 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 QMITKLESIONTREEMODEL_H
 #define QMITKLESIONTREEMODEL_H
 
 // mitk semantic relations UI
 #include "MitkSemanticRelationsUIExports.h"
 #include "QmitkAbstractSemanticRelationsStorageModel.h"
 #include "QmitkLesionTreeItem.h"
 
 // c++
 #include <memory>
 
 /*
 * @brief 
 */
 class MITKSEMANTICRELATIONSUI_EXPORT QmitkLesionTreeModel : public QmitkAbstractSemanticRelationsStorageModel
 {
   Q_OBJECT 
    
 public:
 
   /**
   *	@brief Initialize the root item of the model. The root item does not have a parent item.
   */
   QmitkLesionTreeModel(QObject* parent = nullptr);
   ~QmitkLesionTreeModel();
 
   //////////////////////////////////////////////////////////////////////////
   // overridden virtual functions from QAbstractItemModel
   //////////////////////////////////////////////////////////////////////////
   virtual QModelIndex index(int row, int column, const QModelIndex& itemIndex = QModelIndex()) const override;
   virtual QModelIndex parent(const QModelIndex& itemIndex) const override;
 
   virtual int rowCount(const QModelIndex& itemIndex = QModelIndex()) const override;
   virtual int columnCount(const QModelIndex& itemIndex = QModelIndex()) const override;
 
   virtual QVariant data(const QModelIndex& index, int role = Qt::DisplayRole) const override;
 
   virtual QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const override;
-  //Qt::ItemFlags flags(const QModelIndex &index) const override;
 
   //////////////////////////////////////////////////////////////////////////
   // end override
   //////////////////////////////////////////////////////////////////////////
 
 protected:
   
   // the following functions have to be overridden but are not implemented in this model
   virtual void NodePredicateChanged() override;
   virtual void NodeAdded(const mitk::DataNode* node) override;
   virtual void NodeChanged(const mitk::DataNode* node) override;
   virtual void NodeRemoved(const mitk::DataNode* node) override;
   /**
   * @brief Overridden from 'QmitkAbstractSemanticRelationsStorageModel': This function retrieves all control points
   *        of the current case and stores them to define the header of the tree.
   *        Furthermore all lesions are retrieved and the lesion data is stored and show in the tree view.
   */
   virtual void SetData() override;
 
 private:
 
   void SetLesionData();
   void AddLesion(const mitk::SemanticTypes::Lesion& lesion);
 
   QmitkLesionTreeItem* GetItemByIndex(const QModelIndex& index) const;
 
   std::shared_ptr<QmitkLesionTreeItem> m_RootItem;
   std::vector<mitk::SemanticTypes::ControlPoint> m_ControlPoints;
 
 };
 
 #endif // QMITKLESIONTREEMODEL_H
diff --git a/Modules/SemanticRelationsUI/src/QmitkPatientTableModel.cpp b/Modules/SemanticRelationsUI/src/QmitkPatientTableModel.cpp
index 95137b61dd..635f8eab62 100644
--- a/Modules/SemanticRelationsUI/src/QmitkPatientTableModel.cpp
+++ b/Modules/SemanticRelationsUI/src/QmitkPatientTableModel.cpp
@@ -1,354 +1,357 @@
 /*===================================================================
 
 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.
 
 ===================================================================*/
 
 // semantic relations UI module
 #include "QmitkPatientTableModel.h"
 #include "QmitkSemanticRelationsUIHelper.h"
 
 // semantic relations module
 #include <mitkControlPointManager.h>
 #include <mitkNodePredicates.h>
 #include <mitkSemanticRelationException.h>
 
 #include <QmitkCustomVariants.h>
 #include <QmitkEnums.h>
 
 // qt
 #include <QColor>
 
 QmitkPatientTableModel::QmitkPatientTableModel(QObject* parent /*= nullptr*/)
   : QmitkAbstractSemanticRelationsStorageModel(parent)
   , m_SelectedNodeType("Image")
 {
   // nothing here
 }
 
 QmitkPatientTableModel::~QmitkPatientTableModel()
 {
   // nothing here
 }
 
 QModelIndex QmitkPatientTableModel::index(int row, int column, const QModelIndex& parent/* = QModelIndex()*/) const
 {
   if (hasIndex(row, column, parent))
   {
     return createIndex(row, column);
   }
 
   return QModelIndex();
 }
 
 QModelIndex QmitkPatientTableModel::parent(const QModelIndex& child) const
 {
   return QModelIndex();
 }
 
 int QmitkPatientTableModel::rowCount(const QModelIndex& parent/* = QModelIndex()*/) const
 {
   if (parent.isValid())
   {
     return 0;
   }
 
   return m_InformationTypes.size();
 }
 
 int QmitkPatientTableModel::columnCount(const QModelIndex& parent/* = QModelIndex()*/) const
 {
   if (parent.isValid())
   {
     return 0;
   }
 
   return m_ControlPoints.size();
 }
 
 QVariant QmitkPatientTableModel::data(const QModelIndex& index, int role/* = Qt::DisplayRole*/) const
 {
   if (!index.isValid())
   {
     return QVariant();
   }
 
   if (index.row() < 0 || index.row() >= static_cast<int>(m_InformationTypes.size())
    || index.column() < 0 || index.column() >= static_cast<int>(m_ControlPoints.size()))
   {
     return QVariant();
   }
 
   mitk::DataNode* dataNode = GetCurrentDataNode(index);
   if (nullptr == dataNode)
   {
     return QVariant();
   }
 
   if (Qt::DecorationRole == role)
   {
     auto it = m_PixmapMap.find(dataNode);
     if (it != m_PixmapMap.end())
     {
       return QVariant(it->second);
     }
   }
-  else if (QmitkDataNodeRole == role)
+
+  if (QmitkDataNodeRole == role)
   {
     return QVariant::fromValue<mitk::DataNode::Pointer>(mitk::DataNode::Pointer(dataNode));
   }
-  else if (QmitkDataNodeRawPointerRole == role)
+
+  if (QmitkDataNodeRawPointerRole == role)
   {
     return QVariant::fromValue<mitk::DataNode *>(dataNode);
   }
-  else if (Qt::BackgroundColorRole == role)
+
+  if (Qt::BackgroundColorRole == role)
   {
     auto it = m_LesionPresence.find(dataNode);
     if (it != m_LesionPresence.end())
     {
       return it->second ? QVariant(QColor(Qt::green)) : QVariant(QColor(Qt::transparent));
     }
 
     return QVariant(QColor(Qt::transparent));
   }
 
   return QVariant();
 }
 
 QVariant QmitkPatientTableModel::headerData(int section, Qt::Orientation orientation, int role) const
 {
   if (Qt::Horizontal == orientation && Qt::DisplayRole == role)
   {
     if (m_ControlPoints.size() > section)
     {
       mitk::SemanticTypes::ControlPoint currentControlPoint = m_ControlPoints.at(section);
       // generate a string from the control point
       std::string currentControlPointAsString = mitk::GetControlPointAsString(currentControlPoint);
       return QVariant(QString::fromStdString(currentControlPointAsString));
     }
   }
   if (Qt::Vertical == orientation && Qt::DisplayRole == role)
   {
     if (m_InformationTypes.size() > section)
     {
       mitk::SemanticTypes::InformationType currentInformationType = m_InformationTypes.at(section);
       return QVariant(QString::fromStdString(currentInformationType));
     }
   }
   return QVariant();
 }
 
 Qt::ItemFlags QmitkPatientTableModel::flags(const QModelIndex& index) const
 {
   Qt::ItemFlags flags;
   mitk::DataNode* dataNode = GetCurrentDataNode(index);
   if (nullptr != dataNode)
   {
     flags = Qt::ItemIsEnabled | Qt::ItemIsSelectable;
   }
 
   return flags;
 }
 
 void QmitkPatientTableModel::SetNodeType(const std::string& nodeType)
 {
   m_SelectedNodeType = nodeType;
   UpdateModelData();
 }
 
 void QmitkPatientTableModel::NodePredicateChanged()
 {
   UpdateModelData();
 }
 
 void QmitkPatientTableModel::NodeAdded(const mitk::DataNode* node)
 {
   // does not react to data storage changes
 }
 
 void QmitkPatientTableModel::NodeChanged(const mitk::DataNode* node)
 {
   // nothing here, since the "'NodeChanged'-event is currently sent far too often
   //UpdateModelData();
 }
 
 void QmitkPatientTableModel::NodeRemoved(const mitk::DataNode* node)
 {
   // does not react to data storage changes
 }
 
 void QmitkPatientTableModel::SetPixmapOfNode(const mitk::DataNode* dataNode, QPixmap* pixmapFromImage)
 {
   if (nullptr == dataNode)
   {
     return;
   }
 
   std::map<mitk::DataNode::ConstPointer, QPixmap>::iterator iter = m_PixmapMap.find(dataNode);
   if (iter != m_PixmapMap.end())
   {
     // key already existing
     if (nullptr != pixmapFromImage)
     {
       // overwrite already stored pixmap
       iter->second = pixmapFromImage->scaled(120, 120, Qt::IgnoreAspectRatio);
     }
     else
     {
       // remove key if no pixmap is given
       m_PixmapMap.erase(iter);
     }
   }
   else
   {
     m_PixmapMap.insert(std::make_pair(dataNode, pixmapFromImage->scaled(120, 120, Qt::IgnoreAspectRatio)));
   }
 }
 
 void QmitkPatientTableModel::SetLesionPresence(const mitk::DataNode* dataNode, bool lesionPresence)
 {
   if (nullptr == dataNode)
   {
     return;
   }
 
   std::map<mitk::DataNode::ConstPointer, bool>::iterator iter = m_LesionPresence.find(dataNode);
   if (iter != m_LesionPresence.end())
   {
     // key already existing, overwrite already stored bool value
     iter->second = lesionPresence;
   }
   else
   {
     m_LesionPresence.insert(std::make_pair(dataNode, lesionPresence));
   }
 }
 
 void QmitkPatientTableModel::SetData()
 {
   // get all control points of current case
   m_ControlPoints = m_SemanticRelations->GetAllControlPointsOfCase(m_CaseID);
   // sort the vector of control points for the timeline
   std::sort(m_ControlPoints.begin(), m_ControlPoints.end());
   // get all information types points of current case
   m_InformationTypes = m_SemanticRelations->GetAllInformationTypesOfCase(m_CaseID);
 
   m_PixmapMap.clear();
   m_LesionPresence.clear();
 
   SetDataNodes();
 }
 
 void QmitkPatientTableModel::SetDataNodes()
 {
   std::vector<mitk::DataNode::Pointer> allDataNodes;
   if("Image" == m_SelectedNodeType)
   {
     allDataNodes = m_SemanticRelations->GetAllImagesOfCase(m_CaseID);
   }
   else if("Segmentation" == m_SelectedNodeType)
   {
     allDataNodes = m_SemanticRelations->GetAllSegmentationsOfCase(m_CaseID);
   }
 
   for (const auto& dataNode : allDataNodes)
   {
     // set the pixmap for the current node
     QPixmap pixmapFromImage = QmitkSemanticRelationsUIHelper::GetPixmapFromImageNode(dataNode);
     SetPixmapOfNode(dataNode, &pixmapFromImage);
 
     // set the lesion presence for the current node
     if (m_SemanticRelations->InstanceExists(m_CaseID, m_Lesion))
     {
       bool lesionPresence = lesionPresence = IsLesionPresentOnDataNode(dataNode);
       SetLesionPresence(dataNode, lesionPresence);
     }
     else
     {
       m_LesionPresence.clear();
     }
   }
 }
 
 bool QmitkPatientTableModel::IsLesionPresentOnDataNode(const mitk::DataNode* dataNode) const
 {
   if (m_DataStorage.IsExpired())
   {
     return false;
   }
 
   auto dataStorage = m_DataStorage.Lock();
   try
   {
     mitk::SemanticRelations::DataNodeVector allSegmentationsOfLesion = m_SemanticRelations->GetAllSegmentationsOfLesion(m_CaseID, m_Lesion);
     for (const auto& segmentation : allSegmentationsOfLesion)
     {
       if ("Segmentation" == m_SelectedNodeType)
       {
         if (dataNode == segmentation)
         {
           // found a segmentation of the node that is represented by the selected lesion
           return true;
         }
       }
       else if ("Image" == m_SelectedNodeType)
       {
         // get parent node of the current segmentation node with the node predicate
         mitk::DataStorage::SetOfObjects::ConstPointer parentNodes = dataStorage->GetSources(segmentation, mitk::NodePredicates::GetImagePredicate(), false);
         for (auto it = parentNodes->Begin(); it != parentNodes->End(); ++it)
         {
           if (dataNode == it.Value())
           {
             // found a segmentation of the node that is represented by the selected lesion
             return true;
           }
         }
       }
     }
   }
   catch (const mitk::SemanticRelationException&)
   {
     return false;
   }
 
   return false;
 }
 
 mitk::DataNode* QmitkPatientTableModel::GetCurrentDataNode(const QModelIndex& index) const
 {
   mitk::SemanticTypes::ControlPoint currentControlPoint = m_ControlPoints.at(index.column());
   mitk::SemanticTypes::InformationType currentInformationType = m_InformationTypes.at(index.row());
   try
   {
     std::vector<mitk::DataNode::Pointer> filteredDataNodes;
     if ("Image" == m_SelectedNodeType)
     {
 
       filteredDataNodes = m_SemanticRelations->GetAllSpecificImages(m_CaseID, currentControlPoint, currentInformationType);
     }
     else if ("Segmentation" == m_SelectedNodeType)
     {
       filteredDataNodes = m_SemanticRelations->GetAllSpecificSegmentations(m_CaseID, currentControlPoint, currentInformationType);
     }
 
     if (filteredDataNodes.empty())
     {
       return nullptr;
     }
     return filteredDataNodes.front();
   }
   catch (const mitk::SemanticRelationException&)
   {
     return nullptr;
   }
 }
diff --git a/Plugins/org.mitk.gui.qt.semanticrelations/src/internal/QmitkLesionInfoWidget.cpp b/Plugins/org.mitk.gui.qt.semanticrelations/src/internal/QmitkLesionInfoWidget.cpp
index 1e4fe0fc80..837aaaf405 100644
--- a/Plugins/org.mitk.gui.qt.semanticrelations/src/internal/QmitkLesionInfoWidget.cpp
+++ b/Plugins/org.mitk.gui.qt.semanticrelations/src/internal/QmitkLesionInfoWidget.cpp
@@ -1,398 +1,391 @@
 /*===================================================================
 
 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.
 
 ===================================================================*/
 
 // semantic relations plugin
 #include "QmitkLesionInfoWidget.h"
 #include "QmitkSemanticRelationsNodeSelectionDialog.h"
 
 // semantic relations UI module
 #include <QmitkLesionTextDialog.h>
 
 // semantic relations module
 #include <mitkLesionManager.h>
 #include <mitkNodePredicates.h>
 #include <mitkSemanticRelationException.h>
 
 // qt
 #include <QCompleter>
 #include <QListWidget>
 #include <QMenu>
 #include <QMessageBox>
 #include <QString>
 
-const QBrush QmitkLesionInfoWidget::DEFAULT_BACKGROUND_COLOR = QBrush(Qt::transparent);
-const QBrush QmitkLesionInfoWidget::SELECTED_BACKGROUND_COLOR = QBrush(Qt::green);
-const QBrush QmitkLesionInfoWidget::CONNECTED_BACKGROUND_COLOR = QBrush(Qt::darkGreen);
-
 QmitkLesionInfoWidget::QmitkLesionInfoWidget(mitk::DataStorage* dataStorage, QWidget* parent /*= nullptr*/)
   : QWidget(parent)
   , m_DataStorage(dataStorage)
   , m_SemanticRelations(std::make_unique<mitk::SemanticRelations>(dataStorage))
 {
   Initialize();
 }
 
 QmitkLesionInfoWidget::~QmitkLesionInfoWidget()
 {
   // nothing here
 }
 
 void QmitkLesionInfoWidget::Initialize()
 {
   m_Controls.setupUi(this);
 
   m_Controls.lesionTreeView->setAlternatingRowColors(true);
   m_Controls.lesionTreeView->setSelectionMode(QAbstractItemView::SingleSelection);
-  m_Controls.lesionTreeView->setSelectionBehavior(QAbstractItemView::SelectItems);
+  m_Controls.lesionTreeView->setSelectionBehavior(QAbstractItemView::SelectRows);
   m_Controls.lesionTreeView->setContextMenuPolicy(Qt::CustomContextMenu);
 
   m_StorageModel = new QmitkLesionTreeModel(this);
   if (m_DataStorage.IsExpired())
   {
     return;
   }
 
   auto dataStorage = m_DataStorage.Lock();
   m_StorageModel->SetDataStorage(dataStorage);
   m_Controls.lesionTreeView->setModel(m_StorageModel);
 
   SetUpConnections();
 }
 
 void QmitkLesionInfoWidget::SetUpConnections()
 {
   connect(m_StorageModel, &QmitkLesionTreeModel::ModelUpdated, this, &QmitkLesionInfoWidget::OnModelUpdated);
 
   // connect buttons to modify semantic relations
   connect(m_Controls.addLesionPushButton, &QPushButton::clicked, this, &QmitkLesionInfoWidget::OnAddLesionButtonClicked);
 
   // connect each list widget with a custom slots
-  connect(m_Controls.lesionTreeView->selectionModel(), &QItemSelectionModel::selectionChanged, this, &QmitkLesionInfoWidget::OnSelectionChanged);
+  connect(m_Controls.lesionTreeView->selectionModel(), &QItemSelectionModel::currentChanged, this, &QmitkLesionInfoWidget::OnSelectionChanged);
 
   // connect context menu entries
   connect(m_Controls.lesionTreeView, &QTreeView::customContextMenuRequested, this, &QmitkLesionInfoWidget::OnLesionListContextMenuRequested);
 }
 
 void QmitkLesionInfoWidget::SetCaseID(const mitk::SemanticTypes::CaseID& caseID)
 {
   m_CaseID = caseID;
   m_StorageModel->SetCaseID(caseID);
 }
 
 //////////////////////////////////////////////////////////////////////////
 // Implementation of the QT_SLOTS
 //////////////////////////////////////////////////////////////////////////
 void QmitkLesionInfoWidget::OnModelUpdated()
 {
   m_Controls.lesionTreeView->expandAll();
   int columns = m_Controls.lesionTreeView->model()->columnCount();
   for (int i = 0; i < columns; ++i)
   {
     m_Controls.lesionTreeView->resizeColumnToContents(i);
   }
 }
 
 void QmitkLesionInfoWidget::OnAddLesionButtonClicked()
 {
   if (m_CaseID.empty())
   {
     QMessageBox msgBox;
     msgBox.setWindowTitle("No case ID set.");
     msgBox.setText("In order to add a lesion, please specify the current case / patient.");
     msgBox.setIcon(QMessageBox::Warning);
     msgBox.exec();
     return;
   }
 
   mitk::SemanticTypes::Lesion newLesion = mitk::GenerateNewLesion();
   try
   {
     m_SemanticRelations->AddLesion(m_CaseID, newLesion);
   }
   catch (mitk::SemanticRelationException& e)
   {
     MITK_INFO << "Could not add a new lesion. " << e;
   }
 }
 
-void QmitkLesionInfoWidget::OnSelectionChanged(const QItemSelection& selected, const QItemSelection& deselected)
+void QmitkLesionInfoWidget::OnSelectionChanged(const QModelIndex& current, const QModelIndex& previous)
 {
-  if (nullptr == m_SemanticRelations)
+  if (nullptr == m_SemanticRelations && current.isValid())
   {
     return;
   }
 
-  for (const auto& index : selected.indexes())
+  // only the UID is needed to identify a representing lesion
+  QVariant data = m_StorageModel->data(current, Qt::UserRole);
+  if (data.canConvert<QmitkLesionTreeItem*>())
+  {
+    m_CurrentLesion = data.value<QmitkLesionTreeItem*>()->GetData().GetLesion();
+  }
+  else
   {
-    // only the UID is needed to identify a representing lesion
-    QVariant data = m_StorageModel->data(index, Qt::UserRole);
-    if (data.canConvert<QmitkLesionTreeItem*>())
-    {
-      m_CurrentLesion = data.value<QmitkLesionTreeItem*>()->GetData().GetLesion();
-    }
-    else
-    {
-      return;
-    }
-
-    if (false == m_SemanticRelations->InstanceExists(m_CaseID, m_CurrentLesion))
-    {
-      // no UID found; cannot create a lesion
-      continue;
-    }
-
-    emit LesionChanged(m_CurrentLesion);
+    return;
   }
+
+  if (false == m_SemanticRelations->InstanceExists(m_CaseID, m_CurrentLesion))
+  {
+    // no UID of a existing lesion found; cannot create a lesion
+    return;
+  }
+
+  emit LesionChanged(m_CurrentLesion);
 }
 
 void QmitkLesionInfoWidget::OnLesionListContextMenuRequested(const QPoint& pos)
 {
   QModelIndex index = m_Controls.lesionTreeView->indexAt(pos);
   if (!index.isValid())
   {
     // no item clicked; cannot retrieve the current lesion
     return;
   }
 
   QVariant data = m_StorageModel->data(index, Qt::UserRole);
   mitk::SemanticTypes::Lesion selectedLesion;
   if (data.canConvert<QmitkLesionTreeItem*>())
   {
     selectedLesion = data.value<QmitkLesionTreeItem*>()->GetData().GetLesion();
   }
   else
   {
     return;
   }
 
   QMenu* menu = new QMenu(m_Controls.lesionTreeView);
 
   QAction* linkToSegmentation = new QAction("Link to segmentation", this);
   linkToSegmentation->setEnabled(true);
   connect(linkToSegmentation, &QAction::triggered, [this, selectedLesion] { OnLinkToSegmentation(selectedLesion); });
   menu->addAction(linkToSegmentation);
 
   QAction* setLesionName = new QAction("Set lesion name", this);
   setLesionName->setEnabled(true);
   connect(setLesionName, &QAction::triggered, [this, selectedLesion] { OnSetLesionName(selectedLesion); });
   menu->addAction(setLesionName);
 
   QAction* setLesionClass = new QAction("Set lesion class", this);
   setLesionClass->setEnabled(true);
   connect(setLesionClass, &QAction::triggered, [this, selectedLesion] { OnSetLesionClass(selectedLesion); });
   menu->addAction(setLesionClass);
 
   QAction* removeLesion = new QAction("Remove lesion", this);
   removeLesion->setEnabled(true);
   connect(removeLesion, &QAction::triggered, [this, selectedLesion] { OnRemoveLesion(selectedLesion); });
   menu->addAction(removeLesion);
 
   menu->popup(QCursor::pos());
 }
 
 void QmitkLesionInfoWidget::OnLinkToSegmentation(mitk::SemanticTypes::Lesion selectedLesion)
 {
   if (m_CaseID.empty())
   {
     QMessageBox msgBox;
     msgBox.setWindowTitle("No case ID set.");
     msgBox.setText("In order to link a lesion to a segmentation, please specify the current case / patient.");
     msgBox.setIcon(QMessageBox::Warning);
     msgBox.exec();
     return;
   }
 
   if (m_DataStorage.IsExpired())
   {
     return;
   }
 
   auto dataStorage = m_DataStorage.Lock();
 
   QmitkSemanticRelationsNodeSelectionDialog* dialog = new QmitkSemanticRelationsNodeSelectionDialog(this, "Select segmentation to link to the selected lesion.", "");
   dialog->SetDataStorage(dataStorage);
   dialog->setWindowTitle("Select segmentation node");
   dialog->SetNodePredicate(mitk::NodePredicates::GetSegmentationPredicate());
   dialog->SetSelectOnlyVisibleNodes(true);
   dialog->SetSelectionMode(QAbstractItemView::SingleSelection);
   dialog->SetCaseID(m_CaseID);
 
   int dialogReturnValue = dialog->exec();
   if (QDialog::Rejected == dialogReturnValue)
   {
     return;
   }
 
   auto nodes = dialog->GetSelectedNodes();
   mitk::DataNode::Pointer selectedDataNode = nullptr;
   if (!nodes.isEmpty())
   {
     // only single selection allowed
     selectedDataNode = nodes.front();
   }
 
   if (nullptr == selectedDataNode)
   {
     QMessageBox msgBox;
     msgBox.setWindowTitle("No valid segmentation node selected.");
     msgBox.setText("In order to link the selected lesion to a segmentation, please specify a valid segmentation node.");
     msgBox.setIcon(QMessageBox::Warning);
     msgBox.exec();
     return;
   }
 
   if (false == mitk::NodePredicates::GetSegmentationPredicate()->CheckNode(selectedDataNode))
   {
     QMessageBox msgBox;
     msgBox.setWindowTitle("No segmentation selected");
     msgBox.setText("In order to link the selected lesion to a segmentation, please specify a valid segmentation node.");
     msgBox.setIcon(QMessageBox::Warning);
     msgBox.exec();
     return;
   }
 
   mitk::BaseData* baseData = selectedDataNode->GetData();
   if (nullptr == baseData)
   {
     QMessageBox msgBox;
     msgBox.setWindowTitle("No valid base data.");
     msgBox.setText("In order to link the selected lesion to a segmentation, please specify a valid segmentation node.");
     msgBox.setIcon(QMessageBox::Warning);
     msgBox.exec();
     return;
   }
 
   try
   {
     m_SemanticRelations->LinkSegmentationToLesion(selectedDataNode, selectedLesion);
   }
   catch (const mitk::SemanticRelationException& e)
   {
     std::stringstream exceptionMessage; exceptionMessage << e;
     QMessageBox msgBox;
     msgBox.setWindowTitle("Could not link the selected lesion.");
     msgBox.setText("The program wasn't able to correctly link the selected lesion with the selected segmentation.\n"
       "Reason:\n" + QString::fromStdString(exceptionMessage.str()));
     msgBox.setIcon(QMessageBox::Warning);
     msgBox.exec();
   }
 }
 
 void QmitkLesionInfoWidget::OnSetLesionName(mitk::SemanticTypes::Lesion selectedLesion)
 {
   if (m_CaseID.empty())
   {
     QMessageBox msgBox;
     msgBox.setWindowTitle("No case ID set.");
     msgBox.setText("In order to set a lesion name, please specify the current case / patient.");
     msgBox.setIcon(QMessageBox::Warning);
     msgBox.exec();
     return;
   }
 
   // use the lesion information to set the input text for the dialog
   QmitkLesionTextDialog* inputDialog = new QmitkLesionTextDialog(this);
   inputDialog->setWindowTitle("Set lesion name");
   inputDialog->SetLineEditText(selectedLesion.name);
 
   int dialogReturnValue = inputDialog->exec();
   if (QDialog::Rejected == dialogReturnValue)
   {
     return;
   }
 
   std::string newLesionName = inputDialog->GetLineEditText().toStdString();
 
   selectedLesion.name = newLesionName;
   m_SemanticRelations->OverwriteLesion(m_CaseID, selectedLesion);
 }
 
 void QmitkLesionInfoWidget::OnSetLesionClass(mitk::SemanticTypes::Lesion selectedLesion)
 {
   if (m_CaseID.empty())
   {
     QMessageBox msgBox;
     msgBox.setWindowTitle("No case ID set.");
     msgBox.setText("In order to set a lesion class, please specify the current case / patient.");
     msgBox.setIcon(QMessageBox::Warning);
     msgBox.exec();
     return;
   }
 
   // use the lesion information to set the input text for the dialog
   QmitkLesionTextDialog* inputDialog = new QmitkLesionTextDialog(this);
   inputDialog->setWindowTitle("Set lesion class");
   inputDialog->SetLineEditText(selectedLesion.lesionClass.classType);
 
   // prepare the completer for the dialogs input text field
   mitk::LesionClassVector allLesionClasses = m_SemanticRelations->GetAllLesionClassesOfCase(m_CaseID);
 
   QStringList wordList;
   for (const auto& lesionClass : allLesionClasses)
   {
     wordList << QString::fromStdString(lesionClass.classType);
   }
   QCompleter* completer = new QCompleter(wordList, this);
   completer->setCaseSensitivity(Qt::CaseInsensitive);
   inputDialog->GetLineEdit()->setCompleter(completer);
 
   int dialogReturnValue = inputDialog->exec();
   if (QDialog::Rejected == dialogReturnValue)
   {
     return;
   }
 
   // retrieve the new input lesion class type and check for an already existing lesion class types
   std::string newLesionClassType = inputDialog->GetLineEditText().toStdString();
   mitk::SemanticTypes::LesionClass existingLesionClass = mitk::FindExistingLesionClass(newLesionClassType, allLesionClasses);
   if (existingLesionClass.UID.empty())
   {
     // could not find lesion class information for the new lesion class type
     // create a new lesion class for the selected lesion
     existingLesionClass = mitk::GenerateNewLesionClass(newLesionClassType);
   }
 
   selectedLesion.lesionClass = existingLesionClass;
   m_SemanticRelations->OverwriteLesion(m_CaseID, selectedLesion);
 }
 
 void QmitkLesionInfoWidget::OnRemoveLesion(mitk::SemanticTypes::Lesion selectedLesion)
 {
   if (m_CaseID.empty())
   {
     QMessageBox msgBox;
     msgBox.setWindowTitle("No case ID set.");
     msgBox.setText("In order to remove a lesion, please specify the current case / patient.");
     msgBox.setIcon(QMessageBox::Warning);
     msgBox.exec();
     return;
   }
 
   try
   {
     m_SemanticRelations->RemoveLesion(m_CaseID, selectedLesion);
   }
   catch (const mitk::SemanticRelationException& e)
   {
     std::stringstream exceptionMessage; exceptionMessage << e;
     QMessageBox msgBox;
     msgBox.setWindowTitle("Could not remove the selected lesion.");
     msgBox.setText("The program wasn't able to correctly remove the selected lesion from the semantic relations model.\n"
                    "Reason:\n" + QString::fromStdString(exceptionMessage.str()));
     msgBox.setIcon(QMessageBox::Warning);
     msgBox.exec();
   }
 }
diff --git a/Plugins/org.mitk.gui.qt.semanticrelations/src/internal/QmitkLesionInfoWidget.h b/Plugins/org.mitk.gui.qt.semanticrelations/src/internal/QmitkLesionInfoWidget.h
index f85fc97835..5596a18cc2 100644
--- a/Plugins/org.mitk.gui.qt.semanticrelations/src/internal/QmitkLesionInfoWidget.h
+++ b/Plugins/org.mitk.gui.qt.semanticrelations/src/internal/QmitkLesionInfoWidget.h
@@ -1,100 +1,99 @@
 /*===================================================================
 
 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 QMITKLESIONINFOWIDGET_H
 #define QMITKLESIONINFOWIDGET_H
 
 // semantic relations plugin
 #include <ui_QmitkLesionInfoWidgetControls.h>
 
 // semantic relations UI module
 #include <QmitkLesionTreeModel.h>
 
 // semantic relations module
 #include <mitkSemanticRelations.h>
 
 // mitk
 #include <mitkDataStorage.h>
 
 // qt
 #include <QWidget>
 
 /*
 * @brief The QmitkLesionInfoWidget is a widget that shows and modifies the currently available lesion data of the semantic relations model.
 *
 *   The widget provides a dialogs to add nodes from the data storage to the semantic relations model.
 *   It provides functionality to create new lesions and link them with segmentation nodes.
 *
 *   The QmitkLesionInfoWidget provides three QListWidgets, that show the lesion data and the referenced segmentation data, as
 *   well as the connected image data, depending on the selected lesion.
 */
 class QmitkLesionInfoWidget : public QWidget
 {
   Q_OBJECT
 
 public:
 
   static const QBrush DEFAULT_BACKGROUND_COLOR;
   static const QBrush SELECTED_BACKGROUND_COLOR;
   static const QBrush CONNECTED_BACKGROUND_COLOR;
 
   QmitkLesionInfoWidget::QmitkLesionInfoWidget(mitk::DataStorage* dataStorage, QWidget* parent = nullptr);
   ~QmitkLesionInfoWidget();
 
   void SetCaseID(const mitk::SemanticTypes::CaseID& caseID);
 
   const mitk::SemanticTypes::Lesion& GetSelectedLesion() const { return m_CurrentLesion; }
 
 Q_SIGNALS:
 
   void LesionChanged(const mitk::SemanticTypes::Lesion&);
 
 private Q_SLOTS:
 
   void OnModelUpdated();
   /*
   * @brief Generates a new, empty lesion to add to the semantic relations model for the current case ID.
   */
   void OnAddLesionButtonClicked();
 
-  // slots for the mouse click events of the list widgets
-  void OnSelectionChanged(const QItemSelection& selected, const QItemSelection& deselected);
-  //void OnLesionItemDoubleClicked(QListWidgetItem*);
+  // slots for the mouse click events of tree view's selection model
+  void OnSelectionChanged(const QModelIndex& current, const QModelIndex& previous);
 
   void OnLesionListContextMenuRequested(const QPoint&);
 
   // slots for the context menu actions of the lesion list widget
   void OnLinkToSegmentation(mitk::SemanticTypes::Lesion);
   void OnSetLesionName(mitk::SemanticTypes::Lesion);
   void OnSetLesionClass(mitk::SemanticTypes::Lesion);
   void OnRemoveLesion(mitk::SemanticTypes::Lesion);
 
 private:
 
   void Initialize();
   void SetUpConnections();
 
   Ui::QmitkLesionInfoWidgetControls m_Controls;
   QmitkLesionTreeModel* m_StorageModel;
 
   mitk::WeakPointer<mitk::DataStorage> m_DataStorage;
   std::unique_ptr<mitk::SemanticRelations> m_SemanticRelations;
   mitk::SemanticTypes::CaseID m_CaseID;
 
   mitk::SemanticTypes::Lesion m_CurrentLesion;
 };
 
 #endif // QMITKLESIONINFOWIDGET_H