....
<DataGridTemplateColumn Header="" Width="20" IsReadOnly="True">
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <Image Source="{Binding Option1_Image}" MouseDown="Option1_MouseDown" />
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Header="" Width="20" IsReadOnly="True">
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <Image Source="{Binding Option2_Image}" MouseDown="Option2_MouseDown"/>
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Header="" Width="20" IsReadOnly="True">
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <Image Source="{Binding Option3_Image}" MouseDown="Option3_MouseDown" />
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
...

private void Option1_MouseDown(object sender, MouseButtonEventArgs e)
{
        bool newState;
        var dc = (sender as System.Windows.Controls.Image).DataContext;
        DataRowView row = (DataRowView)dc;
        String rowID = Convert.ToString(row.Row["ID"]);

        newState = myQuery.UpdateIsTogglable(rowID);

        if (newState)
            row.Row["Option1_Image"] = Option1_True;
        else
            row.Row["Option1_Image"] = Option1_False;
}

MemoryStream ms = new MemoryStream();

...

System.Drawing.Image Option1_True = System.Drawing.Image.FromFile(@"ImagesOption1_True.gif");

...

Option1_True.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
Option1_True = ms.ToArray();
ms.SetLength(0);

private void Option1_MouseDown(object sender, MouseButtonEventArgs e)
{
        bool newState;
        var dc = (sender as System.Windows.Controls.Image).DataContext;
        DataRowView row = (DataRowView)dc;
        String rowID = Convert.ToString(row.Row["ID"]);

        newState = myQuery.UpdateIsTogglable(rowID);

        if (newState)
            row.Row["Option1_Image"] = "/myProject;component/Images/Option1_Image.png";
        else
            row.Row["Option1_Image"] = "/myProject;component/Images/Option1_Image.png";
}