[MATLAB] How can modify my axes for my differents sequences with a function returning a figure ?

Good morning everyone ! It's my first time here, so i hope i'll get some help :) ! I'm working on CT scanners, and i did some steps for my internship like registering, eroding, dilating, apply a segmentation algorithm etc. I want to allow the display of each step thanks to my GUI. I have made a function which can display a figure with a scanner and a slider .

function h_fig = display_myCT(StructRGB,numpat)

numpat = numpat + 2;
%%%%%%%%%%%%%
% figure
%%%%%%%%%%%%%

sz = length(StructRGB(numpat,:));
h_fig = figure('Name','image and layers','NumberTitle','Off','Toolbar','figure',...
    'MenuBar','figure','NextPlot','Add');

      sl_min = 1;
      sl_max = sz;
      sl_val = ceil(sz/2);

h_slider = uicontrol(h_fig,'style','slider','Min',sl_min,'Max',sl_max,'Value',sl_val,...
    'SliderStep',[1/sl_max 1/sl_max],'units','normalized','Position',[0 0 0.9 0.05],...
    'Callback',@ResultsSliderCallback);

h_text = uicontrol(h_fig,'style','text','units','normalized','String',num2str(sl_val),...
    'Position',[0.9 0 0.1 0.05]);

hx(1) = axes('parent',h_fig,'Units','Normalized','OuterPosition',[0.0 0.2 0.7 0.7]);

%%%%%%%%%%%

      function ResultsSliderCallback(hObject,eventdata)

          cur_serial = ceil(get(hObject,'Value'));

          set(h_text,'String',num2str(cur_serial));

          mysubplot(hx(1),StructRGB{numpat,cur_serial},cur_serial);

      end    

    function  mysubplot(hx,MonImageRGB,cur_serial)

          if cur_serial==0
              return;
          end

          h_curCurve = findobj([get(hx,'Children');get(h_fig,'Children')],'Type','line',...
              '-or','Type','hggroup','-or','Type','Text','-or','Type','image','-or','Tag','legend');
          if ~isempty(h_curCurve)
              delete(h_curCurve);
          end

          Im = MonImageRGB ;
          imshow(Im,'Parent',hx);

    end  

end

My idea was to create a main, where , at first, we could see the scanners registered, then , modify the axes of this figure, to display the erosion and dilation etc. I don't know if you see my problem. I want that when we carry out each step of my main ( registering etc ) , the scan is modified on the same figure. I am debutant in matlab, i don't know how to organize myself very well in GUI.

Thank you in advance for your help :)