diff --git a/ShoulderCase/@MusclesContainer/createRotatorCuffSlices.m b/ShoulderCase/@MusclesContainer/createRotatorCuffSlices.m
index 104dc23..b5abd92 100644
--- a/ShoulderCase/@MusclesContainer/createRotatorCuffSlices.m
+++ b/ShoulderCase/@MusclesContainer/createRotatorCuffSlices.m
@@ -1,66 +1,67 @@
 function createRotatorCuffSlices(obj)
+  assert(not(obj.shoulder.scapula.coordSys.isEmpty),'Scapula coordinate system not measured.');
   [imageForSegmentation,imageForMeasurements,imagesPixelSpacings] = getSlices(obj);
   saveImages(obj,imageForSegmentation,imageForMeasurements);
   saveImagesPixelSpacings(obj,imagesPixelSpacings);
 end
 
 
 
 function [slice8Bit,slice16Bit,slicesPixelSpacings] = getSlices(obj)
   SCase = obj.shoulder.SCase;
   scapula = obj.shoulder.scapula;
   path = SCase.dataDicomPath;
   rotatorCuffSlicer = DicomVolumeSlicer(path);
 
   % The 3D volume must be normalised for the slices not to be distorted
   rotatorCuffSlicer.setMinimalResolutionDividedBy(2);
   rotatorCuffSlicer.normaliseVolume;
   rotatorCuffSlicer.slice(scapula.coordSys.origin,scapula.coordSys.ML);
 
   % The following lines set the slice to display a 300x300 mm area around the
   % scapula with the "Y" shape of the scapula oriented up
   rotatorCuffSlicer.orientSliceUpwardVector(scapula.coordSys.origin,scapula.coordSys.IS);
   rotatorCuffSlicer.crop(scapula.coordSys.origin-100*scapula.coordSys.IS,300,300);
 
   % Rotator cuff segmentation code requires 1024x1024 pixels images
   if size(rotatorCuffSlicer.sliced,1) > size(rotatorCuffSlicer.sliced,2)
     rotatorCuffSlicer.resize([1024 nan]);
   else
     rotatorCuffSlicer.resize([nan 1024]);
   end
   rotatorCuffSlicer.addEmptyBackgroundToSlice(1024,1024);
 
 
   rawSlice = rotatorCuffSlicer.sliced;
 
   rotatorCuffSlicer.rescaleSliceToUint8;
   slice8Bit = rotatorCuffSlicer.sliced;
   rotatorCuffSlicer.sliced = rawSlice;
 
   rotatorCuffSlicer.rescaleSliceToInt16;
   slice16Bit = rotatorCuffSlicer.sliced;
 
   % Flip the slices for right and left shoulders to give similar slices
   if obj.shoulder.side=='L'
     slice8Bit=rot90(flipud(slice8Bit),2);
     slice16Bit=rot90(flipud(slice16Bit),2);
   end
 
   slicesPixelSpacings = rotatorCuffSlicer.slicedPixelSpacings;
 end
 
 
 
 function saveImages(obj,imageForSegmentation,imageForMeasurements)
   imwrite(imageForSegmentation,...
           fullfile(obj.slicesDataPath,'rotatorCuff_ForSegmentation.png'));
   save(fullfile(obj.slicesDataPath,'rotatorCuff_ForMeasurements.mat'),...
        'imageForMeasurements');
 end
 
 
 
 function saveImagesPixelSpacings(obj,imagesPixelSpacings)
   save(fullfile(obj.slicesDataPath,'rotatorCuff_PixelSpacings.mat'),...
        'imagesPixelSpacings');
 end