Correct cast error that made half of the diffusion workspace non functional
Correct cast error that made half of the diffusion workspace non functional

NicolasSchnitzler/medInria-public,aabadie/medInria-public,rdebroiz/medInria-public,rdebroiz/medInria-public,aabadie/medInria-public,NicolasSchnitzler/medInria-public,NicolasSchnitzler/medInria-public,rdebroiz/medInria-public,aabadie/medInria-public