Page 67 - Demo

Cranialshapeevaluation653The determination of diagnostic cut-offs which can quantify therate of abnormalitywouldbealogicalnextstepQuantificationof therateofseveritycanalsobeusedforobjectiveevaluationofcranialdevelopmentandfollow-upofcraniosynostosispatientsduringandafter treatment Theresultsofdifferentsurgical treatmentscanbecomparedwithouttheuseofharmfulradiationCONCLUSIONInconclusionthisstudypresentedanewmethodtoevaluatecranialshapeabnormalitiesofscaphocephalypatientsandtrigonocephalypatientsThreedimensionalstereophotogrammetryincombinationwithPCAwasabletocalculatethemeancranialshapeandtodescribethenormalvariationofthecranialshapeinacontrolpopulationThisPCAmodelwasabletosignificantlydifferentiatecraniosynostosispatientsfromcontrolsThisisapromisingmethodfortheobjectiveevaluationandidentificationofcraniosynostosisusingsolely3DstereophotogrammetryAPPENDIXPrincipalComponentAnalysis(PCA)wasappliedtothesuperimposedresampledandscaled3DphotographsofthecontrolpopulationEverycranialshapeinthedataset was represented as an 3mx1 element vectorwithmm=4501(numberofvertexpointscalculatedusingtheraycastingalgorithm)ThemeancranialshapeofthecontrolpopulationcontainingN=60cranialshapeswascalculatedusingForeachcranialshapeitsdeviationfromthemeanwascalculatedUsingtheSingular ValueDecomposition(SVD)theeigenvectorsandthecorrespondingeigenvaluesofthecontrolpopulationwerecalculatedCranialshapesofthecontrolpopulationcanbereconstructedby