title: Novel technique for three-dimensional visualisation and quantification of deformable, moving soft-tissue body parts.
abstract: BACKGROUND
  Three-dimensional (3D) imaging of delicate, moving soft-tissue body parts is very difficult. Our understanding of the muscles that control lip movements is based largely on histological and cadaveric studies, which provide scant information about dynamic morphology. Our aim was to develop an innovative scanning technique for the imaging and reconstruction of dynamic orofacial morphology by use of 3D and four-dimensional (4D, ie, 3D plus time) ultrasonography.
  
  
  METHODS
  Four volunteers (including one patient) underwent ultrasonography with 3D/4D imaging systems. To avoid deformation of the delicate orofacial structures, a water bath with an acoustic window was devised. The orofacial part was immersed in the bath throughout scanning, and a timer was used to synchronize lip movements with the 4D scan.
  
  
  RESULTS
  4D views showed the functional differences in superficial and deep muscle groups of the lips, and clearly showed the changes occurring with movement of the lips and mouth. In the patient, a pathological layer and its extension corresponding to surface malformation were clearly identified.
  
  
  CONCLUSIONS
  We have developed a prototype device that has made possible 3D and 4D examination of orofacial anatomy and function. With further refinement of the device and improvement in 4D acquisition timing, this technique may offer a new way of dynamically imaging and quantifying many soft-tissue parts in 3D without deforming structure or disturbing function.
authors.affiliation: Department of Obstetrics and Gynaecology, University College London, UK. jdeng@medphys.ucl.ac.uk
authors.forename: J
authors.initials: J
authors.lastname: Deng
authors.forename: N M
authors.initials: NM
authors.lastname: Newton
authors.forename: M A
authors.initials: MA
authors.lastname: Hall-Craggs
authors.forename: R A
authors.initials: RA
authors.lastname: Shirley
authors.forename: A D
authors.initials: AD
authors.lastname: Linney
authors.forename: W R
authors.initials: WR
authors.lastname: Lees
authors.forename: C H
authors.initials: CH
authors.lastname: Rodeck
authors.forename: D A
authors.initials: DA
authors.lastname: McGrouther
mesh_terms: D000328:Adult; D015982:Bias; D005149:Facial Expression; D005152:Facial Muscles / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008046:Lip / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000502:physiology; D009068:Movement / Q000502:physiology; D015203:Reproducibility of Results; D013997:Time Factors; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods; D014867:Water
chemical_list: D014867:Water