Volumetric CT measurement of the ischial tuberosities for designing analytical models of decubitus ulcers

David R. Holmes, Richard A. Robb

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Decubitus ulcers can have a deleterious effect on the quality of life for some patients, particularly those prone to chronic development of skin ulcerations. The bones of the pelvis are particularly relevant as nearly half of all ulcerations observed in the hospital are in the pelvic region. This research focuses on the development of methods to extract the ischium and adjacent anatomy from volumetric CT data of the pelvis which will be used for patient-specific modeling of high-pressure regions and the treatment of associated ulcers. Six volumetric CT scans were evaluated to determine the size and shape of the ischial tuberosities. Using oblique images computed from the CT data, cross-sectional measurements (approximately Superior-Inferior, Anterior-Posterior, and Left-Right) were made to estimate the size of the ischial tuberosities. Similar measurements were made on the ischial ramus. The mean length of the ischial tuberosities (S-I direction) is 12.35 cm. The mean dimension in the L-R and A-P directions are 2.97 cm and 3.78 cm, respectively. For the ischial ramus, the S-I, L-R, and A-P mean lengths are 6.57 cm, 1.72 cm, and 1.49 cm. Due to a limited field of view for the CT datasets, the thickness of the soft tissue (i.e. Gluteus Maximus and subcutaneous fat) could not be measured. Using the bony measurements and adjacent soft tissue measurements, an investigator would be able estimate the posterior pelvis forces for calculations of pressure on the proximal skin, which could then be used to predict ulcerations in patients, or to design new ulcer-inhibiting seating devices. Current efforts are focused on collecting a large cohort of data with both bony and soft tissue measurements. Future work will incorporate the physical properties of the soft tissue to specifically predict high-pressure regions.

Original languageEnglish (US)
Title of host publicationMedical Imaging 2006
Subtitle of host publicationVisualization, Image-Guided Procedures, and Display
StatePublished - 2006
EventMedical Imaging 2006: Visualization, Image-Guided Procedures, and Display - San Diego, CA, United States
Duration: Feb 12 2006Feb 14 2006

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


OtherMedical Imaging 2006: Visualization, Image-Guided Procedures, and Display
Country/TerritoryUnited States
CitySan Diego, CA


  • CT
  • Decubitus Ulcers
  • Ischial Tuberosities
  • Shape Analysis

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Biomaterials
  • Radiology Nuclear Medicine and imaging


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