umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Virtual reality for simulation of radiographic projections: validation of projection geometry
Umeå University, Faculty of Medicine, Odontology, Oral and Maxillofacial Radiology.
2004 (English)In: Dento-Maxillo-Facial Radiology, ISSN 0250-832X, Vol. 33, no 1, 44-50 p.Article in journal (Refereed) Published
Abstract [en]

Objective: To develop a software for virtual reality (VR) simulation of X-ray images based on perspective projections through a patient model derived from data from a CT examination and to evaluate the accuracy in the projection geometry obtained by the software.

Methods: A VR software was developed on a personal computer, with models of a patient, an X-ray machine and a detector. The model of the patient was derived from data from a CT examination of a dry skull. Simulated radiographic images of the patient model could be rendered as perspective projections based on the relative positions between the models. The projection geometry of the software was validated by developing an artificial CT data set containing high attenuation points as objects to be imaged. The accuracy in projection geometry was evaluated in a systematic way. The distances between two dots, representing the projected test points in the simulated radiographic images, were measured. They were compared with theoretical calculations of the corresponding distances using traditional mathematical tools.

Results: The difference between the simulated and calculated projected distances never exceeded 0.5 mm. The error in simulated projected distances was in most cases within 1%. No systematic errors were revealed.

Conclusion: The software, developed for personal computers, can produce simulated X-ray images with high geometric accuracy based on perspective projections through a CT data set. The software can be used for simulation of radiographic examinations.

Place, publisher, year, edition, pages
2004. Vol. 33, no 1, 44-50 p.
Keyword [en]
virtual systems; radiography; computer simulation; software validation
National Category
Dentistry
Identifiers
URN: urn:nbn:se:umu:diva-17875DOI: 10.1259/dmfr/22722586PubMedID: 15140822OAI: oai:DiVA.org:umu-17875DiVA: diva2:157548
Available from: 2007-11-22 Created: 2007-11-22 Last updated: 2009-11-05Bibliographically approved
In thesis
1. Simulation supported training in oral radiology: methods and impact on interpretative skill
Open this publication in new window or tab >>Simulation supported training in oral radiology: methods and impact on interpretative skill
2007 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Simulation is an important tool when training is hazardous, time consuming, or expensive. Simulation can also be used to enhance reality by adding features normally not available in the real world. The aim with this work has been to develop and evaluate methods that could improve learning in oral radiology utilising a radiation-free simulator environment.

Virtual reality software for radiographic examinations was developed. The virtual environment consisted of a model of a patient, an x-ray machine, and a film. Simulated radiographic images of the patient model could be rendered as perspective projections based on the relative position between the individual models. The software was incorporated in an oral radiology simulator with a training program for interpretation of spatial relations in radiographs. Projection geometry was validated by comparing length dimensions in simulated radiographs with the corresponding theoretically calculated distances. The results showed that projection error in the simulated images never exceeded 0.5 mm.

Dental students participated in studies on skill in interpreting spatial information in radiographs utilising parallax. Conventional and simulator based training methods were used. Training lasted for 90 minutes. Skill in interpreting spatial information was assessed with a proficiency test before training, immediately after training, and eight months after training. Visual-spatial ability was assessed with mental rotations test, version A (MRT-A). Regression analysis revealed a significant (P<0.01) association between visual-spatial ability and proficiency test results after training. At simulator training, proficiency test results immediately after training were significantly higher than before training (P<0.01). Among students with low MTR-A scores, improvement after simulator training was higher than after conventional training. Eight months after simulator training proficiency test results were lower than immediately after training. The test results were, however, still higher than before training.

In conclusion, the simulation software produces simulated radiographs of high geometric accuracy. Acquisition of skill to interpret spatial relations in radiographs is facilitated for individuals with high visual-spatial ability. Simulator training improves acquisition of interpretative skill and is especially beneficial for individuals with low visual-spatial ability. The results indicate that radiology simulation can be an effective training method.

Place, publisher, year, edition, pages
Umeå: Odontologi, 2007. 52 p.
Series
Umeå University odontological dissertations, ISSN 0345-7532 ; 99
Keyword
Virtual reality, simulation, simulator, radiology, radiography, learning, skill acquisition, visual-spatial ability, parallax
National Category
Radiology, Nuclear Medicine and Medical Imaging
Research subject
Odontology
Identifiers
urn:nbn:se:umu:diva-1118 (URN)978-91-7264-293-5 (ISBN)
Public defence
2007-05-25, Sal B, 1D, Tandläkarhögskolan, 9 tr, Umeå, 09:00 (English)
Opponent
Supervisors
Available from: 2007-05-08 Created: 2007-05-08 Last updated: 2009-06-15Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMedhttp://dmfr.birjournals.org/

Authority records BETA

Nilsson, ToreAhlqvist, JanJohansson, MagnusIsberg, Annika

Search in DiVA

By author/editor
Nilsson, ToreAhlqvist, JanJohansson, MagnusIsberg, Annika
By organisation
Oral and Maxillofacial Radiology
In the same journal
Dento-Maxillo-Facial Radiology
Dentistry

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 233 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf