transparent gif

 

Ej inloggad.

Göteborgs universitets publikationer

Comparison of different approaches of estimating the effective dose from CBCT examinations performed using interventional fluoroscopy systems

Författare och institution:
Angelica Svalkvist (Institutionen för kliniska vetenskaper, sektionen för onkologi, radiofysik, radiologi och urologi, Avdelningen för radiofysik); Jonny Hansson (Institutionen för kliniska vetenskaper, sektionen för onkologi, radiofysik, radiologi och urologi, Avdelningen för radiofysik); Magnus Båth (Institutionen för kliniska vetenskaper, sektionen för onkologi, radiofysik, radiologi och urologi, Avdelningen för radiofysik)
Publicerad i:
Nationellt möte om sjukhusfysik 2013, 13-14 november 2013, Varberg,
Publikationstyp:
Konferensbidrag, övrigt
Publiceringsår:
2013
Språk:
engelska
Fulltextlänk:
Sammanfattning (abstract):
Three-dimensional (3D) imaging with interventional fluoroscopy systems is today a common examination. The examination includes the collection of a large number of twodimensional projection images of the patient. The projection images are then used to reconstruct CT like images of the patient. The technique is often referred to as cone-beam CT (CBCT). The resulting patient radiation doses from CBCT examinations have previously been reported to be comparable to the radiation doses from conventional CT examinations. However, determining the radiation doses from CBCT examinations is not a straight-forward task. Especially as detailed exposure parameters from the examinations are not provided by the system commercially available. Hence, variations in exposure parameters between the different projection images included in the examination can not always be accounted for. The aim of this study was therefore to evaluate the errors connected to using different methods for calculating the radiation doses from CBCT examinations performed using interventional fluoroscopy systems. In the study the Siemens Artis Zee interventional fluoroscopy system (Siemens Medical Solutions, Erlangen, Germany) was used. An eight-second DynaCT digital radiography protocol was used to collect images of the anthropomorphic pelvis phantom. The exposure values obtained from the examination was used to perform Monte Carlo based calculations of the effective doses resulting from the examination, using the computer software PCXMC (STUK, Helsinki, Finland). Both individual exposure values (kV and mAs) for each projection image included in the examination and constant mean values (kV/mAs and DAP) for all projections were used as input for the dose calculations. In addition, the effects of not including all the projection images in the dose calculations were investigated. Preliminary results show that the effective dose from a pelvis examination using this system is approximately 6 mSv. Only very small variations in resulting effective doses were found between the different methods used for dose calculations (variations smaller than 4%). The results thereby indicate that simplified dose calculations, e.g. using mean exposure values and/or not accounting for each projection image included in the examination, can be used to estimate the radiation doses from CBCT examinations performed using interventional fluoroscopy systems with reasonable accuracy
Ämne (baseras på Högskoleverkets indelning av forskningsämnen):
MEDICIN OCH HÄLSOVETENSKAP ->
Klinisk medicin ->
Radiologi och bildbehandling ->
Radiofysik
Postens nummer:
236024
Posten skapad:
2016-05-05 21:37

Visa i Endnote-format

Göteborgs universitet • Tel. 031-786 0000
© Göteborgs universitet 2007