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Image quality improvement for medium and large field of view Elekta XVI scans

  • David P. LittleEmail author
Scientific Paper
  • 17 Downloads

Abstract

Cone-beam computed tomography (CBCT) has become the standard imaging technique for many sites treated with Radiotherapy. The Elekta X-ray Volumetric Imaging (XVI) system allows for the acquisition of CBCTs with three different diameters; small (27 cm), medium (41 cm) and large (50 cm) (Elekta in XVI Corrective Maintenance Manual R5.0, Elekta, Stockholm, 2013). Images are used to ensure accurate patient positioning as well as checking for changes in the patient contour or internal geometry, and image quality must be high enough to achieve these goals. This paper describes two simple adjustments which can lead to improved image quality for medium and large field of view (MFOV and LFOV) scans. The first involves measuring a default distance in the XVI software (kV Source to Detector Distance) to improve spatial resolution and geometric scaling of both MFOV and LFOV scans. The second involves correcting a uniformity issue seen at our centre with LFOV scans, allowing us to use this FOV for assessing patient contour changes on large patients. The implementation and effects of both adjustments are explored in this paper, and workflows are proposed for optimising both parameters.

Keywords

Elekta XVI CBCT Image quality 

Notes

Funding

No funding was received for this study.

Compliance with Ethical Standards

Conflict of interest

The author David Little declares that he has no conflict of interest.

Research with animal and human participants

This article does not contain any studies with human participants or animals performed by any of the authors.

Informed consent

No informed consent was required.

References

  1. 1.
    Boda-Heddemann J, Lohr F, Wens F, Flentje M, Guckenberger M (2011) kV cone-beam CT-based IGRT: a clinical review. Strahlenther Onkol 187(5):284–291CrossRefGoogle Scholar
  2. 2.
    Elekta (2013) XVI customer acceptance test R5.0, Elekta, StockholmGoogle Scholar
  3. 3.
    Schneider CA, Rasband WS, Eliceiri KW (2012) NIH image to ImageJ: 25 years of image analysis. Nat Methods 9(7):671–675CrossRefGoogle Scholar
  4. 4.
    Sharpe M, Moseley D, Purdie T, Islam M, Siewerdsen J, Jaffray D (2005) The stability of mechanical calibration for a kV cone beam computed tomography system integrated with linear accelerator. Med Phys 33(1):136–144CrossRefGoogle Scholar
  5. 5.
    Elekta (2013) XVI corrective maintenance manual R5.0. Elekta, StockholmGoogle Scholar
  6. 6.
    Feldkamp LA, Davis LC, Kress JW (1984) Practical cone-beam algorithm. J Optic Soc Am A 1(6):612–619CrossRefGoogle Scholar
  7. 7.
    Mail N, Moseley DJ, Siewerdsen JH, Jaffray DA (2009) The influence of bowtie filtration on cone-beam CT image quality. Med Phys 36(1):22–32CrossRefGoogle Scholar
  8. 8.
    The Phantom Laboratory (2006) Catphan 500 and 600 manual. The Phantom Laboratory, GreenwichGoogle Scholar
  9. 9.
    Schulze R, Heil U, Gross D, Bruellmann DD, Dranischnikow E, Schwanecke U, Schoemer E (2011) Artefacts in CBCT: a review. Dentomaxillofac Radiol 40(5):265–273CrossRefGoogle Scholar

Copyright information

© Australasian College of Physical Scientists and Engineers in Medicine 2019

Authors and Affiliations

  1. 1.Canterbury District Health BoardChristchurch HospitalChristchurchNew Zealand

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