Conference proceeding
MO‐D‐BRC‐05: Reducing Megavoltage Cone Beam CT Imaging Dose without Loss of Spatial Resolution Using a Sintered Pixelated Array System
Medical Physics, Vol.38(6), pp.3713-3713
06/2011
DOI: 10.1118/1.3612969
Abstract
Purpose: To demonstrate that megavoltage cone beam CT (MVCBCT) image quality can be significantly improved without increasing imaging dose or reducing spatial resolution for both head‐ and pelvis‐sized volumes. The improvement is achieved with the combination of an imaging beam line (IBL) with a low atomic number electron target and a novel sintered pixelated array (SPA) detector. Methods: Three Siemens Oncor linear accelerators were equipped with an IBL+SPA system, an IBL system with a conventional Kodak Lanex Fast B scintillator (IBL+LFB), and a 6 MV treatment beam line system with an LFB (TBL+LFB). Head‐ and pelvis‐sized phantom images were acquired with all three systems at imaging doses ranging from 2‐60 cGy. Contrast to noise ratio (CNR) and modulation transfer function (MTF) were calculated from the phantom images. Head and neck, prostate, and lung cancer patients were imaged with the three imaging systems at doses ranging from 2–15 cGy. Results: For head‐ and pelvis‐sized phantom images acquired at 5 cGy or above, the CNR average percentage increases for imaging system upgrades from TBL+LFB to IBL+LFB to IBL+SPA were 52% (p < 1E‐7) and 42% (p < 1E‐6), respectively. The MTFs do not change with imaging system by statistically significant percentages. Soft tissue contrast is generally more easily differentiated on IBL+SPA images than TBL+LFB and IBL+LFB in the patient images. Conclusions: Since CNR scales with the square root of imaging dose, each step in the TBL+LFB to IBL+LFB to IBL+SPA upgrade halves the imaging dose required to obtain a given CNR. No statistically significant change in spatial resolution was observed with any upgrade, suggesting that the pixelation of the SPA prevents a loss in spatial resolution. IBL+SPA patient image quality was always better than that of the TBL+LFB system and as good as or better than that of the IBL+LFB system.
Sponsored partially by Siemens Oncology Care Systems.
Details
- Title: Subtitle
- MO‐D‐BRC‐05: Reducing Megavoltage Cone Beam CT Imaging Dose without Loss of Spatial Resolution Using a Sintered Pixelated Array System
- Creators
- E Breitbach - Medical SolutionsJ Maltz - Medical SolutionsB Gangadharan - Medical SolutionsA Bani‐Hashemi - 2Siemens Medical Solutions, Concord, CAC Anderson - University of IowaS Bhatia - University of IowaJ Stiles - University of IowaD Edwards - Medical SolutionsR Flynn - University of Iowa
- Resource Type
- Conference proceeding
- Publication Details
- Medical Physics, Vol.38(6), pp.3713-3713
- DOI
- 10.1118/1.3612969
- ISSN
- 0094-2405
- eISSN
- 2473-4209
- Number of pages
- 1
- Date published
- 06/2011
- Academic Unit
- Radiation Oncology; Radiology
- Record Identifier
- 9984312971702771
Metrics
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