Program Information

Dual Energy Planar Image Based Localization in the Absence of On-Board CT Images

R Sadagopan*, J Yang , H Li , M.D. Anderson Cancer Center, Houston, TX

Presentations

SU-E-J-256 Sunday 3:00PM - 6:00PM Room: Exhibit Hall

Purpose: To develop a tool enabling soft tissue based image guidance using dual energy radiographs for cases when on-board CT is not available.
Method: Dual energy planar radiographs can be applied to image guidance for targeting lung lesions because the bone based alignment only may not be sufficient as the lesions move. We acquired images of an anthropomorphic thorax phantom at 120 and 60 KVp respectively. Using a weighted logarithmic subtraction of these dual energy images, a soft tissue enhanced and a bone enhanced image were generated and they could be used for the image guidance purpose. Similar processing was also applied to a dual energy image set acquired for a patient undergoing a proton therapy.
Results: The soft tissue enhanced images suppressed bones (ribs and scapula) overlying on lung, thus enabling a better visualization of soft tissue and lesion, while the bone enhanced image suppressed the soft tissue. These enhanced effects were visually apparent without further processing for display enhancements, such as using histogram or edge enhancement technique.
Conclusions: The phantom image processing was encouraging. The initial test on the patient image set showed that other post processing might still be able to add value in visualizing soft tissues in addition to the dual energy soft tissue enhancement. More evaluations are needed to determine the potential benefit of this technique in the clinic.

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