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Sci‐Thur PM Therapy‐11: Tomosynthesis with rotating and stationary radiotherapy cone beams
Author(s) -
Yao W,
Leszczynski K
Publication year - 2006
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.2244625
Subject(s) - transverse plane , optics , physics , beam (structure) , iterative reconstruction , projection (relational algebra) , image resolution , noise (video) , mathematics , artificial intelligence , computer science , algorithm , image (mathematics) , structural engineering , engineering
We examine reconstruction of volumetric objects from megavoltage rotating and stationary beam projections. Quality of the reconstruction depends on the transverse and depth resolutions of the projections. In the rotating beam geometry, as the gantry angle varies, the depth resolution improves and thus more detailed anatomical structure of the object along the central axis of the radiation beam can be reconstructed, while the transverse resolution decreases. In the stationary beam geometry, where the source and detector remain fixed but the location of the object along the beam central ray is varied, the depth resolution is poor while the transverse resolution can be very high. We use the algebraic reconstruction technique (ART) and exact weighting factors to reconstruct 3‐D objects from 2‐D projections. When projections are noise‐free as those generated by a computer, the object is accurately reconstructed as long as the number of iterations is sufficiently high. For real world projections, in which noise can be significant, the reconstruction quality can be poor. Because both the transverse and depth resolutions are important in clinical applications, our work points to potential advantages of combining rotating‐ and stationary‐beam projections.