Iterative image reconstruction for CBCT using edge-preserving prior

Journal Article · Thu Jan 15 04:00:00 EST 2009 · Medical Physics

DOI:https://doi.org/10.1118/1.3036112· OSTI ID:22098406

Jing, Wang; Tianfang, Li; Lei, Xing ^[1]

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1. Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305 (United States)

On-board cone-beam computed tomography (CBCT) is a new imaging technique for radiation therapy guidance, which provides volumetric information of a patient at treatment position. CBCT improves the setup accuracy and may be used for dose reconstruction. However, there is great concern that the repeated use of CBCT during a treatment course delivers too much of an extra dose to the patient. To reduce the CBCT dose, one needs to lower the total mAs of the x-ray tube current, which usually leads to reduced image quality. Our goal of this work is to develop an effective method that enables one to achieve a clinically acceptable CBCT image with as low as possible mAs without compromising quality. An iterative image reconstruction algorithm based on a penalized weighted least-squares (PWLS) principle was developed for this purpose. To preserve edges in the reconstructed images, we designed an anisotropic penalty term of a quadratic form. The algorithm was evaluated with a CT quality assurance phantom and an anthropomorphic head phantom. Compared with conventional isotropic penalty, the PWLS image reconstruction algorithm with anisotropic penalty shows better resolution preservation.

• OSTI ID: 22098406
• Journal Information: Medical Physics, Journal Name: Medical Physics Journal Issue: 1 Vol. 36; ISSN 0094-2405; ISSN MPHYA6
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
97 MATHEMATICS AND COMPUTING
ALGORITHMS
COMPUTERIZED TOMOGRAPHY
IMAGE PROCESSING
ITERATIVE METHODS
LEAST SQUARE FIT
PHANTOMS
QUALITY ASSURANCE
RADIATION DOSES
RADIOTHERAPY