Evaluation of 4D CT acquisition methods designed to reduce artifacts

Sarah J. Castillo, Richard Castillo, Edward Castillo, Tinsu Pan, Geoffrey Ibbott, Peter Balter, Brian Hobbs, Thomas Guerrero

    Research output: Contribution to journalArticle

    12 Citations (Scopus)

    Abstract

    Four-dimensional computed tomography (4D CT) is used to account for respiratory motion in radiation treatment planning, but artifacts resulting from the acquisition and postprocessing limit its accuracy. We investigated the efficacy of three experimental 4D CT acquisition methods to reduce artifacts in a prospective institutional review board approved study. Eighteen thoracic patients scheduled to undergo radiation therapy received standard clinical 4D CT scans followed by each of the alternative 4D CT acquisitions: 1) data oversampling, 2) beam gating with breathing irregularities, and 3) rescanning the clinical acquisition acquired during irregular breathing. Relative values of a validated correlation-based artifact metric (CM) determined the best acquisition method per patient. Each 4D CT was processed by an extended phase sorting approach that optimizes the quantitative artifact metric (CM sorting). The clinical acquisitions were also postprocessed by phase sorting for artifact comparison of our current clinical implementation with the experimental methods. The oversampling acquisition achieved the lowest artifact presence among all acquisitions, achieving a 27% reduction from the current clinical 4D CT implementation (95% confidence interval = 34-20). The rescan method presented a significantly higher artifact presence from the clinical acquisition (37%; p < 0.002), the gating acquisition (26%; p < 0.005), and the oversampling acquisition (31%; p < 0.001), while the data lacked evidence of a significant difference between the clinical, gating, and oversampling methods. The oversampling acquisition reduced artifact presence from the current clinical 4D CT implementation to the largest degree and provided the simplest and most reproducible implementation. The rescan acquisition increased artifact presence significantly, compared to all acquisitions, and suffered from combination of data from independent scans over which large internal anatomic shifts occurred.

    Original languageEnglish (US)
    Pages (from-to)23-32
    Number of pages10
    JournalJournal of Applied Clinical Medical Physics
    Volume16
    Issue number2
    DOIs
    StatePublished - 2015

    Fingerprint

    Four-Dimensional Computed Tomography
    Sorting
    Artifacts
    artifacts
    acquisition
    evaluation
    Computerized tomography
    Radiotherapy
    Tomography
    Radiation
    classifying
    Planning
    Respiration
    breathing
    Research Ethics Committees
    Thorax

    Keywords

    • 4D CT
    • Artifacts
    • Correlation
    • Radiation therapy simulation

    ASJC Scopus subject areas

    • Radiology Nuclear Medicine and imaging
    • Radiation
    • Instrumentation

    Cite this

    Castillo, S. J., Castillo, R., Castillo, E., Pan, T., Ibbott, G., Balter, P., ... Guerrero, T. (2015). Evaluation of 4D CT acquisition methods designed to reduce artifacts. Journal of Applied Clinical Medical Physics, 16(2), 23-32. https://doi.org/10.1120/jacmp.v16i2.4949

    Evaluation of 4D CT acquisition methods designed to reduce artifacts. / Castillo, Sarah J.; Castillo, Richard; Castillo, Edward; Pan, Tinsu; Ibbott, Geoffrey; Balter, Peter; Hobbs, Brian; Guerrero, Thomas.

    In: Journal of Applied Clinical Medical Physics, Vol. 16, No. 2, 2015, p. 23-32.

    Research output: Contribution to journalArticle

    Castillo, SJ, Castillo, R, Castillo, E, Pan, T, Ibbott, G, Balter, P, Hobbs, B & Guerrero, T 2015, 'Evaluation of 4D CT acquisition methods designed to reduce artifacts', Journal of Applied Clinical Medical Physics, vol. 16, no. 2, pp. 23-32. https://doi.org/10.1120/jacmp.v16i2.4949
    Castillo, Sarah J. ; Castillo, Richard ; Castillo, Edward ; Pan, Tinsu ; Ibbott, Geoffrey ; Balter, Peter ; Hobbs, Brian ; Guerrero, Thomas. / Evaluation of 4D CT acquisition methods designed to reduce artifacts. In: Journal of Applied Clinical Medical Physics. 2015 ; Vol. 16, No. 2. pp. 23-32.
    @article{faccc3e09c224448b3a80a62cb1c9c26,
    title = "Evaluation of 4D CT acquisition methods designed to reduce artifacts",
    abstract = "Four-dimensional computed tomography (4D CT) is used to account for respiratory motion in radiation treatment planning, but artifacts resulting from the acquisition and postprocessing limit its accuracy. We investigated the efficacy of three experimental 4D CT acquisition methods to reduce artifacts in a prospective institutional review board approved study. Eighteen thoracic patients scheduled to undergo radiation therapy received standard clinical 4D CT scans followed by each of the alternative 4D CT acquisitions: 1) data oversampling, 2) beam gating with breathing irregularities, and 3) rescanning the clinical acquisition acquired during irregular breathing. Relative values of a validated correlation-based artifact metric (CM) determined the best acquisition method per patient. Each 4D CT was processed by an extended phase sorting approach that optimizes the quantitative artifact metric (CM sorting). The clinical acquisitions were also postprocessed by phase sorting for artifact comparison of our current clinical implementation with the experimental methods. The oversampling acquisition achieved the lowest artifact presence among all acquisitions, achieving a 27{\%} reduction from the current clinical 4D CT implementation (95{\%} confidence interval = 34-20). The rescan method presented a significantly higher artifact presence from the clinical acquisition (37{\%}; p < 0.002), the gating acquisition (26{\%}; p < 0.005), and the oversampling acquisition (31{\%}; p < 0.001), while the data lacked evidence of a significant difference between the clinical, gating, and oversampling methods. The oversampling acquisition reduced artifact presence from the current clinical 4D CT implementation to the largest degree and provided the simplest and most reproducible implementation. The rescan acquisition increased artifact presence significantly, compared to all acquisitions, and suffered from combination of data from independent scans over which large internal anatomic shifts occurred.",
    keywords = "4D CT, Artifacts, Correlation, Radiation therapy simulation",
    author = "Castillo, {Sarah J.} and Richard Castillo and Edward Castillo and Tinsu Pan and Geoffrey Ibbott and Peter Balter and Brian Hobbs and Thomas Guerrero",
    year = "2015",
    doi = "10.1120/jacmp.v16i2.4949",
    language = "English (US)",
    volume = "16",
    pages = "23--32",
    journal = "Journal of applied clinical medical physics / American College of Medical Physics",
    issn = "1526-9914",
    publisher = "American Institute of Physics Publising LLC",
    number = "2",

    }

    TY - JOUR

    T1 - Evaluation of 4D CT acquisition methods designed to reduce artifacts

    AU - Castillo, Sarah J.

    AU - Castillo, Richard

    AU - Castillo, Edward

    AU - Pan, Tinsu

    AU - Ibbott, Geoffrey

    AU - Balter, Peter

    AU - Hobbs, Brian

    AU - Guerrero, Thomas

    PY - 2015

    Y1 - 2015

    N2 - Four-dimensional computed tomography (4D CT) is used to account for respiratory motion in radiation treatment planning, but artifacts resulting from the acquisition and postprocessing limit its accuracy. We investigated the efficacy of three experimental 4D CT acquisition methods to reduce artifacts in a prospective institutional review board approved study. Eighteen thoracic patients scheduled to undergo radiation therapy received standard clinical 4D CT scans followed by each of the alternative 4D CT acquisitions: 1) data oversampling, 2) beam gating with breathing irregularities, and 3) rescanning the clinical acquisition acquired during irregular breathing. Relative values of a validated correlation-based artifact metric (CM) determined the best acquisition method per patient. Each 4D CT was processed by an extended phase sorting approach that optimizes the quantitative artifact metric (CM sorting). The clinical acquisitions were also postprocessed by phase sorting for artifact comparison of our current clinical implementation with the experimental methods. The oversampling acquisition achieved the lowest artifact presence among all acquisitions, achieving a 27% reduction from the current clinical 4D CT implementation (95% confidence interval = 34-20). The rescan method presented a significantly higher artifact presence from the clinical acquisition (37%; p < 0.002), the gating acquisition (26%; p < 0.005), and the oversampling acquisition (31%; p < 0.001), while the data lacked evidence of a significant difference between the clinical, gating, and oversampling methods. The oversampling acquisition reduced artifact presence from the current clinical 4D CT implementation to the largest degree and provided the simplest and most reproducible implementation. The rescan acquisition increased artifact presence significantly, compared to all acquisitions, and suffered from combination of data from independent scans over which large internal anatomic shifts occurred.

    AB - Four-dimensional computed tomography (4D CT) is used to account for respiratory motion in radiation treatment planning, but artifacts resulting from the acquisition and postprocessing limit its accuracy. We investigated the efficacy of three experimental 4D CT acquisition methods to reduce artifacts in a prospective institutional review board approved study. Eighteen thoracic patients scheduled to undergo radiation therapy received standard clinical 4D CT scans followed by each of the alternative 4D CT acquisitions: 1) data oversampling, 2) beam gating with breathing irregularities, and 3) rescanning the clinical acquisition acquired during irregular breathing. Relative values of a validated correlation-based artifact metric (CM) determined the best acquisition method per patient. Each 4D CT was processed by an extended phase sorting approach that optimizes the quantitative artifact metric (CM sorting). The clinical acquisitions were also postprocessed by phase sorting for artifact comparison of our current clinical implementation with the experimental methods. The oversampling acquisition achieved the lowest artifact presence among all acquisitions, achieving a 27% reduction from the current clinical 4D CT implementation (95% confidence interval = 34-20). The rescan method presented a significantly higher artifact presence from the clinical acquisition (37%; p < 0.002), the gating acquisition (26%; p < 0.005), and the oversampling acquisition (31%; p < 0.001), while the data lacked evidence of a significant difference between the clinical, gating, and oversampling methods. The oversampling acquisition reduced artifact presence from the current clinical 4D CT implementation to the largest degree and provided the simplest and most reproducible implementation. The rescan acquisition increased artifact presence significantly, compared to all acquisitions, and suffered from combination of data from independent scans over which large internal anatomic shifts occurred.

    KW - 4D CT

    KW - Artifacts

    KW - Correlation

    KW - Radiation therapy simulation

    UR - http://www.scopus.com/inward/record.url?scp=84930347478&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=84930347478&partnerID=8YFLogxK

    U2 - 10.1120/jacmp.v16i2.4949

    DO - 10.1120/jacmp.v16i2.4949

    M3 - Article

    VL - 16

    SP - 23

    EP - 32

    JO - Journal of applied clinical medical physics / American College of Medical Physics

    JF - Journal of applied clinical medical physics / American College of Medical Physics

    SN - 1526-9914

    IS - 2

    ER -