Sci—Thur AM: YIS - 08: Constructing an Attenuation map for a PET/MR Breast coil

Authors

  • Patrick John C.,

    1. Department of Medical Biophysics, Western University, Knoxville, TN, United States
    2. Department of Oncology, Western University, Knoxville, TN, United States
    3. Imaging, Lawson Health Research Institute, Knoxville, TN, United States
    4. Diagnostic Imaging St Joseph's Health Care London, Knoxville, TN, United States
    5. London Regional Cancer Program, Knoxville, TN, United States
    6. Imaging Laboratories - Robarts Research Institute, Knoxville, TN, United States
    7. Siemens Healthcare Molecular Imaging, Knoxville, TN, United States
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  • So Aaron,

    1. Department of Medical Biophysics, Western University, Knoxville, TN, United States
    2. Department of Oncology, Western University, Knoxville, TN, United States
    3. Imaging, Lawson Health Research Institute, Knoxville, TN, United States
    4. Diagnostic Imaging St Joseph's Health Care London, Knoxville, TN, United States
    5. London Regional Cancer Program, Knoxville, TN, United States
    6. Imaging Laboratories - Robarts Research Institute, Knoxville, TN, United States
    7. Siemens Healthcare Molecular Imaging, Knoxville, TN, United States
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  • Butler John,

    1. Department of Medical Biophysics, Western University, Knoxville, TN, United States
    2. Department of Oncology, Western University, Knoxville, TN, United States
    3. Imaging, Lawson Health Research Institute, Knoxville, TN, United States
    4. Diagnostic Imaging St Joseph's Health Care London, Knoxville, TN, United States
    5. London Regional Cancer Program, Knoxville, TN, United States
    6. Imaging Laboratories - Robarts Research Institute, Knoxville, TN, United States
    7. Siemens Healthcare Molecular Imaging, Knoxville, TN, United States
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  • Faul David,

    1. Department of Medical Biophysics, Western University, Knoxville, TN, United States
    2. Department of Oncology, Western University, Knoxville, TN, United States
    3. Imaging, Lawson Health Research Institute, Knoxville, TN, United States
    4. Diagnostic Imaging St Joseph's Health Care London, Knoxville, TN, United States
    5. London Regional Cancer Program, Knoxville, TN, United States
    6. Imaging Laboratories - Robarts Research Institute, Knoxville, TN, United States
    7. Siemens Healthcare Molecular Imaging, Knoxville, TN, United States
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  • Yartsev Slav,

    1. Department of Medical Biophysics, Western University, Knoxville, TN, United States
    2. Department of Oncology, Western University, Knoxville, TN, United States
    3. Imaging, Lawson Health Research Institute, Knoxville, TN, United States
    4. Diagnostic Imaging St Joseph's Health Care London, Knoxville, TN, United States
    5. London Regional Cancer Program, Knoxville, TN, United States
    6. Imaging Laboratories - Robarts Research Institute, Knoxville, TN, United States
    7. Siemens Healthcare Molecular Imaging, Knoxville, TN, United States
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  • Thompson Terry,

    1. Department of Medical Biophysics, Western University, Knoxville, TN, United States
    2. Department of Oncology, Western University, Knoxville, TN, United States
    3. Imaging, Lawson Health Research Institute, Knoxville, TN, United States
    4. Diagnostic Imaging St Joseph's Health Care London, Knoxville, TN, United States
    5. London Regional Cancer Program, Knoxville, TN, United States
    6. Imaging Laboratories - Robarts Research Institute, Knoxville, TN, United States
    7. Siemens Healthcare Molecular Imaging, Knoxville, TN, United States
    Search for more papers by this author
  • Prato Frank S.,

    1. Department of Medical Biophysics, Western University, Knoxville, TN, United States
    2. Department of Oncology, Western University, Knoxville, TN, United States
    3. Imaging, Lawson Health Research Institute, Knoxville, TN, United States
    4. Diagnostic Imaging St Joseph's Health Care London, Knoxville, TN, United States
    5. London Regional Cancer Program, Knoxville, TN, United States
    6. Imaging Laboratories - Robarts Research Institute, Knoxville, TN, United States
    7. Siemens Healthcare Molecular Imaging, Knoxville, TN, United States
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  • Gaede Stewart

    1. Department of Medical Biophysics, Western University, Knoxville, TN, United States
    2. Department of Oncology, Western University, Knoxville, TN, United States
    3. Imaging, Lawson Health Research Institute, Knoxville, TN, United States
    4. Diagnostic Imaging St Joseph's Health Care London, Knoxville, TN, United States
    5. London Regional Cancer Program, Knoxville, TN, United States
    6. Imaging Laboratories - Robarts Research Institute, Knoxville, TN, United States
    7. Siemens Healthcare Molecular Imaging, Knoxville, TN, United States
    Search for more papers by this author

Abstract

In 2013, around 23000 Canadian women and 200 Canadian men were diagnosed with breast cancer. An estimated 5100 women and 55 men died from the disease. Using the sensitivity of MRI with the selectivity of PET, PET/MRI combines anatomical and functional information within the same scan and could help with early detection in high-risk patients. MRI requires radiofrequency coils for transmitting energy and receiving signal but the breast coil attenuates PET signal. To correct for this PET attenuation, a 3-dimensional map of linear attenuation coefficients (μ-map) of the breast coil must be created and incorporated into the PET reconstruction process. Several approaches have been proposed for building hardware μ-maps, some of which include the use of conventional kVCT and Dual energy CT. These methods can produce high resolution images based on the electron densities of materials that can be converted into μ-maps. However, imaging hardware containing metal components with photons in the kV range is susceptible to metal artifacts. These artifacts can compromise the accuracy of the resulting μ-map and PET reconstruction; therefore high-Z components should be removed. We propose a method for calculating μ-maps without removing coil components, based on megavoltage (MV) imaging with a linear accelerator that has been detuned for imaging at 1.0MeV. Containers of known geometry with F18 were placed in the breast coil for imaging. A comparison between reconstructions based on the different μ-map construction methods was made. PET reconstructions with our method show a maximum of 6% difference over the existing kVCT-based reconstructions.

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