Koninklijke Philips Corporation N.v.

Navdeep Ojha

Michael Andrew Morich

Zhiqiang Hu

Chi-Hua Tung

A radiation therapy planning and follow-up system () includes an MR scanner () with a first bore () which defines an MR imaging region () and a functional scanner (), e.g., a nuclear imaging scanner, or a CT scanner with a second bore () which defines a nuclear or CT imaging region (). The first and second bores () have a diameter of at least 70 cm, and preferably 80-85 cm. A radiation therapy type couch () moves linearly through the MR imaging region () along an MR longitudinal axis and the nuclear or CT imaging region () along a nuclear or CT longitudinal axis which is aligned with the MR longitudinal axis. The couch positions a subject sequentially in the MR and nuclear or CT imaging regions (). A fusion processor combines an image representation generated from data collection in the MR imaging region () and an image representation generated from data collection in the nuclear or CT imaging region () into a composite image representation and a planning processor () generates a radiation therapy treatment plan according to the composite image.

Radiation therapy planning and follow-up system with large bore nuclear and magnetic resonance imaging or large bore CT and magnetic resonance imaging

When generating a magnetic resonance (MR) attenuation map (39), an MR image is segmented to identify a patient's body outline, soft tissue structures, and ambiguous structures comprising bone and/or air. To distinguish between bone and air in the ambiguous structures, a nuclear emission image (e.g., PET) of the same patient or region of interest is segmented. The segmented functional image data is correlated to the segmented MR image data to distinguish between bone and air in the ambiguous structures. Appropriate radiation attenuation values are assigned respectively to identify air voxels and bone voxels in the segmented MR image, and an MR attenuation map is generated from the enhanced segmented MR image, in which ambiguity between air and bone has been resolved. The MR attenuation map is used to generate an attenuation-corrected nuclear image, which is displayed to a user.

MR segmentation using nuclear emission data in hybrid nuclear imaging/MR

When correcting for attenuation in a positron emission tomography (PET) image, a magnetic resonance (MR) image () of a subject is generated with spectroscopic data () describing the chemical composition of one or more of the voxels in the MR image. A table lookup is performed to identify a tissue type for each voxel based on the MR image data and spectral composition data, and an attenuation value is assigned to each voxel based on its tissue type to generate an MR attenuation correction (MRAC) map (). The MRAC map () is used during reconstruction of the nuclear image () to correct for attenuation therein. Additionally, attenuation due to MR coils and other accessories that remain in a nuclear imager field of view during a combined MR/nuclear scan is corrected using pre-generated attenuation correction maps that are applied to a nuclear image after executing an MR scan to identify anatomical landmarks, which are used to align the pre-generated attenuation correction maps to the patient.

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Mayfield Village, OH, United States of America

Navdeep Ojha