Method and magnetic resonance apparatus for synchronous imaging and radiation therapy

A combined system therapy and imaging system, comprising:

• a radiation therapy apparatus;
• a magnetic resonance (MR) imaging apparatus;
• a control computer configured to:
• operate the MR imaging apparatus to acquire a three-dimensional MR volume data set prior to irradiation of the subject, the three-dimensional MR volume data set containing a target volume for irradiation of the subject with a radiation beam;
• determine movement information of the subject;
• continuously determine a location of a central beam of the radiation beam relative to the subject;
• determine that the location of the central beam has changed during the irradiation of the subject;
• calculate during the irradiation of the subject an MR image data set comprising two-dimensional MR slices that are positioned substantially perpendicular to the central beam
• in response to the determination that the location of the central beam has changed, calculating, via the combined system during the irradiation of the subject, a changed MR image data set comprising two-dimensional MR slices that are substantially perpendicular to the central beam,
• wherein the MR image data set and the changed MR data set are each respectively calculated during the irradiation of the subject without using a recorded MR data set in addition to the three-dimensional MR volume data set that was acquired prior to the irradiation of the subject by (i) using the movement information, and (ii) calculating, from the three-dimensional MR volume data set of the subject recorded prior to the irradiation of the subject, the two-dimensional MR slices of the changed MR image data set;
• determine a radiation dose for the irradiation in predetermined regions of the subject using the MR image data set and the changed MR image data set;
• and
• control the irradiation using the determined radiation dose.

A non-transitory, computer-readable data storage medium encoded with programming instructions and being loaded into a computer system of a combined system comprising a radiation therapy apparatus and a magnetic resonance (MR) imaging apparatus, the programming instructions, when executed by the computer system, causing the computer system to:

• operate the MR imaging apparatus to acquire a three-dimensional MR volume data set prior to irradiation of the subject, the three-dimensional MR volume data set containing a target volume for irradiation of the subject with a radiation beam;
• determine movement information of the subject;
• continuously determine a location of a central beam of the radiation beam relative to the subject;
• determine that the location of the central beam has changed during the irradiation of the subject;
• calculate during the irradiation of the subject an MR image data set comprising two-dimensional MR slices that are positioned substantially perpendicular to the central beam;
• in response to the determination that the location of the central beam has changed, calculating, via the combined system during the irradiation of the subject, a changed MR image data set comprising two-dimensional MR slices that are substantially perpendicular to the central beam,
• wherein the MR image data set and the changed MR data set are each respectively calculated during the irradiation of the subject without using a recorded MR data set in addition to the three-dimensional MR volume data set that was acquired prior to the irradiation of the subject by (i) using the movement information, and (ii) calculating, from the three-dimensional MR volume data set of the subject recorded prior to the irradiation the subject, the two-dimensional MR slices of the changed MR image data set;
• determine a radiation dose for the irradiation in predetermined regions of the subject using the MR image data set and the changed MR image data set;
• and
• control the irradiation using the determined radiation dose.