Radiotherapy system for accurate locating of 3D objects from magnetic resonance images

A computer program product comprising machine executable instructions stored on a non-transitory computer readable medium for execution by a processor controlling a system, wherein execution of the machine executable instructions causes the processor to:

• receive magnetic resonance data, the magnetic resonance data comprising three dimensional (3D) image data, or 3D image data and two dimensional (2D) image data, that are acquired using a magnetic resonance imaging apparatus from an organ, wherein the organ is marked by a marker;
• provide reference values of one or more parameters describing the shape of the marker;
• identify in a reconstructed 2D image reconstructed from the 3D image data or from the 2D image data at least one signal void candidate of the marker;
• process the 3D image data and the identified signal void for determining the shape of the marker using magnetic resonance properties of the signal void candidate;
• determine values of the parameters using the determined shape of the marker;
• compare the determined values with the reference values;
• calculate a likelihood that the identified signal void candidate is part of the marker using the comparison result;
• output to a user an indication of the calculated likelihood;
• in response to the outputting, receive a user input with respect to a radiation therapy plan;
• and
• control a radiotherapy apparatus to irradiate the organ using the radiation therapy plan.

A method, comprising:

• using a magnetic resonance imaging system to acquire magnetic resonance data from an organ, wherein the organ is marked by a marker, wherein the magnetic resonance data comprises three dimensional (3D) image data, or 3D image data and two dimensional (2D) image data;
• identifying, in a reconstructed 2D image reconstructed from the 3D image data or from the 2D image data, data at least one signal void candidate of the marker;
• providing reference values of one or more parameters describing the shape of the marker;
• processing the 3D image data and the identified signal void for determining the shape of the marker using magnetic resonance properties of the signal void candidate;
• determining values of the parameters using the determined shape of the marker;
• comparing the determined values with the reference values;
• calculating a likelihood that the identified signal void candidate is part of the marker using the comparison result;
• outputting to a user an indication of the calculated likelihood;
• in response to the outputting of the calculated likelihood, receiving a user input with respect to a radiation therapy plan;
• and
• controlling a radiotherapy apparatus to irradiate the organ in accordance with the radiation therapy plan.