MEDICAL APPARATUS COMPRISING A HADRON THERAPY DEVICE, A MRI, AND A HADRON RADIOGRAPHY SYSTEM

A medical apparatus that comprises: (A) a hadron therapy device adapted for directing an imaging hadron beam having an initial imaging beam energy, along a beam path, said beam path going through and beyond: €¢ a subject of interest comprising a plurality of tissues and crossed by the beam path between upstream and downstream boundaries, and €¢ a target spot located inside a target tissue of the subject of interest; (B) a magnetic resonance imaging device for acquiring magnetic resonance data within an imaging volume comprising a portion of the subject of interest including the target spot and at least the portion of the beam path comprised between the upstream boundary and the target spot; (C) a hadron radiography system (HRS) adapted for acquiring a signal generated by the imaging hadron beam; and (D) a controller configured for determining a water equivalent path length of the beam path between upstream and downstream boundaries, said determination being based, at least, on the signal acquired with the HRS.