Abstract: The radiotherapy treatment planning system is for calculating the radiation dose to be absorbed by an object to be irradiated, prior to radiotherapy. The distribution of contribution output unit outputs the distribution of contribution showing the contribution rates of scattered beam or electron beam to an observational point in each point of the object to be irradiated. The arithmetic unit calculates the absorbed dose of the observational point due to the scattered beam or the absorbed dose due to the electron beam, by summing up each contribution rate multiplied with the electron density at the point corresponding thereto.

Abstract: An artifact suppression system for a magnetic resonance imaging apparatus, comprising static field application means for applying a static field to a subject, RF pulse application means for applying RF pulses, gradient field application means for applying gradient fields which consist of a slice field for designating a tomographic slice, a phase encode field for affording a phase encode magnitude, and a signal read field for encoding a frequency, and sequence control means for controlling a signal acquistion sequence which acquires a magnetic resonance signal from the designated tomographic slice of the subject, and a saturation sequence which saturates spins of movable objects to traverse the designated tomographic slice of the subject for the signal acquisition, before execution of the signal acquisition sequence.