A system for tumor margin assessment of an ex-vivo tissue, comprising: a magnetic resonance imaging scanner controlled by a control unit; an ex-vivo tissue comprising a tumor and a peripheral margin around the tumor; a tissue container holding said ex-vivo tissue, said tissue container being sized such that edges of said tissue are forced against an inner surface of said tissue container to have a predetermined geometry, and wherein said MRI scanner is positioned relative to said tissue container such that said MRI scanner is configured to acquire images of said edges that have the predetermined geometry and of a sensitive region of said tissue which extends into a peripheral margin of said tissue, said sensitive region having a thickness defined by the desired clean margin, i.e. by the desired thickness around said tumor in said tissue which is free of cancerous tissue; and said MRI scanner comprising a coil-magnet assembly comprising magnets, wherein said tissue, placed in said container, is placed under a constant static magnetic field (B o), which is induced by said magnets, and wherein said container is positioned so the sensitive region is within a measured field of view excited by one or more transmit/receive coils operative to generate a time-varying RF B 1 electro-magnetic field pointing towards said tissue, characterised in that said container is fixed on a moving table, wherein said images acquired by said MRI scanner are merged on a display with images of said tissue acquired from other imaging modalities, wherein an image of said tissue in the container, acquired from the other imaging modalities, is displayed, and an overlay of the MRI acquisition data of positive and negative margins is displayed on top of said image, such that the coordinates of the MRI data match the coordinates in the said image. a magnetic resonance imaging scanner controlled by a control unit; an ex-vivo tissue comprising a tumor and a peripheral margin around the tumor; a tissue container holding said ex-vivo tissue, said tissue container being sized such that edges of said tissue are forced against an inner surface of said tissue container to have a predetermined geometry, and wherein said MRI scanner is positioned relative to said tissue container such that said MRI scanner is configured to acquire images of said edges that have the predetermined geometry and of a sensitive region of said tissue which extends into a peripheral margin of said tissue, said sensitive region having a thickness defined by the desired clean margin, i.e. by the desired thickness around said tumor in said tissue which is free of cancerous tissue; and said MRI scanner comprising a coil-magnet assembly comprising magnets, wherein said tissue, placed in said container, is placed under a constant static magnetic field (B o), which is induced by said magnets, and wherein said container is positioned so the sensitive region is within a measured field of view excited by one or more transmit/receive coils operative to generate a time-varying RF B 1 electro-magnetic field pointing towards said tissue, characterised in that said container is fixed on a moving table, wherein said images acquired by said MRI scanner are merged on a display with images of said tissue acquired from other imaging modalities, wherein an image of said tissue in the container, acquired from the other imaging modalities, is displayed, and an overlay of the MRI acquisition data of positive and negative margins is displayed on top of said image, such that the coordinates of the MRI data match the coordinates in the said image.