An incubator's closure assembly adapted to shut the aperture of a magnetic resonance imaging device (MRD) having an open bore extended along the MRD's longitudinal axis with a distal end and proximal end, the bore is terminated by the aperture located in the proximal end, into which a neonate's incubator is inserted, thereby shutting the MRD bore aperture. The closure assembly comprising at least one U-shaped conduit having (i) an array of distal and proximal sealing walls, both are substantially perpendicular to the longitudinal axis and having upwards and downwards directions, and (ii) a recess in between the walls having length, in upwards to downwards direction, and width, in distal to proximal direction, each of the proximal wall and the distal wall comprising a cutout at opposite directions, and wherein in the recess, the ratio of length to width is greater than a predefined value n.