Device for immobilizing a subject in a medical system

A vacuum cushion for immobilizing a subject, comprising:

• a shell;
• a filler material contained within a region defined by the shell;
• and
• multiple radio frequency (RF) coils which are detachably coupled to the vacuum cushion and configured to receive a magnetic resonance (MR) signal related to at least one portion of the subject, wherein the vacuum cushion has a first mode in which the filler material moves within the region defined by the shell, and a second mode conformed to the contour of the at least one portion of the subject, wherein the vacuum cushion includes a chamber defined by a surface located in the region, the multiple radio frequency (RF) coils are coupled to the surface and located in the chamber, the chamber includes a plurality of air-permeable cells separated from each other, each cell of the plurality of air-permeable cells containing filler particles, movement of the filler particles being restricted within the cell,
• the vacuum cushion is configured to switch between the first mode and the second mode,
• a change of a volume of each of at least a portion of the plurality of air-permeable cells causes a switch between the first mode and the second mode, and
• the movement of the filler particles contained in at least one air-permeable cell is more restrained when the device is in the second mode as compared to when the vacuum cushion is in the first mode.