An animal handling system for use in an MRD device, including: a first elongated enclosure having a proximal end, a distal open end and a first geometry, and a second first elongated enclosure having a proximal end, a distal open end and a second geometry. The first second geometry comprises a first cross-sectional area which is larger than a second cross-sectional area of the second geometry. The first elongated enclosure is inserted into a first input port of the MRD device and the second elongated enclosure is inserted in a second input port of the MRD device diametrically opposite to second input port, such that on insertion of the first elongated enclosure into the first input port and insertion of the second elongated enclosure into the second input, the second elongated enclosure slides into the first elongated enclosure through the open distal end of the first elongated enclosure.