Gradient coils and magnetic resonance imaging devices

A gradient coil, comprising a first hollow conductor and a second hollow conductor,

• wherein the first hollow conductor and the second hollow conductor form concentric loops, the a first hollow conductor includes a first conduit for a cooling medium to flow through, the second hollow conductor includes a second conduit for the cooling medium to flow through, the first conduit and the second conduit form a parallel cooling circuit.

A magnetic resonance imaging (MRI) apparatus, comprising a gradient coil, wherein the gradient coil includes a plurality of conductor structures,

• each of the plurality of conductor structures includes one or more coil units wound in a concentric manner,
• each of the one or more coil units includes a plurality of hollow conductors, and a conduit for a cooling medium to pass through is disposed within each of the plurality of hollow conductors,
• the plurality of hollow conductors are connected in series in a circuit, and at least two conduits of the plurality of hollow conductors are connected in parallel.