A mid-turbine frame (“MTF”) for a jet engine is disclosed and comprises a duct that extends between a high pressure turbine (“HPT”) and a low pressure turbine (“LPT”), the duct comprising a plurality of segments that together form an outer annular structure and an inner annular structure, the inner annular structure situated radially inward of the outer annular structure, and/or a plurality of vanes that extend radially outward from the inner annular structure toward the outer annular structure, each vane comprising a channel. Each segment may be coupled to an adjacent segment by a seal.