An implantable infusion device includes a positive pressure reservoir, a pump, a flow restrictor, and an outlet. The device includes a first fluid flow path from the reservoir to the outlet, where the pump is downstream of the reservoir, and the outlet is downstream of the pump. The device further includes a second fluid flow path from the reservoir to the outlet, where the flow restrictor is downstream of the reservoir, and the outlet is downstream of the restrictor. The device may also include one or more controllable, MRI-safe valves to select whether fluid is delivered via the first or second flow path.
