Even the White's PI coils are not compatible with Minelab PI detectors. Minelab DD coils don't work with White's SPP detectors. As someone stated before the resistance and inductance is different.
Is it possible to convert.? Well almost everything is possible. Rip the coil apart and rewire it with same diameter and length of wire that same size Minelab coil is using. And it may work. But you may be better off, building whole coil from the scratch
Karl