High-precision position estimation in PET using artificial neural networks - Mateo, F.; Aliaga, R.J.; Ferrando, N.; Martínez, J.D.; Herrero, V.; Lerche, Ch.W.; Colom, R.J.; Monzó, J.M.; Sebastiá, A.; Gadea, R. (Nuclear Instruments & Methods in Physics Research Section A, 2009)