2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/157706We prove that a nodal quartic threefold $X$ containing no planes is $Q$-factorial provided that it has not more than 12 singular points, with the exception of a quartic with exactly 12 singularities containing a quadric surface. We give some geometrical constructions related to the latter quartic.13 pages; minor correctionsAlgebraic Geometry14E05 (Primary); 14E07, 14J30 (Secondary)text