  Extensive data on strong interaction effects in pionic atoms are analyzed
with a density-dependent isovector scattering amplitude suggested recently by
Weise to result from a density dependence of the pion decay constant. Most of
the so-called `missing s-wave repulsion' is removed when adopting this
approach, thus indicating a partial chiral symmetry restoration in dense
matter. The resulting potentials describe quite well also elastic scattering of
20 MeV pions on Ca. Further tests with elastic scattering are desirable.
