  We study the cokernel of the application given by the Cartan Matrix
$C_\Lambda$ of a finite dimensional $k$-algebra $\Lambda.$ This produces a
finitely generated abelian group, the Cartan group $G_\Lambda,$ which is
invariant under derived equivalences. We are interested in the case when
$G_\Lambda$ is finite. For a standardly stratified algebra, it is shown that
this group is always finite and some interesting connections with the standard
modules are found. As a consequence, it is got that $G_\Lambda$ can be seen as
a measure of how far is a standardly stratified algebra $\Lambda$ to be
quasi-hereditary. Finally, it is also shown that any finite abelian group can
be realized as the Cartan group of some standardly stratified algebra.
