Convergence problems are studied for quasiregular mappings in space. W
e show the continuity of the injectivity radius for arbitrary continuo
us discrete sense-preserving mappings and prove a space version of the
Strebel convergence theorem for the local dilatation. We give the Ber
s-Bojarski convergence theorem in terms of the matrix dilatation. We e
stablish a sharp upper semicontinuity result for distortion coefficien
ts in the mean. These theorems a re used to give some extensions of Li
ouville's theorem (Lavrentiev-Reshetnyak).