ObjectiveThe perfusion profile of vestibular schwannomas (VSs) and the factors that influence it
have yet to be determined.Materials and MethodsTwenty patients with sporadic VS were analyzed by calculating parameters related to the
extravascular extracellular space (EES)—the volume transfer constant between a vessel
and the EES (Ktrans); the EES volume per unit of tissue volume (Ve); and the rate
transfer constant between EES and blood plasma (Kep)—as well as the relative cerebral
blood volume (rCBV), and by correlating those parameters with the size of the tumor and
its structure (solid, cystic, or heterogeneous).ResultsAlthough Ktrans, Ve, and Kep were measurable in all tumors, rCBV was measurable only in
large tumors. We detected a positive correlation between Ktrans and rCBV (r = 0.62,p= 0.031), a negative correlation between Ve and Kep (r = –0.51,p= 0.021), and a positive correlation between Ktrans and Ve only in
solid VSs (r = 0.64,p= 0.048). Comparing the means for small and
large VSs, we found that the former showed lower Ktrans (0.13 vs. 0.029,p< 0.001), higher Kep (0.68 vs. 0.46,p=
0.037), and lower Ve (0.45 vs. 0.83,p< 0.001). The mean Ktrans was
lower in the cystic portions of cystic VSs than in their solid portions (0.14 vs. 0.32,p< 0.001), as was the mean Ve (0.37 vs. 0.78,p< 0.001). There were positive correlations between the solid and cystic portions for
Ktrans (r = 0.71,p= 0.048) and Kep (r = 0.74,p=
0.037).ConclusionIn VS, tumor size appears to be consistently associated with perfusion values. In
cystic VS, the cystic portions seem to have lower Ktrans and Ve than do the solid
portions.