Jorn Helbert picks up the story. The Venus Express team have been doing studies comparing the expected temperature of the surface derived from Magellan altitude data, with their best estimation of the surface temperature using the VIRTIS instrument for about 18 months with a hope of identifying active volcanism. The long and short of it is no - they've not identified any hotspots yet - but they've not been getting much help from Venus.
The majority of the Magellan-identified volcanic features on Venus are in the northern hemisphere. However the orbit which Venus Express is in means that they can only really observe the southern hemisphere. The process of getting these surface images is hard because they have only three infrared windows (95% transparent at a wavelength of 1 micron, 40-60% at 1.1-1.18, and a very slight window at 1.28-1.32 microns). Even in these windows however, they still have clouds