The image on the cover shows noninvasive thermography by magnetic resonance (MR) imaging in two time steps in a representative transverse slice through a presacral rectal recurrence. Gellermann et al. used the proton frequency shift method, i.e. subtracted the phase images at 17 and 57 minutes from an initial phase scan (before power-on). The posterior tumor shows in the central part a fair MR-temperature increase of >10MR-degrees (see color map on the right). In this low-perfused (necrotic) portion of the tumor, MR-degrees and imately equal. Other tissues such as muscles and fat are also evaluable, whereby the fat tissue is used for a zero correction (balancing the B0-drift). Artefacts occur in the region of intestine due to motion and susceptibility effects (anterior). In the tumor margin and in muscles, a superposition of perfusion changes and temperature increases occurs. Aperfusion increase of 5 ml/100 mg/min corresponds approximately to +1MR-deg, while a perfusion decrease will also lower the MR-temperature. To differentiate both variables, dynamic contrast media scans under hyperthermic conditions are required in addition and under investigation. It has been shown that MR-temperatures are correlated with response if acquired in this way. For details, see the article by Gellermann et al. on page 5872 of this issue.