In quantitative PET-imaging, it is essential to correct for the attenuation of photons in tissue. In combined PET/MR-imaging the attenuation correction (AC) is based on MR-data and subsequent tissue class segmentation. The MR-FOV is limited due to B0-inhomogeneities and gradient nonlinearities. Therefore, the AC-map is truncated and reconstructed PET-data are biased. HUGE (B0-Homogenization using gradient enhancement), which determines an optimal readout gradient to compensate gradient nonlinearities, was applied in whole-body PET/MR examinations of 24 oncologic patients. The extension of the MR-FOV for MR-based AC showed an improvement of PET-quantification in integrated PET/MR-imaging by reducing the truncated areas of the AC-map.