Index by author

The authors evaluated multiple parameters of reduced-FOV DTI to optimize image quality. Fifteen healthy individuals underwent cervical spinal cord 3T MRI, including an anatomic 3D Multi-Echo Recombined Gradient Echo, high-resolution full-FOV DTI with a NEX of 3 and 20 diffusion gradient directions, and 5 sets of reduced-FOV DTIs differently balanced in terms of NEX/number of diffusion gradient directions. Qualitatively, reduced-FOV DTI sequences with a NEX of >5 were significantly better rated than the full-FOV DTI and the reduced-FOV DTI with low NEX (N=3) and a high number of diffusion gradient directions (D=20). Quantitatively, the best trade-off was reached by the reduced-FOV DTI with a NEX of 9 and 9 diffusion gradient directions. They conclude that the best compromise was obtained with a NEX of 9 and 9 diffusion gradient directions, which emphasizes the need for increasing the NEX at the expense of the number of diffusion gradient directions for spinal cord DTI, unlike brain imaging.

Twenty-four patients with recurrent high-grade gliomas were scanned before and during bevacizumab treatment with standard and delayed-contrast MRI. The mean change in lesion volumes of responders (overall survival, >1 year) and nonresponders (overall survival, <1 year) was evaluated. Treatment-response-assessment maps (TRAMs) were calculated by subtracting conventional T1WI (acquired a few minutes postcontrast) from delayed T1WI (acquired with a delay of >1 hour postcontrast). These maps depict the spatial distribution of contrast accumulation and clearance. At progression, the increase in lesion volumes in delayed-contrast MR imaging was 37.5% higher than the increase in conventional T1WI. The authors conclude that the benefit of standard and delayed-contrast MRI for assessing and predicting the response to bevacizumab was demonstrated and that the increased sensitivity of delayed-contrast MRI reflects its potential contribution to the management of bevacizumab-treated patients with recurrent HGG.