Projection-reconstruction reduces FOV imaging

Reduced field-of-view (rFOV) imaging was introduced recently as a rapid ima ging technique that improves temporal resolution while maintaining spatial resolution. It is based on undersampling in k-space and utilizes the fact t hat the dynamics of an evolving process are often confined to a local area within the full FOV. In the work presented here the reduced FOV approach is applied to projection-reconstruction MRI and compared to the original spin -warp implementation. Results are presented that clearly demonstrate the in creased robustness of the projection reconstruction version of rFOV imaging . The technique is successfully applied to an MR-guided biopsy scenario (ex -vivo) and to cine cardiac imaging. Finally an algorithm is proposed that u ses the intrinsic advantages of radial k-space sampling to evaluate the pro jection data to control the adjustment of position and size of the reduced FOV window. (C) 1999 Elsevier Science Inc.