Three-dimensional FLASH Imaging

Abstract

Sixteen patients with a variety of brain and spine tumors were examined with T1-weighted spin echo and three-dimensional (3D) fast low-angle shot (FLASH) (60.degree. flip angle) techniques before and after administration of Gd-diethylenetriamine pentaacetic acid (DTPA) to assess the utility of volume imaging in parenchymal and dural disease. Reconstructions were performed on a Kontron MIP magnetic resonance (MR) workstation and compared with the corresponding spin echo images. Good 3D FLASH examinations (n = 9) were seen with a variety of echo times (6-17 ms) and repetition times (40-100 ms). Fair (n = 4) and poor (n = 3) examinations were usually associated with motion artifact, especially the coronal acquisitions. Spin echo images were all considered of good quality. An increase in confidence of diagnosis was seen in nine cases following contrast medium administration, based on either enhancement of an abnormality (n = 7) or failure of enhancement (n = 2). Three-dimensional FLASH imaging combined with Gd-DTPA holds promise to develop into a clinically valuable sequence allowing good patient throughput and ability to reconstruction in any plane and sensitivity to abnormalities of the blood-brain barrier or vascularity. However, some problems remain, including motion and susceptibility artifacts, long reconstruction time, and loss of resolution in reconstruction due to anisotropic volume.