Applicability and advantages of flow artifact-insensitive fluid-attenuatedinversion-recovery MR sequences for imaging the posterior fossa

We describe a new sequence, flow artifact-insensitive fluid-attenuated inve rsion recovery (FAIS-FLAIR), that capitalizes on the advantages of fluid-at tenuated inversion recovery (FLAIR) while minimizing FLAIR-related artifact s such as those often encountered in the posterior fossa, Twenty eight pati ents with posterior fossa disease underwent PAIS-FLAIR, conventional FLAIR, and spin-echo MR studies, and the findings yielded by the three techniques were compared. In this patient population, postcontrast FAIS-FLAIR imaging was obtained in 20 patients and compared with postcontrast T1-weighted ima ges, The images were assessed for lesion conspicuity by three radiologists. FAIS-FLAIR markedly reduces the inflow artifacts from noninverted CSF on F LAIR images, It does so with and without contrast agent administration, and produces higher lesion conspicuity compared with T1- and T2-weighted spin- echo sequences and conventional FLAIR images of the posterior fossa.