Comparison of contrast-enhanced T1-weighted FLAIR with BLADE, and spin-echo T1-weighted sequences in intracranial MRI

PURPOSE We compared periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER, BLADE) MR technique with spin echo (SE) technique for evaluation of artifacts, and detection and delineation of brain lesions. MATERIALS AND METHODS Contrast-enhanced T1-weighted fluid attenuated inversion recovery (FLAIR) images with BLADE technique (CE T1W-FLAIR BLADE) and contrast-enhanced T1-weighted SE (CE T1W-SE) were performed in 50 patients with intracranial enhancing lesions. These techniques were compared by two neuroradiologists for qualitative analysis of artifacts, lesion detectability, lesion delineation from adjacent structures, and preferred imaging technique; and for quantitative variables, i.e., lesion-to-background and lesion-to-cerebrospinal fluid (CSF) contrast-to-noise (CNR) ratios. Reader agreement was assessed by kappa statistics. RESULTS All lesions depicted with the CE T1W-SE were also detected with the CE T1W-FLAIR BLADE technique. Delineation of lesions was better on CE T1W-FLAIR BLADE in the majority of patients. Flow-related artifacts were considerably reduced with CE T1W-FLAIR BLADE. A star-like artifact at the level of the 4(th) ventricle was noted on CE T1W-FLAIR BLADE but not on CE T1W-SE. The lesion-to-background CNR and lesion-to-CSF CNR did not show a statistically significant difference between the two techniques. CE T1W-FLAIR BLADE images were preferred by the observers over the CE T1 w-SE images, indicating good interobserver agreement (k = 0.70). CONCLUSION CET1W-FLAIR BLADE-technique is superior to CE T1W-SE for delineation of lesions and reduction of flow-related artifacts, especially within the posterior fossa, and is preferred by readers. CE T1 W-FLAIR BLADE may be an alternative approach to imaging, especially for posterior fossa lesions.