Fast FLAIR of the brain: the range of appearances in normal subjects and its application to quantification of white-matter disease

Abstract

Axial fast FLAIR images of the brains of 40 normal volunteers in four age groups between 16 and 55 years were examined and the number and size of areas of increased white-matter signal recorded. Increased signal in the corticospinal tract region was seen at the level of the internal capsule in all subjects, extending up towards the centrum semiovale and down towards the pons for 0.5-5.5 cm (median 2.5 cm). In all cases the IIIrd and IVth ventricles were outlined by a thin line of high signal. Focal areas of high signal (caps) were seen around the frontal and occipital horns in 90% and 77% respectively; 54% of caps were asymmetrical. None of the above features varied with the age or sex of the subject, but the numbers of discrete white matter 'lesions' increased with age. The findings are used to suggest guidelines for the identification of areas of 'normal' high signal to be excluded in quantification of lesions on fast FLAIR images.

Comparison of 3D FLAIR, 2D FLAIR, and 2D T2-Weighted MR Imaging of Brain Stem Anatomy

“…Our results indicate that 3D FLAIR images delineated white matter tracts with higher contrast than 2D FLAIR images and 2D T2WI. Gawne-Cain et al 9 reported that an increased signal intensity was seen in the CST in healthy volunteers on fast FLAIR images at 1.5T MR imaging. In our study, the CST exhibited the highest contrast on 3D FLAIR compared with 2D FLAIR images and 2D T2WI.…”

A Comparison of 3T and 7T in the Detection of Small Parenchymal Veins Within MS Lesions

“…12 Such lesions are thought to reflect foci of ischemia or infarction which arise because of microangiopathic disease. 13 This study suggests that 7T T 2 * imaging could facilitate the differentiation between MS lesions and small ichaemic WM lesions by demonstrating differences in their vascular anatomy.…”

Reproducibility of quantitative structural and physiological MRI measurements

“…Similarly, periependymal white matter hyperintensity volume was reproducible, but count less so. Pulsation of ventricular cerebrospinal fluid and subject motion may cause artifacts, with partial volume averaging impeding accurate segmentation of small (<1 cm 3 ) periependymal lesions (De Coene et al., 1992; Gawne‐Cain, Silver, Moseley, & Miller, 1997; Kates, Atkinson, & Brant‐Zawadzki, 1996). Subcortical lesions are unaffected by cerebral spinal fluid (CSF) pulsation artifacts and had higher ICC.…”