Effect of T1 relaxation time on lesion contrast enhancement in flair MR imaging: a study using computer-generated brain maps.
OBJECTIVE
Using computer-generated brain maps, we aimed to define T1 relaxation time thresholds above which a T2 hyperintense (compared with surrounding white matter) lesion became hypointense on fluid-attenuated inversion recovery (FLAIR) MR imaging. Thresholds were identified for FLAIR MR imaging sequences with different echo times (TEs).


CONCLUSIONS
Thresholds for T1 relaxation times increased as TE increased during FLAIR MR imaging sequences. Such thresholds defined the transition from hyperintense to hypointense lesions.
Melhem
E R
ER
Department of Radiology and Radiological Sciences, The Johns Hopkins Hospital, The Johns Hopkins Medical Institutions, 600 N. Wolfe St., Baltimore, MD 21287-2182, USA.
Itoh
R
R
D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D013997:Time Factors