Influence of imaging parameters on high-intensity cerebrospinal fluid artifacts in fast-FLAIR MR imaging.
OBJECTIVE
High-intensity CSF artifacts at the basal cisterns on MR images are often seen when a fast fluid-attenuated inversion recovery (FLAIR) technique is used. We investigated the influences of four optional fast-FLAIR sequence parameters on the high-intensity CSF artifacts.


METHODS
A total of 377 patients (age range, 1 week to 91 years; mean 40.6 years; 186 female, 191 male) were examined with axial fast-FLAIR images obtained (TR/TE(eff)/TI, 8800/133/2200) with a 1.5-T system during 6 months. The effects of the optional addition of inferior inflow saturation (thickness, 80 mm), section flow compensation, and tailored radiofrequency (TRF) pulses, plus the choice of interleaving acquisition factors of 2 or 3, were evaluated for the presence of high-intensity CSF artifacts on the fast-FLAIR images. Two radiologists independently reviewed the fast-FLAIR images in 76 patients; afterward, a single observer reviewed the remainder of the images.


RESULTS
The interobserver agreement rate in 76 cases was more than 90%. The use of TRF and/or three interleaving acquisitions resulted in a substantial reduction in the incidence of high-intensity CSF artifacts from about 80% to 40% (P <.05, two-sample two-sided Z test). Inferior inflow saturation and section flow compensation did not significantly improve image quality (P >.05). The results were consistent with the image quality ranking obtained in five healthy volunteers.


CONCLUSIONS
The appropriate choice of sequence parameters in fast-FLAIR imaging reduces the incidence of high-intensity CSF artifacts that are frequently encountered in the presence of rapid CSF flow.
Wu
Hsiu-Mei
HM
Department of Radiology, Johns Hopkins University, Baltimore, MD, USA.
Yousem
David M
DM
Chung
Hsiao-Wen
HW
Guo
Wan-Yuo
WY
Chang
Cheng-Yen
CY
Chen
Cheng-Yu
CY
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D001921:Brain / Q000473:pathology; D002555:Cerebrospinal Fluid; D002648:Child; D002675:Child, Preschool; D002946:Cisterna Magna; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation