Comparison of magnetic resonance imaging sequences with computed tomography to detect low-grade subarachnoid hemorrhage: Role of fluid-attenuated inversion recovery sequence.
OBJECTIVE
To compare computed tomography (CT) with magnetic resonance imaging (MRI) for the presumptive diagnosis and localization of acute and subacute low-grade subarachnoid hemorrhage (SAH).


METHODS
We consecutively enrolled 45 patients clinically suspected of low-grade SAH, comparing them with a control group. We obtained axial nonenhanced CT scans as well as fluid-attenuated inversion recovery (FLAIR) and T2-weighted gradient echo (T2*) MRI sequences at 1.0 T. Two neuroradiologists scrutinized the presence of blood at 26 different regions in the intracranial subarachnoid space (SAS).


RESULTS
Three of 45 patients had normal CT and MRI scans, and SAH was excluded by lumbar puncture. We demonstrated SAH on CT scans in 28 of 42 (66.6%) patients, T2* sequences in 15 of 42 (35.7%) patients, and FLAIR sequences in 42 of 42 (100%) patients. Fluid-attenuated inversion recovery sequences were superior to CT in 16 of the 26 evaluated regions.


CONCLUSIONS
The FLAIR sequence was superior for presumptive diagnosis and localization of acute and subacute low-grade SAH, representing a potential tool in this setting.
da Rocha
Antônio José
AJ
Section of Radiology, Santa Casa de Misericórdia de São Paulo, São Paulo, Brazil.
da Silva
Carlos Jorge
CJ
Gama
Hugo Pereira Pinto
HP
Baccin
Carlos Eduardo
CE
Braga
Flávio Túlio
FT
Cesare
Fabiane de Araújo
Fde A
Veiga
José Carlos Esteves
JC
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed