Detection of hemorrhagic hypointense foci in the brain on susceptibility-weighted imaging clinical and phantom studies.
OBJECTIVE
To determine the sensitivity of susceptibility-weighted imaging (SWI) for depicting hemorrhagic hypointense foci of the brain in comparison with gradient-recalled echo (GRE)- and GRE-type single-shot echo-planar imaging (GREI, GRE-EPI), and to assess the basic characteristics of the susceptibility effect by using a phantom.


METHODS
We prospectively examined 16 patients (9 males, 7 females, aged 10-74 years, mean 43 years) with hypointense foci using SWI, GREI, and GRE-EPI at a 1.5-T magnetic resonance (MR) unit. The contrast-to-noise ratio (CNR), sensitivity to small hypointese foci, and artifacts were evaluated. To assess the basic characteristics of SWI, we performed a phantom study using different concentrations of superparamagnetic iron oxide (SPIO).


RESULTS
The CNR of lesions was significantly greater for SWI than the other images (P < .0001). SWI detected the greatest number of small hypointense foci, even in the near-skull-base and infratentorial regions. Quantitative and qualitative analyses in our clinical and phantom studies demonstrated that the degree of artifacts was similar with SWI and GREI.


CONCLUSIONS
SWI was best for detecting small hemorrhagic hypointense foci. Artifacts of SWI were similar to GREI.
Akter
Masuma
M
Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan.
Hirai
Toshinori
T
Hiai
Yasuhiro
Y
Kitajima
Mika
M
Komi
Masanori
M
Murakami
Ryuji
R
Fukuoka
Hirofumi
H
Sasao
Akira
A
Toya
Ryo
R
Haacke
E Mark
EM
Takahashi
Mutsumasa
M
Hirano
Teruyuki
T
Kai
Yutaka
Y
Morioka
Motohiro
M
Hamasaki
Kiyotoshi
K
Kuratsu
Jun-Ichi
J
Yamashita
Yasuyuki
Y
D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology*; D002648:Child; D017352:Echo-Planar Imaging / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D020300:Intracranial Hemorrhages / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity