Air microbubbles as MR susceptibility contrast agent at 1.5 Tesla.
Air microbubbles have been investigated recently at high magnetic field strength (2 Tesla or greater) as potential MR susceptibility contrast agents. We used a phantom to measure their susceptibility at 1.5 T to clarify their usefulness for this purpose. The phantom, filled with fresh Levovist suspension at 4 different doses (67 to 125 mg/mL), was continuously scanned with a gradient-echo technique at a temporal resolution of 10 s. The transverse relaxation increase (R2*) by microbubbles demonstrated a time course of exponential decay at each dose (time-constant, 39 to 57 s). The dependency of R2* on microbubble volume fraction was linear, with a slope of 89 s-1 per percentage microbubble volume fraction. Our study represents the first step towards applying microbubbles as susceptibility contrast agents at 1.5 T.
Ueguchi
Takashi
T
Department of Radiology, Osaka University Hospital, Japan. ueguchi@hp-rad.med.osaka-u.ac.jp
Tanaka
Yuko
Y
Hamada
Seiki
S
Kawamoto
Risa
R
Ogata
Yuji
Y
Matsumoto
Mitsuhiro
M
Nakamura
Hironobu
H
Johkoh
Takeshi
T
D000388:Air; D003287:Contrast Media; D008279:Magnetic Resonance Imaging / Q000379:methods*; D045423:Microbubbles; D019047:Phantoms, Imaging; D011134:Polysaccharides
D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508