Early detection of radiation-induced liver injury in rat by superparamagnetic iron oxide-enhanced MR imaging.
The detectability of early liver injury induced by irradiation was studied using magnetic resonance (MR) imaging enhanced with superparamagnetic iron oxide (SPIO), a tissue-specific contrast agent against the reticuloendothelial system (RES). In rat, 3 days after focal irradiation (0-10 Gy), MR imaging was performed and specimens were obtained to observe the phagocytic function of RES. The irradiated portion of the liver was visualized with a clear demarcation from the nonirradiated part by SPIO-enhanced MR images as a decrease in negative enhancement reflecting the function of RES (P < 0.05), whereas this was impossible with nonenhanced MR images. Significant regression was observed as a dose-related change of the signal intensity in the irradiated portion on SPIO-enhanced MR images (R = 0.867, P < 0.0001). SPIO-enhanced MR imaging was reliable for detecting the range and extent of liver injury a few days after low-dose irradiation, and it may be a useful procedure for verifying the target area in clinical cases of radiation therapy.
Morimoto
N
N
First Department of Medicine, Chiba University School of School of Medicine, Japan. morimoto@ho.chiba-u.ac.jp
Ebara
M
M
Kato
H
H
Obata
T
T
Fujita
J
J
Kondo
F
F
Tsujii
H
H
Saisho
H
H
D000818:Animals; D003287:Contrast Media; D004307:Dose-Response Relationship, Radiation; D005260:Female; D052203:Ferrosoferric Oxide; D007501:Iron; D008099:Liver / Q000293:injuries* / Q000473:pathology / Q000528:radiation effects*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D010087:Oxides; D011833:Radiation Injuries, Experimental / Q000175:diagnosis*; D051381:Rats; D017208:Rats, Wistar; D012044:Regression Analysis; D013997:Time Factors
D003287:Contrast Media; D010087:Oxides; D007501:Iron; D052203:Ferrosoferric Oxide