Published in:
01-12-2014 | Research Article
Delayed hepatic signal recovery on ferucarbotran-enhanced magnetic resonance images in a rat model with regional liver irradiation
Authors:
Toshihiro Furuta, Masayuki Yamaguchi, Ryutaro Nakagami, Masaaki Akahane, Manabu Minami, Kuni Ohtomo, Hirofumi Fujii
Published in:
Magnetic Resonance Materials in Physics, Biology and Medicine
|
Issue 6/2014
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Abstract
Object
To determine whether superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging could demonstrate signal recovery delay in irradiated areas of rat livers. We also investigated the relationship between MR imaging and histological findings.
Materials and methods
Twelve rats received 20 μmol iron/kg of SPIO followed by X-irradiation to the right upper abdomen 4 h later. Radiation doses were 0, 50 and 70 Gy. Hepatic signals were assessed on unenhanced T
2
*
-weighted images for up to 7 days using a 9.4-Tesla scanner. The livers were excised on day 7 and examined histologically.
Results
Normalized relative signal intensity of 70 Gy-irradiated right liver lobe (2.36 ± 0.22) and 50 Gy-irradiated right liver lobe (2.37 ± 0.46) was significantly lower than that of the non-irradiated right liver lobe (4.04 ± 0.28) on day 7, respectively (p < 0.05). Pearson product-moment correlation coefficient between relative intensity of the liver and the number of hepatic iron deposits was −0.588 (p < 0.01).
Conclusion
Superparamagnetic iron oxide-enhanced MR imaging could demonstrate signal recovery delay in irradiated areas of rat livers. It seems that the signal recovery delay in irradiated areas was due to SPIO-derived iron deposition. Hepatic signal recovery could be a novel diagnostic marker for delineation of irradiated areas.