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Selective Imaging of Malignant Ascites in a Mouse Model of Peritoneal Metastasis Using in Vivo Dynamic Nuclear Polarization-Magnetic Resonance Imaging
journal contribution
posted on 2016-02-09, 16:42 authored by Hinako Eto, Fuminori Hyodo, Kenji Nakano, Hideo UtsumiThe
presence of malignant ascites in advanced cancer patients is associated
with both a poor prognosis and quality of life with a risk of abdominal
infection and sepsis. Contemporary noninvasive visualization methods
such as ultrasound, computed tomography, and magnetic resonance imaging
(MRI) often struggle to differentiate malignant ascites from surrounding
tissues. This study aimed to determine the utility of selective H2O imaging in the abdominal cavity with a free radical probe
and deuterium oxide (D2O) contrast agent using in vivo dynamic nuclear polarization-MRI (DNP-MRI). Phantom
imaging experiments established a linear relationship between H2O volume and image intensity using in vivo DNP-MRI. Similar results were obtained when the radical-D2O probe was used to determine selective and spatial information on
H2O in vivo, modeled by the injection
of saline into the abdominal cavity of mice. To demonstrate the utility
of this method for disease, malignant ascites in peritoneal metastasis
animal model was selected as one of the typical examples. In vivo DNP-MRI of peritoneal metastasis animal model was
performed 7–21 days after intraperitoneal injection of luciferase,
stably expressing the human pancreatic carcinoma (SUIT-2). The image
intensity with increasing malignant ascites was significantly increased
at days 7, 16, and 21. This increase corresponded to in vivo tumor progression, as measured by bioluminescent imaging. These
results suggest that H2O signal enhancement in DNP-MRI
using radical-D2O contrast is positively associated with
the progression of dissemination and could be a useful biomarker for
malignant ascites with cancer metastasis.