Early detection of precancerous tissue has significantly improved survival of most
cancers including
colorectal cancer (CRC). Animal models designed to study the early stages of
cancer are valuable for identifying molecular events and response indicators that correlate with the onset of disease. The goal of this work was to investigate magnetic resonance (MR) colonography in a mouse model of CRC on a clinical MR imager. Mice treated with
azoxymethane and
dextran sulfate sodium were imaged by serial MR colonography (MRC) from initiation to
euthanasia. Magnetic resonance colonography was obtained with both T1- and T2-weighted images after administration of a
Fluorinert enema to remove residual
luminal signal and intravenous contrast to enhance the colon wall. Individual
tumor volumes were calculated and validated ex vivo. The
Fluorinert enema provided a clear differentiation of the lumen of the colon from the mucosal lining.
Inflammation was detected 3 days after
dextran sulfate sodium exposure and subsided during the next week.
Tumors as small as 1.2 mm(3) were detected and as early as 29 days after initiation. Individual
tumor growths were followed over time, and
tumor volumes were measured by MR imaging correlated with volumes measured ex vivo. The use of a
Fluorinert enema during MRC in mice is critical for differentiating mural processes from intraluminal debris. Magnetic resonance colonography with
Fluorinert enema and intravenous contrast enhancement will be useful in the study of the initial stages of
colon cancer and will reduce the number of animals needed for preclinical trials of prevention or intervention.