PURPOSE: To compare 3.0T and 1.5T MR systems in terms of the effect of superparamagnetic iron oxide (SPIO) on tumor-to-liver contrast in T2*-weighted gradient-echo MRI. MATERIALS AND METHODS: SPIO-enhanced gradient-echo MR images of the liver with four different TEs (3, 5.3, 6.5, and 8.5 msec) were obtained by means of 1.5T and 3.0T systems. Quantitative analyses of relative signal intensities (SIs) and relative tumor contrast and qualitative analyses of image quality and lesion conspicuity of the liver were performed in 22 patients, 16 of whom had malignant liver tumors. RESULTS: With both 1.5T and 3.0T, at TE=8.4 msec, the relative SI of liver and relative tumor contrast were significantly (P<0.01) lower and higher, respectively, than that for any of the other TEs. There were no significant differences in the relative SI of the liver, relative tumor contrast, image quality, and tumor conspicuity for the same TE between the 1.5T and 3.0T systems. CONCLUSION: Our results showed that the effect of SPIO on tumor-to-liver contrast at T2*-weighted gradient-echo imaging was similar for the 1.5T and 3.0T systems, and that the 8.4-msec TE was optimal of the four TEs used in this study at 3.0T. Copyright (c) 2009 Wiley-Liss, Inc.
PURPOSE: To compare 3.0T and 1.5T MR systems in terms of the effect of superparamagnetic iron oxide (SPIO) on tumor-to-liver contrast in T2*-weighted gradient-echo MRI. MATERIALS AND METHODS:SPIO-enhanced gradient-echo MR images of the liver with four different TEs (3, 5.3, 6.5, and 8.5 msec) were obtained by means of 1.5T and 3.0T systems. Quantitative analyses of relative signal intensities (SIs) and relative tumor contrast and qualitative analyses of image quality and lesion conspicuity of the liver were performed in 22 patients, 16 of whom had malignant liver tumors. RESULTS: With both 1.5T and 3.0T, at TE=8.4 msec, the relative SI of liver and relative tumor contrast were significantly (P<0.01) lower and higher, respectively, than that for any of the other TEs. There were no significant differences in the relative SI of the liver, relative tumor contrast, image quality, and tumor conspicuity for the same TE between the 1.5T and 3.0T systems. CONCLUSION: Our results showed that the effect of SPIO on tumor-to-liver contrast at T2*-weighted gradient-echo imaging was similar for the 1.5T and 3.0T systems, and that the 8.4-msec TE was optimal of the four TEs used in this study at 3.0T. Copyright (c) 2009 Wiley-Liss, Inc.