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摘要
Using ultra-high-field contrast-enhanced magnetic resonance imaging (MRI), an increase of field strength is associated with a decrease of T (1) relaxivity. Yet, the impact of this effect on signal characteristics and contrast-enhanced pathology remains unclear. Hence, we evaluated the potential of a 17.6-T MRI to assess contrast-enhancing parts of experimentally induced rat gliomas compared to 3 T. %26lt;br%26gt;A total of eight tumor-bearing rats were used for MRI assessments either at 17.6 T (four rats) or at 3 T (four rats) at 11 days after stereotactic implantation of F98 glioma cells into the right frontal lobe. T (1)-weighted sequences were used to investigate signal-to-noise-ratios, contrast-to-noise-ratios, and relative contrast enhancement up to 16 min after double-dose contrast application. In addition, tumor volumes were calculated and compared to histology. %26lt;br%26gt;The 17.6-T-derived contrast-enhancing volumes were 31.5 +/- 15.4 mm(3) at 4 min, 38.8 +/- 12.7 mm(3) at 8 min, 51.1 +/- 12.6 mm(3) at 12 min, and 61.5 +/- 10.8 mm(3) at 16 min after gadobutrol injection. Corresponding histology-derived volumes were clearly higher (138.8 +/- 8.4 mm(3); P %26lt; 0.01). At 3 T, contrast-enhancing volumes were 85.2 +/- 11.7 mm(3) at 4 min, 107.3 +/- 11.0 mm(3) at 8 min, 117.0 +/- 10.5 mm(3) at 12 min, and 129.1 +/- 10.0 mm(3) at 16 min after contrast agent application. Averaged histology-derived volumes (139.1 +/- 13.4 mm(3)) in this group were comparable to the 16-min volume (P (a dagger%26quot;16 min) = 0.38). Compared to ultra-high-field MRI, all 3-T-derived volumes were significantly higher (P %26lt; 0.02). %26lt;br%26gt;Compared to 3-T-derived images and histology, tumor volumes were underestimated by approximately 50 % at 17.6 T. Hence, contrast-enhanced 17.6-T MRI provided no further benefits in tumor measurement compared to 3 T.
- 出版日期2013-6
