Use of a clinical MRI scanner for preclinical research on rats

This study evaluated the feasibility of imaging rat brains using a human whole-body 3-T magnetic resonance imaging (MRI) scanner with specially developed transmit-and-receive radiofrequency coils. The T(1)- and T(2)-weighted images obtained showed reasonable contrast. Acquired contrast-free time-of-flight magnetic resonance angiography images clearly showed the cortical middle cerebral artery (MCA) branches, and interhemispheric differences could be observed. Dynamic susceptibility contrast MRI at 1.17 mm(3) voxel resolution, performed three times following administration of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA, 0.1 mmol/kg), demonstrated that the arterial input function (AIF) can be obtained from the MCA region, yielding cerebral blood flow (CBF), cerebral blood volume, and mean transit time (MTT) maps. The hypothalamus (HT) to parietal cortex (Pt) CBF ratio was 45.11 +/- 2.85%, and the MTT was 1.29 +/- 0.40 s in the Pt region and 2.32 +/- 0.17 s in the HT region. A single dose of Gd-DTPA enabled the assessment of AIF within MCA territory and of quantitative CBF in rats.