Fast left ventricular mass and volume assessment in mice with three-dimensional guide-point modeling

Abstract

Purpose To investigate the accuracy (vs. standard manual analysis) and precision (scan–rescan reproducibility) of three-dimensional guide-point modeling (GPM) for the assessment of left ventricular (LV) function in mice. Methods Six male wildtype C57/Bl6 mice (weight 26.2 ± 1.1 g) were scanned twice, 3 days apart. Each scan was performed twice, at 0.2 mm/pixel with one average and at 0.1 mm/pixel with two averages. The 24 studies were anonymized and analyzed in blinded fashion using GPM and standard manual slice summation. Results The average error between GPM and standard analysis was 2.3 ± 5.8 mg in mass, 1.7 ± 3.2 μL in end-diastolic volume, 2.3 ± 3.1 μL in end-systolic volume, −2.7 ± 4.3% in ejection fraction, −0.6 ± 3.3 μL in stroke volume, and −0.31 ± 1.56 ml · min−1 in cardiac output (mean difference ± SD of differences, n = 24). The average time taken was 8.0 ± 2.5 minutes for 3D GPM and 48.5 ± 8.9 minutes for standard analysis (n = 24). Scan–rescan reproducibility results were similar to the standard analysis. No significant differences were found using linear mixed effects modeling in either accuracy or precision between scan resolutions or analysis method. Conclusion 3D GPM enables fast analysis of mouse LV function, with similar accuracy and reproducibility to standard analysis. An image resolution of 0.2 mm/pixel with one average is adequate for LV function studies. J. Magn. Reson. Imaging 2009.