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 microL in end-diastolic volume, 2.3 +/- 3.1 microL in end-systolic volume, -2.7 +/- 4.3% in ejection fraction, -0.6 +/- 3.3 microL 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.