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 Ϯ 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 Ϯ 5.8 mg in mass, 1.7 Ϯ 3.2 L in enddiastolic volume, 2.3 Ϯ 3.1 L in end-systolic volume, Ϫ2.7 Ϯ 4.3% in ejection fraction, Ϫ0.6 Ϯ 3.3 L in stroke volume, and Ϫ0.31 Ϯ 1.56 ml ⅐ min Ϫ1 in cardiac output (mean difference Ϯ SD of differences, n ϭ 24). The average time taken was 8.0 Ϯ 2.5 minutes for 3D GPM and 48.5 Ϯ 8.9 minutes for standard analysis (n ϭ 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.

<em>In Vivo</em> Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

“…Earlier MicroCT studies confirmed that quantitative evaluation of global cardiac function is feasible in murine cardiovascular disease models and that pronounced decrease in global heart function takes place soon after LAD artery occlusion. These findings are in agreement with previous reports in that marked reduction in LVSV, LVEF, and CO occurred already on day 1 after occlusion 29,[40][41][42][43] . It is noteworthy to mention that cardiac functional performance is dependent on the type and degree of anesthesia, thus for accurate measurements the heart rate during image acquisition should be kept as physiological as possible 44 .…”

Long-Term Left Ventricular Remodelling in Rat Model of Nonreperfused Myocardial Infarction: Sequential MR Imaging Using a 3T Clinical Scanner

“…The analysis time in our study (25 ± 5 minutes) was longer than previously reported values (10 and 8 minutes) using other SASS [42, 43]. Nevertheless, these studies conducted cardiac analysis in mouse heart, thus the number of slices covering the whole heart with the same slice thickness was lower.…”

Accelerating global left-ventricular function assessment in mice using reduced slice acquisition and three-dimensional guide-point modelling

“…Mice were given subcutaneous buprenorphine (0.8 mg/kg) for pain relief. Six control (male, 26.2 ± 1.1 g) and five mice with 8 weeks old myocardial infarction (female, 24.8 ± 2.2 g) were subjected to CMR (data from full slice analysis of the control mice have been reported previously [6]).…”

“…The total imaging time required for the evaluation of LV mass and volume therefore represents a major bottleneck for high throughput evaluation of mouse models. Recently, three-dimensional (3D) guide point modeling (GPM) has been shown to achieve fast evaluation of LV mass and volumes in normal mice [6]. This method enables a 3D geometric model of the LV to be interactively customized to the geometry and motion of the particular animal.…”