The acute myocardial infarction(AMI) is the most frequent cause of death in the population of western countries. AMI has been mimicked in a variety of animal models and the murine model of AMI has been extensively studied as a means of clarifying changes associated with ischemic heart disease, and testing the effectiveness of new therapies[1]. The aim of this study was to test the feasibility of using cine MRI acquired with retrospective gating to quantify global and regional left ventricle function in mice with AMI. AMI was induced in mice(n=30) by left anterior descendent coronary ligation; 10 sham mice constituted the control group. All the mice were imaged 9 days after the surgery. Cine images were obtained using a 4.7T scanner(Bruker AvanceII) with retrospective gating(IntraGate). Whole left ventricle(LV) was acquired in contiguous short axial slices and in each image LV endocardium was detected and divided into 6 sectors. For each sector, regional fractional area change(RFAC) and LV thickness were computed and used as indices of regional wall motion and function[2]. To allow the easy visualization of the results of regional LV wall motion and wall thickness of the entire ventricle in a single image, the RFAC and LV thickness were displayed in a bull’s eye format(Figure 1). Global LV end-diastolic volume, end-systolic volume and stroke volume, the ejection fraction and LV mass were also calculated (Table 1). The LV was larger in the myocardial infarcted mice, which showed a decreased ejection fraction, peak filling and peak ejection rates, and increased mass. RFAC and LV thickness progressively decreased from base to apex in the infarcted mice, being least in the anterior and antero-septal sectors, in line with the occlusion. In conclusion, cine MRI with retrospective gating reduces acquisition times and trigger-related problems in studies of AMI. Regional LV function analysis by bull’s eye is a feasible and immediate methods allowing the localization of the effects of the induced infarction and may therefore be used in pre- and post-treatment studies. Figure 1: Bull’s eye representations of mean RFAC (left) and mean LV wall thickness (right) in the control and AMI mice. The slices from the LV apex to base are shown from the inner to the outer circle. The red and the green tones indicate lower and higher values, respectively: the corresponding scales are shown as colour bars beside the panels. Table 1: Global LV parameters in control and AMI group (EDV: end-diastolic volume; ESV: end-systolic volume; SV: stroke volume; EF: ejection fraction). *: p<.05 (unpaired t-test). Control AMI EDV (μl) 36±4 92±25* ESV (μl) SV (μl) EF (μl) LV mass (mg) 10±3 26±3 72±7 77±8 66±27* 26±4 31±10* 96±23* References [1] L. Monassier, A. Constantinesco, Standards of mouse model phenotyping. Edited by De Agelis MH, Chambon P, Brown S. Wiley VCH, Weinheim, 2006. [2] E.G. Caiani, E. Toledo, P. MacEneaney, D. Bardo, S. Cerutti, R.M. Lang, V. Mor-Avi Automated interpretation of regional left ventricular wall motion from cardiac magnetic resonance imaging. Journal of Cardiovascular Magnetic Resonance, 8, 427-433, 2006

Feasibility of quantitative analysis of regional left ventricular function in the post-infarct mouse by magnetic resonance imaging with retrospective gating / M. Franzosi, U. Guerrini, L. Castiglioni, L. Sironi, E. Nobili, E. Tremoli, E.G. Caiani. ((Intervento presentato al convegno Next step : la giovane ricerca avanza tenutosi a Milano nel 2010.

Feasibility of quantitative analysis of regional left ventricular function in the post-infarct mouse by magnetic resonance imaging with retrospective gating

M. Franzosi
Primo
;
U. Guerrini
Secondo
;
L. Castiglioni;L. Sironi;E. Nobili;E. Tremoli
Penultimo
;
2010

Abstract

The acute myocardial infarction(AMI) is the most frequent cause of death in the population of western countries. AMI has been mimicked in a variety of animal models and the murine model of AMI has been extensively studied as a means of clarifying changes associated with ischemic heart disease, and testing the effectiveness of new therapies[1]. The aim of this study was to test the feasibility of using cine MRI acquired with retrospective gating to quantify global and regional left ventricle function in mice with AMI. AMI was induced in mice(n=30) by left anterior descendent coronary ligation; 10 sham mice constituted the control group. All the mice were imaged 9 days after the surgery. Cine images were obtained using a 4.7T scanner(Bruker AvanceII) with retrospective gating(IntraGate). Whole left ventricle(LV) was acquired in contiguous short axial slices and in each image LV endocardium was detected and divided into 6 sectors. For each sector, regional fractional area change(RFAC) and LV thickness were computed and used as indices of regional wall motion and function[2]. To allow the easy visualization of the results of regional LV wall motion and wall thickness of the entire ventricle in a single image, the RFAC and LV thickness were displayed in a bull’s eye format(Figure 1). Global LV end-diastolic volume, end-systolic volume and stroke volume, the ejection fraction and LV mass were also calculated (Table 1). The LV was larger in the myocardial infarcted mice, which showed a decreased ejection fraction, peak filling and peak ejection rates, and increased mass. RFAC and LV thickness progressively decreased from base to apex in the infarcted mice, being least in the anterior and antero-septal sectors, in line with the occlusion. In conclusion, cine MRI with retrospective gating reduces acquisition times and trigger-related problems in studies of AMI. Regional LV function analysis by bull’s eye is a feasible and immediate methods allowing the localization of the effects of the induced infarction and may therefore be used in pre- and post-treatment studies. Figure 1: Bull’s eye representations of mean RFAC (left) and mean LV wall thickness (right) in the control and AMI mice. The slices from the LV apex to base are shown from the inner to the outer circle. The red and the green tones indicate lower and higher values, respectively: the corresponding scales are shown as colour bars beside the panels. Table 1: Global LV parameters in control and AMI group (EDV: end-diastolic volume; ESV: end-systolic volume; SV: stroke volume; EF: ejection fraction). *: p<.05 (unpaired t-test). Control AMI EDV (μl) 36±4 92±25* ESV (μl) SV (μl) EF (μl) LV mass (mg) 10±3 26±3 72±7 77±8 66±27* 26±4 31±10* 96±23* References [1] L. Monassier, A. Constantinesco, Standards of mouse model phenotyping. Edited by De Agelis MH, Chambon P, Brown S. Wiley VCH, Weinheim, 2006. [2] E.G. Caiani, E. Toledo, P. MacEneaney, D. Bardo, S. Cerutti, R.M. Lang, V. Mor-Avi Automated interpretation of regional left ventricular wall motion from cardiac magnetic resonance imaging. Journal of Cardiovascular Magnetic Resonance, 8, 427-433, 2006
magnetic resonance imaging; myocardial infarction; retrospective gating
Settore BIO/14 - Farmacologia
Università degli Studi di Milano
Feasibility of quantitative analysis of regional left ventricular function in the post-infarct mouse by magnetic resonance imaging with retrospective gating / M. Franzosi, U. Guerrini, L. Castiglioni, L. Sironi, E. Nobili, E. Tremoli, E.G. Caiani. ((Intervento presentato al convegno Next step : la giovane ricerca avanza tenutosi a Milano nel 2010.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/167636
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