Results Results Methods Introduction References
Cardiac and Respiratory-Gated Aortic Valve Ultrasound Imaging in Mice 1
ARVIN H. SOEPRIATNA1, PAVLOS P. VLACHOS1,2, CRAIG J. GOERGEN1
Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, USA 2 School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, USA
Results
Introduction End-Diastole
Background
mm
D
C
3
NCC mm
2.64 ± 0.16
Aortic Valve Annulus Area During Diastole (mm2)
2.20 ± 0.16
RCC Area (mm2)
0.59 ± 0.09
LCC Area (mm2)
0.75 ± 0.08 0.85 ± 0.11
Short-Axis
I
…
…
S
Figure 1: (A) Vevo2100 high-frequency small animal ultrasound system (50 MHz, VisualSonics) was used to image the heart of adult C57BL/6 mice (n=4; male 38 ± 14 weeks old). (B) Cardiac and respiratory gated 4D imaging was performed to visualize the dynamics of the left ventricle and the aortic valve leaflets across the cardiac cycle at 1000 frames/second.4
Peak-Systole
S L
R
P
L
1mm
1mm
A
A
S
S P
1mm
R
Parameter
Measured
I
1mm I
Respiration Gating
R
P
End-Diastole
4
Coronal
A
A
…
A
P
Peak-Systole Peak-Systole L I
S R
P
A
L I
Figure 4: 3D renderings of the left ventricular lumen (red) and myocardial wall (blue) at end-diastole and peak-systole.
mm
Long-Axis
ECG R-Peak Delay
Aortic Valve Annulus Area During Systole (mm2)
NCC Area (mm2)
S R
Figure 2: (Left) Representative ultrasound images of a mouse aortic valve during (A) end-diastole and (B) peak-systole with the three aortic leaflets and the aortic orifice highlighted (C,D). RCC: right coronary cusp; LCC: left-coronary cusp; NCC: non-coronary cusp; and AO: aortic orifice. Table 1 (right) summarizes the dimensions of the aortic valve leaflets. Data are shown as mean ± standard deviation.
Methods
1
AO
Measured
C
RC
C
C LC C C R
Use a gated ultrasound imaging technique to capture aortic valve leaflet geometries and dynamics with high spatiotemporal resolution in mice.
2
Parameter
mm
NCC
B
End-Diastole End-Diastole
B
A
Objective
A
Peak-Systole
LC
• Mouse models of valvular diseases are important in pathophysiological studies and in investigating potential therapeutic treatments.1 • Valve imaging in mice is challenging due to their small size and fast heart rates. • Conventional echocardiographic assessment of cardiac valves in mice typically uses high frequency ultrasound with: o Long axis M-mode for annular diameter measurements.2,3 - Limitation: Inability to characterize leaflet geometries. o Long axis Color Doppler for flow quantification.2,3 - Limitation: Insufficient temporal resolution needed to identify location of valve regurgitation.
Results
L P
1mm
R
L I
1mm
Conclusion and Future Work • Cardiac and respiratory-gated ultrasound can be used to visualize the motion of valve leaflets throughout the cardiac cycle in mice.4 • The proposed technique allows for the structural characterization of valve leaflets and left ventricular dynamics. • Future Work: Image murine models of valve diseases to identify impairment in valvular dynamics and characterize effect on LV function, ultimately improving translation of pre-clinical rodent students.
EDV (μL)
41 ± 9
PSV (μL)
13 ± 4
SV (μL)
28 ± 7
Acknowledgements
EF (%)
68 ± 6
This project was supported by the AHA (14SDG18220010) and Purdue University. The authors have no conflicts of interest to disclose.
CO (mL/min)
14 ± 3
Figure 3: (Left) Segmentation of a 3D data set at end-diastole and peak-systole showing the left ventricular lumen (red) and myocardial wall (blue). Table 2 (right) summarizes the volumes and function of the left ventricle. EDV: end-diastolic volume; PSV: peak-systolic volume; SV: stroke volume; EF: ejection fraction; and CO: cardiac output. Data are shown as mean ± standard deviation.
References [1] Roosens, B et al., Int J Cardiol, 165(3):398-409, 2013. [2] Hinton, R et al., Am J Physiol Heart Circ Physiol, 294(6):H2480-8, 2008. [3] Miller, J et al., Circ Res, 108(11):1392-412, 2011. [4] Damen, F et al., Under review.
ARVIN H. SOEPRIATNA1, PAVLOS P. VLACHOS1,2, CRAIG J. GOERGEN1
Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, USA 2 School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, USA
Results
Introduction End-Diastole
Background
mm
D
C
3
NCC mm
2.64 ± 0.16
Aortic Valve Annulus Area During Diastole (mm2)
2.20 ± 0.16
RCC Area (mm2)
0.59 ± 0.09
LCC Area (mm2)
0.75 ± 0.08 0.85 ± 0.11
Short-Axis
I
…
…
S
Figure 1: (A) Vevo2100 high-frequency small animal ultrasound system (50 MHz, VisualSonics) was used to image the heart of adult C57BL/6 mice (n=4; male 38 ± 14 weeks old). (B) Cardiac and respiratory gated 4D imaging was performed to visualize the dynamics of the left ventricle and the aortic valve leaflets across the cardiac cycle at 1000 frames/second.4
Peak-Systole
S L
R
P
L
1mm
1mm
A
A
S
S P
1mm
R
Parameter
Measured
I
1mm I
Respiration Gating
R
P
End-Diastole
4
Coronal
A
A
…
A
P
Peak-Systole Peak-Systole L I
S R
P
A
L I
Figure 4: 3D renderings of the left ventricular lumen (red) and myocardial wall (blue) at end-diastole and peak-systole.
mm
Long-Axis
ECG R-Peak Delay
Aortic Valve Annulus Area During Systole (mm2)
NCC Area (mm2)
S R
Figure 2: (Left) Representative ultrasound images of a mouse aortic valve during (A) end-diastole and (B) peak-systole with the three aortic leaflets and the aortic orifice highlighted (C,D). RCC: right coronary cusp; LCC: left-coronary cusp; NCC: non-coronary cusp; and AO: aortic orifice. Table 1 (right) summarizes the dimensions of the aortic valve leaflets. Data are shown as mean ± standard deviation.
Methods
1
AO
Measured
C
RC
C
C LC C C R
Use a gated ultrasound imaging technique to capture aortic valve leaflet geometries and dynamics with high spatiotemporal resolution in mice.
2
Parameter
mm
NCC
B
End-Diastole End-Diastole
B
A
Objective
A
Peak-Systole
LC
• Mouse models of valvular diseases are important in pathophysiological studies and in investigating potential therapeutic treatments.1 • Valve imaging in mice is challenging due to their small size and fast heart rates. • Conventional echocardiographic assessment of cardiac valves in mice typically uses high frequency ultrasound with: o Long axis M-mode for annular diameter measurements.2,3 - Limitation: Inability to characterize leaflet geometries. o Long axis Color Doppler for flow quantification.2,3 - Limitation: Insufficient temporal resolution needed to identify location of valve regurgitation.
Results
L P
1mm
R
L I
1mm
Conclusion and Future Work • Cardiac and respiratory-gated ultrasound can be used to visualize the motion of valve leaflets throughout the cardiac cycle in mice.4 • The proposed technique allows for the structural characterization of valve leaflets and left ventricular dynamics. • Future Work: Image murine models of valve diseases to identify impairment in valvular dynamics and characterize effect on LV function, ultimately improving translation of pre-clinical rodent students.
EDV (μL)
41 ± 9
PSV (μL)
13 ± 4
SV (μL)
28 ± 7
Acknowledgements
EF (%)
68 ± 6
This project was supported by the AHA (14SDG18220010) and Purdue University. The authors have no conflicts of interest to disclose.
CO (mL/min)
14 ± 3
Figure 3: (Left) Segmentation of a 3D data set at end-diastole and peak-systole showing the left ventricular lumen (red) and myocardial wall (blue). Table 2 (right) summarizes the volumes and function of the left ventricle. EDV: end-diastolic volume; PSV: peak-systolic volume; SV: stroke volume; EF: ejection fraction; and CO: cardiac output. Data are shown as mean ± standard deviation.
References [1] Roosens, B et al., Int J Cardiol, 165(3):398-409, 2013. [2] Hinton, R et al., Am J Physiol Heart Circ Physiol, 294(6):H2480-8, 2008. [3] Miller, J et al., Circ Res, 108(11):1392-412, 2011. [4] Damen, F et al., Under review.
