In Cardiac Ultrasound

The use of ultrasound for cardiac imaging and investigation of hemodynamics has been revolutionary in the diagnosis and treatment of heart disease. Currently, ultrasound techniques available for use on a limited clinical or investigational basis include intravascular ultrasound, 3D and 4D imaging, and embryonic cardiac imaging. Intravascular ultrasound uses catheters with ultrasound transducers mounted on the tips. These transducers are capable of cross-sectional imaging or true sector imaging using phased-array ultrasound transducers mounted on their tips (3,14).

As technology has improved, relatively small catheters and high-frequency transducers are available for imaging of the aorta and pulmonary arteries, aortic and pulmonary valves, and coronary arteries. Coronary artery imaging has been particularly useful in heart transplant patients as a means to detect intimal thickening associated with chronic rejection (15) and in patients with Kawasaki syndrome who develop coronary artery aneurysms (3). Intravascular ultrasound has also been used for intracardiac monitoring of interventional procedures (14).

Three-dimensional imaging technology has been improved so that cardiac images can be displayed in real time (called 4D imaging). Three- and 4D images are useful for creation of a movable 3D image to assist with surgical planning (1).

Cardiac Motion Quantification

Fig. 4. Two-dimensional and motion-mode (M-mode) images obtained from parasternal short-axis views. (A) View through the base of the heart in diastole. (B) Same imaging plane in systole with the pulmonary valve open. M-mode measurements of the right ventricle, aorta, and left atrium (E) are obtained in this plane. (C) Cross-sectional or short-axis view of the left ventricle at the level of the papillary muscles in diastole. (D) Same plane in systole. This is the appropriate level for quantification of left ventricular function by shortening fraction. (F) M-mode recording at the level of the mitral valve, a plane just above that seen in C and D. Abnormalities of mitral valve motion can be demonstrated in this plane. Ao, aorta; D, diastole; IVS, = interventricular septum; LA, left atrium; LV, left ventricle; LV, left ventricle, diastole; LVS, left ventricle, systole; PA, main pulmonary artery; RA, right atrium; RV, right ventricle; S, systole.

Fig. 4. Two-dimensional and motion-mode (M-mode) images obtained from parasternal short-axis views. (A) View through the base of the heart in diastole. (B) Same imaging plane in systole with the pulmonary valve open. M-mode measurements of the right ventricle, aorta, and left atrium (E) are obtained in this plane. (C) Cross-sectional or short-axis view of the left ventricle at the level of the papillary muscles in diastole. (D) Same plane in systole. This is the appropriate level for quantification of left ventricular function by shortening fraction. (F) M-mode recording at the level of the mitral valve, a plane just above that seen in C and D. Abnormalities of mitral valve motion can be demonstrated in this plane. Ao, aorta; D, diastole; IVS, = interventricular septum; LA, left atrium; LV, left ventricle; LV, left ventricle, diastole; LVS, left ventricle, systole; PA, main pulmonary artery; RA, right atrium; RV, right ventricle; S, systole.

Right Ventricle Dimensions

Fig. 5. (A) Two-dimensional apical four-chamber view of the heart in diastole (open mitral valve). (B) Same imaging plane in systole (closed atrioventricular valves). The pulsed wave Doppler tracing (C) demonstrates mitral inflow toward the transducer (above the baseline) and aortic outflow away from the transducer (below the baseline). The mitral valve inflow tracing shows passive filling of the left ventricle during early diastole (E) followed by active filling of the left ventricle in late diastole with the onset of atrial contraction (A). Aortic outflow occurs in systole. LA, left atrium; LV, left ventricle; MV, mitral valve; RA, right atrium; RV, right ventricle.

Fig. 5. (A) Two-dimensional apical four-chamber view of the heart in diastole (open mitral valve). (B) Same imaging plane in systole (closed atrioventricular valves). The pulsed wave Doppler tracing (C) demonstrates mitral inflow toward the transducer (above the baseline) and aortic outflow away from the transducer (below the baseline). The mitral valve inflow tracing shows passive filling of the left ventricle during early diastole (E) followed by active filling of the left ventricle in late diastole with the onset of atrial contraction (A). Aortic outflow occurs in systole. LA, left atrium; LV, left ventricle; MV, mitral valve; RA, right atrium; RV, right ventricle.

Unfortunately, to date available large transducer sizes and slow image processing capabilities make 3D and 4D imaging inappropriate for routine cardiac ultrasound examinations (7).

Last, ultrasound imaging technology has been improved so that the heart can be studied during embryonic development. For example, pregnant mice can be anesthetized and undergo fetal cardiac imaging as early as 8-9 d after conception so that the anatomy and blood flow patterns can be observed during both normal and abnormal cardiac development (16-18).

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Responses

  • Magnus
    What is 3D multi plane reconstruction of the heart in ultrasound?
    3 years ago

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