A 10 MHz ultrasonic system accurately measured myocardial thickening with a resolution of 0.02 mm, comparing favorably with the two-crystal transit-time method in 25 dogs.
A novel single-transducer ultrasonic method accurately measures myocardial thickening with high resolution, offering a valid alternative to transit-time dimension gauges for assessing regional ventricular function.
We have developed a method for measuring myocardial thickening from a single ultrasonic transducer attached to the epicardium. Displacement of the underlying myocardial tissue is measured by following the phase of the echoes within a sample volume range-gated across the myocardium. The output is in the form of an analog signal. To verify the accuracy, resolution, and limitations of the system, we derived the equations relating the position of a reflector to the phase of its echo and compared the system output in vitro to a known input using a single moving target and a random distribution of scatterers, and in vivo to that of an ultrasonic transit-time dimension gauge. The results demonstrate that the 10 MHz system can accurately follow the motion of single or multiple targets with a resolution of 0.02 mm. In 25 dogs myocardial thickening measured with the displacement system compared favorably in both waveform and magnitude with thickening measured by the two-crystal transit-time method. Applications for the displacement method include: quantification of regional ventricular function in animal models of cardiovascular diseases, measurement of endocardial to epicardial differences in the deformation of regional myocardium during the cardiac cycle, and evaluation of regional cardiac function in patients during and after corrective cardiac surgery.
Hartley et al. (Tue,) conducted a other in Myocardial thickening measurement (n=25). Ultrasonic method for measuring tissue displacement (10 MHz system) vs. Two-crystal transit-time method was evaluated on Accuracy and resolution of myocardial thickening measurement. A 10 MHz ultrasonic system accurately measured myocardial thickening with a resolution of 0.02 mm, comparing favorably with the two-crystal transit-time method in 25 dogs.