Below, a comparison of the parasternal long-axis view using the P8-4 phased array probe at 5.7MHz (fundamental frequency), then with tissue harmonic imaging turned on at 6.2MHz and 7.2MHz, and finally, with the 11M3 microconvex probe at 6.2MHz (fundamental).

Phased array, 5.7MHz (fundamental)

Phased array, 6.2MHz (harmonics)

Phased array, 7.2MHz (harmonics)

Microconvex, 6.2MHz (fundamental)

Apical view: phased array vs microconvex

As you can see, for basic cardiac screening, the microconvex probe is more than capable. The problem comes with colour Doppler is needed.

Phased array vs microconvex probe in Colour Doppler mode

For cardiology, the microconvex probe just cannot deliver any useful information on blood flow within the heart when colour Doppler is activated. When used on an application for which it is designed, however, the performance is exceptional. In the video below, colour Doppler is activated in ‘low flow’ mode over the kidney:

Here, power Doppler has been activated: