A brand-new multidimensional linear array probe for medical ultrasound imaging was evaluated. This probe is composed of 192 transducers in a 40mm scanning direction and 6 in the elevational direction. Axial, lateral and elevational resolutions were evaluated. The spatial resolutions of a conventional single-array linear probe, composed of 192 transducers in 40mm directions were also evaluated and compared.
Elevational resolution was measured with a specially ordered phantom consisting of fine parallel stainless-steel wires immersed in a water bath. The wires were placed parallel to the scanning direction of the probe. Elevational resolution was defined as the maximal distance between two parallel wires when both wires were displayed in a single image. The resolution was measured at a depth of 5, 10, 15, 20 and 30mm from the surface of the probe.
Lateral and axial resolutions were measured with a ready made phantom consisting of fine nylon pins at various depths in a tissue mimicking gel. Resolution was defined as the dimensions of the pins in the image.
The multidimensional array probe provided superior elevational resolution near the surface of the probe, and gradually degraded along the probe. The elevational resolution of the single-array probe gradually improved along the probe. Between the two probes, the resolution was reversed at 30mm depth.
The multidimensional array probe consistently provided superior lateral and axial resolutions consistently.
From the point of spatial resolution, the multidimensional array probe has an advantage, especially near the probe.
