An ultrasonic virtual point detector is constructed using the center of a ring transducer. The
virtual point detector provides ideal omnidirectional detection free of any aperture effect.
Compared with a real point detector, the virtual one has lower thermal noise and can be
scanned with its center inside a physically inaccessible medium. When applied to
photoacoustic tomography, the virtual point detector provides both high spatial resolution
and high signal-to-noise ratio. It can also be potentially applied to other ultrasound-related …