Streak artifact suppression in photoacoustic computed tomography using adaptive back projection.

For photoacoustic computed tomography (PACT), an insufficient number of ultrasound detectors can cause serious streak-type artifacts. These artifacts get overlaid on top of image features, and thus locally jeopardize image quality and resolution. Here, a reconstruction algorithm, termed Contamination-Tracing Back-Projection (CTBP), is proposed for the mitigation of streak-type artifacts. During reconstruction, CTBP adaptively adjusts the back-projection weight, whose value is determined by the likelihood of contamination, to minimize the negative influences of strong absorbers. An iterative solution of the eikonal equation is implemented to accurately trace the time of flight of different pixels. Numerical, phantom and in vivo experiments demonstrate that CTBP can dramatically suppress streak artifacts in PACT and improve image quality.