Realistic digital phantoms for prostate ultrasound and photoacoustic imaging

Abstract

In this work, we introduce the first realistic digital phantoms for prostate ultrasound and photoacoustic (PA) imaging in the male pelvic region. Our model encompasses surrounding tissues or organs around the prostate, including fat, bones (including femoral heads), muscles, urinary bladder, rectum, anal canal, penile bulb, neurovascular bundles, and seminal vesicles. Each digital phantom set contains five parameters: speed of sound, density, acoustic attenuation, optical absorption, and reduced optical scattering. The anatomical structures were derived from open-source computed tomography (CT) and magnetic resonance imaging (MRI) data from the Gold Atlas Project. The acoustic parameters, including the speed of sound and attenuation of the prostate, were obtained from an ex vivo prostate study utilizing the QTscan ultrasound tomography (UST) platform at the National Institutes of Health. All other parameters were acquired from the literature. By employing atlas data from four pelvises and UST images of 62 ex vivo prostate specimens, we generated 248 sets of digital phantoms. Additionally, we demonstrate a practical application, showcasing the identification of the effective insonification window for prostate UST. The developed digital phantoms are made open source and can be found at https://github.com/ywu115/Prostate-digital-phantoms. They can be leveraged for imaging device design, image formation studies, image reconstruction validation, and diagnostic and treatment planning for numerous prostate studies using ultrasound and PA imaging. Since the digital phantoms cover the entire male pelvic region, they can potentially be extended to other applications, such as bladder cancer imaging, cyst detection in seminal vesicles, hernias, and treatment planning for point-of-care ultrasound.