Three-dimensional contrast-ultrasound dispersion imaging for prostate cancer localization, a feasibility study

摘要

Prostate cancer (PCa) is the type of cancer with the highest incidence in men in Western countries. To date, reliable tools for PCa localization are lacking. Recently, contrast-ultrasound dispersion imaging (CUDI) by spatiotemporal analysis performed on transrectal dynamic contrast-enhanced ultrasound (DCE-US) has been proposed as a promising option for PCa localization. This technique evaluates the spatial similarity between indicator dilution curves in a ring-shaped kernel and its center pixel. Until now, CUDI has been performed in 2D only. Hence, each imaged plane requires a separate bolus injection of contrast agent, motion compensation is limited, and out-of-plane contrast flow cannot be observed. 3D DCE-US can potentially solve the aforementioned issues, permitting the analysis of the entire prostate with a single bolus injection. In this work, we implemented a full 4D spatiotemporal similarity analysis. Its feasibility to localize PCa was evaluated in 2 patients by qualitatively comparing similarity maps obtained by 3D CUDI with those obtained by 2D CUDI in the corresponding planes and with histopathologic results from 12-core systematic biopsies. All results showed good agreement, confirming the feasibility of 3D CUDI for PCa localization and encouraging extension of the study to a larger dataset. Additionally, the characteristics - and in particular the spatial and temporal resolution - of 3D DCE-US were analyzed with respect to the requirements for CUDI. Both the spatial and temporal resolution were considered to be sufficient for CUDI.