This paper explores the benefits of interactive three-dimensional (3D) visualization of stimuli using a computer aided detection (CAD) system of pulmonary embolisms (PEs), on computed tomography pulmonary angiography (CTPA) views. We designed a new CAD method that prompts the PE sites on CTPA views; we then utilized two interactive approaches of 3D visualization to assess CAD performance. This collaboration allows different methodologies to be used to assess PE-CAD performance, by comparison with the common method in which radiologists are prompted with CAD stimuli directly on the CTPA views. Both 3D approaches are based on the voxel size of the CTPA examination, and consider the acquisition settings. A set of ten retrospective CTPA cases were collected, with different acquisition parameters, in terms of voxel size and spatial resolution. 3D visualization CAD performance was examined by an experienced radiologist. Both 3D visualization methods proved to have a constructive impact on improving CAD performance. The rate of true positive (TP) responses increased by 27%; while the rate of false positive (FP) responses dropped by 31%. We concluded that evaluation of PE-CAD performance utilizing interactive 3D visualization could increase or ascertain the correct rate of TP stimuli, as well as noticeably reduce FP responses.
Keywords: 3D visualization; Computer aided detection; Computerized tomography pulmonary angiography CTPA.