Three-dimensional, distendable bladder phantom for optical coherence tomography and white light cystoscopy

Abstract

Abstract. We describe a combination of fabrication techniques and a general process to construct a threedimensional (3-D) phantom that mimics the size, macroscale structure, microscale surface topology, subsurface microstructure, optical properties, and functional characteristics of a cancerous bladder. The phantom also includes features that are recognizable in white light (i.e., the visual appearance of blood vessels), making it suitable to emulate the bladder for emerging white light þ optical coherence tomography (OCT) cystoscopies and other endoscopic procedures of large, irregularly shaped organs. The fabrication process has broad applicability and can be generalized to OCT phantoms for other tissue types or phantoms for other imaging modalities. To this end, we also enumerate the nuances of applying known fabrication techniques (e.g., spin coating) to contexts (e.g., nonplanar, 3-D shapes) that are essential to establish their generalizability and limitations. We anticipate that this phantom will be immediately useful to evaluate innovative OCT systems and software being developed for longitudinal bladder surveillance and early cancer detection. © The Authors.Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Multimodal 3D cancer-mimicking optical phantom

“…The core shape for the phantom was procured from a 3D model of the bladder, as described previously [15]. A general overview of the fabrication process is shown in Fig.…”

“…To induce a surface roughness similar to bladder rugae, the mold was coated with crumpled aluminum foil prior to air-brushing [15].…”

“…Step 5: Sandwich molding [15] was used to create the muscularis propria layer. An outer mold, made of two halves, was 3D-printed and designed to have a gap thickness of 4 mm.…”

“…Most tissue-mimicking phantoms simulate flat regions of healthy tissue [11,12]. Notable exceptions to this include work by Yang et al to fabricate a fluorescently-labeled esophageal phantom [13], work by Bisaillon et al to fabricate tubular artery phantoms with disease-mimicking inclusions for intravascular OCT [14], work by Lurie et al to fabricate a multi-layered, distendable, 3D optical phantom of the bladder with stage-T2 tumor inclusions [15] and a modification of the latter technique to mimic a wider range of bladder cancer pathologies (i.e., dysplasia, CIS, nonmuscle invasive and muscle invasive tumors) [16]. Limitations of these earlier works include, respectively, limitations in the range of possible optical properties needed to mimic various layers of epithelial tissue; an inability to fabricate phantoms for non-tubular, irregularly-shaped organs such as bladder; an inability to mimic early-stage bladder cancers; restriction to a planar substrate.…”

Rapid prototyping of biomimetic vascular phantoms for hyperspectral reflectance imaging

“…However, the clinical relevance of these results may be questionable due to the lack of biologically relevant morphology. In recent studies, there have been increasing efforts to develop tissue phantoms with more complex morphology that can provide insights into clinical issues, such as the effect of device and tissue parameters on performance in measuring diagnostic parameters 3,4 (e.g., spatial dimensions of tissue structures indicative of disease onset/progression). These approaches may also provide more useful methods for guiding device development and enabling objective device performance assessment and intercomparison.…”