Dual optical modality endoscopic imaging of cancer development in the mouse colon

Abstract

Background and Objective We utilize a miniature, dual-modality endoscope that combines fluorescence-based surface magnifying chromoendoscopy (SMC) and optical coherence tomography (OCT) to follow the anatomical changes that occur during adenoma development in the mouse colon. Materials and Methods Twenty-five mice were treated with the carcinogen azoxymethane (AOM) to induce tumor development in the distal colon, or were treated with saline as control, and were imaged over six months. OCT detects adenoma number with high sensitivity and specificity and can measure lesion size. In methylene blue-lavaged colons, SMC detects changes in the colonic crypts. SMC images of control mouse colons exhibit reticulated patterns of crypts of equal size, forming either a dot or honeycomb pattern. Results Images of AOM-treated colons show mild crypt irregularities even in grossly normal tissue. Images of small to medium adenoma exhibit larger crypts, more intense signal, and irregular spacing whereas those of large adenoma have heterogeneous, intense signal and loss of crypt structure. Conclusions The combination of OCT and SMC permits the detection of neoplastic events from the earliest stages of crypt irregularities before gross tissue changes are noted, through to measuring the growth of protruding adenoma.

Expanding Functionality of Commercial Optical Coherence Tomography Systems by Integrating a Custom Endoscope

“…By contrast, the crypts on the adenoma in the AOM-treated mouse are elongated and irregular. These results are similar to those previously reported by our group using chromoendoscopy on the same mouse model of colon cancer [ 27 ]. Previous endoscopic OCT systems that provided only two-dimensional data visualized murine colonic crypts only intermittently and required ultrahigh resolution [ 11 ].…”

Time-serial Assessment of Drug Combination Interventions in a Mouse Model of Colorectal Carcinogenesis Using Optical Coherence Tomography

“…[32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][49][50][51][52] We have recently shown that imaging of mouse models with OCT, fluorescence imaging, and MPM at multiple time points is possible and allows for the detection of microscopic and macroscopic changes in the tissue with disease progression. [52][53][54] In this study, we applied endoscopic OCT time-serial imaging to determine the effectiveness of DFMO and lowdose sulindac treatments in a mouse model of CRC. We tested two treatment regimens: chemopreventive and chemotherapeutic, and corroborated the final time point endoscopy results with IHC analysis of colon tissue for biochemical assessment of drug interventions.…”

High-resolution rectoscopy using MHz optical coherence tomography: a step towards real time 3D endoscopy

“…OCT offers the non-invasive acquisition of complete three-dimensional image datasets with microscopic precision, which has been explored in preliminary research. These study highlights its potential in gastroenterology, with encouraging endoscopic colon OCT images demonstrated in animal models [9][10][11][12][13][14][15] , as well as ex vivo in human samples [16][17][18][19][20] . In initial clinical attempts 16,[21][22][23][24][25][26] , a probe-based OCT system was predominantly used, employing catheters licensed for coronary applications.…”