Task-based imaging of colon cancer in the Apc^Min/+ mouse model

Abstract

Optical coherence tomography (OCT), laser-induced fluorescence (LIF), and laser-scanning confocal microscopy (LSCM) were used for the task of multimodal study of healthy and adenomatous mouse colon. The results from each modality were compared with histology, which served as the gold standard. The Apc(Min/+) genetic mouse model of colon cancer was compared with wild-type mice. In addition, a special diet was used for the task of studying the origins of a 680 nm autofluorescent signal that was previously observed in colon. The study found close agreement among each of the modalities and with histology. All four modalities were capable of identifying diseased tissue accurately. The OCT and LSCM images provided complementary structural information about the tissue, while the autofluorescence signal measured by LIF and LSCM provided biochemical information. OCT and LIF were performed in vivo and nondestructively, while the LSCM and histology required extraction of the tissue. The magnitude of the 680 nm signal correlates with chlorophyll content in the mouse diet, suggesting that the autofluorescent compound is a dietary metabolite.

Optical coherence tomography today: speed, contrast, and multimodality

“…Pan et al 185 suggested that an ALA fluorescence-guided endoscopic OCT could enhance the efficiency and sensitivity of early bladder cancer diagnosis and demonstrated in animal studies that the specificity of fluorescence detection of transitional cell carcinoma was significantly enhanced by fluorescence-guided OCT. Tumlinson et al 205 have demonstrated a combined miniaturized OCT and laser-induced fluorescence (LIF) spectroscopy imaging catheter for in vivo mouse colon imaging to monitor the disease progression in mouse colon longitudinally and to identify colorectal adenomatous mouse colon. [206][207][208] OCT images showed significant changes in mucosal layer thickness and loss of visibility of tissue boundary lines between healthy and diseased tissue. Similarly, the LIF spectra of healthy and diseased tissues were distinguishable by the emissions at 405 and 680 nm.…”

Serial endoscopy in azoxymethane treated mice using ultra-high-resolution optical coherence tomography

“…Limited resolution also made it difficult to differentiate confounders such as lymphoid aggregates and fecal material from neoplasms. [9][10][11][12][13][14][15][16][17][18][19][20] We expected that a higher resolution device would be able to visualize these structures. An ultrahigh resolution (UHR) OCT endoscope with 5 mm resolution in air has been developed and utilized to perform in vivo imaging in rabbit colon.…”

Preclinical Models of Glioblastoma in Radiobiology: Evolving Protocols and Research Methods

“…The major disadvantages are; autofl uorescence of skin, and tissue, due to several cellular components that can interfere signifi cantly with signal from fl uorescent reporters if emission wavelengths overlap [ 87 ]. Additionally, chlorophyll present in standard mouse food autofl uoresces, thus interfering with many common reporters [ 88 ].…”