Pilot Clinical Evaluation of a Confocal Microlaparoscope for Ovarian Cancer Detection.

OBJECTIVE: The aim of this study is to evaluate the performance of a confocal fluorescence microlaparoscope for in vivo detection of ovarian cancer. METHODS/MATERIALS: Seventy-one patients scheduled for open or laparoscopic oophorectomy were consented for the imaging study. High-resolution confocal microlaparoscopic images of the epithelial surface of the ovary were acquired in vivo or ex vivo after tissue staining using acridine orange. Standard histologic evaluation of extracted tissue samples was performed and used as the gold standard of disease diagnosis. Trained human observers from different specialties viewed the microlaparoscopic images, rating each image on a 6-point scale ranging from "definitely not cancer" to "definitely cancer." Receiver operating characteristic curves were generated using these scores and the gold standard histopathologic diagnosis. Area under the receiver operating characteristic curve (AUC) was calculated as a performance metric. RESULTS: Forty-five of the consented patients were used in the final evaluation study. From these 45 patients, 63 tissue locations or samples were identified and imaged with the confocal microlaparoscope. Twenty of the samples were high-grade cancers, and the remaining 43 samples were normal or noncancerous. Twenty-three of the samples were imaged in vivo, and the remaining 40 samples were imaged ex vivo. The average AUC score and standard error (SE) for detection of cancer in all images were 0.88 and 0.02, respectively. An independent-samples t test was conducted to compare AUC scores for in vivo and ex vivo conditions. No statistically significant difference in the AUC score for in vivo (AUC, 0.850; SE, 0.049) and ex vivo (AUC, 0.888; SE, 0.027) conditions was observed, t(6) = 1.318, P = 0.2355. CONCLUSIONS: Area under the receiver operating characteristic curve scores indicate that high-resolution in vivo images obtained by the confocal laparoscope can distinguish between normal and malignant ovarian surface epithelium. In addition, in vivo performance is similar to that which can be obtained from ex vivo tissue.

Analysis of multimode fiber bundles for endoscopic spectral-domain optical coherence tomography.

A theoretical analysis of the use of a fiber bundle in spectral-domain optical coherence tomography (OCT) systems is presented. The fiber bundle enables a flexible endoscopic design and provides fast, parallelized acquisition of the OCT data. However, the multimode characteristic of the fibers in the fiber bundle affects the depth sensitivity of the imaging system. A description of light interference in a multimode fiber is presented along with numerical simulations and experimental studies to illustrate the theoretical analysis.

Design and Performance of a Multi-Point Scan Confocal Microendoscope.

Confocal fluorescence microendoscopy provides high-resolution cellular-level imaging via a minimally invasive procedure, but requires fast scanning to achieve real-time imaging in vivo. Ideal confocal imaging performance is obtained with a point scanning system, but the scan rates required for in vivo biomedical imaging can be difficult to achieve. By scanning a line of illumination in one direction in conjunction with a stationary confocal slit aperture, very high image acquisition speeds can be achieved, but at the cost of a reduction in image quality. Here, the design, implementation, and experimental verification of a custom multi-point aperture modification to a line-scanning multi-spectral confocal microendoscope is presented. This new design improves the axial resolution of a line-scan system while maintaining high imaging rates. In addition, compared to the line-scanning configuration, previously reported simulations predicted that the multi-point aperture geometry greatly reduces the effects of tissue scatter on image quality. Experimental results confirming this prediction are presented.