Browsing by Author "Lee, Michelle H."
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Item Diagnosis of Neoplasia in Barrett’s Esophagus using Vital-dye Enhanced Fluorescence Imaging(JoVE, 2014) Perl, Daniel P.; Parikh, Neil; Chang, Shannon; Peng, Paul; Thekkek, Nadhi; Lee, Michelle H.; Polydorides, Alexandros D.; Mitcham, Josephine; Richards-Kortum, Rebecca; Anandasabapathy, SharmilaThe ability to differentiate benign metaplasia in Barrett’s Esophagus (BE) from neoplasia in vivo remains difficult as both tissue types can be flat and indistinguishable with white light imaging alone. As a result, a modality that highlights glandular architecture would be useful to discriminate neoplasia from benign epithelium in the distal esophagus. VFI is a novel technique that uses an exogenous topical fluorescent contrast agent to delineate high grade dysplasia and cancer from benign epithelium. Specifically, the fluorescent images provide spatial resolution of 50 to 100 μm and a field of view up to 2.5 cm, allowing endoscopists to visualize glandular morphology. Upon excitation, classic Barrett’s metaplasia appears as continuous, evenly-spaced glands and an overall homogenous morphology; in contrast, neoplastic tissue appears crowded with complete obliteration of the glandular framework. Here we provide an overview of the instrumentation and enumerate the protocol of this new technique. While VFI affords a gastroenterologist with the glandular architecture of suspicious tissue, cellular dysplasia cannot be resolved with this modality. As such, one cannot morphologically distinguish Barrett’s metaplasia from BE with Low-Grade Dysplasia via this imaging modality. By trading off a decrease in resolution with a greater field of view, this imaging system can be used at the very least as a red-flag imaging device to target and biopsy suspicious lesions; yet, if the accuracy measures are promising, VFI may become the standard imaging technique for the diagnosis of neoplasia (defined as either high grade dysplasia or cancer) in the distal esophagus.Item In vivo classification of colorectal neoplasia using high-resolution microendoscopy: Improvement with experience(Wiley, 2015) Parikh, Neil D.; Perl, Daniel; Lee, Michelle H.; Chang, Shannon S.; Polydorides, Alexandros D.; Moshier, Erin; Godbold, James; Zhou, Elinor; Mitcham, Josephine; Richards-Kortum, Rebecca; Anandasabapathy, SharmilaBackground and Aims: High-resolution microendoscopy (HRME) is a novel, low-cost “optical biopsy” technology that allows for subcellular imaging. The study aim was to evaluate the learning curve of HRME for the differentiation of neoplastic from non-neoplastic colorectal polyps. Methods: In a prospective cohort fashion, a total of 162 polyps from 97 patients at a single tertiary care center were imaged by HRME and classified in real time as neoplastic (adenomatous, cancer) or non-neoplastic (normal, hyperplastic, inflammatory). Histopathology was the gold standard for comparison. Diagnostic accuracy was examined at three intervals over time throughout the study; the initial interval included the first 40 polyps, the middle interval included the next 40 polyps examined, and the final interval included the last 82 polyps examined. Results: Sensitivity increased significantly from the initial interval (50%) to the middle interval (94%, P = 0.02) and the last interval (97%, P = 0.01). Similarly, specificity was 69% for the initial interval but increased to 92% (P = 0.07) in the middle interval and 96% (P = 0.02) in the last interval. Overall accuracy was 63% for the initial interval and then improved to 93% (P = 0.003) in the middle interval and 96% (P = 0.0007) in the last interval. Conclusions: In conclusion, this in vivo study demonstrates that an endoscopist without prior colon HRME experience can achieve greater than 90% accuracy for identifying neoplastic colorectal polyps after 40 polyps imaged. HRME is a promising modality to complement white light endoscopy in differentiating neoplastic from non-neoplastic colorectal polyps.Item In vivo diagnostic accuracy of high resolution microendoscopy in differentiating neoplastic from non-neoplastic colorectal polyps: a prospective study(The American Journal of Gastroenterology, 2014) Parikh, Neil; Perl, Daniel; Lee, Michelle H.; Shah, Brijen; Young, Yuki; Chang, Shannon S.; Shukla, Richa; Polydorides, Alexandros D.; Moshier, Erin; Godbold, James; Zhou, Elinor; Mitchaml, Josephine; Richards-Kortum, Rebecca; Anandasabapathy, SharmilaHigh-resolution microendoscopy (HRME) is a low-cost, モoptical biopsyヤ technology that allows for subcellular imaging. The purpose of this study was to determine the in vivo diagnostic accuracy of the HRME for the differentiation of neoplastic from non-neoplastic colorectal polyps and compare it to that of high-definition white-light endoscopy (WLE) with histopathology as the gold standard. Three endoscopists prospectively detected a total of 171 polyps from 94 patients that were then imaged by HRME and classified in real-time as neoplastic (adenomatous, cancer) or non-neoplastic (normal, hyperplastic, inflammatory). HRME had a significantly higher accuracy (94%), specificity (95%), and positive predictive value (87%) for the determination of neoplastic colorectal polyps compared to WLE (65%, 39%, and 55%, respectively). When looking at small colorectal polyps (less than 10 mm), HRME continued to significantly outperform WLE in terms of accuracy (95% vs. 64%), specificity (98% vs. 40%) and positive predictive value (92% vs. 55%). These trends continued when evaluating diminutive polyps (less than 5 mm) as HRME's accuracy (95%), specificity (98%), and positive predictive value (93%) were all significantly greater than their WLE counterparts (62%, 41%, and 53%, respectively). In conclusion, this in vivo study demonstrates that HRME can be a very effective modality in the differentiation of neoplastic and non-neoplastic colorectal polyps. A combination of standard white-light colonoscopy for polyp detection and HRME for polyp classification has the potential to truly allow the endoscopist to selectively determine which lesions can be left in situ, which lesions can simply be discarded, and which lesions need formal histopathologic analysis.Item Modular video endoscopy for in vivo cross-polarized and vital-dye fluorescence imaging of Barrett's-associated neoplasia(SPIE, 2013-02) Thekkek, Nadhi; Pierce, Mark C.; Lee, Michelle H.; Polydorides, Alexandros D.; Flores, Raja M.; Anandasabapathy, Sharmila; Richards-Kortum, Rebecca R.A modular video endoscope is developed and tested to allow imaging in different modalities. This system incorporates white light imaging (WLI), cross-polarized imaging (CPI), and vital-dye fluorescence imaging (VFI), using interchangeable filter modules. CPI and VFI are novel endoscopic modalities that probe mucosal features associated with Barrett's neoplasia. CPI enhances vasculature, while VFI enhances glandular architecture. In this pilot study, we demonstrate the integration of these modalities by imaging areas of Barrett's metaplasia and neoplasia in an esophagectomy specimen. We verify that those key image features are also observed during an in vivo surveillance procedure. CPI images demonstrate improved visualization of branching blood vessels associated with neoplasia. VFI images show glandular architecture with increased glandular effacement associated with neoplasia. Results suggests that important pathologic features seen in CPI and VFI are not visible during standard endoscopic white light imaging, and thus the modalities may be useful in future in vivo studies for discriminating neoplasia from Barrett's metaplasia. We further demonstrate that the integrated WLI/CPI/VFI endoscope is compatible with complementary high-resolution endomicroscopy techniques such as the high-resolution microendoscope, potentially enabling two-step (“red-flag” widefield plus confirmatory high-resolution imaging) protocols to be enhanced.Item Quantitative analysis of high-resolution microendoscopic images for diagnosis of neoplasia in patients with Barrett’s esophagus(Elsevier, 2016) Shin, Dongsuk; Lee, Michelle H.; Polydorides, Alexandros D.; Pierce, Mark C.; Vila, Peter M.; Parikh, Neil D.; Rosen, Daniel G.; Anandasabapathy, Sharmila; Richards-Kortum, Rebecca R.Background and Aims: Previous studies show that microendoscopic images can be interpreted visually to identify the presence of neoplasia in patients with Barrett’s esophagus (BE), but this approach is subjective and requires clinical expertise. This study describes an approach for quantitative image analysis of microendoscopic images to identify neoplastic lesions in patients with BE. Methods: Images were acquired from 230 sites from 58 patients by using a fiberoptic high-resolution microendoscope during standard endoscopic procedures. Images were analyzed by a fully automated image processing algorithm, which automatically selected a region of interest and calculated quantitative image features. Image features were used to develop an algorithm to identify the presence of neoplasia; results were compared with a histopathology diagnosis. Results: A sequential classification algorithm that used image features related to glandular and cellular morphology resulted in a sensitivity of 84% and a specificity of 85%. Applying the algorithm to an independent validation set resulted in a sensitivity of 88% and a specificity of 85%. Conclusions: This pilot study demonstrates that automated analysis of microendoscopic images can provide an objective, quantitative framework to assist clinicians in evaluating esophageal lesions from patients with BE. (Clinical trial registration number: NCT01384227 and NCT02018367.)Item Quantitative evaluation of in vivo vital-dye fluorescence endoscopic imaging for the detection of Barrett’s-associated neoplasia(SPIE, 2015) Thekkek, Nadhi; Lee, Michelle H.; Polydorides, Alexandros D.; Rosen, Daniel G.; Anandasabapathy, Sharmila; Richards-Kortum, RebeccaCurrent imaging tools are associated with inconsistent sensitivity and specificity for detection of Barrett’s-associated neoplasia. Optical imaging has shown promise in improving the classification of neoplasia in vivo. The goal of this pilot study was to evaluate whether in vivo vital dye fluorescence imaging (VFI) has the potential to improve the accuracy of early-detection of Barrett’s-associated neoplasia. In vivo endoscopic VFI images were collected from 65 sites in 14 patients with confirmed Barrett’s esophagus (BE), dysplasia, or esophageal adenocarcinoma using a modular video endoscope and a high-resolution microendoscope (HRME). Qualitative image features were compared to histology; VFI and HRME images show changes in glandular structure associated with neoplastic progression. Quantitative image features in VFI images were identified for objective image classification of metaplasia and neoplasia, and a diagnostic algorithm was developed using leave-one-out cross validation. Three image features extracted from VFI images were used to classify tissue as neoplastic or not with a sensitivity of 87.8% and a specificity of 77.6% (AUC=0.878). A multimodal approach incorporating VFI and HRME imaging can delineate epithelial changes present in Barrett’s-associated neoplasia. Quantitative analysis of VFI images may provide a means for objective interpretation of BE during surveillance.