Background: Endoscopic optical coherence tomography (EOCT) is a high-resolution, cross-sectional tissue-imag- ing technique that provides microscopic morphologic information. EOCT should detect dysplasia in Barrett‘s...Background: Endoscopic optical coherence tomography (EOCT) is a high-resolution, cross-sectional tissue-imag- ing technique that provides microscopic morphologic information. EOCT should detect dysplasia in Barrett‘s epithelium, but this has not been established in a prospective blinded study. This study evaluated the accuracy of EOCT for the diagnosis and the exclusion of dysplasia in patients with Barrett‘s esophagus. Methods: A 2.4 mm diameter EOCT probe was modified for use with a cap-fitted, two -channel endoscope. Pairs of EOCT image streams and jumbo biopsy specimens were obtained. Endoscopy/EOCT procedures were performed by 4 endoscopists who separa tely reviewed the EOCT digital images for the absence or the presence of dysplas ia (low grade, high grade, or cancer) for each biopsy specimen obtained. The end oscopists were blinded to the interpretation of the pathology. An experienced pa thologist blinded to the endoscopic/EOCT findings evaluated each biopsy for the absence or the presence of dysplasia. The setting of the study was a major acade mic medical center. Adult patients with documented Barrett‘s esophagus greater than 2 cm were included in the study. The main outcome measurement was the accur acy of EOCT in the detection of dysplasia in patients with Barrett‘s esophagus. Results: A total of 314 usable EOCT image stream/biopsy pairs were obtained in 33 patients. By using histology as the standard, the performance of EOCT was sensitivity, 68%; specificity, 82%; positive predictive value, 53%; negative predictive value, 89%; and diagnostic accuracy, 78%. Diagnostic accuracy for the 4 endoscopists ranged from 56%to 98%. Limitations of the study were the variability in endoscopists‘accuracy rates, difficulty in real-time interpretation, and the need for refined criteria of dysplasia by EOCT imaging. Conclusions: The current EOCT system has an accuracy of 78%for the detection of dysplasia in patients with Barrett‘s esophagus. EOCT could be used to target biopsies to areas of Barrett‘s epithelium with a higher probability for the presence of dysplasia. However, further modifications, including increased resolution and identification of further pot ential OCT characteristics of dysplasia, are needed before EOCT can be used clin ically.展开更多
Goals/Background: Previous studies have demonstrated low yield and conflicting results as to the ability of technetium 99m labeled red blood cell (TRBC) scintigraphy to accurately localize the site of bleeding in acut...Goals/Background: Previous studies have demonstrated low yield and conflicting results as to the ability of technetium 99m labeled red blood cell (TRBC) scintigraphy to accurately localize the site of bleeding in acute lower gastrointestinal hemorrhage. Our objective was to evaluate the accuracy of TRBC scintigraphy in clinical day-to-day practice at our institution and to determine predictors of a positive test. Methods: A retrospective medical records review of all patients who underwent TRBC scintigraphy over a 5-year period was conducted at a single academic medical center. The site of bleeding found on TRBC scintigraphy was correlated with the endoscopic, angiographic, surgical, and pathologic findings in each patient. Results: A total of 127 scans were performed in 115 patients. Forty-nine scans were positive (39%) and 78 were negative (61%). Forty-two patients had further evaluation after a positive scan, and the bleeding site was confirmed to be accurate in 20 of 42 patients (48%). A contradictory bleeding site was found in 5 of 49 positive scans (10%). Patients transfused greater than 2 units of packed red blood cells within 24 hours preceding the TRBC scan were twice as likely to have a positive scan (64%) than those transfused 2 units or less (32%) (P = 0.002). Multivariate analysis demonstrated that the number of units of blood transfused within 24 hours prior to the TRBC scan and the lowest recorded hematocrit were significantly different between patients with positive and negative scans. There was no difference in the rate of endoscopy between patients with a positive or negative scan result. Conclusions: TRBC scintigraphy has a relatively low yield in the evaluation of acute lower gastrointestinal bleeding. Objective selection criteria such as number of units of packed red blood cells transfused prior to obtaining the scan may increase the overall yield.展开更多
文摘Background: Endoscopic optical coherence tomography (EOCT) is a high-resolution, cross-sectional tissue-imag- ing technique that provides microscopic morphologic information. EOCT should detect dysplasia in Barrett‘s epithelium, but this has not been established in a prospective blinded study. This study evaluated the accuracy of EOCT for the diagnosis and the exclusion of dysplasia in patients with Barrett‘s esophagus. Methods: A 2.4 mm diameter EOCT probe was modified for use with a cap-fitted, two -channel endoscope. Pairs of EOCT image streams and jumbo biopsy specimens were obtained. Endoscopy/EOCT procedures were performed by 4 endoscopists who separa tely reviewed the EOCT digital images for the absence or the presence of dysplas ia (low grade, high grade, or cancer) for each biopsy specimen obtained. The end oscopists were blinded to the interpretation of the pathology. An experienced pa thologist blinded to the endoscopic/EOCT findings evaluated each biopsy for the absence or the presence of dysplasia. The setting of the study was a major acade mic medical center. Adult patients with documented Barrett‘s esophagus greater than 2 cm were included in the study. The main outcome measurement was the accur acy of EOCT in the detection of dysplasia in patients with Barrett‘s esophagus. Results: A total of 314 usable EOCT image stream/biopsy pairs were obtained in 33 patients. By using histology as the standard, the performance of EOCT was sensitivity, 68%; specificity, 82%; positive predictive value, 53%; negative predictive value, 89%; and diagnostic accuracy, 78%. Diagnostic accuracy for the 4 endoscopists ranged from 56%to 98%. Limitations of the study were the variability in endoscopists‘accuracy rates, difficulty in real-time interpretation, and the need for refined criteria of dysplasia by EOCT imaging. Conclusions: The current EOCT system has an accuracy of 78%for the detection of dysplasia in patients with Barrett‘s esophagus. EOCT could be used to target biopsies to areas of Barrett‘s epithelium with a higher probability for the presence of dysplasia. However, further modifications, including increased resolution and identification of further pot ential OCT characteristics of dysplasia, are needed before EOCT can be used clin ically.
文摘Goals/Background: Previous studies have demonstrated low yield and conflicting results as to the ability of technetium 99m labeled red blood cell (TRBC) scintigraphy to accurately localize the site of bleeding in acute lower gastrointestinal hemorrhage. Our objective was to evaluate the accuracy of TRBC scintigraphy in clinical day-to-day practice at our institution and to determine predictors of a positive test. Methods: A retrospective medical records review of all patients who underwent TRBC scintigraphy over a 5-year period was conducted at a single academic medical center. The site of bleeding found on TRBC scintigraphy was correlated with the endoscopic, angiographic, surgical, and pathologic findings in each patient. Results: A total of 127 scans were performed in 115 patients. Forty-nine scans were positive (39%) and 78 were negative (61%). Forty-two patients had further evaluation after a positive scan, and the bleeding site was confirmed to be accurate in 20 of 42 patients (48%). A contradictory bleeding site was found in 5 of 49 positive scans (10%). Patients transfused greater than 2 units of packed red blood cells within 24 hours preceding the TRBC scan were twice as likely to have a positive scan (64%) than those transfused 2 units or less (32%) (P = 0.002). Multivariate analysis demonstrated that the number of units of blood transfused within 24 hours prior to the TRBC scan and the lowest recorded hematocrit were significantly different between patients with positive and negative scans. There was no difference in the rate of endoscopy between patients with a positive or negative scan result. Conclusions: TRBC scintigraphy has a relatively low yield in the evaluation of acute lower gastrointestinal bleeding. Objective selection criteria such as number of units of packed red blood cells transfused prior to obtaining the scan may increase the overall yield.
