Recent advances in optical molecular imaging allow identification of morphologic and biochemical changes in tissues associated with gastrointestinal (GI) premalignant lesions earlier and in real-time. This focused review series introduces high-resolution imaging modalities that are being evaluated preclinically and clinically for the detection of early GI cancers, especially Barrett esophagus and esophageal adenocarcinoma. Although narrow band imaging, autofluorescence imaging, and chromoendoscopy are currently applied for this purpose in the clinic, further adoptions of probe-based confocal laser endomicroscopy, high-resolution microendoscopy, optical coherence tomography, and metabolomic imaging, as well as imaging mass spectrometry, will lead to detection at the earliest and will guide predictions of the clinical course in the near future in a manner that is beyond current advancements in optical imaging. In this review article, the readers will be introduced to sufficient information regarding this matter with which to enjoy this new era of high technology and to confront science in the field of molecular medical imaging.
Adenocarcinoma ; Barrett Esophagus* ; Diagnostic Imaging ; Mass Spectrometry ; Metabolomics ; Molecular Imaging* ; Narrow Band Imaging ; Optical Imaging ; Tomography, Optical Coherence ; Biomarkers

The diagnosis of Barrett's esophagus generally is based on the endoscopic examination. The findings include columnar epithelium lining the distal esophagus and the presence of specialized intestinal metaplasia in biopsy specimens from that columnar epithelium. However, the diagnostic yield of dysplasia with standard endoscopy is suboptimal. To improve detection of Barrett's esophagus and surveillance for dysplasia and cancer, many new endoscopic techniques including chromoendoscopy, magnification endoscopy, narrow band imaging, autofluorescence endoscopy, optical coherence tomography, and confocal laser endomicroscopy are used. We will review standard endoscopic findings and advanced imaging modalities for Barrett's esophagus.
Barrett Esophagus ; Biopsy ; Endoscopy ; Epithelium ; Esophagus ; Metaplasia ; Narrow Band Imaging ; Tomography, Optical Coherence

Photoacoustic (PA) imaging is a hybrid biomedical imaging method that exploits both acoustical Epub ahead of print and optical properties and can provide both functional and structural information. Therefore, PA imaging can complement other imaging methods, such as ultrasound imaging, fluorescence imaging, optical coherence tomography, and multi-photon microscopy. This article reviews techniques that integrate PA with the above imaging methods and describes their applications.
Complement System Proteins ; Microscopy ; Multimodal Imaging* ; Optical Imaging ; Tomography, Optical Coherence ; Ultrasonography

Optical imaging visualizes tissue function and structure by analyzing the properties of absorption, scattering, or reflection. Light in the near-infrared spectrum relatively penetrate human tissue well. Diffuse optical imaging (DOI) is a functional imaging modality which can evaluate the perfusion and metabolism of human tissue and tumor by analyzing the optical properties of hemoglobin, water, and lipid. Optical coherence tomography (OCT) acquires the cross-sectional images by analyzing the coherence pattern of the reflected light from the human tissue. OCT has higher resolution more than 15 times compared to conventional imaging modalities like ultrasonography, computed tomography, or magnetic resonance imaging. Optical imaging has advantages of harmlessness, noninvasiveness, and high resolution. However, it has limitation in the penetration depth. In this review, mechanism of DOI and OCT and their clinical application in the otorhinolaryngology field will be discussed.
Absorption ; Humans ; Magnetic Resonance Imaging ; Metabolism ; Optical Imaging* ; Otolaryngology* ; Perfusion ; Tomography, Optical Coherence ; Ultrasonography ; Water

To improve the detection rate of gastrointestinal tumors, image-enhanced endoscopy has been widely used during screening and surveillance endoscopy in Korea. In addition to narrow band imaging (NBI) with/without magnification, various types of electronic chromoendoscopies have been used, including autofluorescence imaging, I-scan, and flexible spectral imaging color enhancement. These technologies enable the accurate characterization of tumors because they enable visualization of microvascular and microsurface patterns. The present review focuses on understanding the principle and clinical applications of advanced imaging technologies other than NBI.
Endoscopy ; Korea ; Mass Screening ; Narrow Band Imaging* ; Optical Imaging

Recently, several new endoscopic imaging techniques have been developed, including endoscopic ultrasonography, narrow band imaging, autofluorescence imaging, and confocal laser endomicroscopy. Preliminary studies have reported promising results in diagnosing gastric cancer with these new endoscopic imaging techniques. For wider clinical application, however, more evidence is required to show the clinical efficacy of these advanced endoscopic techniques in the diagnosis of gastric cancer. For the treatment of early gastric cancer, endoscopic submucosal dissection methods have recently been developed. Endoscopic submucosal dissection enables en bloc resection of large lesions and lesions with accompanying ulcerations, as the lesion is directly dissected along the submucosal layer using a high-frequency electrosurgical knife. With the development of the endoscopic submucosal dissection technique and the accumulation of long-term outcome data, the applications for endoscopic resection for early gastric cancer are expanding.
Diagnosis* ; Endosonography ; Narrow Band Imaging ; Optical Imaging ; Stomach Neoplasms* ; Ulcer

Recently, several new endoscopic imaging techniques have been developed, including endoscopic ultrasonography, narrow band imaging, autofluorescence imaging, and confocal laser endomicroscopy. Preliminary studies have reported promising results in diagnosing gastric cancer with these new endoscopic imaging techniques. For wider clinical application, however, more evidence is required to show the clinical efficacy of these advanced endoscopic techniques in the diagnosis of gastric cancer. For the treatment of early gastric cancer, endoscopic submucosal dissection methods have recently been developed. Endoscopic submucosal dissection enables en bloc resection of large lesions and lesions with accompanying ulcerations, as the lesion is directly dissected along the submucosal layer using a high-frequency electrosurgical knife. With the development of the endoscopic submucosal dissection technique and the accumulation of long-term outcome data, the applications for endoscopic resection for early gastric cancer are expanding.
Diagnosis* ; Endosonography ; Narrow Band Imaging ; Optical Imaging ; Stomach Neoplasms* ; Ulcer

Based on the analysis of the theoretical calculation model of axial resolution of optical coherence tomograph for the posterior segment of the human eye, a set of testing device for measuring its axial resolution is designed and developed. In view of a commercial ophthalmic optical coherence tomograph in clinical use, its axial resolution is calculated to be 5.07 μm theoretically, and the actual measurement value is 5.45 μm. The uncertainty of the detection device is evaluated and the result is (5.45±0.10) μm. The measurement error introduced by the testing device is very small. Meanwhile, the axial resolution measured by the testing device meets the requirements of the instrument(≤ 6 μm).
Algorithms ; Eye ; diagnostic imaging ; Humans ; Tomography, Optical Coherence ; Uncertainty

OBJECTIVETo evaluate the application value of Optical Coherence Tomography (OCT) in the diagnosis of the depth of burn wound.

METHODSDeep partial-thickness scald models of Skh-1 mice were reproduced using self-made steam scald appliance. The scald wounds were scanned with OCT 3 hours, or 3 and 8 days after injury respectively. Scanned wound tissue was harvested for histological examination right after each episode of OCT imaging. Normal skin of mice was scanned and examined with the above-mentioned methods at the same time.

RESULTSCompared with those of the normal skin, collagen in the dermis was denatured after steam scald, and it was imaged as vanishing or reduction in birefringence in OCT detection. The structure change intensity was related to the pathological process of the wounds and consistent with the corresponding histological results.

CONCLUSIONSOCT is a noninvasive technique. It can be used to diagnose the depth of burn wound in real time.

OBJECTIVE: To develop a few-shot learning (FSL) approach for classifying optical coherence tomography (OCT) images in patients with inherited retinal disorders (IRDs). METHODS: In this study, an FSL model based on a student-teacher learning framework was designed to classify images. 2,317 images from 189 participants were included. Of these, 1,126 images revealed IRDs, 533 were normal samples, and 658 were control samples. RESULTS: The FSL model achieved a total accuracy of 0.974-0.983, total sensitivity of 0.934-0.957, total specificity of 0.984-0.990, and total F1 score of 0.935-0.957, which were superior to the total accuracy of the baseline model of 0.943-0.954, total sensitivity of 0.866-0.886, total specificity of 0.962-0.971, and total F1 score of 0.859-0.885. The performance of most subclassifications also exhibited advantages. Moreover, the FSL model had a higher area under curves (AUC) of the receiver operating characteristic (ROC) curves in most subclassifications. CONCLUSION This study demonstrates the effective use of the FSL model for the classification of OCT images from patients with IRDs, normal, and control participants with a smaller volume of data. The general principle and similar network architectures can also be applied to other retinal diseases with a low prevalence.
Humans ; Tomography, Optical Coherence ; Deep Learning ; Retinal Diseases/diagnostic imaging* ; Retina/diagnostic imaging* ; ROC Curve