Deep Learning aplicado en imágenes fotoacústicas para la Identificación del cáncer de seno / Deep Learning Applied in Photoacoustic Images for the Identification of Breast Cancer

La Imagen Fotoacústica (PAI por sus siglas en inglés), es una modalidad de imagen híbrida que fusiona la iluminación óptica y la detección por ultrasonido. Debido a que los métodos de imágenes ópticas puras no pueden mantener una alta resolución, la capacidad de lograr imágenes de contraste óptico de alta resolución en tejidos biológicos hace que la fotoacústica (PA por sus siglas en inglés) sea una técnica prometedora para varias aplicaciones de imágenes clínicas. En la actualidad el Aprendizaje Profundo (Deep Learning) tiene el enfoque más reciente en métodos basados en la PAI, donde existe una gran cantidad de aplicaciones en análisis de imágenes, en especial en el área del campo biomédico, como lo es la adquisición, segmentación y reconstrucciones de imágenes de tomografía computarizada. Esta revisión describe las últimas investigaciones en PAI y un análisis sobre las técnicas y métodos basados en Deep Learning, aplicado en diferentes modalidades para el diagnóstico de cáncer de seno(AU)

Photoacoustic Imaging (PAI) is a hybrid imaging modality that combines optical illumination and ultrasound detection. Because pure optical imaging methods cannot maintain high resolution, the ability to achieve high resolution optical contrast images in biological tissues makes Photoacoustic (PA) a promising technique for various clinical imaging applications. At present, Deep Learning has the most recent approach of methods based on PAI where there are a large number of applications in image analysis especially in the area of ​​the biomedical field, such as acquisition, segmentation and reconstructions of computed tomography imaging. This review describes the latest research in PAI and an analysis of the techniques and methods based on Deep Learning applied in different modalities for the diagnosis of breast cancer(AU)

Progress of motion artifact correction in photoacoustic microscopy and photoacoustic tomography / 生物医学工程学杂志

Photoacoustic imaging (PAI) is a rapidly developing hybrid biomedical imaging technology, which is capable of providing structural and functional information of biological tissues. Due to inevitable motion of the imaging object, such as respiration, heartbeat or eye rotation, motion artifacts are observed in the reconstructed images, which reduce the imaging resolution and increase the difficulty of obtaining high-quality images. This paper summarizes current methods for correcting and compensating motion artifacts in photoacoustic microscopy (PAM) and photoacoustic tomography (PAT), discusses their advantages and limits and forecasts possible future work.

Multimodal photoacoustic imaging: systems, applications, and agents

No abstract available.

Simulation Platform of Photoacoustic Imaging Based on Finite Element and -space Pseudospectral Method / 中国医疗器械杂志

Numerical simulation is a powerful technology for photoacoustic imaging (PAI) in both theory studies and practical applications. In this paper, a simulation platform for PAI was designed and implemented based on Matlab. The simulation platform utilized finite element method (FEM) and -space pseudospectral method to calculate the forward and inverse problem of PAI. And a graphical user interface (GUI) was realized. Structural design, work process and other operating details of the platform was also provided. By compared with theoretical temporal waveform of photoacoustic signal and reconstruction results of COMSOL, the validity and reliability was verified. And a reliable simulation tool was proposed for PAI.

Photoacoustic Imaging for Differential Diagnosis of Benign Polyps versus Malignant Polyps of the Gallbladder: A Preliminary Study

OBJECTIVE: To investigate the feasibility of ex vivo multispectral photoacoustic (PA) imaging in differentiating cholesterol versus neoplastic polyps, and benign versus malignant polyps, of the gallbladder. MATERIALS AND METHODS: A total of 38 surgically confirmed gallbladder polyps (24 cholesterol polyps, 4 adenomas, and 10 adenocarcinomas) from 38 patients were prospectively included in this study. The surgical specimens were set on a gel pad immersed in a saline-filled container. The PA intensities of polyps were then measured, using two separate wavelength intervals (421–647 nm and 692–917 nm). Mann-Whitney U test was performed for the comparison of normalized PA intensities between the cholesterol and neoplastic polyps, and between the benign and malignant polyps. Kruskal-Wallis test was conducted for the comparison of normalized PA intensities among the cholesterol polyps, adenomas, and adenocarcinomas. RESULTS: A significant difference was observed in the normalized PA intensities between the cholesterol and neoplastic polyps at 459 nm (median, 1.00 vs. 0.73; p = 0.032). Comparing the benign and malignant polyps, there were significant differences in the normalized PA intensities at 765 nm (median, 0.67 vs. 0.78; p = 0.013), 787 nm (median, 0.65 vs. 0.77; p = 0.034), and 853 nm (median, 0.59 vs. 0.85; p = 0.028). The comparison of the normalized PA intensities among cholesterol polyps, adenomas, and adenocarcinomas demonstrated marginally significant differences at 765 nm (median, 0.67 vs. 0.66 vs. 0.78, respectively; p = 0.049). CONCLUSION: These preliminary results indicate that benign versus malignant gallbladder polyps might exhibit different spectral patterns on multispectral PA imaging.

Removal of calcium hydroxide from Weine Type II systems using photon-induced photoacoustic streaming, passive ultrasonic, and needle irrigation: a microcomputed tomography study

ABSTRACT Objective This study compared the effectiveness of Er:YAG laser-activated irrigation (PIPS), passive ultrasonic irrigation (PUI) with EndoUltra and standard needle irrigation (SNI) in the removal of calcium hydroxide [Ca(OH)2] from the mesial roots of Weine Type II mandibular molars. Material and Methods Thirty mandibular molars were screened by µCT for the presence of mesial roots with complex intra-canal anatomy and a common apical foramen. The teeth were enlarged to a standardized 25/.06 preparation and filled with Ca(OH)2 paste. Specimens were divided into three groups (n=10) according to the technique used for Ca(OH)2 removal: PIPS, at 15 Hz and 20 mJ using a 9 mm long, 600 µm diameter tip; PUI using a 15/.02 tip; and SNI (30 Ga. side-vented needle). Equal volumes of 8.25% NaOCl and 17% EDTA were used in all groups. µCT was used to measure the initial amount of Ca(OH)2 present and to assess the residual volume of Ca(OH)2 following each irrigation protocol. Data were analyzed using Tukey HSD and Kruskal-Wallis tests (α=5%). Results The mean volume of Ca(OH)2 before removal was significantly higher in the coronal third than in the middle and apical third (p<0.001). Ca(OH)2 was similarly removed from the coronal and middle thirds with the three methods used (p>0.05). PIPS (median 0%; IQR: 0-0) showed significant higher Ca(OH)2 removal in the apical third than PUI (median 100%, IQR: 85-100) and SNI (median 47%; IQR: 16-72) (p<0.001). Conclusions PIPS laser-activation was more effective for the removal of Ca(OH)2 from mesial roots of mandibular molars with Weine Type II canal configurations than PUI with EndoUltra and SNI.

Clinical photoacoustic imaging of cancer

Photoacoustic imaging is a hybrid technique that shines laser light on tissue and measures optically induced ultrasound signal. There is growing interest in the clinical community over this new technique and its possible clinical applications. One of the most prominent features of photoacoustic imaging is its ability to characterize tissue, leveraging differences in the optical absorption of underlying tissue components such as hemoglobin, lipids, melanin, collagen and water among many others. In this review, the state-of-the-art photoacoustic imaging techniques and some of the key outcomes pertaining to different cancer applications in the clinic are presented.