Optical coherence tomography angiography for choroidal neovascularization in pathological myopia and neovascular age-related macular degeneration in combination with axial myopia in comparative analysis

Background. Optical coherence tomography angiography (OCTA) is currently an important method of visualization and assessment of fundus pathology in various diseases. The study of combined pathologies is not well covered.The aim: to compare OCTA features during choroidal neovascularization (CNV) in pathological myopia (PM) and in neovascular age-related macular degeneration in combination with axial myopia (nAMD + M) against the background of anti-VEGF therapy.Materials and methods. A prospective study included 70 eyes with active CNV. Comparative analysis of parameters was carried out between two groups: with PM – 47 eyes; with nAMD + M – 23 eyes.Results. 4 OCTA patterns were established in both groups: dense, loose, mixed and unidentifi able. With PM, dense pattern was found in 28 (59.57 %) eyes, loose pattern – in 16 (34.04 %), mixed pattern– in 2 (4.26 %), unidentifi able pattern – in 1 (2.13 %). In the nAMD + M group, dense pattern was rare – in 1 (4.35 %) eye, loose pattern – in 7 (30.44 %), mixed pattern – in 9 (39.13 %), unidentifi able pattern – in 6 (26.08 %). The fi rst group was characterized by a dense pattern that was found at a younger age, the second group was characterized by dense and mixed patterns. The greatest area and density of CNV were found with a loose pattern in both groups (p < 0.05). The observation period until the stabilization of CNV was achieved was longer in the loose and mixed patterns in the PM group, and in the loose and unidentifi able – in the nAMD + M group (p < 0.05). Loose and unidentifi able patterns require more injections. The halo was determined by the presence of intraretinal fluid in the retina. Conclusion. OCTA showed common features and distinctive features in the course of CNV in patients with PM and nAMD + M during anti-VEGF therapy. OCTA can be useful in assessing CNV activity and predicting the eff ect of treatment.

Convolutional Neural Networks for Breast Density Classification: Performance and Explanation Insights

We propose and evaluate a procedure for the explainability of a breast density deep learning based classifier. A total of 1662 mammography exams labeled according to the BI-RADS categories of breast density was used. We built a residual Convolutional Neural Network, trained it and studied the responses of the model to input changes, such as different distributions of class labels in training and test sets and suitable image pre-processing. The aim was to identify the steps of the analysis with a relevant impact on the classifier performance and on the model explainability. We used the grad-CAM algorithm for CNN to produce saliency maps and computed the Spearman’s rank correlation between input images and saliency maps as a measure of explanation accuracy. We found that pre-processing is critical not only for accuracy, precision and recall of a model but also to have a reasonable explanation of the model itself. Our CNN reaches good performances compared to the state-of-art and it considers the dense pattern to make the classification. Saliency maps strongly correlate with the dense pattern. This work is a starting point towards the implementation of a standard framework to evaluate both CNN performances and the explainability of their predictions in medical image classification problems.

Near-Infrared Tunable Laser Absorption Spectroscopic Acetylene Sensor System Using a Novel Three Mirror-Based, Dense Pattern Gas Cell

By contrast with the widely reported traditional two mirror-based Herriott cell, a three mirror-based dense pattern gas cell was proposed, of which the modeling and design were proven to be effective through a comparison between the simulated spot pattern and effective path length and those of the experimental results. A mechanical structure was designed to adjust the position/angle of the three mirrors for aligning the optical path. The experimentally measured reflection number was 60, resulting in an optical path length of ~11 m, which agrees well with the theoretical value of 10.95 m. Combined with a near-infrared laser with a center wavenumber located at an acetylene (C2H2) absorption line of 6521.2 cm−1, a C2H2 sensor system was established to verify the feasibility of the three mirror-based gas cell. Assisted by a data acquisition (DAQ) card, a LabVIEW platform was developed to generate the drive signal of the laser and acquire the second harmonic (2f) signal from the output of the detector. Through Allan variance analysis, the limit of detection (LoD) of the sensor system is 4.36 ppm at an average time of 0.5 s; as the average time exceeds 10 s, the LoD is <1 ppm. The proposed model and design of the three mirror-based gas cell can be used to realize similar gas cells with different absorption path lengths for gas detection based on infrared absorption spectroscopy.

Radial Endobronchial Ultrasonography with a Guide Sheath for the Diagnosis of Diffuse Parenchymal Lung Diseases

Background Radial-endobronchial ultrasonography (R-EBUS) is a useful bronchoscopic tool for the diagnosis of solitary pulmonary peripheral lesions. However, the utility of R-EBUS for the diagnosis of diffuse parenchymal lung disease (DPLD) remains unclear. This study aimed to examine the characteristics of R-EBUS patterns in association with computed tomography (CT) findings in diagnosing DPLD. Methods Transbronchial lung biopsy (TBLB) was performed using R-EBUS and a guide sheath (GS) in consecutive 35 patients with suspected DPLD on chest CT between March–November 2017. Consolidation, ground glass opacity (GGO), reticular, and nodular patterns were diagnosed, and the mean CT Hounsfield units in the sampled area were measured in patients with consolidation. R-EBUS characteristics and their association with CT findings and pathological diagnostic yield were evaluated. Results R-EBUS showed a dense pattern only in patients with consolidation, and a blizzard pattern in patients with consolidation, GGO, reticular, and nodular patterns on CT. The biopsied area’s mean CT value was significantly higher in patients with dense than with blizzard patterns (p < 0.0001), and pathological findings were also dense in patients with R-EBUS dense pattern. The pathological diagnostic yield was significantly higher in patients with overt R-EBUS patterns than in patients without R-EBUS patterns by obtaining better lung tissue samples with the GS (p < 0.0001). Conclusions Dense and blizzard R-EBUS patterns were novel findings in diagnosing DPLD, and TBLB with R-EBUS-GS may be a valuable tool in diagnosing DPLD

Dual-Gas Sensor of CH4/C2H6 Based on Wavelength Modulation Spectroscopy Coupled to a Home-Made Compact Dense-Pattern Multipass Cell

A sensitive dual-gas sensor for the detection of CH4 and C2H6 is demonstrated. Two tunable semiconductor lasers operating at 1.653 μm (for CH4 monitoring) and 1.684 μm (for C2H6) were used as the light source for spectroscopic measurements of CH4 and C2H6. Long-path absorption in a home-made compact dense-pattern multipass cell (Leff = 29.37 m) was employed, combined with wavelength modulation and second harmonic detection. Simultaneous detection of CH4 and C2H6 was achieved by separated wavelength modulations of the two lasers. Modulation frequencies and amplitudes were optimized for sensitivity detection of CH4 and C2H6 simultaneously. The dual-gas sensor exhibits 1σ detection limits of 1.5 ppbv for CH4 in 140 s averaging time and 100 ppbv for C2H6 in 200 s.

Molecular systematics of marine gregarine apicomplexans from Pacific tunicates, with descriptions of five novel species of Lankesteria

The eugregarines are a group of apicomplexan parasites that mostly infect the intestines of invertebrates. The high level of morphological variation found within and among species of eugregarines makes it difficult to find consistent and reliable traits that unite even closely related lineages. Based mostly on traits observed with light microscopy, the majority of described eugregarines from marine invertebrates has been classified into a single group, the Lecudinidae. Our understanding of the overall diversity and phylogenetic relationships of lecudinids is very poor, mainly because only a modest amount of exploratory research has been done on the group and very few species of lecudinids have been characterized at the molecular phylogenetic level. In an attempt to understand the diversity of marine gregarines better, we surveyed lecudinids that infect the intestines of Pacific ascidians (i.e. sea squirts) using ultrastructural and molecular phylogenetic approaches; currently, these species fall within one genus, Lankesteria. We collected lecudinid gregarines from six ascidian host species, and our data demonstrated that each host was infected by a different species of Lankesteria: (i) Lankesteria hesperidiiformis sp. nov., isolated from Distaplia occidentalis, (ii) Lankesteria metandrocarpae sp. nov., isolated from Metandrocarpa taylori, (iii) Lankesteria halocynthiae sp. nov., isolated from Halocynthia aurantium, (iv) Lankesteria herdmaniae sp. nov., isolated from Herdmania momus, (v) Lankesteria cf. ritterellae, isolated from Ritterella rubra, and (vi) Lankesteria didemni sp. nov., isolated from Didemnum vexillum. Visualization of the trophozoites with scanning electron microscopy showed that four of these species were covered with epicytic folds, whereas two of the species were covered with a dense pattern of epicytic knobs. The molecular phylogenetic data suggested that species of Lankesteria with surface knobs form a clade that is nested within a paraphyletic assemblage species of Lankesteria with epicytic folds.