Overlay Images Research Articles

3D Printed Heart Models Illustrating Myocardial Perfusion Territories to Augment Echocardiography and Electrocardiography Interpretation

Visualizing the vascular territories of coronary arteries during echocardiography or electrocardiography (ECG) requires trainees to mentally relate and overlay 2D sonographic images or cardiac lead projections with 3D anatomical representations of the ventricular walls and their respective blood supply. To facilitate the acquisition of these competencies, this study focuses on the feasibility of developing low-cost, open-sourced 3D printed heart models with standard ultrasound views or ECG lead projections illustrating the myocardial perfusion territories. A 3D digital heart model was cut to reflect the typical cardiac ultrasound views. The 4-chamber view model was further punctured for the paths of the precordial and limb leads of an ECG. Painting coronary arteries on the surface and internal views of the 3D prints illustrated vessel territories. Students, residents, and staff were surveyed during bedside ultrasound simulation sessions and ECG teaching half-days. Results demonstrated clear appreciation of 3D printed models, which suggests such models can easily be implemented by other institutions to augment trainees' experience during skill acquisition.

Subjective and Objective Assessment of Monoenergetic and Polyenergetic Images Acquired by Dual-Energy CT in Breast Cancer.

ObjectiveTo objectively and subjectively assess and compare the characteristics of monoenergetic images [MEI (+)] and polyenergetic images (PEI) acquired by dual-energy CT (DECT) of patients with breast cancer.Materials and MethodsThis retrospective study evaluated the images and data of 42 patients with breast cancer who had undergone dual-phase contrast-enhanced DECT from June to September 2019. One standard PEI, five MEI (+) in 10-kiloelectron volt (keV) intervals (range, 40–80 keV), iodine density (ID) maps, iodine overlay images, and Z effective (Zeff) maps were reconstructed. The contrast-to-noise ratio (CNR) and the signal-to-noise ratio (SNR) were calculated. Multiple quantitative parameters of the malignant breast lesions were compared between the arterial and the venous phase images. Two readers independently assessed lesion conspicuity and performed a morphology analysis.ResultsLow keV MEI (+) at 40–50 keV showed increased CNR and SNRbreast lesion compared with PEI, especially in the venous phase ([CNR: 40 keV, 20.10; 50 keV, 14.45; vs. PEI, 7.27; p < 0.001], [SNRbreast lesion: 40 keV, 21.01; 50 keV, 16.28; vs. PEI, 10.77; p < 0.001]). Multiple quantitative DECT parameters of malignant breast lesions were higher in the venous phase images than in the arterial phase images (p < 0.001). MEI (+) at 40 keV, ID, and Zeff reconstructions yielded the highest Likert scores for lesion conspicuity. The conspicuity of the mass margin and the visual enhancement were significantly better in 40-keV MEI (+) than in the PEI (p = 0.022, p = 0.033, respectively).ConclusionCompared with PEI, MEI (+) reconstructions at low keV in the venous phase acquired by DECT improved the objective and subjective assessment of lesion conspicuity in patients with malignant breast lesions. MEI (+) reconstruction acquired by DECT may be helpful for the preoperative evaluation of breast cancer.

Analyzing the Integrin Adhesome by In Situ Proximity Ligation Assay.

The in situ proximity ligation assay (PLA) is capable of detecting single protein events such as protein protein-interactions and posttranslational modifications (e.g., protein phosphorylation) in tissue and cell samples prepared for analysis by immunofluorescent or immunohistochemical microscopy. The targets are detected using two primary antibodies which must be from different host species. A pair of secondary antibodies (PLA probes) conjugated to complementary oligonucleotides is applied to the sample, and a signal is generated only when the two PLA probes are in close proximity by their binding to the two primary antibodies that have bound to their targets in close proximity. The signal from each pair of PLA probes is visualized as an individual fluorescent spot. These PLA signals can be quantified (counted) using image analysis software (ImageJ), and also assigned to a specific subcellular location based on microscopy image overlays. In principle, in situ PLA offers a relatively simple and sensitive technique to analyze interactions among any proteins for which suitable antibodies are available. Integrin-mediated focal adhesions (FAs) are large multiprotein complexes consisting of more than 150 proteins, also known as the integrin adhesome, which link the extracellular matrix (ECM) to the actin cytoskeleton and regulate the functioning of mechanosignaling pathways. The in situ PLA approach is well suited for examining the spatiotemporal aspects of protein posttranslational modifications and protein interactions occurring in dynamic multiprotein complexes such as integrin mediated focal adhesions.

On the (Im)Practicality of Adversarial Perturbation for Image Privacy

Abstract Image hosting platforms are a popular way to store and share images with family members and friends. However, such platforms typically have full access to images raising privacy concerns. These concerns are further exacerbated with the advent of Convolutional Neural Networks (CNNs) that can be trained on available images to automatically detect and recognize faces with high accuracy. Recently, adversarial perturbations have been proposed as a potential defense against automated recognition and classification of images by CNNs. In this paper, we explore the practicality of adversarial perturbation-based approaches as a privacy defense against automated face recognition. Specifically, we first identify practical requirements for such approaches and then propose two practical adversarial perturbation approaches – (i) learned universal ensemble perturbations (UEP), and (ii) k-randomized transparent image overlays (k-RTIO) that are semantic adversarial perturbations. We demonstrate how users can generate effective transferable perturbations under realistic assumptions with less effort. We evaluate the proposed methods against state-of-theart online and offline face recognition models, Clarifai.com and DeepFace, respectively. Our findings show that UEP and k-RTIO respectively achieve more than 85% and 90% success against face recognition models. Additionally, we explore potential countermeasures that classifiers can use to thwart the proposed defenses. Particularly, we demonstrate one effective countermeasure against UEP.

A workflow for 3D-CLEM investigating liver tissue.

Correlative light and electron microscopy (CLEM) is a method used to investigate the exact same region in both light and electron microscopy (EM) in order to add ultrastructural information to a light microscopic (usually fluorescent) signal. Workflows combining optical or fluorescent data with electron microscopic images are complex, hence there is a need to communicate detailed protocols and share tips & tricks for successful application of these methods. With the development of volume-EM techniques such as serial blockface scanning electron microscopy (SBF-SEM) and Focussed Ion Beam-SEM, correlation in three dimensions has become more efficient. Volume electron microscopy allows automated acquisition of serial section imaging data that can be reconstructed in three dimensions (3D) to provide a detailed, geometrically accurate view of cellular ultrastructure. In addition, combining volume-EM with high-resolution light microscopy (LM) techniques decreases the resolution gap between LM and EM, making retracing of a region of interest and eventual overlays more straightforward. Here, we present a workflow for 3D CLEM on mouse liver, combining high-resolution confocal microscopy with SBF-SEM. In this workflow, we have made use of two types of landmarks: (1) near infrared laser branding marks to find back the region imaged in LM in the electron microscope and (2) landmarks present in the tissue but independent of the cell or structure of interest to make overlay images of LM and EM data. Using this approach, we were able to make accurate 3D-CLEM overlays of liver tissue and correlate the fluorescent signal to the ultrastructural detail provided by the electron microscope. This workflow can be adapted for other dense cellular tissues and thus act as a guide for other three-dimensional correlative studies. LAY DESCRIPTION: As cells and tissues exist in three dimensions, microscopy techniques have been developed to image samples, in 3D, at the highest possible detail. In light microscopy, fluorescent probes are used to identify specific proteins or structures either in live samples, (providing dynamic information), or in fixed slices of tissue. A disadvantage of fluorescence microscopy is that only the labeled proteins/structures are visible, while their cellular context remains hidden. Electron microscopy is able to image biological samples at high resolution and has the advantage that all structures in the tissue are visible at nanometer (10-9 m) resolution. Disadvantages of this technique are that it is more difficult to label a single structure and that the samples must be imaged under high vacuum, so biological samples need to be fixed and embedded in a plastic resin to stay as close to their natural state as possible inside the microscope. Correlative Light and Electron Microscopy aims to combine the advantages of both light and electron microscopy on the same sample. This results in datasets where fluorescent labels can be combined with the high-resolution contextual information provided by the electron microscope. In this study we present a workflow to guide a tissue sample from the light microscope to the electron microscope and image the ultra-structure of a specific cell type in the liver. In particular we focus on the incorporation of fiducial markers during the sample preparation to help navigate through the tissue in 3D in both microscopes. One sample is followed throughout the workflow to visualize the important steps in the process, showing the final result; a dataset combining fluorescent labels with ultra-structural detail.

Artificial Intelligence for Automated Overlay of Fundus Camera and Scanning Laser Ophthalmoscope Images.

PurposeThe purpose of this study was to evaluate the ability to align two types of retinal images taken on different platforms; color fundus (CF) photographs and infrared scanning laser ophthalmoscope (IR SLO) images using mathematical warping and artificial intelligence (AI).MethodsWe collected 109 matched pairs of CF and IR SLO images. An AI algorithm utilizing two separate networks was developed. A style transfer network (STN) was used to segment vessel structures. A registration network was used to align the segmented images to each. Neither network used a ground truth dataset. A conventional image warping algorithm was used as a control. Software displayed image pairs as a 5 × 5 checkerboard grid composed of alternating subimages. This technique permitted vessel alignment determination by human observers and 5 masked graders evaluated alignment by the AI and conventional warping in 25 fields for each image.ResultsOur new AI method was superior to conventional warping at generating vessel alignment as judged by masked human graders (P < 0.0001). The average number of good/excellent matches increased from 90.5% to 94.4% with AI method.ConclusionsAI permitted a more accurate overlay of CF and IR SLO images than conventional mathematical warping. This is a first step toward developing an AI that could allow overlay of all types of fundus images by utilizing vascular landmarks.Translational RelevanceThe ability to align and overlay imaging data from multiple instruments and manufacturers will permit better analysis of this complex data helping understand disease and predict treatment.

High‐resolution depth measurements in digital microscopic surgery

AbstractFully digital microscopes are becoming more and more common in surgical applications. In addition to high‐resolution stereoscopic images of the operating field, which can be transmitted over long distances or stored directly, these systems offer further potentials by supporting the surgical workflow based on their fully digital image processing chain. For example, the image display can be adapted to the respective surgical scenario by adaptive color reproduction optimization or image overlays with additional information, such as the tissue topology. Knowledge of this topology can be used for computer‐assisted or augmented‐reality‐guided microsurgical treatments and enables additional features such as spatially resolved spectral reconstruction of surface reflectance. In this work, a new method for high‐resolution depth measurements in digital microsurgical applications is proposed, which is based on the principle of laser triangulation. Part of this method is a sensor data fusion procedure to properly match the laser scanner and camera data. In this context, a strategy based on radial basis function interpolation techniques is presented to handle missing or corrupt data, which, due to the measuring principle, can occur on steep edges and through occlusion. The proposed method is used for the acquisition of high‐resolution depth profiles of various organic tissue samples, proving the feasibility of the proposed concept as a supporting technology in a digital microsurgical workflow.

A PROOF OF CONCEPT STUDY FOR [18F]-SODIUM FLUORIDE IMAGING OF NEPHROCALCINOSIS IN DONOR KIDNEYS AND EXPLANTED RENAL ALLOGRAFTS

Dutch Kidney Transplant Study Group. Introduction: Nephrocalcinosis is an important factor in the decline of graft function after kidney transplantation and is associated with both inferior graft function and poor graft survival. In invasive kidney allograft biopsies, microcalcifications are demonstrated in 12% - 43% of biopsies at one-year up to 79% at 10-years after kidney transplantation. As first step towards a potential non-invasive imaging method for identification of kidney microcalcifications, we performed a proof of concept study for ex-vivo [18F]-sodium fluoride ([18F]-NaF) imaging in donor kidneys and explanted renal allografts. Materials and Methods: Human kidney samples were obtained after deceased organ donation (n = 7) and after transplantectomy (n = 13). Three µm paraffin-embedded sections were used for histological evaluation of calcification (Alizarin Red and Von Kossa staining) and autoradiography imaging after a 30 minutes incubation with the radiopharmaceutical [18F]-NaF. Semi-automated detection of calcifications in tissue sections was performed and areas of [18F]-NaF activity were identified, resulting in overlay images of histology and tracer activity (Figure 1). The calcifications were classified according to their localization in the glomerular or tubulointerstitial area. Correlations between histology and autoradiography findings were presented as Spearman’s rho. Results: Transplantectomy samples were obtained at a median of 33 (IQR 9 – 66) months after transplantation, deceased organ donor samples were obtained from discarded kidneys. Microcalcifications were identified in 19 out 20 Alizarin Red stained samples, predominantly in cortical tissue. Tubulointerstitial microcalcifications were seen in 19 out 20 samples, with a median of 5.5 (IQR 2 – 10.3) per samples, and glomerular microcalcifications were seen in 7 out 20 samples, with a median of 1 (IQR 1 – 3) per sample. With autoradiography, [18F]-NaF activity was found in 19 out 20 samples, with an area surface of tracer activity of ≤5% in 13 and >5% in 6 out of 20 samples. Alizarin Red staining of microcalcifications demonstrated good correlation with [18F]-NaF activity (Spearman’s rho of 0.81, P<0.001) (Figure 2), whereas Von Kossa staining demonstrated weak correlation with [18F]-NaF activity (0.59, p=0.006).Conclusion: In this proof of concept study, we demonstrated that ex-vivo [18F]-NaF binding in human kidney parenchym samples has good correlation with histology-proven microcalcifications. This is the first step towards a non-invasive imaging method to identify microcalcifications in active nephrocalcinosis. The use of [18F]-NaF may lead to better understanding of the role of microcalcifications in the decline of graft function after transplantation.

Hyperspectral enhanced reality (HYPER) for anatomical liver resection.

Clinical evaluation of the demarcation line separating ischemic from non-ischemic liver parenchyma may be challenging. Hyperspectral imaging (HSI) is a noninvasive imaging modality, which combines a camera with a spectroscope and allows quantitative imaging of tissue oxygenation. Our group developed a software to overlay HSI images onto the operative field, obtaining HSI-based enhanced reality (HYPER). The aim of the present study was to evaluate the accuracy of HYPER to identify the demarcation line after a left vascular inflow occlusion during an anatomical left hepatectomy. In the porcine model (n = 3), the left branches of the hepatic pedicle were ligated. Before and after vascular occlusion, HSI images based on tissue oxygenation (StO2), obtained through the Near-Infrared index (NIR index), were regularly acquired and superimposed onto RGB video. The demarcation line was marked on the liver surface with electrocautery according to HYPER. Local lactates were measured on blood samples from the liver surface in both ischemic and perfused segments using a strip-based device. At the same areas, confocal endomicroscopy was performed. After ligation, HSI demonstrated a significantly lower oxygenation (NIR index) in the left medial lobe (LML) (0.27% ± 0.21) when compared to the right medial lobe (RML) (58.60% ± 12.08; p = 0.0015). Capillary lactates were significantly higher (3.07mmol/L ± 0.84 vs. 1.33 ± 0.71mmol/L; p = 0.0356) in the LML versus RML, respectively. Concordantly, confocal videos demonstrated the absence of blood flow in the LML and normal perfusion in the RML. HYPER has made it possible to correctly identify the demarcation line and quantify surface liver oxygenation. HYPER could be an intraoperative tool to guide perfusion-based demarcation line assessment and segmentation.

The Development of Augmented Reality Mobile Information System (ARMIS) influences the Psychological Factors in Consumers’ Preferences

Nowadays, the technologies had experienced massive changes. With the enhancement of technologies, enable devices, software as well as application to be synergised together and creating a new system. The synergised new system enables humankinds to have more productive live ahead in the future. Augmented Reality Mobile Information System (ARMIS) is a system developed using smart phone devices, web studio, mobile application and Quick Response (QR) Code; used to create an overlay image that able to portray the information of products. This system was developed due to the price checker in hypermarket giving out several problems towards the hypermarket customer & retailers, such as giving out a few information regarding towards the product, consuming more electric current, it hidden somewhere in the store and the linear barcode which holding less information. The crucial concept of ARMIS is development of QR Code, development of AR, development of mobile application and the implementation of ARMIS into smart phone devices. Using the model of Alessi Trollip, the product had undergone a few procedures in its development. The main objectives are to develop and introduce ARMIS and to test the ARMIS reliability whether it meets the need of the consumer. ARMIS system also had undergone the Alpha Test where the survey was done towards the The Store hypermarket’s customer in Kangar, Perlis, multimedia expert possesses Master or Ph.D and as well as the KPDNKK’s officer.

Iodine overlays to improve differentiation between peritoneal carcinomatosis and benign peritoneal lesions.

Peritoneal carcinomatosis (PC) is a prognostically relevant metastatic disease which may be difficult to depict in postoperative patients, particularly in early stages. This study aimed to determine whether PC could be diagnosed more accurately when using a combination of spectral detector CT (SDCT)-derived conventional images (CI) and iodine overlay images (IO) compared with CI only. Thirty patients with PC and 30 patientswith benign peritoneal alterations (BPA) who underwent portal-venous abdominal SDCT were included. Four radiologists determined the presence/absence of PC for each patient and assessed lesion conspicuity, diagnostic certainty, and image quality using 5-point Likert scales. Subjective assessment was conducted in two sessions comprising solely CI and CI/IO between which a latency of 6weeks was set. Iodine uptake and HU attenuation were determined ROI-based to analyze quantitative differentiation of PC/BPA. Specificity for PC was significantly higher when using CI/IO compared with using CI only (0.86 vs. 0.78, p ≤ 0.05), while sensitivity was comparable (0.79 vs. 0.81, p = 1). In postoperative patients, the increase in specificity was the highest (0.93 vs. 0.80, p ≤ 0.05). Lesion conspicuity was rated higher in CI/IO (4 (3-5)) compared with that in CI only (3 (3-4); p ≤ 0.05). Diagnostic certainty was comparable (both 4 (3-5); p = 0.5). CI/IO received the highest rating for overall image quality and assessability (CI/IO 5 (4-5) vs. CI 4 (4-4) vs. IO 4 (3-4); p ≤ 0.05). Area under the receiver operating characteristics curve (AUC) for quantitative differentiation between PC and BPA was higher for iodine (AUCIodine = 0.95, AUCHU = 0.90). Compared with CI, combination of CI/IO improves specificity in the assessment of peritoneal carcinomatosis at comparable sensitivity, particularly in postoperative patients. • Combination of iodine overlays and conventional images improves specificity when assessing patients with peritoneal carcinomatosis at comparable sensitivity. • Particularly in postsurgical patients, iodine overlays could help to avoid false-positive diagnosis of peritoneal disease. • Iodine overlays alone provided inferior image quality and assessability than conventional images, while the combination of both received the highest ratings. Iodine overlays should therefore be used in addition to and not as a substitute for conventional images.

CHARACTERISTICS AND CLASSIFICATION OF TYPE 3 NEOVASCULARIZATION WITH B-SCAN FLOW OVERLAY AND EN FACE FLOW IMAGES OF OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

To study B-scan flow overlay and en face flow optical coherence tomography angiography (OCT-A) images of Type 3 neovascularization (NV) and to characterize a staging system for Type 3 NV based on the OCT-A findings. We retrospectively collected data on consecutive treatment-naive eyes with Type 3 NV. All eyes underwent fluorescein angiography, indocyanine green angiography, structural spectral domain OCT, and OCT-A (AngioPlex). Localization and extension of abnormal flows detected by B-scan flow overlay and en face OCT-A images were assessed. Of 24 eyes of 22 patients with Type 3 NV, B-scan flow overlay images showed that 4.2% had telangiectatic flow in the deep retinal layer without outer plexiform layer disruption (Stage 1), 8.3% had downward intraretinal flow and subretinal flow without retinal pigment epithelium disruption (Stage 2), and 87.5% had downward flow and retinal pigment epithelium disruption (Stage 3). Of the Stage 3 eyes, 95.2% showed flow signal penetrating at the site of the retinal pigment epithelium disruption on the B-scan flow overlay images. We showed the characteristics of Type 3 NV using B-scan flow overlay and en face OCT-A images. B-scan flow overlay OCT-A images seem useful to improve the detection and accurate diagnosis of Type 3 NV.

Deep Recognition of Vanishing-Point-Constrained Building Planes in Urban Street Views.

This paper presents a new approach to recognizing vanishing-point-constrained building planes from a single image of street view. We first design a novel convolutional neural network (CNN) architecture that generates geometric segmentation of per-pixel orientations from a single street-view image. The network combines two-stream features of general visual cues and surface normals in gated convolution layers, and employs a deeply supervised loss that encapsulates multi-scale convolutional features. Our experiments on a new benchmark with fine-grained plane segmentations of real-world street views show that our network outperforms state-of-the-arts methods of both semantic and geometric segmentation. The pixel-wise segmentation exhibits coarse boundaries and discontinuities. We then propose to rectify the pixel-wise segmentation into perspectively-projected quads based on spatial proximity between the segmentation masks and exterior line segments detected through an image processing. We demonstrate how the results can be utilized to perspectively overlay images and icons on building planes in input photos, and provide visual cues for various applications.

Augmented reality and artificial intelligence-assisted surgical navigation: Technique and cadaveric feasibility study.

Purpose:Augmented reality-based image overlay of virtual bony spine anatomy can be projected onto real spinal anatomy using computer tomography-generated DICOM images acquired intraoperatively. The aim of the study was to develop a technique and assess the accuracy and feasibility of lumbar vertebrae pedicle instrumentation using augmented reality-assisted surgical navigation.Subjects and Methods:An augmented reality and artificial intelligence (ARAI)-assisted surgical navigation system was developed. The system consists of a display system which hovers over the surgical field and projects three-dimensional (3D) medical images corresponding with the patient's anatomy. The system was registered to the cadaveric spine using an optical tracker and arrays with reflective markers. The virtual image overlay from the ARAI system was compared to 3D generated images from intraoperative scans and used to percutaneously navigate a probe to the cortex at the corresponding pedicle starting point. Intraoperative scan was used to confirm the probe position. Virtual probe placement was compared to the actual probe position in the bone to determine the accuracy of the navigation system.Results:Four cadaveric thoracolumbar spines were used. The navigated probes were correctly placed in all attempted levels (n = 24 levels), defined as Zdichavsky type 1a, Ravi type I, and Gertzbein type 0. The virtual overlay image corresponded to the 3D generated image in all the tested levels.Conclusions:The ARAI surgical navigation system correctly and accurately identified the starting points at all the attempted levels. The virtual anatomy image overlay precisely corresponded to the actual anatomy in all the tested scenarios. This technology may lead more uniform outcomes between surgeons and decrease minimally invasive spine surgery learning curves.

Augmented Reality Underpinned Instructional Design (ARUIDs) for Cogno-Orchestrative Load

In modern times the research and technology in the education sector have revolutionized the teaching-learning environment. Traditional methodologies are being supported by tech-savvy practices. These practices demand young learners to be more advanced, and modern teachers to be more efficient. Under k-12 education program, Science, Technology, Engineering and Mathematics (STEM) are the desired domains to be learned and pursued as future professions today. It is, therefore, apparent to prepare young learners in these domains at an early stage. This situation requires an increased mental load on learners as well as on teachers. Modern technology comes to resolve this situation to some extent where computers, Augmented Reality (AR), Virtual reality (VR) gadgets, etc. help both the learners and the teachers in decreasing their mental load. The orchestration load of the teachers and cognitive load of the learners can further be decreased using AR applications. AR can overlay virtual 3D images on real objects and enhance learning in a fun way. This paper introduces the development of Augmented Reality Learning System (ARLS) followed by an Electronics Kit to make young learners understand the basic fundamentals of science such as electricity, current, electric circuits, working of light switch, thermister, light-dependent register (LDR) and capacitor-based circuits. This ARLS makes use of the markers overlaid on Tangible User Interface (TUI) and shows virtual functioning of these electrical/electronic circuits. The combination of TUI and ARLS results the formation of Augmented Reality Underpinned Design Kit (ARUID Kit). Students work individually on this ARUID kit to gain new learning experience of science fundamentals.

Augmented reality for image guidance in transoral robotic surgery.

With the advent of precision surgery, there have been attempts to integrate imaging with robotic systems to guide sound oncologic surgical resections while preserving critical structures. In the confined space of transoral robotic surgery (TORS), this offers great potential given the proximity of structures. In this cadaveric experiment, we describe the use of a 3D virtual model displayed in the surgeon's console with the surgical field in view, to facilitate image-guided surgery at the oropharynx where there is significant soft tissue deformation. We also utilized the 3D model that was registered to the maxillary dentition, allowing for real-time image overlay of the internal carotid artery system. This allowed for real-time visualization of the internal carotid artery system that was qualitatively accurate on cadaveric dissection. Overall, this shows that virtual models and image overlays can be useful in image-guided surgery while approaching different sites in head and neck surgery with TORS.

Detection of Development and Density Urban Build-Up Area with Satellite Image Overlay

The growth dynamics of urban areas and the increase in land requirements are a series of each other influence each other The method used in this study is a quantitative method through spatial analysis using Geographic Information Systems. The purpose of this study was to see the extent to which the development of urban areas using the Urban Index (UI) method. Data analysis carried out by overlapping techniques using a map of the built area of Land Use in 2013 and the results of image interpretation for the built area in 2017. The results of the study showed that there was a percentage increase in the built area from 2013 to 2017 of 12.67%. Then from the total area of Makassar City, around 60.72% of the area built in 2013, and there was a significant increase in 2017 to 76.30%. The process of expansion of built-up land without control often impacts on the loss of land that has ecological functions and then impacts on the emergence of environmental problems. One of the things that can be done to prevent the adverse effects of the development of built land is to monitor and predict its development so that solutions can found before the adverse effects occur.

Diagnostic value of spectral reconstructions in detecting incidental skeletal muscle metastases in CT staging examinations

BackgroundTo investigate if iodine density overlay maps (IDO) and virtual monoenergetic images at 40 keV (VMI40keV) acquired from spectral detector computed tomography (SDCT) can improve detection of incidental skeletal muscle metastases in whole-body CT staging examinations compared to conventional images.MethodsIn total, 40 consecutive cancer patients who underwent clinically-indicated, contrast-enhanced, oncologic staging SDCT were included at this retrospective study: 16 patients with n = 108 skeletal muscle metastases confirmed by prior or follow-up CT, 18F-FDG-PET, MRI or histopathology, and a control group of 24 patients without metastases. Four independent readers performed blinded, randomized visual detection of skeletal muscle metastases in conventional images, IDO and VMI40keV, indicating diagnostic certainty for each lesion on a 5-point Likert scale. Quantitatively, ROI-based measurements of attenuation (HU) in conventional images and VMI40keV and iodine concentration in IDO were conducted. CNR was calculated and receiver operating characteristics (ROC) analysis of quantitative parameters was performed.ResultsRegarding subjective assessment, IDO (63.2 (58.5–67.8) %) and VMI40keV (54.4 (49.6–59.2) %) showed an increased sensitivity for skeletal muscle metastases compared to conventional images (39.8 (35.2–44.6) %). Specificity was comparable in VMI40keV (69.8 (63.2–75.8) %) and conventional images (69.2 (60.6–76.9) %), while in IDO, it was moderately increased to 74.2 (65.3–78.4) %. Quantitative image analysis revealed that CNR of skeletal muscle metastases to circumjacent muscle was more than doubled in VMI40keV (25.8 ± 11.1) compared to conventional images (10.0 ± 5.3, p ≤ 0.001). Iodine concentration obtained from IDO and HU acquired from VMI40kev (AUC = 0.98 each) were superior to HU attenuation in conventional images (AUC = 0.94) regarding differentiation between healthy and metastatic muscular tissue (p ≤ 0.05).ConclusionsIDO and VMI40keV provided by SDCT improve diagnostic accuracy in the assessment of incidental skeletal muscle metastases compared to conventional CT.

The determination of some stand parameters using SfM-based spatial 3D point cloud in forestry studies: an analysis of data production in pure coniferous young forest stands

Benefiting from current unmanned air vehicle (UAV) and remote sensing techniques, the present study aims to estimate tree count (TC), tree height (TH), and tree crown cover area (TCCA) in a young Calabrian pine stand via canopy height model (CHM). Overlay images obtained using Quadcopter were used to generate two spatial three-dimensional (3D) cloud points in two different qualities. Point clouds were processed using R program in order to produce tree data using CHM. The sensitivity of CHM-based tree data was revealed using 318 tree measurements in 32 different sampling units. Estimation and measurement values were classified based on their structure from motion (SfM) quality and cover classes, and the statistical relationships among them were analyzed. Without any classification, R2 was calculated for TC, THMean, and TCCATotal estimations and field measurements. R2 values were calculated as 0.865, 0.778, and 0.869, respectively, for SfMHighest CHM, while they were calculated as 0.863, 0.736, and 0.843, respectively, for SfMMedium CHM. In addition, sensitivity and performance ranking in different groups were determined based on root mean square error (RMSE) and mean absolute percentage error (MAPE) values. A significant difference was observed among groups in terms of quality and cover for TH, while no significant differences were observed for TCCA. Therefore, it is possible to estimate the properties of SfM CHM-based young coniferous stand. It was understood that tree density, crown shape, and branching influenced the accuracy of the present study. The developed UAV (Drone)-SfM is a promising technique for further small-scale forestry studies.

Simulating vascular leakage on optical coherence tomography angiography using an overlay technique with corresponding thickness maps

BackgroundTo demonstrate a technique for using optical coherence tomography angiography (OCTA) to simulate leakage in eyes with diabetic macular oedema and determine the sensitivity and positive predictive value of detecting...