2D Grayscale Research Articles

Three-dimensional greyscale transrectal ultrasound-guidance and biopsy core preembedding for detection of prostate cancer: Dutch clinical cohort study

BackgroundTo overcome the limitations regarding two dimensional (2D) greyscale (GS) transrectal ultrasound (TRUS)-guided biopsy in prostate cancer (PCa) detection and tissue packaging in biopsy processing, there is an ongoing focus on new imaging and pathology techniques. A three-dimensional (3D) model of the prostate with biopsy needle guidance can be generate by the Navigo™ workstation (UC-care, Israel). The SmartBX™ system (UC-care, Israel) provides a prostate biopsy core preembedding method. The aim of this study was to compare cancer detection rates between the 3D TRUS-guidance and preembedding method with conventional 2D GS TRUS-guidance among patients undergoing prostate biopsies.MethodsWe retrospectively analyzed the records of all patients who underwent prostate biopsies for PCa detection at our institution from 2007 to 2016. The cohort was divided into a 2D GS TRUS-guidance cohort (from 2007 to 2013, n = 1149) and a 3D GS TRUS-guidance with preembedding cohort (from 2013 to 2016, n = 469). Effect of 3D GS TRUS-guidance with preembedding on detection rate of PCa and clinically significant PCa (Gleason score ≥ 7 or > 2 biopsy cores with a Gleason score 6) was compared to 2D GS TRUS-guidance using regression models.ResultsDetection rate of PCa and clinically significant PCa was 39.0 and 24.9% in the 3D GS TRUS cohort compared to 33.5 and 19.0% in the 2D GS TRUS cohort, respectively. On multivariate regression analysis the use of 3D GS TRUS-guidance with preembedding was associated with a significant increase in detection rate of PCa (aOR = 1.33; 95% CI: 1.03–1.72) and clinically significant PCa (aOR = 1.47; 95% CI: 1.09–1.98).ConclusionOur results suggest that 3D GS TRUS-guidance with biopsy core preembedding improves PCa and clinically significant PCa detection compared to 2D GS TRUS-guidance. Additional studies are needed to justify the application of these systems in clinical practice.

Optimum adaptive array stochastic resonance in noisy grayscale image restoration

Considering the widespread noise interference in the two-dimensional (2D) image transmission processing, we proposed an optimal adaptive bistable array stochastic resonance (SR)-based grayscale image restoration enhancement method under low peak signal-to-noise ratio (PSNR) environments. In this method, the Hilbert scanning is adopted to reduce the dimension of the original grayscale image. The 2D image signal is converted into a one-dimensional (1D) binary pulse amplitude modulation (BPAM) signal. Meanwhile, we use the adaptive bistable array SR module to enhance the 1D low SNR BPAM signal. In order to obtain the restored image, we transform the enhanced BPAM signal into a 2D grayscale image signal. Simulation results show that the proposed method significantly outperforms the classical image restoration methods (i.e., mean filter, Wiener filter and median filter) both on the grayscale level and the PSNR of the restored image, particularly in a low PSNR scenario. Larger array size brings better image restoration effect.

Reversible shape change structures by grayscale pattern 4D printing

Structures and devices with reversible shape change (RSC) are highly desirable in many applications such as mechanical actuators, soft robotics, and artificial muscles. In this paper, we propose to use 3D grayscale printing method to create reversible self-folding structures. The grayscale pattern was used to control the light intensity distribution of a UV projector in a digital light processing 3D printer such that the same photo irradiation time leads to different curing degrees and thus different crosslinking densities at different locations in the polymer during 3D printing. After leaching the uncured oligomers inside the loosely crosslinked network, bending deformation could be induced due to the volume shrinkage. The bending deformation was reversed if the bent structure absorbed acetone and swelled. Using this method, we designed and created RSC structures such as reversible pattern transformation and self-expanding/shrinking structures, auxetic metamaterial, structures mimicking the blossom of a flower. The grayscale 4D printing method provides us a simple and efficient way to create active structures and has great potential in the application of smart structures, composite materials, soft robotics and endovascular stent.

Research on X-ray image processing technology for laser welded joints of aluminum alloy

Weldment X-ray image processing has great significance on the subsequent segmentation and extraction of weld seam and defects. In the current study, X-ray image for laser welding of aluminum alloy was adopted as experimental object. A new image denoising algorithm was proposed, which was combined with weighted adaptive median filter and noise-reduction algorithm based on wavelet transform. An improved adaptive fuzzy enhancement algorithm was put forward, which was based on traditional Pal-King fuzzy enhancement algorithm. Different noise-reduction algorithms were performed to denoise the X-ray image. Comprehensive evaluation of noise-reduction effect was conducted by comparing the processing effect, 3D grayscale distribution, and image quality evaluation index after different denoising algorithms. Moreover, fuzzy entropy and fuzzy index were used to estimate the enhancement effect of traditional Pal-King fuzzy enhancement algorithm and improved adaptive fuzzy enhancement algorithm. The results revealed that the noise-reduction effect and the image quality obtained by proposed algorithm were better than separately using weighted adaptive median filter or noise-reduction algorithm based on wavelet transform. Furthermore, after processing with improved adaptive fuzzy enhancement algorithm, the image detail information was more prominent, and sense of hierarchy was stronger.

PRospective Imaging of CErvical cancer and neoadjuvant treatment (PRICE) study: role of ultrasound to assess residual tumor in locally advanced cervical cancer patients undergoing chemoradiation and radical surgery

To determine the diagnostic performance of two-dimensional (2D) ultrasound parameters, three-dimensional (3D) power Doppler and contrast-enhanced indices in detecting residual disease in locally advanced cervical cancer patients triaged to neoadjuvant treatment followed by radical surgery. Between October 2010 and June 2014, we screened 108 women with histologically documented locally advanced cervical cancer Stage IB2-IVA, of whom 88 were included in the final analysis. 2D ultrasound parameters, 3D power Doppler and contrast-ultrasound parameters were assessed 5 weeks after the end of neoadjuvant chemoradiation therapy. The pathological response was defined as complete (absence of any residual tumor after treatment) or partial (including microscopic and/or macroscopic residual tumor at pathology examination). The two response groups were compared and receiver-operating characteristics (ROC) curves generated to determine the best cut-off value of sonographic tumor diameter to predict residual disease. Histology was considered as reference. Complete pathological response to chemoradiation was observed in 40 (45.5%) patients and partial response in 48 (54.5%). The presence of residual disease, as confirmed at pathology examination, was detected by 2D grayscale ultrasound with a sensitivity of 64.6% and specificity of 65%. Color Doppler examination in the cases with lesions visualized on grayscale imaging detected the presence of residual disease, confirmed at pathology, with a sensitivity of 87.1% and specificity of 21.4%. The best area under the ROC curve (0.817) was for the detection of pathological residual disease of at least 6 mm in diameter, using a cut-off value of 12 mm for the largest tumor diameter assessed using 2D grayscale ultrasound (sensitivity, 95%; specificity, 70.6%). Neither 3D vascular indices nor contrast-ultrasound parameters obtained for lesions suspected at ultrasound following chemoradiation differed significantly between patients with histological complete and those with partial response. Our results show that grayscale and color Doppler ultrasound have a low level of diagnostic performance in detecting residual disease after neoadjuvant chemoradiation in patients with locally advanced cervical cancer. The best performance was achieved in detection of macroscopic (≥ 6 mm) residual disease. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Can 3-Dimensional Power Doppler Indices Improve the Prenatal Diagnosis of a Potentially Morbidly Adherent Placenta in Patients With Placenta Previa?

(Am J Obstet Gynecol. 2017;217(2):202.e1–202.e13) The incidence of morbidly adherent placenta (MAP), a condition that can result in life-threatening hemorrhage and other maternal morbidities, has been on the rise. Traditionally, 2-dimensional (2D) ultrasound has been used to diagnose MAP and severe MAP (increta and percreta). This diagnosis is subjective as it relies on clinician interpretation of the ultrasound examination. This study aimed to evaluate the ability of a 3D power Doppler technique to diagnose MAP and severe MAP, as compared with gray-scale 2D ultrasound.

Validity of Gray Scale Sonography along with Color Doppler Spectral Analysis for the detection of Malignant Breast Tumour

Background: Detection of mass in the breastis very essential for the early treatment.Objective: The purpose of the present study was to validate the Doppler sonography to detect the pathological lesions of breast.Methodology: This cross sectional study was carried out in the Department of Radiology and Imaging in collaboration with the Department of Surgery and Department of Pathology at Banghabandhu Sheikh Mujib Medical University (BSMMU), Dhaka from July 2008 to June 2009 for a period of one (01) year. Clinically suspected women with breast mass who were attended in the OPD or inpatient department were selected purposively as study population. All the patients were examined by 2-D Real-Time B-Mode Ultrasonography by using high frequency (7.5 MHz) linear transducer. Blood flow was studied using Duplex sonography in which Gray scale 2D sonography was combined with Pulsed Doppler. Test of validity was done for color Doppler Sonographic findings in evaluation of benign and malignant breast lesion.Result:A total number of 50 cases were recruited for this study. Out of 50 cases,25 cases true positive, 1 false negative, 2 false positive, 22 true negative confirmed by histopathology. Here sensitivity and specificity of color Doppler ultrasonography are 92.59% and 86.95% respectively. Here accuracy of color Doppler study is 90.0% and the positive predictive value was 89.28% and negative predictive value was 90.9%.Conclusion: Color Doppler Ultrasonography is a useful imaging method in the differentiation between benign and malignant breast masses.Journal of National Institute of Neurosciences Bangladesh, 2017;3(1): 10-13

Second trimester marginal cord insertion is associated with adverse perinatal outcomes

Objectives: To determine the feasibility in visualizing placental cord insertion (PCI) during second-trimester fetal anatomical survey and the association between marginal cord insertion (MCI) and preterm delivery (PTD) and low birth weight (LBW). Our secondary objectives were to evaluate the association of MCI with adverse composite obstetrical and neonatal outcomes.Methods: A prospective cohort study was performed over a 28-month period. Women with singleton pregnancies presenting for routine anatomical survey between 18 and 22 weeks’ gestation were included. PCI site was visualized on 2D grayscale and color Doppler and the shortest distance from the sagittal and transverse planes to the placental edge were recorded. MCI was diagnosed when any of measured distances was ≤2 cm. Correlations were assessed via bivariate chi-squared, independent t-test analyses and Fisher’s exact tests. Regression models evaluated associations between MCI and adverse composite outcomes.Results: Three hundred one women were included and PCI was feasible in all cases. The incidence of MCI was 11.3% (n = 34). Baseline characteristics between those with and without MCI were similar, except for story of prior PTD, which was greater among those with MCI (17.65 versus 7.17%, p = .04). MCI was associated with increased likelihood of LBW (RR four; 95%CI, 1.46–10.99) and PTD (RR 3.2; 95%CI, 1.53–6.68); in multivariate analysis, we found associations between MCI and composite adverse obstetrical (RR 2.33; 95%CI, 1.30–4.19) and neonatal (RR 2.46; 95%CI, 1.26–4.81) outcomes.Conclusions: Evaluation of PCI is feasible in all cases. Second-trimester MCI is associated with increased likelihood for LBW, PTD, and composite adverse obstetrical and neonatal outcomes.

Edge Detection on DICOM Image using Triangular Norms in Type-2 Fuzzy

In image processing, edge detection is an important venture. Fuzzy logic plays a vital role in image processing to deal with lacking in quality of an image or imprecise in nature. This present study contributes an authentic method of fuzzy edge detection through image segmentation. Gradient of the image is done by triangular norms to extract the information. Triangular norms (T norms) and triangular conorms (T conorms) are specialized in dealing uncertainty. Therefore triangular norms are chosen with minimum and maximum operators for the purpose of morphological operations. Also, mathematical properties of aggregation operator to represent the role of morphological operations using Triangular Interval Type-2 Fuzzy Yager Weighted Geometric (TIT2FYWG) and Triangular Interval Type-2 Fuzzy Yager Weighted Arithmetic (TIT2FYWA) operators are derived. These properties represent the components of image processing. Here Edge detection is done for DICOM image by converting into 2D gray scale image, using Type-2 fuzzy MATLAB and which is the novelty of this work.

An automated blastomere identification method for the evaluation of day 2 embryos during IVF/ICSI treatments

PurposeEvaluation of human embryos is one of the most important challenges in vitro fertilization (IVF) programs. The morphology and the morphokinetic parameters of the early cleaving embryo are of critical clinical importance. This stage spans the first 48 h post-fertilization, in which the embryo is dividing in smaller blastomeres at specific time-points. The morphology, in combination with the symmetry of the blastomeres seems to be powerful features with strong prognostic value for embryo evaluation. To date, the identification of these features is based on human inspection in timed intervals, at best using camera systems that simply work as surveillance systems without any precise alerting and decision support mechanisms. The purpose of the study presented in this paper was to develop a computer vision technique to automatically detect and identify the most suitable cleaving embryos (preferably at day 2 post-fertilization) for embryo transfer (ET) during IVF/ICSI treatments. Methods and resultsTo this end, texture and geometrical features were used to localize and analyze the whole cleaving embryo in 2D grayscale images captured during in vitro embryo formation. Because of the ellipsoidal nature of blastomeres, the contour of each blastomere was modeled with an optimal fitting ellipse while the mean eccentricity of all ellipses is computed. The mean eccentricity in combination with the number of blastomeres forms the feature space on which the final criterion for the embryo evaluation was based. ConclusionsExperimental results with low quality 2D grayscale images demonstrated the effectiveness of the proposed technique and provided evidence of a novel automated approach for predicting embryo quality.

Unsupervised Feature Mapping via Stacked Sparse Autoencoder for Automated Detection of Large Pulmonary nodules in CT Images

We present a novel and efficient false positive reduction stage, using stacked sparse autoencoder, for the automatic detection of large nodules in computed tomography (CT) images. The discriminative features are automatically learnt in unsupervised manner. The initial candidates are segmented using candidate detection method specifically designed for the large nodules. For each candidate, 3D grayscale clusters are computed and, are later resized into a uniform size of 10 × 10 × 5 for feature mapping. Finally, a softmax layer is used for the binary classification. Data augmentation, sparsity regularization, and L2 weight regularization are applied to overcome the generalization issue. On 899 CT scans taken from LIDC-IDRI, our method yields a high detection sensitivity of 90 % with only 4 false positives per scan and an area under receiver operating curve of 0.983. An external validation on a completely independent dataset from PCF is also performed to evaluate the potency of the proposed method. We showed that the proposed stacked sparse autoencoder is efficient enough to be accommodated as a false positive reduction phase in a computer-aided-detection system. DOI: http://dx.doi.org/10.5755/j01.eie.23.6.19695

Nanofabrication of 80 nm asymmetric T shape gates for GaN HEMTs

This paper tackles the issue of current collapse frequently seen in AlGaN/GaN based high electron mobility transistors, caused by peak electric field on the device surface around the gate edges, which are worsened when shrinking the gate length down to sub-100nm for high frequency operation. To improve the device performance, a new configuration of T shape gates with asymmetric arms is proposed, based on our device simulation results. 3D grayscale electron beam lithography was developed to fabricate various shapes of the asymmetric T shape gates, indicating that such kind of gate configuration is technically feasible. The asymmetric T shape gates developed in this work to some extent can suppress the electric field on the gate edge efficiently as well as reduce the parasitic capacitance between the gate and the drain, leading to higher operation frequency. Applications of such a gate onto the GaN based HEMTs are hopefully to achieve high breakdown voltage for high frequency operation.

EP15.02: Prenatal diagnosis of abnormally invasive placenta

Abnormally invasive placenta (AIP) is a clinical term. It describes a placenta that does not separate spontaneously at the delivery because of abnormal implantation into the uterine wall. In this report we present 12 cases of AIP diagnosed for 6 years 2011-2016. All cases were diagnosed prenatally by 2D gray scale, colour Doppler and 3D ultrasound according the “European working group of AIP” criteria. The outcome of the cases was: - 1 resection of anterior uterine wall and 11 Caesarean hysterectomies with complications: - 6 resections of bladder - 2 relaparotomy after post operative bleeding - 1 vaginal hematoma - 8 excessive peripartal blood loss more than 5-6 litre Every ultrasound image presents more than one marker for AIP. The incidence of AIP in our hospital has increased with the rising number of Caesarean deliveries. In 90th – 2000th the frequency of AIP is 0.02% between 2011 - 2015 is 0.05% and at last year is rise to 0.09%. Supporting information can be found in the online version of this abstract Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Pore-scale characterization of tight sandstone in Yanchang Formation Ordos Basin China using micro-CT and SEM imaging from nm- to cm-scale

In this work, we measured the porosity, permeability, electrical resistivity and NMR T2 spectrum of the tight sandstone samples from Yanchang Formation Ordos Basin China. The experimental results indicate weak correlation between porosity and other bulk properties. A workflow of multi-scale digital rock technique is proposed to characterize pore geometry and connectivity in order to understand the ability of fluid flow or electric conduct of tight sandstones. A series of SEM images tiles (MAPS technique) with a resolution of 100nm in a large field of view (FOV) are first recorded on one end surface of sample and then stitched together to reveal fine pore structure, pore type and pore size distribution. Energy-Dispersive SEM (EDS-SEM) is performed on one the same end of the samples to obtain a mineralogy mapping which will be further used to identify mineralogy. The samples with the diameter of 25.4mm are scanned by X-ray Micro Computed Tomography (CT) to obtain 3D grayscale images, on which image registration, segmentation and cluster-labelling algorithms are applied to generate multi-mineral digital rock and investigate pore connectivity in 3D. The results of digital rock analysis demonstrate that the pore space of tight sandstone is classified into three types, residual intergranular pore, dissolved pore and micro pore in clay mineral. The results of pore size distribution for each type of pore indicate that the micro pore in clay dominates pore space in tight sandstone. The original intergranular pores are partly filled by clay minerals, where the micro pores contained in form percolation pathway and control the fluid flow through pore pace. The permeability and electrical properties of tight sandstones are dominated by micro pore and have higher dependence of the pore structure than only on porosity. The multi-mineral digital rock proposed in the study can be further applied in numerical simulation of bulk properties and quantitate analysis in nano-geoscience.

An automated algorithm for the detection of cortical interruptions on high resolution peripheral quantitative computed tomography images of finger joints.

ObjectivesTo introduce a fully-automated algorithm for the detection of small cortical interruptions (≥0.246mm in diameter) on high resolution peripheral quantitative computed tomography (HR-pQCT) images, and to investigate the additional value of manual correction of the automatically obtained contours (semi-automated procedure).MethodsTen metacarpophalangeal joints from seven patients with rheumatoid arthritis (RA) and three healthy controls were imaged with HR-pQCT. The images were evaluated by an algorithm according to the fully- and semi-automated procedure for the number and surface of interruptions per joint. Reliability between the fully- and semi-automated procedure and between two independent operators was tested using intra-class correlation coefficient (ICC) and the proportion of matching interruptions. Validity of single interruptions detected was tested by comparing it to visual scoring, as gold standard. The positive predictive value (PPV) and sensitivity were calculated.ResultsThe median number of interruptions per joint was 14 (range 2 to 59) and did not significantly differ between the fully- and semi-automated procedure (p = 0.37). The median interruption surface per joint was significantly higher with the fully- vs. semi-automated procedure (respectively, 8.6mm2 vs. 5.8mm2 and 6.1mm2, p = 0.01). Reliability was almost perfect between the fully- and semi-automated procedure for both the number and surface of interruptions (ICC≥0.95) and the proportion of matching interruptions was high (≥76%). Also the inter-operator reliability was almost perfect (ICC≥0.97, proportion of matching interruptions 92%). The PPV ranged from 27.6% to 29.9%, and sensitivity from 69.7% to 76.3%. Most interruptions detected with the algorithm, did show an interruption on a 2D grayscale image. However, this interruption did not meet the criteria of an interruption with visual scoring.ConclusionThe algorithm for HR-pQCT images detects cortical interruptions, and its interruption surface. Reliability and validity was comparable for the fully- and semi-automated procedures. However, we advise the use of the semi-automated procedure to assure quality. The algorithm is a promising tool for a sensitive and objective assessment of cortical interruptions in finger joints assessed by HR-pQCT.

Efficiently Storing Well-Composed Polyhedral Complexes Computed Over 3D Binary Images

A 3D binary image I can be naturally represented by a combinatorial-algebraic structure called cubical complex and denoted by Q(I), whose basic building blocks are vertices, edges, square faces and cubes. In Gonzalez-Diaz et al. (Discret Appl Math 183:59–77, 2015), we presented a method to “locally repair” Q(I) to obtain a polyhedral complex P(I) (whose basic building blocks are vertices, edges, specific polygons and polyhedra), homotopy equivalent to Q(I), satisfying that its boundary surface is a 2D manifold. P(I) is called a well-composed polyhedral complex over the picture I. Besides, we developed a new codification system for P(I), encoding geometric information of the cells of P(I) under the form of a 3D grayscale image, and the boundary face relations of the cells of P(I) under the form of a set of structuring elements. In this paper, we build upon (Gonzalez-Diaz et al. 2015) and prove that, to retrieve topological and geometric information of P(I), it is enough to store just one 3D point per polyhedron and hence neither grayscale image nor set of structuring elements are needed. From this “minimal” codification of P(I), we finally present a method to compute the 2-cells in the boundary surface of P(I).

Fetal intracranial hemorrhage: sonographic criteria and merits of prenatal diagnosis

Purpose: To determine the sonographic criteria for diagnosis of fetal intracranial hemorrhage (ICH), using both gray scale ultrasound, and tomographic ultrasound imaging (TUI).Materials and methods: A prospective multicenter study, recruiting patients at risk of fetal ICH over four years. All cases with fetal ICH had serial ultrasound assessments, including TUI, fetal and postnatal MRIs.Results: Twenty-one patients were diagnosed with fetal ICH, two cases had extracerebral (subdural) hemorrhage, 16 cases had intracerebral (intraventricular) hemorrhage and three cases had combined hemorrhage. The mean gestational age at which they were diagnosed was 29.8 ± 5.2 weeks. Seventy-six percent of cases had no identifiable risk factors. IUGR was associated with 57.9% of cases. Using grey scale ultrasound, we demonstrated clear cut sonographic criteria for diagnosis of fetal ICH. TUI enabled us to detect some midline cerebral lesions not detected by grey scale 2D ultrasound alone. Fetal and postnatal MRI confirmed those findings.Conclusion: Ultrasonography can be used in the detection, classification and monitoring the progression of various types of ICH. TUI is an additional diagnostic tool that might help to detect the exact size, and extent of those lesions. Fetal MRI is not superior, but might aid in the diagnosis.

Multi-scale contrast enhancement of oriented features in 2D images using directional morphology

This paper presents a multi-scale contrast enhancement scheme for improving the visual quality of directional features present in 2D gray scale images. Directional morphological filters are employed to locate and extract the scale-specific image features with different orientations which are subsequently stored in a set of feature images. The final enhanced image is constructed by weighted combination of these feature images with the original image. While construction, the feature images corresponding to progressively smaller scales are made to have higher proportion of contribution through the use of progressively larger weights. The proposed method has been formulated, implemented and executed on a set of real 2D gray scale images with oriented features. The experimental results visually establish the efficacy of the method. The proposed method has been compared with other similar methods both on subjective and objective basis and the overall performance is found to be satisfactory.

Topology-based image segmentation using LBP pyramids

In this paper, we present a new image segmentation algorithm which is based on local binary patterns (LBPs) and the combinatorial pyramid and which preserves structural correctness and image topology. For this purpose, we define a codification of LBPs using graph pyramids. Since the LBP code characterizes the topological category (local max, min, slope, saddle) of the gray level landscape around the center region, we use it to obtain a minimal image representation in terms of the topological characterization of a given 2D grayscale image. Based on this idea, we further describe our hierarchical texture aware image segmentation algorithm and compare its segmentation output and the minimal image representation.

Imaging Artifacts in Echocardiography.

Artifacts are frequently encountered during echocardiographic examinations. An understanding of the physics and underlying assumptions of ultrasound processing involved with image generation is important for accurate interpretation of 2D grayscale, spectral Doppler, color flow Doppler, and 3D artifacts and their clinical implications.