Diagonal Measurement Research Articles

Adaptive Ghost Imaging Based on 2D-Haar Wavelets

To improve the imaging speed of ghost imaging and ensure the accuracy of the images, an adaptive ghost imaging scheme based on 2D-Haar wavelets has been proposed. This scheme is capable of significantly retaining image information even under under-sampling conditions. By comparing the differences in light intensity distribution and sampling characteristics between Hadamard and 2D-Haar wavelet illumination patterns, we discovered that the lateral and longitudinal information detected by the high-frequency 2D-Haar wavelet measurement basis could be used to predictively adjust the diagonal measurement basis, thereby reducing the number of measurements required. Simulation and experimental results indicate that this scheme can still achieve high-quality imaging results with about a 25% reduction in the number of measurements. This approach provides a new perspective for enhancing the efficiency of computational ghost imaging.

Mixture-efficient identification of high-order herbal essential oil synergy using a normalized DiaMOND design

In this study, the effect of high-order combinations of Rosmarinus officinalis L. (R) EO with other essential oils obtained from selected Moroccan medicinal and aromatic plants, namely, Thymus satureioides Coss. (T), Origanum compactum Benth. (O), Pelargonium roseum L. (P), Artemisia herba-alba Asso. (A), and Salvia officinalis L. (S), was evaluated. The chemical composition of EOs was determined by GC/MS. Their antibacterial effect was determined using the microdilution method, whereas their antioxidant activity was evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing antioxidant power (FRAP) methods. The type of interaction between EOs was evaluated by the diagonal measurement of n-way drug interactions (DiaMOND). Antioxidant and antibacterial activity results demonstrate that O. compactum, T. satureioides, and P. roseum EOs tested alone showed significant efficacy. Using Principal Component Analysis (PCA) and hierarchical clustering analysis (HCA) modeling, one three-way combination (RST) was found with particularly strong synergistic DPPH radical scavenging (FIC3 = 0.50) and Fe3+ reducing (FIC3 = 0.48) properties. This combination also produced the highest activity against four bacteria strains (FIC3 = 0.38 for S. aureus, FIC3 = 0.38 for E. faecalis, FIC3 = 0.44 for E. coli, and FIC3 = 0.79 for P. aeruginosa). This mixture was, therefore, combined with conventional antibiotics. The results of all combinations showed a synergistic effect against four bacteria strains, which were tested with FIC2 ranging between 0.11 and 0.97. Our findings showed that a three-way combination of RST EOs constitutes a promising approach for possible application in the food and pharmaceutical industries.

Using mathematical ideas from carpet and carpet-weavers as a context for designing mathematics tasks

In this study, the mathematics of carpet will be introduced by presenting the lifestyle of two expert carpet-weavers from Kerman, Iran, who work for many years in carpet-weaving activities through an explanation of carpet weavers’ culture. This explanation reveals that carpet weavers can do mathematics and solve related real-world problems without academic education in mathematics according to their needs through practical activities. The main purpose of this study is to investigate the mathematical ideas in the art of carpet weavers, and the ethnography approach is used as a methodological framework. Our findings showed that there are many mathematical concepts in the carpet weaving process, such as mirror axes, parallel and diagonal lines, geometric shapes, ratio, and measurement which can be used as context for developing enrich and meaningful mathematical tasks.

The restricted isometry property of block diagonal matrices for group-sparse signal recovery

Group-sparsity is a common low-complexity signal model with widespread application across various domains of science and engineering. The recovery of such signal ensembles from compressive measurements has been extensively studied in the literature under the assumption that measurement operators are modeled as densely populated random matrices. In this paper, we turn our attention to an acquisition model intended to ease the energy consumption of sensing devices by splitting the measurements up into distinct signal blocks. More precisely, we present uniform guarantees for group-sparse signal recovery in the scenario where a number of sensors obtain independent partial signal observations modeled by block diagonal measurement matrices. We establish a group-sparse variant of the classical restricted isometry property (RIP) for block diagonal sensing matrices acting on group-sparse vectors, and provide conditions under which subgaussian block diagonal random matrices satisfy this group-RIP with high probability. Two different scenarios are considered in particular. In the first scenario, we assume that each sensor is equipped with an independently drawn measurement matrix. We later lift this requirement by considering measurement matrices with constant block diagonal entries. In other words, every sensor is equipped with a copy of the same prototype matrix. The problem of establishing the group-RIP is cast into a form in which one needs to establish the concentration behavior of the suprema of chaos processes which involves estimating Talagrand's γ 2 functional. As a side effect of the proof, we present an extension to Maurey's empirical method to provide new bounds on the covering number of sets consisting of finite convex combinations of possibly infinite sets.

Reinforced Effect on Brick Wall Using Timber Wall as a Retrofitting Method

The purpose of this study is to utilize timber material to enhance the in-plane shear strength and deformation capacity of a brick wall. The proposed strengthening method is light-weight and easy to assemble and includes a timber frame, plywood panel, M12 threaded rod with chemical epoxy, and the hold-down anchor. To evaluate the effectiveness of the reinforced brick wall, three walls were tested under a cyclic horizontal load and static compression stress: the brick wall (BW wall), the reinforced brick wall with timber (BW-T wall), and the reinforced brick wall with timber and the hold-down anchor (BW-TA wall). The proposed prediction method of the Kamiya and Inayama Murakami models assessed the BW-TA wall. The rocking was caused by the failure of BW and BW-T walls. However, because the BW-T wall failed in the lowest part of the wall, the timber part retained the original shape of the brick wall. When the diagonal on the BW-TA wall failed, the horizontal load at maximum load increased by 22%, and the drift angle calculated from the diagonal measurement increased 4.6 times.

Investigation of the High-order Effect of Rosmarinus officinalis, Salvia officinalis, and Thymus satureioides Essential Oils with Antibiotics on the Membrane Integrity of Salmonella typhi

The development of pathogenic Salmonella typhi strains resistant to several classes of antibiotics has become a worldwide main health care concern. Combinations of plant essential oils and drugs provide a promising approach to overcome drug resistance. This study investigates the potential antibacterial activity of EOs extracted from Rosmarinus officinalis, Salvia officinalis, and Thymus satureioides, individually and in combination with conventional antibiotics against S. typhi. The screening of 27 antibiotics was performed by the disc diffusion method, and the minimum inhibitory concentration of the selected antibiotics and EOs were determined by the broth microdilution method. At the same time, the interactions between EO and drugs were assessed by determining the fractional inhibitory concentration (FIC) using the diagonal measurement of n-way drug interactions method. The mechanism of antibacterial effect against S. typhi was evaluated by measuring the product of lipid peroxidation (MDA), potassium leakage from the bacteria cells, and scanning electron microscopy. Antibacterial screening indicated that nine antibiotics induced strong antibacterial activity against S. typhi with MIC values ranging from 2 to 85 µg/mL. Moreover, the EOs revealed an interesting effect against S. typhi, with MIC values ranging between 0.068 and 1.25 mg/mL. The combination of R. officinalis, T. satureioides EOs, and piperacillin/tazobactam provided a strong and reproducible synergistic effect against S. typhi. This combination seemed to amplify the antibacterial activity of EOs and antibiotics against S. typhi by increasing their potency in disrupting bacterial cell membrane integrity. These findings suggest that this combination could be a promising option for controlling the emergence of multidrug-resistant S. typhi.

Effect of proton beam irradiation on the tracking efficiency of CMOS image sensors

A star tracker provides accurate space positioning and reference for satellites, intercontinental strategic missiles, and other spacecrafts. However, the main imaging unit of the star sensor – the image sensor – is affected by the space radiation environment and, in turn, affects the precision with which the star is located by the star tracker. In this study, the parameter degradation of a CMOS image sensor (CIS) after proton irradiation with different fluences was investigated. An outfield test platform for star map collection was built using the star sensor lens and image collection system. The influence of dark current, dark-current nonuniformity, and photo-response nonuniformity of the irradiated CIS on the star diagonal distance measurement error and star-point centroid position detection accuracy was studied. The results showed that with increasing proton fluences, the CIS noise increased, leading to an increase in the error in the measured diagonal distance of the star and a decrease in the star’s position detection accuracy. Among these parameters, the dark current plays the greatest role in influencing the measurement accuracy of the star tracker. Furthermore, when a tracker is exposed to space radiation with fluences that are same as those used in this experiment, it is beneficial to reduce the integration time. This reduction in the time will decrease the noise and improve the position measurement accuracy.

Addressing antimicrobial resistance with the IDentif.AI platform: Rapidly optimizing clinically actionable combination therapy regimens against nontuberculous mycobacteria.

Background: Current standard of care (SOC) regimens against nontuberculous mycobacteria (NTM) usually result in unsatisfactory therapeutic responses, primarily due to multi-drug resistance and antibiotic susceptibility-guided therapies. In the midst of rising incidences in NTM infections, strategies to develop NTM-specific treatments have been explored and validated.Methods: To provide an alternative approach to address NTM-specific treatment, IDentif.AI was harnessed to rapidly optimize and design effective combination therapy regimens against Mycobacterium abscessus (M. abscessus), the highly resistant and rapid growth species of NTM. IDentif.AI interrogated the drug interaction space from a pool of 6 antibiotics, and pinpointed multiple clinically actionable drug combinations. IDentif.AI-pinpointed actionable combinations were experimentally validated and their interactions were assessed using Bliss independence model and diagonal measurement of n-way drug interactions.Results: Notably, IDentfi.AI-designed 3- and 4-drug combinations demonstrated greater %Inhibition efficacy than the SOC regimens. The platform also pinpointed two unique drug interactions (Levofloxacin (LVX)/Rifabutin (RFB) and LVX/Meropenem (MEM)) that may serve as the backbone of potential 3- and 4-drug combinations like LVX/MEM/RFB, which exhibited 58.33±4.99 %Inhibition efficacy against M. abscessus. Further analysis of LVX/RFB via Bliss independence model pointed to dose-dependent synergistic interactions in clinically actionable concentrations.Conclusions: IDentif.AI-designed combinations may provide alternative regimen options to current SOC combinations that are often administered with Amikacin, which has been known to induce ototoxicity in patients. Furthermore, IDentif.AI pinpointed 2-drug interactions may also serve as the backbone for the development of other effective 3- and 4-drug combination therapies. The findings in this study suggest that this platform may contribute to NTM-specific drug development.

Image Super-Resolution Through Compressive Sensing-based Recovery.

The primary aim of image super-resolution techniques is to produce a high resolution (HR) image from a low resolution (LR) image efficiently. Deep learning algorithms are being extensively used to address the ill-posed problem of single image super-resolution which requires extremely large data-sets and high processing power. When one does not have access to large data-sets or have limited processing power, an alternative technique may be in order. In this study, we have developed a novel positive scale image resizing method inspired by compressive sensing (CS). We have considered the image super-resolution as a CS recovery problem in which a low resolution image is assumed as a compressed measurement and the required interpolated image is treated as output of the CS-based recovery. In the proposed HR recovery method, a deterministic binary block diagonal measurement matrix, (DBBD), is used as measurement matrix since it maintains the visual similarity between the low and high resolution images. Then along with a sparsification matrix, the sparse representation of HR image is first recovered and subsequently the dense HR image is obtained. The proposed method is applied to medical and non-medical images. The HR images obtained using the traditional proximal, bilinear and bi-cubic interpolation techniques are compared with those obtained using the proposed method. The proposed CS inspired method delivers superior HR images than the traditional techniques. The superiority of the proposed method is attributed to the unique usage of the DBBD matrix and the CS recovery algorithm to obtain a high resolution image without any prior training data-set.

Accuracy of using diagonal measurements of maxillary canine, first premolar and first molar teeth in sex determination in a Pondicherry Cohort

Introduction: Sex may be determined from various parts of the human body like the skull remains, femur, humerus etc. However, in forensic cases, when human skeletal remains (such as skull, pelvis, femur, humerus, radius, clavicle, and ulnae etc.) are fragmented or incomplete, the teeth may be used for sex determination. The aim and objective of the present study: i) To assess the degree of sexual dimorphism in maxillary canines, first premolars and first molars using diagonal diameters of the crown (mesiobuccal-distolingual: MBDL, mesiolingual–distobuccal: MLDB/ DBML). ii) To determine the accuracy of maxillary canines, first premolars and first molars using diagonal measurements of the crown in sex determination. Materials and Methods: This study included 30 participants with equal gender ratio i.e 15 males:15 females and age ranged from 18 to 30 years. The participants were selected from Pondicherry population who visited to our department. Crown diagonal measurement of canines, first premolars and first molars were taken from right and left sides with the help of digital caliper (resolution of 0.1mm, accuracy of ±0.2mm). Data was analysed statistically usingdescriptive analysisand discriminant function analysis. Results: All crown diagonal dimensions in male revealed higher mean value than female except left premolar MBDL crown dimensions (male=7.8600, female=7.8733). There was significant difference in mean value of MBDL crown dimension of left canine, left first molar and right first molar between males than females. MBDL crown dimension of left maxillary canine exhibited the highest accuracy (66.7%) for sex determination with 60% in males and 73.3% in females. Conclusion: We conclude that diagonal crown (MBDL crown) dimension of left maxillary canine and first molar, right maxillary first molar can be used as an aid for gender determination where linear crown width (MD and BL) measurements cannot be taken or used as an aid along with other accepted procedu

Errors in the Vickers diagonal length measurement caused by different designs of microscopes

The errors in the Vickers diagonal length measurement are discussed from the point of view of the design of microscope. Effects of the numerical aperture (NA) of an objective lens are evaluated through the experiment. With smaller NA, the resolving power of the microscope gets worse and the depth of focus gets deeper as predicted Rayleigh’s criterion. The relationship between the repeatability of diagonal length and the objective NA follows the theory. In addition, the variation of NA relates the measured diagonal length. Those effects are much significant than the image resolution or the minimum count of a measuring system.

Low-cost and high-efficiency privacy-protection scheme for distributed compressive video sensing in wireless multimedia sensor networks

As a new video coding technology, distributed compressive video sensing (DCVS) uses compressed sensing (CS) independent encoding and joint decoding. Since DCVS breaks through the constraint of traditional video coding, it is suitable for resource-constrained wireless multimedia sensor networks (WMSNs). However, two major issues related to DCVS in WMSNs need to be solved urgently: one is to balance the storage burden of encoder and recovery quality of decoder; the other is to provide privacy-protection for video coding and transmission. We intend to break out of the existing limitations and design a new scheme which can simultaneously ensure privacy protection and high-efficiency coding for DCVS in WMSNs. Firstly, the two-pattern adaptive group of pictures selection is adopted to distinguish key frames and non-key frames. Secondly, the deterministic binary block diagonal measurement matrix is optimized to reduce sampling complexity. Thirdly, the scrambling-substitution-diffusion encryption method is proposed to resist various typical or potential attacks. Numerous experiments demonstrate that our scheme can not only perform valid and high-efficiency video coding, but also meet the demands of real-time and secure data transmission in WMSNs.

Volumetric error measurement and compensation of three-axis machine tools based on laser bidirectional sequential step diagonal measuring method

This paper proposes an approach to the measurement, modeling, and compensation of the volumetric errors for three-axis machine tools, using laser bidirectional sequential step diagonal measurement. Disparate measuring tracks are specially arranged for forward and backward paths, and the conforming error decoupling method is demonstrated. By decoupling, all the geometric errors which can result in volumetric errors are distinguished simultaneously, including translational and angular errors. In comparison with the traditional unidirectional measuring method, the proposed bidirectional method distinguishes more geometric errors (the angular errors) by measuring the same four body diagonals. Uncertainty analysis based on the Monte Carlo simulation was conducted, followed by experimental validation on a vertical machining center. The result of the experiment indicates that the diagonal systematic deviation of positioning is reduced by 90% after volumetric compensation.

Kambin's triangle and the position of the dorsal nerve root in the lumbar neural foramen.

As a result of the increased utilization of neurosurgical arthroscopic techniques, investigations into population and sex-specific trends of anatomical considerations have become increasingly important. This study aimed to investigate and describe aspects of the neuroanatomical morphometry of lumbar spines in a cadaveric and magnetic resonance imaging (MRI) sample. Twenty white adult (>18 years) cadavers (9 males; 11 females) were obtained under Ethical clearance. The lumbar regions were dissected and the position of the dorsal root ganglion (DRG) and dimensions of Kambin's triangle were determined. Twenty-six black adult (>18 years) MRI scans (17 males; 9 females) were obtained from an Academic Hospital and were used to determine the dimensions of the neural foramen and the DRGs within. The ganglia were mostly at the midline of the caudal pedicle. Similar to previous studies, the diagonal measurement from Kambin's triangle was the largest and the vertical measurement the shortest. Skeletal and soft-tissue measurements indicated distinct trends when moving caudolaterally in the spine. Soft-tissue parameters from the current study were within the upper limits of those from previous studies, whereas skeletal parameters were in agreement with those reported by previous authors. Results from this study suggest a variation of certain parameters between studies with varying population groups and therefore supports the need for and the importance of possible population-specific trends of anatomical parameters considered during surgical procedures.

Plug and play self-configurable IoT gateway node for telemonitoring of ECG

In the era of IoT and hyperconnection, an efficient electrocardiogram (ECG) telemonitoring system in wireless body area network (WBAN) demands an easy to use, self-configurable, secure, plug and play system with minimum hardware and computational complexities. The compression and quantization parameters required for an efficient representation of ECG signal will vary from patient to patient, from lead to lead, and from time to time. To this end, we propose a compressed sensing based WBAN with self-configurable gateway node (CS-SCGN) using deterministic binary block diagonal (DBBD) measurement matrix. The self-configurability is brought in through a low complex method for adaptive tuning of parameters with a careful choice of measurement matrix and data length. The redundant data transfer between sensor nodes and gateway node is avoided by addressing the diverse requirements in ECG remote health monitoring through three modes of configuration in the proposed system. A further reduction in communication and storage cost is achieved by optimizing the number of bits transmitted by sensor nodes by automatically tuning the compression ratio and quantization depth based on the dynamics of ECG signal. The self-configuration algorithm is designed to run at the gateway node in such a way as to optimize the power efficiency of sensor nodes without causing an extra power drain at the gateway node. Also, we investigate the feasibility of using smartphone as an IoT gateway node for performing primary processing to provide local utility before sending the received data to the remote server. The energy efficiency and real-time feasibility of the proposed algorithm are evaluated by implementing the gateway node on Odroid-XU4 board which runs on the same processor as in the latest smartphones. The experimental results indicate that our proposed self-configurable system at the gateway node makes the entire ECG telemonitoring system flexible, plug and play, patient independent and power-efficient.

Improving the Signal-to-Noise Ratio of Superresolution Imaging Based on Single-Pixel Camera

Based on the theories of single-pixel camera and compressed sensing image reconstruction, the sparse basis, the projection method of measurement matrix, and the signal reconstruction algorithm are optimized. First, for the sparse representation of image, the restraint matrix is designed combining the characteristics of wavelet sparse coefficients to enhance the sparse representation ability of the discrete wavelet base, which improves the quality of image reconstruction and imaging by single-pixel camera. Then, in the single-pixel camera system, the projection method is improved according to the characteristics of the digital mirror device micromirror, and a new bilateral projection method based on the block diagonal measurement matrix is proposed to realize the superresolution imaging of the outdoor scene, reducing the number of measurement and improving the imaging quality. Finally, for the algorithm of image reconstruction, combining the characteristics of convex optimization and nonconvex optimization algorithms, a new algorithm from convex optimization approximately to nonconvex optimization algorithm is proposed, and compared with the traditional image reconstruction algorithm, such as greedy pursuit algorithm, minimum norm algorithm, and image interpolation, the peak signal-to-noise ratio and imaging quality of reconstructed images are effectively improved. The feasibility of the proposed methods is demonstrated by simulation experiments and imaging experiments of single-pixel camera.

Information Formulation of the UDU Kalman Filter.

A new information formulation of the Kalman filter is presented where the information matrix is parameterized as the product of an upper triangular matrix, a diagonal matrix, and the transpose of the triangular matrix (UDU factorization). The UDU factorization of the Kalman filter is known for its numerical stability, this work extends the technique to the information filter. A distinct characteristic of the new algorithm is that measurements can be processed as vectors, while the classic UDU factorization requires scalar measurement processing, i.e. a diagonal measurement noise covariance matrix.

ENHANCING LASER STEP DIAGONAL MEASUREMENT BY MULTIPLE SENSORS FOR FAST MACHINE TOOL CALIBRATION

The volumetric performance of machine tools is limited by the remaining relative deviation between desired and real tool tip position. Being able to predict this deviation at any given functional point enables methods for compensation or counteraction and hence reduce errors in manufacturing and uncertainties for on-machine measurement tasks. Time-efficient identification and quanitification of different contributions to the resulting deviation play a key role in this strategy. The authors pursue the development of an optical sensor system for step diagonal measurement methods, which can be integrated into the working volume of the machine due to its compact size, enabling fast measurements of the axes’ motion error including roll, pitch and yaw and squareness errors without significantly interrupting the manufacturing process. The use of a frequency-modulating interferometer and photosensitive arrays in combination with a Gaussian laser beam allow for measurements at comparable accuracy, lower cost and smaller dimensions compared to state-of-the-art optical measuring appliances for offline machine tool calibration. For validation of the method a virtual machine setup and raytracing simulation is used which enables the investigation of systematic errors like sensor hardware misalignment.

Efficient measurement and factorization of high-order drug interactions in Mycobacterium tuberculosis.

Combinations of three or more drugs are used to treat many diseases, including tuberculosis. Thus, it is important to understand how synergistic or antagonistic drug interactions affect the efficacy of combination therapies. However, our understanding of high-order drug interactions is limited because of the lack of both efficient measurement methods and theoretical framework for analysis and interpretation. We developed an efficient experimental sampling and scoring method [diagonal measurement of n-way drug interactions (DiaMOND)] to measure drug interactions for combinations of any number of drugs. DiaMOND provides an efficient alternative to checkerboard assays, which are commonly used to measure drug interactions. We established a geometric framework to factorize high-order drug interactions into lower-order components, thereby establishing a road map of how to use lower-order measurements to predict high-order interactions. Our framework is a generalized Loewe additivity model for high-order drug interactions. Using DiaMOND, we identified and analyzed synergistic and antagonistic antibiotic combinations against Mycobacteriumtuberculosis. Efficient measurement and factorization of high-order drug interactions by DiaMOND are broadly applicable to other cell types and disease models.

CORRELATION OF ARTICULAR CARTILAGE THICKNESS MEASUREMENTS MADE WITH MAGNETIC RESONANCE IMAGING, MAGNETIC RESONANCE ARTHROGRAPHY, AND COMPUTED TOMOGRAPHIC ARTHROGRAPHY WITH GROSS ARTICULAR CARTILAGE THICKNESS IN THE EQUINE METACARPOPHALANGEAL JOINT.

Veterinary Radiology & UltrasoundVolume 58, Issue 2 p. 237-237 CorrigendumFree Access CORRELATION OF ARTICULAR CARTILAGE THICKNESS MEASUREMENTS MADE WITH MAGNETIC RESONANCE IMAGING, MAGNETIC RESONANCE ARTHROGRAPHY, AND COMPUTED TOMOGRAPHIC ARTHROGRAPHY WITH GROSS ARTICULAR CARTILAGE THICKNESS IN THE EQUINE METACARPOPHALANGEAL JOINT This article corrects the following: CORRELATION OF ARTICULAR CARTILAGE THICKNESS MEASUREMENTS MADE WITH MAGNETIC RESONANCE IMAGING, MAGNETIC RESONANCE ARTHROGRAPHY, AND COMPUTED TOMOGRAPHIC ARTHROGRAPHY WITH GROSS ARTICULAR CARTILAGE THICKNESS IN THE EQUINE METACARPOPHALANGEAL JOINT Erin G. Porter, Matthew D. Winter, Barbara J. Sheppard, Clifford R. Berry, Jorge A. Hernandez, Volume 57Issue 5Veterinary Radiology & Ultrasound pages: 515-525 First Published online: August 1, 2016 First published: 13 March 2017 https://doi.org/10.1111/vru.12462AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL In Porter et al.1 the following information was not published in Results and Discussion sections. Results section, page 520, first column: The new information should have been inserted at the end of the second paragraph. “The pixel dimensions calculated from the MRI and CT parameters used in the study are provided in Table 1. In our study, the average diagonal pixel measurement used for measuring cartilage thickness on MRI was about 0.79 mm. The average gross cartilage thickness on the third metacarpal bone was 1.03 mm and on the proximal phalanx was 1.15 mm. This indicates an error in measurement of about 77% for the third metacarpal bone and 69% for the proximal phalanx.2 Table 1. The pixel dimensions calculated from the MRI and CT parameters MRI Pulse sequence Vertical Resolution (mm) Horizontal resolution (mm) Diagonal resolution (mm) PD-FS 0.53 0.47 0.71 T1-FS 0.76 0.45 0.88 SSFP 0.67 0.45 0.81 SPGR-FS 0.58 0.47 0.75 CT arthrography 0.29 0.29 0.41 Discussion section, page 521, second column: The new information should have been inserted at the end of the first paragraph describing limitations of the study. “Some of the cartilage thickness measurements in this study were too small for the spatial resolution capabilities of magnetic resonance imaging system. The spatial resolution of the computed tomographic system was adequate to support the measurements made.” ACKNOWLEDGMENTS We would like to thank Manuel Arreola, PhD for his help in assessing the system resolution. We apologize for these errors. REFERENCE 1Porter EG, Winter MD, Sheppard BJ, Berry CR, Hernandez JA. Correlation of articular cartilage thickness measurements made with magnetic resonance imaging, magnetic resonance arthrography, and computed tomographic arthrography with gross articular cartilage thickness in the equine metacarpophalangeal joint. Vet Radiol Ultrasound 2016; 57: 515– 525. Volume58, Issue2March/April 2017Pages 237-237 ReferencesRelatedInformation