Accurate Size Measurement Research Articles

Metallic material microstructure grain size measurements from backscattering signals in ultrasonic array data sets

Ultrasound backscattering signals from material microstructures can be used to evaluate the material microstructure grain size. This typically involves making pulse-echo immersion measurements at multiple locations using a focused ultrasonic transducer in order to obtain an accurate estimate of the root-mean-square amplitude of the back-scattered signal at a specified focal position. However, this restricts some practical applications of using such techniques in, for example, on-line measurements in high-value manufacturing and in-service inspections where multiple immersion measurements are not feasible to use. The main benefit of using ultrasonic phased arrays is that one array probe at one position can focus ultrasound beams at multiple points using different focal laws either physically or in data postprocessing. Potentially this means that accurate grain size measurements can be obtained from a single array measurement. In this paper, the classic backscattering method for conventional transducers is adapted to be used for full matrix capture datasets from an ultrasonic array. Three-dimensional ultrasonic models are developed in the proposed inverse process to measure material microstructure grain size. Experimental validations were performed on two metallic materials: copper (EN1652) and bright mild steel (BS970). A good agreement is shown between the experimentally measured grain sizes from array data and metallography measurements. Compared to the classic pulse-echo immersion back-scattering measurements, the proposed method enables accurate measurement of grain size in a direct contact configuration at fewer locations. This has potential to make on-line grain size measurements possible.

Variability in Liver Size Measurements Using Different View Angles in Ultrasound Imaging.

The aim of this study was to compare liver size measurements in different conventional B-mode ultrasound image (US) field views using magnetic resonance imaging (MRI) measurement as a reference. After receiving Institutional Review Board approval and informed consent, three operators measured the largest sagittal and transverse dimensions of adult livers on three US image field views (90°, 120°, and 140°) with a single curvilinear transducer. We analyzed the differences in liver size across three image field views using one-way analysis of variance (ANOVA) and examined the correlations between MRI and ultrasound measurements using Spearman regression. We used 95% Bland-Altman limits of agreement (95% LOA) to analyze the confidence interval for liver size measurements between MRI and US. Intra-observer and inter-observer reliability in measuring liver size were assessed using intraclass correlation coefficient (ICC). Based on sagittal liver length, 28 adult participants (7 men and 21 women, mean age 43 years) were divided into Group 1 (<17 cm, n = 10) or Group 2 (≥17 cm, n = 18). There was a significant difference in the liver size measurements across the three image field views (P < .001) in both groups. The highest correlation in liver size measurements between MRI and US was with ultra-wide-view (R2 = .87 in sagittal; R2 = .79 in transverse). Bland-Altman LOA also indicated good agreement between MRI and ultra-wide-view measurements. Intra-observer and inter-observer reliability in measuring liver size were good (ICC = 0.82-0.98). The study suggests that ultrasound ultra-wide-view provides the most accurate liver size measurement and good intra- and inter-operator reliability.

Proper application of DNA dyes in agarose gel electrophoresis.

Various dyes are used to visualize DNA bands in agarose gel electrophoresis (AGE) by the methods of pre- or post-staining. The DNA dye user's guides generally state that the binding of the dye to DNA will affect DNA mobility in electrophoresis, thus recommending post-staining for accurate measurement of DNA size. However, many AGE performers prefer pre-staining procedures for reasons such as convenience, real-time observation of DNA bands, and/or the use of a minimal amount of dye. The detrimental effect of the dye on DNA mobility and the associated risk for inaccurate measurement of DNA size are often overlooked by AGE performers. Here we quantitatively determine the impact on DNA migration imposed by frequently used dyes, including GelRed, ethidium bromide (EB), and Gold View. It was observed that pre-staining with GelRed and EB significantly slowed down DNA migration to cause as much as 39.1% overestimation on the size of sample DNA, whereas Gold View had little effect. The slowdown of DNA migration increased with dye concentration until it plateaued when the dye concentration reached a saturated level. Thus, to take advantage of pre-staining, saturated levels of DNA dyes should always be applied for both DNA samples and DNA markers to ensure a fair comparison of DNA sizes. In addition, GelRed and EB display much higher sensitivity than Gold View in the detection of DNA bands in post-staining. The saturated concentrations, cost considerations, and other useful features of these frequently used dyes are summarized for the information of AGE performers.

Point Cloud Measurement of Rubber Tread Dimension Based on RGB-Depth Camera

To achieve an accurate measurement of tread size after fixed-length cutting, this paper proposes a point-cloud-based tread size measurement method. Firstly, a mathematical model of corner points and a reprojection error is established, and the optimal solution of the number of corner points is determined by the non-dominated sorting genetic algorithm II (NSGA-II), which reduces the reprojection error of the RGB-D camera. Secondly, to address the problem of the low accuracy of the traditional pixel metric ratio measurement method, the random sampling consensus point cloud segmentation algorithm (RANSAC) and the oriented bounding box (OBB) collision detection algorithm are introduced to complete the accurate detection of the tread size. By comparing the absolute error and relative error data of several groups of experiments, the accuracy of the detection method in this paper reaches 1 mm, and the measurement deviation is between 0.14% and 2.67%, which is in line with the highest accuracy standard of the national standard. In summary, the RGB-D visual inspection method constructed in this paper has the characteristics of low cost and high inspection accuracy, which is a potential solution to enhance the pickup guidance of tread size measurement.

Application of instance segmentation algorithm incorporating attention mechanism and BiFPN for sinter ore particle size recognition

The particle size composition of sinter plays a decisive role in the output and energy consumption of blast furnace ironmaking. To reduce energy consumption and achieve efficient production, accurate measurement of sinter particle size and distribution has become an important issue. Due to the problems of adhesion, large size difference and edge effect in sinter image, the traditional image segmentation algorithm makes it difficult to effectively separate sinter. This paper proposes an intelligent recognition method of sinter particle size based on an improved BlendMask instance segmentation algorithm. Bidirectional feature pyramid network is used to replace the feature pyramid network structure (FPN), and the attention mechanism Convolutional Block Attention Module (CBAM) is introduced to improve the ability to extract shallow features and enhance the ability to identify adherent sinter. The test results show that the average detection accuracy mean average precision (mAP) of the model proposed in this article is 71.0%, and the mAP50 is 93.8%. The average segmentation accuracy mAP is 68.0% and mAP50 is 93.8%. The identified sinter images were then edge-refined using morphological methods to collect statistics on the particle size distribution of the sinter. Compared with the actual measured sinter particle size, the average relative error is 4.9%. This method can accurately identify sinter in complex environments, improve the production efficiency of sinter, optimise resource utilisation and reduce personnel costs and has important application prospects.

Computer vision–based surface defect identification method for weld images

Welding is the main connection type used in steel structure bridges. As the weld quality significantly affects the performance of a structure, weld defect detection is crucial in the performance evaluation of bridges. With the continuous development of computer vision (CV) techniques and image acquisition equipment, CV-based methods are being increasingly applied to weld defect detection. However, accurate identification of welding defects from several images is challenging. This paper proposes a CV-based method for detecting and quantifying surface porosity defects in welds. CV techniques were used to identify and extract weld defects, and the pixel-level sizes of the weld defects were obtained. The actual sizes of the weld defects were calculated based on a conversion between the image size and actual size. The results show that the proposed image processing method has low complexity and high accuracy in detecting weld defects, providing accurate measurement of the defect size. It is a fast and non-contact detection method for weld defect detection.

Estimating Poly(N-isopropylacrylamide) size in solution below the LCST using fluorescence correlation spectroscopy with non-covalent bound fluorophores

Accurate size measurements of nanosized polymer chains in dilute solutions is important for understanding polymer behavior, however, these measurements can be challenging to implement accurately, and are technique dependent. Here we explore the use of Fluorescence Correlation Spectroscopy (FCS) to determine the size of single polymer chains in dilute solutions (<2 wt%). FCS, a technique with single molecule sensitivity, generally requires the use of covalently labelled polymers which can distort physicochemical behavior. Here, FCS based size measurements were based on the non-covalent interaction of fluorophores (Alexa 405, Atto 390, and Atto 425) with PNIPAm in water at 25 °C (below the Lower Critical Solution Temperature).FCS estimated size (hydrodynamic radius) of three different MW PNIPAm samples in water were: 5.0 ± 1.0 nm (28.5 kDa), 5.0 ± 1.0 nm (38 kDa), 3.3 ± 0.5 nm (55.5 kDa), in reasonable agreement with theoretical calculations. Accuracy was directly related to the fraction of PNIPAm-bound fluorophore, which were, for 1 wt% PNIPAm solutions in water: ∼11.5 % (Atto 390), ∼8.1 % (Atto 425), and 4 % (Alexa 405). This method has several advantages in that it does not require a covalent labelling of PNIPAm, it can be implemented on very small sample volumes, and allows for in-situ measurements.

Impact of spleen volume on post-allogenic hematopoietic transplant outcomes in myelofibrosis: Utility of 3D volumetrics in splenomegaly.

6558 Background: Splenomegaly is a hallmark of myelofibrosis, thought to be correlated with graft failure and worsened overall survival in transplant patients. Past studies have utilized manual spleen measurement, potentially affecting accuracy. Using 3D volume can more precisely measure spleen size. Hence, the true impact of splenomegaly on transplant outcomes remains unclear. In this retrospective study, we examined myelofibrosis patients who underwent HCT and, using 3D volumetrics, analyzed the impact of splenomegaly and volume reduction over time on post HCT outcomes. Methods: This retrospective study included 130 City of Hope myelofibrosis patients with pre HCT imaging (2004–2023). Patients were divided into pre HCT spleen volume of &gt;3000 cc and &lt;3000 cc, with &gt;3000 cc considered massive splenomegaly. Spleen volume was measured using Vitrea 3D volumetric software. For each patient, depending on imaging available, volume was measured 0-3 months pre HCT, 3-6 months, 6-9 months, and 9-12 months post HCT with corresponding volume reduction calculations. Pre HCT spleen volume was also temporally correlated with several post HCT outcomes. Results: Median age at HCT was 60 (17-75), and 95% of patients received the Fludarabine/Melphalan conditioning regimen. Median spleen volume pre HCT was 1150 cc (41-6695 cc). Sixteen patients measured &gt;3000cc, and 114 patients measured &lt;3000cc. Median spleen volume 3-6 months post HCT was 661 cc (80-1731 cc) with a median 48% volume reduction. The data suggests that majority of volume reduction occurred during this time (table). Five-year overall survival (OS) was 72.8%. Relapse was 11.0% at 1 year and 14.7% at 5 years. NRM at 5 years was 17.3%. ANC engraftment peaked at 28 days at 92.3%. Pre HCT spleen volume (&lt;1000 cc, 1000-2000 cc, &gt;2000 cc) did not have a significant impact on OS (P = 0.992), disease free survival (P = 0.783), relapse (P = 0.187), NRM (P = 0.627), or ANC Engraftment (P = 0.526). There was a statistically insignificant downward trend for platelet engraftment (P = 0.162). For patients with or without massive splenomegaly (&gt;3000cc), there was no significant effect with any of the analyzed post HCT outcomes. Conclusions: This retrospective study includes an analysis of spleen volume by 3D volumetrics, a more accurate measurement of spleen size, and whether it significantly impacts post HCT outcomes. Our data analysis demonstrates that splenomegaly, massive or not, does not significantly impact transplant outcomes for patients receiving a reduced intensity conditioning regimen.[Table: see text]

A comparison of ultrasound-based testis volume with Prader orchidometry and stability of testis size relative to peers from birth to 28weeks.

Testis volume, an indicator of the reproductive development during minipuberty, is commonly measured by Prader orchidometer, despite ultrasound being the gold standard. Data are lacking on the longitudinal relationship between these two measures and on the stability of boys' relative testis size across infancy. To examine the relationship between ultrasound-based and orchidometer-based testis volume measurements and to assess the stability of relative testis size among individual boys in the study. The Infant Feeding and Early Development study is a longitudinal cohort of healthy infants recruited from hospitals in the Philadelphia area during 2010-2013. We measured testis size from birth to 28weeks in 147 infants using Prader orchidometry (nine study visits) and ultrasound (five study visits). We modeled testis growth, extracted predicted volumes for each boy on each day of the study, and ranked these volumes from smallest to largest. The average testis volume trajectory exhibited linear growth over the first 16weeks followed by slower growth and then a plateau. Prader orchidometry overestimated testis size by almost 3-fold, compared to ultrasound. A range of ultrasound volumes corresponded to each bead size (e.g., bead size of 1 cm3 corresponded to an ultrasound-based volume between 0.11 and 0.87 cm3). Infants changed rankings of median of 22 positions (of 147) across the entire 6-month follow-up. Infants' ranks near birth were highly correlated with their ranks at the end of the study. Consistent with other studies, we found wide variability in testis size during infancy and that Prader orchidometry overestimates testis size. When compared to ultrasound, orchidometry only crudely estimates testis size in this age group. Ultrasound-based volumes generally showed stability in relative testis size across infancy. Accurate measurement of testis size is difficult using orchidometry in infants. This highlights the need for ultrasound for accurate measurement, with a one-time measurement likely sufficient to determine relative testis size across the first 6 months of infancy.

An effective and accurate flow size measurement using funnel-shaped sketch

Accurate measurement of network traffic is an essential part of current network management tasks. Sketch is a kind of probabilistic data structure widely accepted in network measurement. However, it is challenging for classic sketches to reduce the storage cost with little loss of accuracy for highly skewed network traffic. Therefore, most sketch-based schemes store elephant flows and mouse flows separately to deal with the skewed network traffic. But they are not usually suitable for estimating the size of mouse flows and thus may lose some information of traffic. To this end, a novel sketch, called Funnel Sketch (FS), is proposed in this paper. FS utilizes a funnel-shaped architecture to separately store the elephant flows and mouse flows, while maintaining the mouse flows as possible. Thus, FS can not only adapt to skewed network traffic to improve memory efficiency, but also accurately estimate the size of mouse and elephant flows with efficient memory consumption. Moreover, FS is implemented on CPU and OVS platform to evaluate its performance. The experimental results show that FS greatly reduces the error by 90% for flow size estimation and elephant flow detection compared with the state-of-the-art sketch-based schemes.

Accurate measurement of field size is essential for analysis of smallholder survey data

ContextAgronomic surveys play a vital role in identifying on-farm yield constraints and opportunities to increase productivity, input-use efficiency, and farmer profit. These surveys typically rely on farmer-reported data, where crop yield and applied inputs per hectare are estimated based on farmer-reported total harvested output and applied inputs per field and associated field size. At question is how accurate field size is, which is vital in the case of smallholders as small inaccuracies can lead to large biases in estimated yield and inputs. ObjectivesThe goals of this study are to assess current approaches to determine field size in smallholders, analyze biases between measurements and farmer estimates, and their influence on the analysis of the survey data. Cost-effective approaches for accurate field size measurement are also discussed. MethodsWe reviewed published studies that used survey data collected from smallholders to determine the extent to which field size is independently validated by researchers. Subsequently, we used data from thousands of smallholder fields in Southeast Asia to compare farmer-reported versus measured field size and examined the associated impact on estimated yields, inputs, and their relationships. ResultsWe found that most published studies using survey data did not validate field size reported by farmers. Furthermore, our analysis of the field size data from smallholders in Southeast Asia showed substantial differences between farmer-reported and measured field size, resulting in significant biases in estimated yield and applied inputs, and leading to spurious relationships between them. ConclusionUncertainty in field size can mislead analysis of smallholder survey data. ImplicationsFuture studies relying on survey data from smallholders should incorporate measurements of field size for accurate determination of crop yield and inputs.

Discrepancies in Splenic Size Measurement: A Comparative Analysis of Ultrasound and Computed Tomography.

The accurate measurement of splenic size is essential for the diagnosis and management of various gastrointestinal and hematological conditions. While ultrasound (US) and computed tomography (CT) are widely used imaging modalities for assessing splenic size, discrepancies between their measurements have been observed in clinical practice. This study aimed to analyze the measurement differences between US and CT and identify factors influencing these differences. A retrospective analysis of 598 asymptomatic patients who underwent both abdominal US and CT was conducted. Measurements of splenic size obtained from US, axial CT, and coronal CT scans were compared, and various factors such as patient demographics, operator experience, and imaging parameters were evaluated to elucidate their impact on the measurement discrepancies. The results revealed that US consistently underestimated splenic size compared to CT. The magnitude of the discrepancy was influenced by factors such as patient age, body mass index (BMI), depth of the spleen from skin on US and that on CT, visibility of the splenic hilum on US, sonic window quality, and operator experience. This study underscores the importance of considering these factors when interpreting splenic measurements obtained from different imaging modalities in clinical practice.

A deep learning-based approach for fully automated segmentation and quantitative analysis of muscle fibers in pig skeletal muscle

Muscle fiber properties exert a significant influence on pork quality, with cross-sectional area (CSA) being a crucial parameter closely associated with various meat quality indicators, such as shear force. Effectively identifying and segmenting muscle fibers in a robust manner constitutes a vital initial step in determining CSA. This step is highly intricate and time-consuming, necessitating an accurate and automated analytical approach. One limitation of existing methods is their tendency to perform well on high signal-to-noise ratio images of intact, healthy muscle fibers but their lack of validation on more complex image datasets featuring significant morphological changes, such as the presence of ice crystals. In this study, we undertake the fully automatic segmentation of muscle fiber microscopic images stained with myosin adenosine triphosphate (mATPase) activity using a deep learning architecture known as SOLOv2. Our objective is to efficiently derive accurate measurements of muscle fiber size and distribution. Tests conducted on actual images demonstrate that our method adeptly handles the intricate task of muscle fiber segmentation, yielding quantitative results amenable to statistical analysis and displaying reliability comparable to manual analysis.

Optimization Scheme of Measuring Accuracy of Bearing Seat Size Based on Machine Vision

At present, the size measurement of industrial workpieces is mainly manual measurement and CMM measurement, which cannot meet the requirements of high precision, high efficiency and low error rate in industrial production at the same time. In order to solve the above problems, this paper uses monocular vision technology to propose an optimization scheme of workpiece size measurement accuracy based on machine vision, which takes the height and declination Angle between the camera lens and the workpiece as variables. Firstly, the image was captured by camera calibration correction, and morphological methods such as gray-scale, denoising, expansion and corrosion were used for image pre-processing. Secondly, features were extracted using double-threshold canny edge detection algorithm and connected domain algorithm. Finally, the bearing seat size was measured using the minimum external rectangle algorithm. The experiment shows that the higher the distance between the camera lens and the stage, the larger the error is when the image information can be collected completely. The greater the Angle between the center of the camera lens and the center of the workpiece, the greater the error; The device not only meets the precision requirements, but also has the advantages of fast response speed, which can meet the needs of industrial applications.

A target containing phantom for accuracy assessment of cone-beam CT-guided histotripsy.

Histotripsy is a nonionizing, noninvasive, and nonthermal focal tumor therapy. Cone-beam computed tomography (CBCT) guidance was developed for targeting tumors not visible on ultrasound. This approach assumes cavitation is formed at the geometrical focal point of the therapy transducer. In practice, the exact location might vary slightly between transducers. In this study, we present a phantom with an embedded target to evaluate CBCT-guided histotripsy accuracy and assess the completeness of treatments. Spherical (2.8cm) targets with alternating layers of agar and radiopaque barium were embedded in larger phantoms with similar layers. The layer geometry was designed so that targets were visible on pre-treatment CBCT scans. The actual histotripsy treatment zone was visualized via the mixing of adjacent barium and agar layers in post-treatment CBCT images. CBCT-guided histotripsy treatments of the targets were performed in six phantoms. Offsets between planned and actual treatment zones were measured and used for calibration refinement. To measure targeting accuracy after calibration refinement, six additional phantoms were treated. In a separate investigation, two groups (N=3) of phantoms were treated to assess visualization of incomplete treatments ("undertreatment" group: 2cm treatment within 2.8cm tumor, "mistarget" group: 2.8cm treatment intentionally shifted laterally). Treatment zones were segmented (3D Slicer 5.0.3), and the centroid distance between the prescribed target and actual treatment zones was quantified. In the calibration refinement group, a 2mm offset in the direction of ultrasound propagation (Z) was measured. After calibration refinement, the centroid-to-centroid distance between prescribed and actual treatment volumes was 0.5±0.2mm. Average difference between the prescribed and measured treatment sizes in the incomplete treatment groups was 0.5±0.7mm. In the mistarget group, the distance between prescribed and measured shifts was 0.2±0.1mm. The proposed prototype phantom allowed for accurate measurement of treatment size and location, and the CBCT visible target provided a simple way to detect misalignments for preliminary quality assurance of CBCT-guided histotripsy.

Accurate nanoparticle size measurement by combining photometry and tracking analysis

Accurate determination of nanoparticle size is paramount in various fields, including molecular imaging, food safety, drug delivery, and nanobiotechnology. Conventional methods face limitations in accurately resolving different size distributions. Here, we introduce an approach to measure size distribution by combining photometry and tracking analysis of single particles. Our approach is based on a plasmonic dark field imaging system to image and track individual nanoparticles. Scattering intensity, spot size, and diffusion coefficient are quantified and fed into the machine learning model to establish the relationship with particle sizes. Compared with conventional methods, our approach shows improved accuracy in size measurement. To verify the universality of our method, we further demonstrate the sizing capability at diverse and complex conditions, enabling us to discriminate particle size differences within 20 nm in polydisperse systems.

Comparative Study of Droplet Diameter Distribution: Insights from Experimental Imaging and Computational Fluid Dynamics Simulations

The interfacial area between two phases plays a crucial role in the mass transfer rate of gas–liquid processes such as absorption. In this context, the droplet size distribution within the flow field of a droplet-based absorber significantly affects the surface area, thereby influencing the absorption efficiency. This study focuses on developing a computational fluid dynamics (CFD) model to predict the size and distribution of water droplets free-falling in a transparent square tube. This model serves as a digital twin of our experimental setup, enabling a comparative analysis of experimental and computational results. For the accurate measurement of droplet size and distribution, specialized experimental equipment was developed, and a high-speed camera along with Fiji software was used for the capturing and processing of droplet images. At the point of injection and at two different heights, the sizes and distributions of falling droplets were measured using this setup. The interaction between the liquid water droplets and the gas phase within the square tube was modeled using the Eulerian–Lagrangian (E-L) framework in the STAR-CCM+ software. The E-L multiphase CFD model yielded approximations with errors ranging from 11 to 27% for various average mean diameters, including d10, d20, d30, and d32, of the liquid droplets at two distinct heights (200 mm and 400 mm) for both nozzle plates. This comprehensive approach provides valuable insights into the dynamics of droplet-based absorption processes.

Embedding and cross-sectioning as a sample preparation procedure for accurate and representative size and shape measurement of nanopowders

Reliable measurement of the size of polydisperse, complex-shaped commercial nanopowders is a difficult but necessary task, e.g., for regulatory requirements and toxicity risk assessment. Suitable methods exist for the accurate characterization of the size of non-aggregated, stabilized, spherical and monodisperse nanoparticles. In contrast, industrial nanoscale powders usually require dedicated sample preparation procedures developed for the analysis method of choice. These nano-powders tend to agglomerate and/or aggregate, a behavior which in combination with an innate broad particle size distribution and irregular shape often significantly alters the achievable accuracy of the measured size parameters. The present study systematically tests two commercially available nanoscale powders using different sample preparation methods for correlative analysis by scanning electron microscopy, dynamic light scattering, Brunauer–Emmet–Teller method and differential mobility analysis. One focus was set on the sample preparation by embedding nanoparticles in carbon-based hot-mounting resin. Literature on this topic is scarce and the accuracy of the data extracted from cross sections of these particles is unclearly stated. In this paper systematic simulations on the deviation of the size parameters of well-defined series of nanoparticles with different shapes from the nominal value were carried out and the contributing factors are discussed.

A Preclinical Blinded Randomized-Controlled Trial Evaluating the Clinical Relevance of Polyp Size Measurement Using a Virtual Scale Endoscope.

The virtual scale endoscope (VSE) helps endoscopists measure colorectal polyp size more accurately compared to visual assessment (VA). However, previous studies were not adequately powered to evaluate the sizing of polyps at clinically relevant size thresholds and relative accuracy for size subgroups. We created 64 artificial polyps of varied sizes and Paris class morphology, randomly assigned 1:1 to be measured (383 total measurement datapoints with VSE and VA by 6 endoscopists blinded to true size) in a colon model. We added data from two previous trials (480 measurement datapoints). We evaluated for correct classification of polyps into size groups at 3 mm, 5 mm, 10 mm, and 20 mm size thresholds and the relative size measurement accuracy for diminutive polyps (≤5 mm), small polyps (5-9 mm), large polyps at 10-19 mm, and polyps (≥20). VSE had significantly less size group misclassifications at the 5 mm, and 10 mm thresholds (28 percent vs. 45 percent, P = 0.0159 and 26 percent vs. 44 percent, P = 0.0135, respectively). For the 3 mm and 20 mm thresholds, VSE had lower misclassifications; however, this was not statistically significant (36 percent vs. 46 percent, P = 0.3853 and 38 percent vs. 41 percent, P = 0.2705, respectively). The relative size measurement accuracy was significantly higher for VSE compared to VA for all size subgroups (diminutive (P < 0.01), small polyps (P < 0.01), 10-19 mm (P < 0.01), and ≥20 mm (P < 0.01)). VSE outperforms VA in categorizing polyps into size groups at the clinically relevant size thresholds of 5 mm and 10 mm. Using VSE resulted in significantly higher relative measurement accuracy for all size subgroups.

Measuring Size of Colorectal Polyps Using a Virtual Scale Endoscope or Visual Assessment: A Randomized Controlled Trial.

This study aimed to compare the accuracy of polyp size measurements using a virtual scale endoscope (VSE) with an integrated laser-based adaptive scale function and visual assessment (VA) during colonoscopies. We conducted a single-blinded, prospective randomized controlled trial. Eligible patients (aged 45-80 years) undergoing screening, surveillance, or diagnostic colonoscopies were randomly assigned (1:1) into 2 groups. In the intervention group, all detected polyps were measured for size using VSE; in the control group, all polyps were measured using VA. Size measurements were compared with a reference standard of digital caliper measurement immediately post polypectomy. The primary outcome was the relative accuracy of real-time VSE measurement compared with VA. Secondary outcomes included the mean differences and the correlations between VSE or VA sizes and the reference standard of measurement. Overall, 230 patients were enrolled and randomized. The relative size measurement accuracy of VSE was 84% in 118 polyps, which was significantly higher than that of VA (105 polyps; 68.4%, P < 0.001). VSE resulted in a significantly higher percentage of size measurements within 25% of true size compared with VA (81.4% vs 41%, P < 0.001). VSE had a significantly lower percentage for >5-mm polyps incorrectly sized as 1-5 mm compared with VA (13.5% vs 57.1%; P < 0.001) and a significantly lower percentage for >3-mm polyps incorrectly sized as 1-3 mm compared with VA (11.3% vs 56.5%; P < 0.001). VSE significantly improves the size measurement accuracy of colorectal polyps during colonoscopies compared with VA and results in fewer misclassifications at relevant decision-making size thresholds.