Volumetric Measurement Method Research Articles

Does volumetric measurement of ADC values achieve higher diagnostic performance in bladder cancer MRI?

Apparent diffusion coefficient (ADC) value is an important part of bladder cancer magnetic resonance imaging (MRI) assessment and can predict the aggressive and invasive potentials. There is growing interest in whole tumor volume measurements. To investigate if the volumetric ADC measurement method will significantly exceed the diagnostic performance of the selected region of interest (ROI) method in everyday practice. A prospective evaluation was carried out of 50 patients with bladder cancer by two radiologists. The mean and the minimum ADC values were measured using both methods. The inter-reader agreement was determined by the intraclass correlation coefficient. The ADC values were compared between different grades, states of muscle invasion, and lympho-vascular invasion (LVI); then, validity was evaluated using receiver operating characteristic (ROC) curves. Areas under the curve (AUC) were then compared for the level of statistical significance. The inter-observer agreement was excellent for the ADC values using both methods. The volumetric measurement provides higher mean and lower minimum ADC values with statistically significant differences (P <0.00001). The highest diagnostic accuracy for differentiating tumor grade and predicting muscle invasion was for the minimum ADC by a selected ROI. However, the differences between the achieved AUCs were of no statistical significance. None of the ADC values predicted LVI with statistical significance. The selected ROI and volumetric measurement methods of mean and minimum ADC in bladder cancer yield different values, still having comparable diagnostic performance with accurate ROI sampling. The minimum ADC value by ROI is preferred in everyday clinical practice.

Comparison of Volumetric Measurement Method With Region of Interest Drawing Method for Liver Fat Quantification

Comparison of Volumetric Measurement Method With Region of Interest Drawing Method for Liver Fat Quantification

Comparing a knowledge-based 3D reconstruction algorithm to TomTec 3D echocardiogram algorithm in measuring left cardiac chamber volumes in the pediatric population.

Three-dimensional echocardiography (3DE) is an emerging method for volumetric cardiac measurements; however, few vendor-neutral analysis packages exist. Ventripoint Medical System Plus (VMS3.0+) proprietary software utilizes a validated Magnetic resonance imaging (MRI) database of normal ventricular and atrial morphologies to calculate chamber volumes. This study aimed to compare left ventricular (LV) and atrial (LA) volumes obtained using VMS3.0+ to Tomtec echocardiography analysis software. Healthy controls (n=98) aged 0-18 years were prospectively recruited and 3D DICOM datasets focused on the LV and LA acquired. LV and LA volumes and ejection fractions were measured using TomTec Image Arena 3D LV analysis package and using VMS3.0+. Pearson correlation coefficients, Bland-Altman's plots, and intraclass coefficients (ICC) were calculated, along with analysis time. There was a very good correlation between Ventripoint Medical System (VMS) and Tomtec LV systolic (r2 =.88, ICC .89 [95% CI .81, .94]), and diastolic (r2 =.88, ICC .90 [95% CI .77, .95]) volumes, and between VMS and Tomtec LA diastolic (r2 =.75, ICC .89 [95% CI .81, .93]) and systolic (r2 =.88, ICC .91 [95% CI .78, .96]) volumes on linear regression models. Natural log transformations eliminated heteroscedasticity, and power transformations provided the best fit. The time (mins) to analyze volumes using VMS were less than using Tomtec (LV VMS 2.3±.5, Tomtec 3.3±.8, p<.001; LA: VMS 1.9±.4, Tomtec 3.4±1.0, p<.001). There was a very good correlation between knowledge-based (VMS3.0+) and 3D (Tomtec) algorithms when measuring 3D echocardiography-derived LA and LV volumes in pediatric patients. VMS was slightly faster than Tomtec in analyzing volumetric measurements.

Three-Dimensional evaluation of the effect of platelet-rich fibrin on edema in lower impacted third molar surgery performed with piezosurgery.

Platelet-rich fibrin (PRF) are widely used in impacted lower third molar (IL3M) 7 surgery and its effect on postoperative edema was generally analysed with linear methods. To analyze the effectiveness of platelet-rich fibrin (PRF) applied to the socket after tooth extraction in impacted lower third molar (IL3M) surgery performed with piezosurgery in the reduction of edema observed in the postoperative period, together with conventional (linear) and three-dimensional (volumetric) measurement methods. The study was designed as a prospective randomized split-mouth study and was conducted on 30 patients with bilateral IL3M teeth. Extraction of the patients' IL3M teeth was performed in the same session with the help of piezosurgery. After the extraction, PRF was randomly applied to one socket, but it was not applied to the other socket, which formed the control group. On the first, second, and seventh days after the procedure, volume was measured using 3dMD, and the distance between the topographic guide points was measured using a flexible ruler. The results were analyzed statistically. Alveolar osteitis (AO) presence was also recorded. A significant improvement in edema was observed in both groups, but no significant difference was found between the groups (P > 0.05). A moderate correlation was found between the two methods of measuring edema. AO was not seen in any patient. Although PRF reduces edema after IL3M tooth extraction and 3dMD is effective in its evaluation, it has no statistical advantage over classical methods.

Differential staining lowers the false positive detection in a novel volumetric measurement technique of microplastics

A novel method for the volumetric detection of microplastics in various environmental (soil, water) and food (fish, meat) matrices was developed. The method is based on the Nile Red staining of microplastics while eliminating probable interference by other organic polymers such as lignin, chitin, cellulosic materials, and other organic substances using a mixture of three water-based dyes (Calcofluor White, Evans Blue, and 4,6-diamidino-2-phenylindole [DAPI]). The excitation/emission ‘sweet spot’ was determined for water based blue dyes to detect them in a single channel for effective elimination of probable contaminations. Detection of microplastic particles using the Nile Red method was validated by comparing with traditional detection of microplastics via Fourier transform infrared spectroscopy (FTIR). Volumetric measurements of the microplastics present in environmental samples were made possible using Z-stack confocal microscopy images backed by threshold-based 3D segmentation. Regularly shaped microplastic materials were used to validate the volumetric measurement method. The proposed volumetric determination method will be very useful for screening microplastics in diverse media and improving the prevailing method using FTIR.

A novel volumetric velocity measurement method for small seeding tracers in large volumes

This paper presents the volumetric velocity measurement method of small seeding tracer with diameter 5µm ∼ 100µm for volumes of ≥ 500cm3. The size of seeding tracer is between helium-filled soap bubbles (HFSB) and di-ethyl-hexyl-sebacic acid ester(DEHS) droplets. The targeted measurement volume dimension is equivalent to the volume of HFSB, which will give a higher resolution of turbulence study. The relations between particle size, imaging and light intensity are formulated. The estimation of the imaging results is computed for the setup design. Finally, the methodology is demonstrated for turbulence velocity measurements in the jet flow, in which the velocities of averaged diameter 15µm air filled soap bubbles are measured in a volume of 7200cm3.

Development of a method for isobaric large temperature jump adsorption experiments

Adsorption heat pumps offer the possibility to provide cold from waste heat, and can therefore be an important component for an environmentally friendly and sustainable cooling supply. A new accurate measurement method is developed to evaluate the progress of performance improvement in this area through new material and heat transfer concepts. The new method covers the entire sample range from very small to large sample sizes and also allows measurements in the poorly accessible transition region of medium sample sizes in the range from 1 to 10 g. A comparison with the conventional volumetric method in large temperature jump adsorption experiments is carried out using granular TiAPSO-34 in a flatbed configuration as adsorbent. The sample mass is varied from 300 mg to 1709 mg and the influence on the adsorption rate is compared using the characteristic time constants describing the dynamics of the adsorption reaction. It can be shown that the time constant for the new method is almost constant with a maximum deviation of 9% while the characteristic time constant for the conventional method varies up to 64%. The difference in adsorptive loading per adsorbent varies from 0.193 to 0.197 for the new method and from 0.100 to 0.190 for the conventional method. The new measurement method thus provides significantly more reliable results for the design of adsorption heat pumps than the previous volumetric measurement method. From the experimental results it can also be concluded that the new measurement method can be used in the present case up to sample sizes of 600 g which makes the gravimetric version of the large temperature jump method obsolete in this case.

A new method for volumetric measurement of the normal female cervix by three-dimensional transvaginal ultrasound.

Until now, there have been few studies that have used imaging modalities to assess the volume of a non-pregnant female cervix; the first study did so with magnetic resonance imaging [1], and the remaining two with three-dimensional ultrasound [2, 3]. The two latter studies showed that a geometric formula for regular cylinders can be used to determine normal cervical volume [1, 3].

Accuracy assessment of a novel semiautomatic method evaluating bone grafts around the dental implant: an in vitro and ex vivo study

The present study aimed to evaluate the accuracy and repeatability of morphological contour interpolation (MCI)-based semiautomatic segmentation method for volumetric measurements of bone grafts around dental implants. Three in vitro (one with a cylinder and two with a geometrically complex form) and four ex vivo models (peri-implant cylinder-shaped bone defect) were created for imitating implant placement with simultaneous guided bone regeneration (GBR) procedure. Cone beam computerized tomography (CBCT) scans of all models were obtained with the same parameters. For volumetric measurements, the actual volumes of bone grafts in models were assessed by computer-aided calculation and both manual and MCI-based methods were utilized as test methods. The accuracy of the methods was evaluated by comparing the measured value and the actual volume. The repeatability was assessed by calculating the coefficients of variation of repeated measurements. For the accuracy of three dimensional (3D) reconstructions, the computer-designed corresponding models were set as the reference and the morphological deviation of 3D surface renderings created by two methods were evaluated by comparing with reference. Besides, measurement time was recorded and a comparison between the two methods was performed. High accuracy of the MCI-based segmentation method was found with a discrepancy between the measured value and actual value never exceeding − 7.5%. The excellent repeatability was shown with coefficients of variation never exceeding 1.2%. The MCI-based method showed less measurement time than the manual method and its 3D surface rendering showed a lower deviation from the reference.

Improving Inter-Laboratory Reproducibility in Measurement of Biochemical Methane Potential (BMP)

Biochemical methane potential (BMP) tests used to determine the ultimate methane yield of organic substrates are not sufficiently standardized to ensure reproducibility among laboratories. In this contribution, a standardized BMP protocol was tested in a large inter-laboratory project, and results were used to quantify sources of variability and to refine validation criteria designed to improve BMP reproducibility. Three sets of BMP tests were carried out by more than thirty laboratories from fourteen countries, using multiple measurement methods, resulting in more than 400 BMP values. Four complex but homogenous substrates were tested, and additionally, microcrystalline cellulose was used as a positive control. Inter-laboratory variability in reported BMP values was moderate. Relative standard deviation among laboratories (RSDR) was 7.5 to 24%, but relative range (RR) was 31 to 130%. Systematic biases were associated with both laboratories and tests within laboratories. Substrate volatile solids (VS) measurement and inoculum origin did not make major contributions to variability, but errors in data processing or data entry were important. There was evidence of negative biases in manual manometric and manual volumetric measurement methods. Still, much of the observed variation in BMP values was not clearly related to any of these factors and is probably the result of particular practices that vary among laboratories or even technicians. Based on analysis of calculated BMP values, a set of recommendations was developed, considering measurement, data processing, validation, and reporting. Recommended validation criteria are: (i) test duration at least 1% net 3 d, (ii) relative standard deviation for cellulose BMP not higher than 6%, and (iii) mean cellulose BMP between 340 and 395 NmLCH4 gVS−1. Evidence from this large dataset shows that following the recommendations—in particular, application of validation criteria—can substantially improve reproducibility, with RSDR &lt; 8% and RR &lt; 25% for all substrates. The cellulose BMP criterion was particularly important. Results show that is possible to measure very similar BMP values with different measurement methods, but to meet the recommended validation criteria, some laboratories must make changes to their BMP methods. To help improve the practice of BMP measurement, a new website with detailed, up-to-date guidance on BMP measurement and data processing was established.

Application of rib surface positioning ruler combined with volumetric CT measurement technique in endoscopic minimally invasive thoracic wall fixation surgery

Application value of rib surface positioning ruler combined with volumetric CT measurement in selection of the incision for minimally invasive internal fixation of rib fracture was investigated. A total of 80 patients who received internal fixation of rib fractures in Tianjin Hospital Affiliated to Tianjin University (Tianjin, China) from May 2018 to April 2019 were selected. Patients were treated with the rib surface positioning ruler combined with volumetric CT measurement method (n=42) or traditional positioning method (n=38). The following parameters were compared between the two groups: Preset incision accuracy, operation incision length, operation time, intraoperative bleeding volume, postoperative wound drainage volume and postoperative pain score. Compared with the traditional positioning method, rib surface positioning ruler combined with volumetric CT measurement method can improve preset incision accuracy, reduce operation time, incision length, intraoperative bleeding volume, postoperative wound drainage volume, and postoperative pain score, with statistically significant differences (P<0.05). In conclusion, the application of rib surface positioning ruler combined with volumetric CT measurement technique has obvious effect on the selection of incision for internal fixation of rib fracture, and is an effective method worth promoting.

Inter-observer and Intra-observer Variability in Volume Measurements of the Lower Extremity Using Perometer.

Background: The swelling of the extremities seen in lymphedema can be measured with many different volumetric devices; however, many methods lack important characteristics including reproducibility and independence from the subjectivity and skill of the operator. The aim of this study was to validate the use of the Perometer® as a possible standard for volumetric measurement methods based on the inter-observer and intra-observer variability when using a standard method of Perometry®. Methods and Results: Volumetric measurements were performed on 10 healthy test subjects by 5 individuals (the observers) who had been instructed in the measurement techniques to be used. The inter-observer variability was assessed by having the five observers measure all the test subjects both in the morning and in the early afternoon. The intra-observer variability was examined by having each observer measure all the 10 test subjects 4 times in a row in the aforementioned time frames. A data set was created using the measurements, allowing for the assessment of other parameters including variation of volume between the right and left leg and daily variation in swelling. Statistical measurements were performed using the Statistical Package for the Social Sciences (SPSS), from which it was determined that there was no statistically significant inter-observer (p-value 0.997) and intra-observer variation (p-value 0.995) based on a significance level of >5%. Furthermore, it was observed that a statistically significant difference in volume occurred in the leg volume during the day. Conclusion: It was concluded that the use of the Perometer provides consistent measurements of volume independent of the observer and therefore appears to provide a candidate standard for volumetric measurements.

Design and clinical validation of a software program for automated measurement of mammographic breast density

BackgroundMammographic breast density is an important predictor of breast cancer, but its measurement has limitations related to subjectivity of visual evaluation or to difficult access for automatic volumetric measurement methods. Herein, we describe the design and clinical validation of Aguida, a software program for automated quantification of breast density from flat mammography images.Materials and methodsThe software program was developed in MatLab. After image segmentation separating the background from the breast image, the operator positions a cursor defining a region of interest on the pectoralis major muscle from the mediolateral oblique view. Then, in the craniocaudal view, the threshold for separation of the dense tissue is based on the optical density of the pectoral muscle, and the proportion of dense tissue is calculated by the program. Mammograms obtained from 2 different occasions in 291 women were used for clinical evaluation.ResultsThe intraclass correlation coefficient (ICC) between breast density measurements by the software and by a radiologist was 0.96, with a bias of only 0.67 percentage points and a 95% limit of agreement of 13.5 percentage points; the ICC was 0.94 in the interobserver reliability assessment by two radiologists with different experience; and the ICC was 0.98 in the intraobserver reliability assessment. The distribution among the density classes was close to the values obtained with the volumetric software.ConclusionsMeasurement of breast density with the Aguida program from flat mammography images showed high agreement with the visual determination by radiologists, and high inter- and intra-observer reliability.

Experimental investigation of freon mixture spreading over the structured Sulzer 500X packing at single drip point irrigation

The paper presents the results of experimental studies on liquid spreading over the Sulzer 500X packing at single drip point irrigation. The experiments were carried out using a 10% mixture of R114/R21 freons on one packing layer with a diameter of 0.6 m. The flow rate of liquid flowing from the lower edge of the packing was measured automatically by a flow meter moving along the packing sheets with a given step. The flow meter used volumetric measurement method. The receiving collector of flow meter is 50x50 mm in size, operating range of flow measurement is 0.05–50 ml/s. Distributions of liquid over the packing were measured at single-jet irrigation in the range of jet flow rates 2.5 < qirrig < 60 ml/s. Spreading zone in the case of irrigation by a single jet is limited by the corrugation channels coming from the irrigation point. The pattern of spreading at low-flow jet irrigation has the shape of a dome with a low flow rate at the outlet of corrugation channels, which limit the spreading zone. With an increase in the flow rate, the share of liquid in these channels increases and dominates over other parts of the spreading zone.

Comparative Volume Analysis of Alveolar Defects by 3D Simulation.

A precise volumetric assessment of maxillary alveolar defects in patients with cleft lip and palate can reduce donor site morbidity or allow accurate preparation of bone substitutes in future applications. However, there is a lack of agreement regarding the optimal volumetric technique to adopt. This study measured the alveolar bone defects by using two cone-beam computed tomography (CBCT)-based surgical simulation methods. Presurgical CBCT scans from 32 patients with unilateral or bilateral clefts undergoing alveolar bone graft surgery were analyzed. Two hands-on CBCT-based volumetric measurement methods were compared: the 3D real-scale printed model-based surgical method and the virtual surgical method. Different densities of CBCT were compared. Intra- and inter-examiner reliability was assessed. For patients with unilateral clefts, the average alveolar defect volumes were 1.09 ± 0.24 and 1.09 ± 0.25 mL (p > 0.05) for 3D printing- and virtual-based models, respectively; for patients with bilateral clefts, they were 2.05 ± 0.22 and 2.02 ± 0.27 mL (p > 0.05), respectively. Bland–Altman analysis revealed that the methods were equivalent for unilateral and bilateral alveolar cleft defect assessment. No significant differences or linear relationships were observed between adjacent different densities of CBCT for model production to obtain the measured volumes. Intra- and inter-examiner reliability was moderate to good (intraclass correlation coefficient (ICC) > 0.6) for all measurements. This study revealed that the volume of unilateral and bilateral alveolar cleft defects can be equally quantified by 3D-printed and virtual surgical simulation methods and provides alveolar defect-specific volumes which can serve as a reference for planning and execution of alveolar bone graft surgery.

Longitudinal and Transversal Behavior of Multifilament Yarn Subjected to Longitudinal Load Using Image Analysis

The understanding of textile yarns behavior is of paramount relevance for the textile industry, mainly for technical applications. This describes the research work to introduce an alternative method for both yarns diameter and volumetric measurement using image analysis. Its main goal is to better describe the transverse dynamic behavior of multifilament yarns when submitted to tensile loads. Methods for measuring yarns diameter found in the literature are described and discussed. The proposed method presents significant advantages allowing the possibility to perform tests without interruption, as well as the ability to generate a greater amount of data, providing more accurate results. Longitudinal tensile tests using two types of multifilament polyamide yarns were performed and their actual dynamic behavior is analyzed using the experimental results.

A versatile scanning method for volumetric measurements of velocity and density fields

Understanding turbulence in a stratified environment requires a detailed picture of both the velocity field and the density field. Experimentally, this represents a significant measurement challenge, especially when full three-dimensional data is needed to accurately characterise the turbulent fields. This paper presents a new approach to obtaining such data through well-resolved, near-instantaneous volume-spanning measurements. This is accomplished using a simultaneous particle image velocimetry and planar-laser-induced fluorescence scanning setup that is highly versatile while allowing precise overlapping light sheets in a volume. Moreover, the approach detailed here allows for complex scan sequences over varying volumes without the need for mechanical adjustment. To demonstrate the technique, preliminary results from the buoyancy-driven exchange flow through an inclined duct connecting two reservoirs of different density fluids are shown.

Morning Plasma Melatonin Differences in Autism: Beyond the Impact of Pineal Gland Volume.

While low plasma melatonin, a neuro-hormone synthesized in the pineal gland, has been frequently associated with autism, our understanding of the mechanisms behind it have remained unclear. In this exploratory study, we hypothesized that low melatonin levels in ASD could be linked to a decrease of the pineal gland volume (PGV). PGV estimates with magnetic resonance imaging (MRI) with a voxel-based volumetric measurement method and early morning plasma melatonin levels were evaluated for 215 participants, including 78 individuals with ASD, 90 unaffected relatives, and 47 controls. We first found that both early morning melatonin level and PGV were lower in patients compared to controls. We secondly built a linear model and observed that plasma melatonin was correlated to the group of the participant, but also to the PGV. To further understand the relationship between PGV and melatonin, we generated a normative model of the PGV relationship with melatonin level based on control participant data. We found an effect of PGV on normalized melatonin levels in ASD. Melatonin deficit appeared however more related to the group of the subject. Thus, melatonin variations in ASD could be mainly driven by melatonin pathway dysregulation.

Nondestructive, longitudinal measurement of collagen scaffold degradation using computed tomography and gold nanoparticles.

Biodegradable materials, such as collagen scaffolds, are used extensively in clinical medicine for tissue regeneration and/or as an implantable drug delivery vehicle. However, available methods to study biomaterial degradation are typically invasive, destructive, and/or non-volumetric. Therefore, the objective of this study was to investigate a new method for nondestructive, longitudinal, and volumetric measurement of collagen scaffold degradation. Gold nanoparticles (Au NPs) were covalently conjugated to collagen fibrils during scaffold preparation to enable contrast-enhanced imaging of collagen scaffolds. The X-ray attenuation of as-prepared scaffolds increased linearly with increased Au NP concentration such that ≥60 mM Au NPs provided sufficient contrast to measure scaffold degradation. Collagen scaffold degradation kinetics were measured to increase during in vitro enzymatic degradation in media with an increased concentration of collagenase. The scaffold degradation kinetics measured by micro-CT exhibited lower variability compared with gravimetric measurement and were validated by measurement of the release of Au NPs from the same samples by optical spectroscopy. Thus, Au NPs and CT synergistically enabled nondestructive, longitudinal, and volumetric measurement of collagen scaffold degradation.

Development and Evaluation of a New In Vivo Volume Measuring System in Mouse Tail Lymphedema Model.

Backgrounds: Secondary lymphedema is a common complication of parasitization and breast or gynecologic cancer therapy; however, options for the treatment of lymphedema are ineffective and limited. A mouse tail model is one of the most successful animal models for a lymphatic study. Lymphedema of the mouse tail is characterized by increases in the volume of the extremity caused by accumulation of tissue fluid, proliferation of fibroblasts and adipocytes, and excessive production of collagen. However, the study of lymphedema using mouse has been plagued with difficulty in directly assessing physiologic changes owing to limitations in the measurement of the mouse tail volume. Furthermore, the mouse tail volume cannot be obtained using the general in vivo measurement method such as volumetric water displacement. Methods and Results: Lymphatic researchers have used the truncated cone formula to approximate the volume as used in the numerical approximation of a cylindrical figure. Although this formula is simple and easy to use, it has difficulties of repeatability and accuracy because the measurement procedure is highly subjective and the accuracy depends on the number of divided segments on the tail. In this article, two novel volumetric measurement methods for the mouse tail model were introduced. The methods were evaluated and compared using three mice with surgically created lymphedema on the tails. Conclusions: The two continuous measuring methods showed a possibility to improve the conventional method by continuous measurement using visual and physical detecting methods. The proposed methods facilitate the extraction of longitudinal section-specific information, which can be an important clue in a lymphatic study.