Water Displacement Measurements Research Articles

Comparison of analog and digitally evaluated volume of the female breast in reconstructive breast surgery. Validation of a noninvasive measurement method with 3D camera1.

Reconstructive surgery is established as a standard treatment option after mastectomy due to cancer. It is crucial to patients to achieve a natural and symmetric looking breast through reconstruction. Anthropometric measurements are used to assess the objective symmetry of the breast, which are prone to errors and difficult to reproduce. The aim of this work is to validate breast volumetry using three-dimensional surface imaging. We compared preoperatively analog and digitally evaluated volume of the breast with our gold standard, direct water displacement measurement of the mastectomy specimen. We examined 34 breast specimens in total. Each measurement method (Breast Sculptor, VAM, Breast-V) for breast volume/mass determination demonstrates acceptable agreement ranges when compared with resected volumes and masses. The strongest volumetry instrument is Breast Sculptor (digital), the weakest is Breast-V (analog). 3D surface imaging is a quick, effective, and convenient method to evaluate breast shape and volume. The accuracy, reproducibility, and reliability of 3D surface imaging were comparable with MRI in our study.This takes us a step closer to the long-term goal of establishing robust instruments to plan breast reconstructive surgery, achieve better surgical results, and contribute to quality assurance in breast surgery.

Technical aspects and validation of custom digital algorithms for hand volumetry.

Establishing baseline measurements on normative data is essential to evaluate standards of care and the impact of clinical or surgical treatments. Hand volume determination is relevant in pathological conditions where the anatomical structures might undergo modifications like post-treatment chronic edema. For example, one of the consequences of breast cancer treatment is the possibility of developing uni-lateral lymphedema on the upper limbs. Arm and forearm volumetrics are well-studied techniques, whereas hand volumetry computation poses several challenges both from the clinical and digital perspectives. The current work has explored routine clinical and customized digital methodologies for hand volume appraisal on healthy subjects. Clinical hand volumes computed by water displacement or circumferential measurements were compared to digital volumetry calculated from 3D laser scans. Digital volume quantification algorithms exploited the gift wrapping concept or cubic tessellation of acquired 3D shapes. This latter digital technique is parametric, and a calibration methodology to define the resolution of the tessellation has been validated. Results on a group of normal subjects demonstrated that the volumes computed from digital hand representations extracted by tessellation return values similar to the clinical water displacement volume assessment at low tolerances. The current investigation suggested that the tessellation algorithm could be considered a digital equivalent of water displacement for hand volumetrics. Future studies are needed to confirm these results in people with lymphedema.

Use of the Cephalic Vein in DIEP Breast Reconstruction Does Not Increase Risk of Lymphedema of the Ipsilateral Arm.

Flap failure is a rare but devastating complication in deep inferior epigastric perforator (DIEP) flap reconstructions. Common causes of partial or complete flap failure are related to venous congestion. Although the cephalic vein is usually a safe and reliable recipient vein for additional venous outflow, there is a hypothesized risk of donor-arm lymphedema secondary to lymphatic vessel damage in the vicinity of the cephalic vein or related to scarring and reduced venous backflow of the arm. The aim was to assess whether the cephalic vein as an additional recipient vessel, by means of the superficial inferior epigastric vein in DIEP flap breast reconstruction, was associated with long-term volume changes of the arm and/or symptoms of lymphedema. Arm volume was assessed preoperatively in patients scheduled to undergo unilateral delayed DIEP flap breast reconstruction at Uppsala University Hospital, Sweden, between 2001 and 2007. Long-term postoperative assessments were performed in 2015 to 2016. Water displacement and circumferential measurement were assessed preoperatively and postoperatively by the same lymphedema therapists. Patients were divided into two groups: DIEP reconstruction with the cephalic vein or without. Fifty-four patients fulfilled the inclusion criteria and completed the study, with a mean follow-up time of 136 months. There was no increased occurrence of lymphedema in the group undergoing DIEP flap reconstruction with the cephalic vein as extra venous drainage, based on an analysis of change from baseline in arm volume difference.This study shows that the cephalic vein can be used for secondary venous outflow in DIEP breast reconstruction without long-term risk of ipsilateral arm volume increase or symptoms of lymphedema. Risk, II.

Preliminary Study on The Effect of Time on Hydrogen Production from Electrolysis of The Seawater

To know the effect of electrode type on the production of hydrogen gas through the electrolysis of sea water, this research was conducted. At a constant potential difference of 12 Volt, the electrolysis process is carried out by alternately using graphite and copper as electrodes. The electrolysis process time was varied from 10 to 55 minutes with increments every 5 minutes for each electrode. The results showed that the use of copper in the electrolysis of sea water produced a maximum of 82 ml of hydrogen gas better than 76 ml of graphite with a total processing time of 5 hours and 25 minutes. The results also show that the production of hydrogen gas in graphite has the largest hydrogen production rate in the first 10 minutes, but continues to decline, while the copper electrode has the largest hydrogen production rate at 220 minutes and decreases when the electrolysis process reaches 270 minutes when the electric current experiences drop. This can be understood due to the corrosion of the electrode by chlorine, which causes the electrode life to be limited. Meanwhile, the water displacement measurement method is used to determine the volume of hydrogen gas produced from the electrolysis of seawater in this study.

Evolutionary ensemble feature selection learning for image‐based assessment of lymphedema arm volume

SummaryArm lymphedema is a side effect of surgery and radiation therapy in patients with breast cancer. There are several methods to measure lymphedema arm volume, such as water displacement (WD) and circumferential measurement (CM). Although these techniques have a satisfactory level of accuracy, they have some limitations for clinical use in practical applications. To overcome these drawbacks, a horizontal‐vertical image scanning (HVIS) tool, is presented as a valid method for arm volume measurement. To predict the arm volume, an evolutionary ensemble feature selection learning (named EEFSL) comprising different base learners (KNN, SVM, ANFIS, Decision Tree, and Naïve Bayes) is presented. In order to improve the performance of the EEFSL model, its hyperparameters are optimized using genetic algorithm (GA). The hyperparameters include the weights of different base learners and the specific features for each base learner. The fitness function of GA is to maximize the correlation between predicted and actual arm volumes. The proposed method was successfully developed for arm measurement of 60 arms from 30 women with arm lymphedema. Obtained results indicate that the proposed HVIS‐EEFSL method is a reliable and valid technique to measure arm volume of patients with lymphedema, suitable for daily clinical use instead of WD and CM.

Rapid weight loss in free ranging pygmy killer whales (Feresa attenuata) and the implications for anthropogenic disturbance of odontocetes

Understanding the impacts of foraging disruptions to odontocete body condition is fundamental to quantifying biological effects of human disturbance and environmental changes on cetacean populations. Here, reductions in body volume of free-ranging pygmy killer whales (Feresa attenuata) were calculated using repeated measurements of the same individuals obtained through Unoccupied Aerial System (UAS)-photogrammetry during a prolonged disruption in foraging activity arising from a 21-day stranding event. Stranded individuals were used to verify UAS-derived volume and length estimates through 3D-imaging, water displacement, and post-mortem measurements. We show that (a) UAS estimates of length were within 1.5% of actual body length and UAS volume estimates were within 10–13% of actual volume, (b) foraging disruption resulted in a daily decrease of 2% of total body mass/day, and (c) pygmy killer whales can lose up to 27% of their total body weight within 17 days. These findings highlight the use of UAS as a promising new method to remotely monitor changes in body condition and animal health, which can be used to determine the potential effects of anthropogenic disturbance and environmental change on free-ranging odontocetes.

Evaluation of the reliability of a new simple device for standardized breast volume measurements

Despite the breast volume being an essential metric component of any aesthetic or reconstructive breast surgery, up to date, there has been no accepted measurement technique that is globally accepted by breast surgeons. Appropriate measurement might lead to decrease of the reoperation rates. We introduced a novel technique that provides simply accurate volume measurement. Thirty patients with breast cancer who were scheduled for modified radical mastectomy were included in the study. Preoperative breast volume measurement using the novel device and breast MRI studies was done for all patients; meanwhile, the gold standard technique (direct water displacement measurement of mastectomy specimen) was used to measure the volume of breast specimen following mastectomy. There were strongly positive correlations between the device and gold standard technique (r = 0.957) in 23 patients, and (r = 0.997) in 30 patients when MRI was compared to gold standard measurements. In group 1 (breast volume < 500), there is a strong correlation between the device and gold standard (r = 0.914) and for the MRI and gold standard (r = 0.965). In group 2 (500–1000), there was also a strong correlation between the device and gold standard (r = 0.986) and for the MRI and gold standard (r = 0.989) as well. The novel device had been proven to be cost-efficient, simple, reproducible technique with minimal learning curve. It provides reliably comparable results to gold standard techniques and MRI measurement in breast volumes up to 1000 cc. It utilized simple material and basic principles that can be easily used in most settings. Level of evidence: Level IV, diagnostic study.

Estimates for Assessment of Lymphedema: Reliability and Validity of Extremity Measurements.

Background: Measuring lymphedema with high accuracy is important for several reasons. The aim of this study was to assess the reliability and validity of three routinely used methods to estimate limb volumes.Methods and Results: Inverse water displacement, girth measurements, and Perometer measurements were executed. Although standard techniques were used, extra precautions were taken to maximize accuracy within and between observers. Water displacement, and girth and Perometer measurements resulted in standard deviations of 0.7%–0.8%, 0.5%, and 0.4%–1.0%, respectively.Conclusion: Measuring limb volumes using routine methods is not easy. Even under optimal conditions, the measurements are quite dependent on the observer. For practical situations, an easy, objective, and reliable method is lacking.

A virtual environment to evaluate the arm volume for lymphedema affected patients

Background and ObjectiveThe paper presents a novel procedure based on 3D scanning and 3D modelling to automatically assess linear and volumetric measurements of an arm and to be further applied to patients affected by post breast cancer lymphedema. The aim is the creation of a virtual platform easily usable by medical personnel to get more objective evaluations during the lymphedema treatment. MethodsThe procedure is based on the 3D scanning of the arm using the Occipital Structure Sensor and an ad-hoc developed application, named Lym 3DLab. Lym 3DLab emulates the traditional measurement methods, which consist in taking manual circumference measurements or using the water displacement method. These measurements are also used to design the compression stockings, the typical orthopaedic device used for lymphedema treatment. A validation test has been performed to compare the measurements computed by Lym 3DLab with both water displacement and manual circumference measurements. Eight volunteers have been involved who are not affected by lymphedema. Furthermore, a specific usability test has been performed to evaluate the 3D scanning procedure by involving four physiotherapists. ResultsThe comparison between the volumes has highlighted how all the 3D acquired models have their volumes inside a range of acceptability. This range has been defined by considering the sensitivity error of the tape measure used to measure the water displacement. The comparison between the perimeters of cross sections computed with Lym 3DLab and the circumference measurements has shown results that are very accurate with an average difference of 2 mm. The measure errors have been considered negligible by the medical personnel who have evaluated the proposed procedure more accurate than the traditional ones. The test with physiotherapists has shown a high level of usability of the whole virtual environment, but the 3D scanning procedure requires an appropriate training of the personnel to make the 3D acquisition as fast and efficient as possible. ConclusionsThe achieved results and the physiotherapists’ feedback allow planning a future test with patients affected by lymphedema in collaboration with the hospital. A further test has been planned to use the computed measurements to design orthopaedic compression stockings.

Evidence of stage progression in a novel, validated fluorescence-navigated and microsurgical-assisted secondary lymphedema rodent model.

Secondary lymphedema (SL)is a frequent and devastating complication of modern oncological therapy and filarial infections. A lack of a reliable preclinical model to investigate the underlying mechanism of clinical stage progression has limited the development of new therapeutic strategies. Current first line treatment has shown to be merely symptomatic and relies on lifetime use of compression garments and decongestive physiotherapy. In this study, we present the development of a secondary lymphedema model in 35 rats using pre- and intraoperative fluorescence-guided mapping of the lymphatics and microsurgical induction. In contrast to the few models reported so far, we decided to avoid the use of radiation for lymphedema induction. It turned out, that the model is nearly free of complications and capable of generating a statistically significant limb volume increase by water displacement measurements, sustained for at least 48 days. A translational, accurate lymphatic dysfunction was visualized by a novel VIS-NIR X-ray ICG-Clearance-Capacity imaging technology. For the first-time SL stage progression was validated by characteristic histological alterations, such as subdermal mast cell infiltration, adipose tissue deposition, and fibrosis by increased skin collagen content. Immunofluorescence confocal microscopy analysis suggested that stage progression is related to the presence of a characteristic α SMA+/HSP-47+/vimentin+ fibroblast subpopulation phenotype. These findings demonstrate that the in-vivo model is a reliable and clinically relevant SL model for the development of further secondary lymphedema therapeutic strategies and the analysis of the veiled molecular mechanisms of lymphatic dysfunction.

Exploring the Use of 3D Scanning to Determine Whole-Body Volume While Wearing a Triathlon Wetsuit

Background: Commercial 3 Dimension (3D) scanners are relatively new to anthropometry. The purpose of this study was to explore ability of using a 3D imaging instrument to measure body volume with and without wearing a wetsuit. Three experiments were conducted to achieve this purpose: (1) to determine if the 3D imaging instrument could accurately measure volume of static objects; (2) to determine the resolution of accuracy of measuring volume of static objects; and (3) to compare whole-body volume of wearing a wetsuit using 3D imaging as well as another body volume measure (air displacement technique). Methods: Three experiments were performed: (1) measurement of volume of a mannequin head and a box using a 3D scanner, water displacement (for mannequin head), and dimension measurements (for box) techniques for determining volume, (2) volume measurements of 1, 2, and 3 layers of neoprene to assess the resolution capabilities of the 3D scanner, and (3) body volume with and without wearing a wetsuit using a 3D scanner and BodPod (air displacement instrument). Results: (1) Mannequin head volume using the 3D scanner was 1.46% greater than a water displacement technique; the box volume from scanning was significantly greater than volume calculated by measuring dimensions of a box. (2) The volume of a single layer of neoprene was 25.3% less with scanning than the criterion; the volume of two layers was 27.2% less than the criterion; the volume of three layers was not significantly different from the criterion. (3) Body volume was not influenced by the interaction of wetsuit and device; body volume was on average 5% greater with wetsuit than without regardless of instrument. Conclusions: We demonstrated that body volume as measured by a 3D scanner increased when a wetsuit was worn.

Use of a Novel Portable Three-Dimensional Imaging System to Measure Limb Volume and Circumference in Patients with Filarial Lymphedema.

The World Health Organization's Global Program to Eliminate Lymphatic Filariasis (LF) has reduced LF transmission worldwide, but millions remain affected by filarial lymphedema. Tools for clinically monitoring lymphedema in developing nations are limited. We tested a novel, portable, infrared three-dimensional imaging system (3DIS) against water displacement (WD) and tape measurement of limb circumference (TMLC) among patients with filarial leg lymphedema in Galle, Sri Lanka. Outcomes were accuracy and reproducibility of imaging system measurements. In parallel, we also tested the reproducibility of skin thickness ultrasound (STU) measurements. We examined 52 patients (104 limbs) with lymphedema of stages 0-6 (N = 28, 19, 20, 21, 2, 4, and 10, respectively). 3DIS measurements correlated nearly perfectly with WD (r2 = 0.9945) and TMLC values (r2 > 0.9801). The median time required to acquire imaging system measurements for both legs was 2.1 minutes, compared with 17, 7, and 29 minutes, respectively, for WD, TMLC, and STU. Median interexaminer coefficients of variation (CVs) for volume measurements were 1.1% (interquartile range [IQR] 0.5-2.1%) for WD and 1.7% (IQR 1.2-2.4%) for the 3DIS. CVs for circumference measurements were 1.4% (IQR 0.8-2.4%) by TMLC and 1.3% (0.8-1.9%) by 3DIS. Median interexaminer CV for STU was 13.7% (IQR 8.5-21.3%). The portable imaging system noninvasively provided accurate and reproducible limb volume and circumference measurements in approximately 2 minutes per patient. This portable technology has the potential to greatly improve assessment and monitoring of lymphedema in the clinic and in the field.

Abstract: Validation of Vectra 3D Imaging for Quantitative Volumetric Measurement of Upper Extremity Lymphedema

INTRODUCTION: Secondary lymphedema of the upper limb is a common sequela following lymphadenectomy during oncologic surgery. The gold standard for evaluating treatment outcomes in upper limb lymphedema is limb volume measurement, with tape measurement being the method most commonly used. However, current techniques lack sensitivity to localized changes. In this study, the Vectra 3D imaging system was utilized to accurately and precisely obtain volume measurements of the upper limb in patients with lymphedema. METHODS: A feasibility study was performed in 11 patients with lymphedema and 22 upper extremities; 24 arms were evaluated in total. Three-dimensional images were taken of the upper extremities and Vectra 3D software was used to calculate the volume of the hand, forearm, and upper arm. These measurements were compared to traditional circumference (tape) and water displacement measurements. RESULTS: The twenty-four arm volumes ranged from 1517 to 4050 cc. The Vectra 3D provided precise and accurate volume measurements (average standard deviation ±1.0% of total volume). Measurements of the forearm and upper arm correlated with circumference measurements (R2 = 0.991) and were in good agreement, with the mean difference between measurement techniques being 2.8 ± 2.0%. Three-dimensional measurements of hand, forearm, and upper arm correlated with water measurements (R2= 0.990) and had a mean difference between measurement techniques of 2.6 ± 2.1%. CONCLUSION: The Vectra 3D system provides precise and accurate data comparable to the most commonly used technique to estimate limb volume (tape measurement) and gold-standard water volume measurement. Three-dimensional imaging also offers several advantages, including time efficiency and obtaining localized measurements with high spatial resolution.

Oncology Section EDGE Task Force on Urogenital Cancer Outcomes: Clinical Measures of Lymphedema—A Systematic Review

Background: Valid and reliable tools to assess lymphedema are necessary to accurately evaluate status and to objectively document and measure the results of interventions. Understanding the advantages and disadvantages of each measure can inform the clinician's choice of the appropriate tool to be used in the clinic or research setting. Purpose: To identify reliable and valid measurement techniques that are sensitive to change for assessing edema volume or soft tissue change in the lower extremities or genital region of patients with lymphedema. Methods: A systematic review of the literature was conducted to assess the published psychometric properties and clinical feasibility of each method identified. Task Force members independently reviewed each measure using the Cancer EDGE Rating Form. Results: Both water displacement and circumferential measurement methods by tape measure were rated as Highly Recommended to quantify lower-extremity limb volume. Water displacement was determined to be the criterion standard by which all other assessments of volume are benchmarked. Both optoelectric volumetry and bioelectric impedance analysis were rated as Recommended, and ultrasound was rated Not Recommended. Conclusion: The Urogenital Cancer EDGE Task Force highly recommends water displacement and circumferential tape measurement for use as reliable methods for assessment and documentation of change of limb volume in this patient population. Early detection of subclinical lower-extremity lymphedema in this patient population remains challenging, as there is no “index” limb that can be proven to be uninvolved in a patient population with documented pelvic node dissection/irradiation. No articles were found to support valid and reliable genital lymphedema volume measurement.

Abstract P33: Validation of Vectra 3D Imaging for Quantitative Volumetric Measurement of Upper Extremity Lymphedema

BACKGROUND: Secondary lymphedema of the arm is a complication of lymph node removal in cancer surgery. Limb volume measurements are considered the gold standard in evaluating outcomes in upper limb lymphedema. However, current techniques for volume measurement are limited by a lack of sensitivity to localized changes. The aim of this study was to determine whether the Vectra 3D imaging system could feasibly achieve accurate volume measurements of the upper limb. METHODS: A feasibility study was performed in 10 patients with lymphedema of the upper limb. Vectra 3D software was used to generate images and calculate volume of the hand, forearm, and upper arm. These measurements were compared to circumference (tape) and water displacement measurements. RESULTS: Ten patients with lymphedema of the arm were enrolled for volume measurement. Arm volumes ranged from 1517 to 4050 cc. The Vectra 3D provided precise volume measurements (average standard deviation +/- 0.8%). Measurements of the forearm and upper arm correlated with circumference measurements (R2 = 0.991) and were in good agreement, with the mean difference between measurement techniques being 2.8 ± 2.0%. Three dimensional measurements of hand, forearm, and upper arm also correlated with water measurements (R2 = 0.994) and had a mean difference between measurement techniques of 2.2 ± 1.8%. CONCLUSIONS: The Vectra 3D provides accurate and precise data comparable to the most commonly used technique to estimate limb volume (tape measurement) and gold-standard water volume measurement. Three dimensional imaging also offers several advantages, including time efficiency and obtaining localized measurements.

Comparison of Upper Extremity Volumes Measured with Water Displacement and Circumferential Measurement

Bu calismanin amaci, su tasirma yontemi ile olculen ust ekstremite hacmi ile antropometrik olcumlerinden hesaplanan ust ekstremite hacim degerlerinin karsilastirilmasidir. Calismaya beden egitimi ve spor yuksekokulunda ogrenim goren toplam 21 erkek gonullu olarak katilmistir. Iki bolumden olusan bu calismanin birinci bolmunde, calismaya katilan deneklerin kol hacmini belirlenmesinde su tasirma yontemi kullanilmis ikinci bolumunde ise cevresel olcumler kullanilarak kol hacim belirlenmistir. Sporcularin cevresel kol hacmi Frustum yontemi ile olculurken kol hacmi olcum araci ile de su tasirmadan elde edilen kol hacmi belirlenmistir. Verilerin analizinde su tasirma yontemi ile olculen ust ekstremite hacmi ile antropometrik olcumlerinden hesaplanan ust ekstremite hacim degerlerinin karsilastirilmasi amaciyla Esli Ornekler icin T Testi kullanilmistir. Yapilan t-testi sonuclari su tasirma yontemi ile olculen ust ekstremite hacmi ile antropometrik olcumlerinden hesaplanan ust ekstremite hacim degerleri arasinda istatistiksel acidan anlamli bir fark yoktur (t(12)=2.229, p=0.046). Sonuc olarak, calismadaki bulgular su tasirma yontemi ile olculen ust ekstremite hacmi ile antropometrik olcumlerinden hesaplanan ust ekstremite hacim degerlendirildiginde kol hacmi bulgulari uzerinde farklilasmaya neden olmamaktadir.

Wood Specific Gravity Variations and Biomass of Central African Tree Species: The Simple Choice of the Outer Wood.

ContextWood specific gravity is a key element in tropical forest ecology. It integrates many aspects of tree mechanical properties and functioning and is an important predictor of tree biomass. Wood specific gravity varies widely among and within species and also within individual trees. Notably, contrasted patterns of radial variation of wood specific gravity have been demonstrated and related to regeneration guilds (light demanding vs. shade-bearing). However, although being repeatedly invoked as a potential source of error when estimating the biomass of trees, both intraspecific and radial variations remain little studied. In this study we characterized detailed pith-to-bark wood specific gravity profiles among contrasted species prominently contributing to the biomass of the forest, i.e., the dominant species, and we quantified the consequences of such variations on the biomass.MethodsRadial profiles of wood density at 8% moisture content were compiled for 14 dominant species in the Democratic Republic of Congo, adapting a unique 3D X-ray scanning technique at very high spatial resolution on core samples. Mean wood density estimates were validated by water displacement measurements. Wood density profiles were converted to wood specific gravity and linear mixed models were used to decompose the radial variance. Potential errors in biomass estimation were assessed by comparing the biomass estimated from the wood specific gravity measured from pith-to-bark profiles, from global repositories, and from partial information (outer wood or inner wood).ResultsWood specific gravity profiles from pith-to-bark presented positive, neutral and negative trends. Positive trends mainly characterized light-demanding species, increasing up to 1.8 g.cm-3 per meter for Piptadeniastrum africanum, and negative trends characterized shade-bearing species, decreasing up to 1 g.cm-3 per meter for Strombosia pustulata. The linear mixed model showed the greater part of wood specific gravity variance was explained by species only (45%) followed by a redundant part between species and regeneration guilds (36%). Despite substantial variation in wood specific gravity profiles among species and regeneration guilds, we found that values from the outer wood were strongly correlated to values from the whole profile, without any significant bias. In addition, we found that wood specific gravity from the DRYAD global repository may strongly differ depending on the species (up to 40% for Dialium pachyphyllum).Main ConclusionTherefore, when estimating forest biomass in specific sites, we recommend the systematic collection of outer wood samples on dominant species. This should prevent the main errors in biomass estimations resulting from wood specific gravity and allow for the collection of new information to explore the intraspecific variation of mechanical properties of trees.

3D stereophotogrammetry in upper-extremity lymphedema: An accurate diagnostic method

Upper-extremity lymphedema is a frequent complication in patients treated for breast cancer. Current diagnostic methods for the upper-extremity volume measurements are cumbersome or time consuming. The purpose of this study was to assess the validity and reliability of three-dimensional (3D) stereophotogrammetry for volume measurements in patients with upper-extremity lymphedema. Patients with unilateral upper-extremity lymphedema were included. The water displacement volume measurement of both arms was performed using a standardized method. In addition, 3D stereophotogrammetry volume measurements were conducted. Eleven patients (22 arms) were included. The mean volumes obtained by 3D stereophotogrammetry and water displacement show a high correlation, with a Pearson's correlation coefficient of 0.99 (p = 0.01). The variance calculated by 3D stereophotogrammetry measurements (205 mL) was statistically significant less than that obtained via water displacement measurements (1540 mL) (p < 0.001). 3D stereophotogrammetry is an accurate method for measuring upper-extremity volume in patients with lymphedema and gives a lower variance value compared to that of the water displacement measurements. We recommend the use of this method in the diagnosis and follow-up of patients with lymphedema.

Computerized Dead-Space Volume Measurement of Face Masks Applied to Simulated Faces.

The dead-space volume (VD) of face masks for metered-dose inhaler treatments is particularly important in infants and young children with asthma, who have relatively low tidal volumes. Data about VD have been traditionally obtained from water displacement measurements, in which masks are held against a flat surface. Because, in real life, masks are placed against the face, VD is likely to differ considerably between masks depending upon their contour and fit. The aim of this study was to develop an accurate and reliable way to measure VD electronically and to apply this technique by comparing the electronic VD of commonly available face masks. Average digital faces were obtained from 3-dimensional images of 270 infants and children. Commonly used face masks (small and medium) from various manufacturers (Monaghan Medical, Pari Respiratory Equipment, Philips Respironics, and InspiRx) were scanned and digitized by means of computed tomography. Each mask was electronically applied to its respective digital face, and the VD enclosed (mL) was computerized and precisely measured. VD varied between 22.6 mL (SootherMask, InspiRx) and 43.1 mL (Vortex, Pari) for small masks and between 41.7 mL (SootherMask) and 71.5 mL (AeroChamber, Monaghan Medical) for medium masks. These values were significantly lower and less variable than measurements obtained by water displacement. Computerized techniques provide an innovative and relatively simple way of accurately measuring the VD of face masks applied to digital faces. As determined by computerized measurement using average-size virtual faces, the InspiRx masks had a significantly smaller VD for both small and medium masks compared with the other masks. This is of considerable importance with respect to aerosol dose and delivery time, particularly in young children. (ClinicalTrials.gov registration NCT01274299.).

3D ultrasound system to investigate intraventricular hemorrhage in preterm neonates

Intraventricular hemorrhage (IVH) is a common disorder among preterm neonates that is routinely diagnosed and monitored by 2D cranial ultrasound (US). The cerebral ventricles of patients with IVH often have a period of ventricular dilation (ventriculomegaly). This initial increase in ventricle size can either spontaneously resolve, which often shows clinically as a period of stabilization in ventricle size and eventual decline back towards a more normal size, or progressive ventricular dilation that does not stabilize and which may require interventional therapy to reduce symptoms relating to increased intracranial pressure. To improve the characterization of ventricle dilation, we developed a 3D US imaging system that can be used with a conventional clinical US scanner to image the ventricular system of preterm neonates at risk of ventriculomegaly. A motorized transducer housing was designed specifically for hand-held use inside an incubator using a transducer commonly used for cranial 2D US scans. This system was validated using geometric phantoms, US/MRI compatible ventricle volume phantoms, and patient images to determine 3D reconstruction accuracy and inter- and intra-observer volume estimation variability. 3D US geometric reconstruction was found to be accurate with an error of <0.2%. Measured volumes of a US/MRI compatible ventricle-like phantom were within 5% of gold standard water displacement measurements. Intra-class correlation for the three observers was 0.97, showing very high agreement between observers. The coefficient of variation was between 1.8–6.3% for repeated segmentations of the same patient. The minimum detectable difference was calculated to be 0.63 cm3 for a single observer. Results from ANOVA for three observers segmenting three patients of IVH grade II did not show any significant differences (p > 0.05) for the measured ventricle volumes between observers. This 3D US system can reliably produce 3D US images of the neonatal ventricular system. There is the potential to use this system to monitor the progression of ventriculomegaly over time in patients with IVH.