Accuracy and precision of multiple body composition methods and associations with muscle strength in athletes of varying hydration: The Da Kine Study.

BACKGROUND: Athletes vary in hydration status due to ongoing training regimes, diet demands, and extreme exertion. With water being one of the largest body composition compartments, its variation can cause misinterpretation of body composition assessments meant to monitor strength and training progress. In this study, we asked what accessible body composition approach could best quantify body composition in athletes with a variety of hydration levels. METHODS: The Da Kine Study recruited collegiate and intramural athletes to undergo a variety of body composition assessments including air-displacement plethysmography (ADP), deuterium-oxide dilution (D2O), dual-energy X-ray absorptiometry (DXA), underwater-weighing (UWW), 3D-optical (3DO) imaging, and bioelectrical impedance (BIA). Each of these methods generated 2- or 3-compartment body composition estimates of fat mass (FM) and fat-free mass (FFM) and was compared to equivalent measures of the criterion 6-compartment model (6CM) that accounts for variance in hydration. Body composition by each method was used to predict abdominal and thigh strength, assessed by isokinetic/isometric dynamometry. RESULTS: In total, 70 (35 female) athletes with a mean age of 21.8 ± 4.2 years were recruited. Percent hydration (Body Water6CM/FFM6CM) had substantial variation in both males (63-73 %) and females (58-78 %). ADP and DXA FM and FF M had moderate to substantial agreement with the 6C model (Lin's Concordance Coefficient [CCC] = 0.90-0.95) whereas the other measures had lesser agreement (CCC <0.90) with one exception of 3DO FFM in females (CCC = 0.91). All measures of FFM produced excellent precision with %CV < 1.0 %. However, FM measures in general had worse precision (% CV < 2.0 %). Increasing quartiles (significant p < 0.001 trend) of 6CM FFM resulted in increasing strength measures in males and females. Moreover, the stronger the agreement between the alternative methods to the 6CM, the more robust their correlation with strength, irrespective of hydration status. CONCLUSION: The criterion 6CM showed the best association to strength regardless of the hydration status of the athletes for both males and females. Simpler methods showed high precision for both FM and FFM and those with the strongest agreement to the 6CM had the highest strength associations. SUMMARY BOX: This study compared various body composition analysis methods in 70 athletes with varying states of hydration to the criterion 6-compartment model and assessed their relationship to muscle strength. The results showed that accurate and precise estimates of body composition can be determined in athletes, and a more accurate body composition measurement produces better strength estimates. The best laboratory-based techniques were air displacement plethysmography and dual-energy x-ray absorptiometry, while the commercial methods had moderate-poor agreement. Prioritizing accurate body composition assessment ensures better strength estimates in athletes.

Validating 3D indexes in the non-surgical pectus excavatum patient.

BACKGROUND/PURPOSE: In recent years there has been an increased interest in three-dimensional (3D) imaging for the assessment of chest wall deformities. Some studies have proven a correlation between 3D and traditional cross-sectional images but only for patients who already had an indication for a computed tomography (CT) scan prior to surgery; mainly due to their severity. Our aim is to determine the accuracy and reliability of the measures obtained by a portable 3D scanner in a cohort of pectus excavatum (PE) patients with different severity grades, as well as in controls. METHODS: We conducted a study comparing radiological and optical indexes on magnetic resonance imaging (MRI) and 3D surface images. We used a hand-held 3D scanner to obtain the optical Haller Index (3DHI) and Correction Index (3DCI) and a limited MRI scan to obtain the traditional indexes. A statistical analysis was carried out to determine the correlation between optical and radiological measures, plus a subjective severity evaluation. RESULTS: Twenty-eight patients and controls were enrolled in the study. In both the control and PE groups, there was a significant positive correlation between the indexes, especially for the CI. There were no differences in correlation regarding gender, age or severity. CI appears to better discriminate amongst the different severity groups and controls. CONCLUSION: 3D surface imaging is feasible and appropriate to use to assess PE, regardless of the severity or characteristics of the individual patient. Even with a small hand-held device, we can obtain accurate images and measures which are especially useful for the assessment of the nonsurgical pectus patient.

Comparative Analysis of Hyaluronidase-Mediated Degradation Among Seven Hyaluronic Acid Fillers in Hairless Mice.

PURPOSE: Hyaluronic acid (HA) is the most common injectable dermal filler used for soft-tissue augmentation, and can be removed non-surgically by directly injecting hyaluronidase. In this study, the hyaluronidase-mediated degradation of different types of HA fillers implanted subcutaneously at the back of hairless mice having filler residence time of four days or three months were compared. METHODS: Two sites at the back of female hairless mice were subcutaneously implanted with 0.1-mL of one of the seven HA fillers (NLL, NL, NDL, NVL, and ND, JUVX+, and RESLYFT) and injected with 30 IU or 60 IU hyaluronidase per 0.1-mL filler after reaching a filler residence time of 4 or 91 days, respectively. Filler bolus projection was measured using three-dimensional optical imaging over a 72 h period, and the implantation sites were histologically examined 2 weeks after hyaluronidase injection. RESULTS: Following hyaluronidase injection, all seven HA fillers showed a rapid decrease of filler volume within 24 h, and complete degradation was confirmed by histological examination after 2 weeks. There was no significant difference in filler volume reduction rate among the seven HA fillers, and no evidence of macroscopic or microscopic adverse effects were observed at the implantation sites. CONCLUSION: All seven HA fillers show comparable susceptibility to hyaluronidase-mediated degradation. HA fillers with prolonged filler residence time may require a higher dose of hyaluronidase to achieve efficient degradation owing to tissue integration.

3D optical/CT as a preclinical companion imaging platform for glioblastoma drug development.

Multimodality 3D Optical Imaging (OI)/CT has the potential to play a major role in drug development for glioblastomas (GBM), as it is an accessible preclinical method. To demonstrate the potential of 3D OI/CT to visualize orthotopic GBM implantation, we labeled GBM cells with Cy7 and imaged their location using 3D OI/CT. To confirm the accuracy of the spatial localization and demonstrate the ability to image locoregionally delivered therapies, we labeled mouse albumin with Cy7 (Cy7ALB) and delivered it via locoregional infusion 1 mm or 3 mm into the brain and demonstrated correlation of signal between the 3D OI/CT and post necropsy brain slices. In addition, we demonstrated the potential of systemically delivered Cy7ALB contrast to detect blood-brain barrier (BBB) permeability caused by orthotopic GBMs using 3D OI/CT. We also tested the potential of 3D OI/CT to assess focal BBB permeability induced by high intensity focused ultrasound (HIFU), a methodology being used in clinical trials to noninvasively permeabilize the BBB for systemic therapeutic delivery to GBM. We demonstrated the ability of systemic Cy7ALB contrast together with 3D OI/CT to accurately assess real-time HIFU-induced BBB permeability, which correlated to post necropsy imaging of brains. Furthermore, we demonstrated that 3D OI/CT can also image the therapeutic distribution of a Cy7-labeled anti-PD-1 antibody, a prototype translational antibody therapy. We successfully imaged real-time antibody distribution after HIFU-induced BBB permeability, which correlated with post necropsy Cy7 signal and translational PET imaging after injection of [89Zr] anti-PD-1 antibody. Thus, we demonstrated the broad potential of using 3D OI/CT as an accessible preclinical tool to develop anti-GBM therapies.

A Simplified Method for Three-Dimensional Optical Imaging and Measurement of Patients with Chest Wall Deformities.

BACKGROUND: Pectus excavatum and carinatum are two of the most commonly observed chest wall deformities in pediatrics. The standard diagnostic evaluation for these conditions includes either chest radiograph (CXR) or computed tomography (CT). Our research aims to develop a novel and reliable way of quantifying chest wall deformities in the clinic setting without radiation exposure. METHODS: Using a handheld structured light scanner, we created three-dimensional (3D) models of patients with chest wall deformities through an IRB-approved protocol. Raters from a variety of backgrounds were then asked to take measurements based on the 3D model utilizing commercially available 3D graphical software. The standard deviation of the measurements and intraclass correlation coefficient (ICC) were then calculated to quantify inter-rater reliability. RESULTS: Sixty patients with pectus excavatum (Haller index range 2.0-6.38) and pectus carinatum were enrolled and imaged in our outpatient clinic using a structured light scanner. Five patients were used to verify interuser reliability. The standard deviation of all the measurements was 2.2 mm. The ICC for absolute agreement was 0.99139, with 1.0 being perfect correlation. CONCLUSION: Structured light scanners provide an alternative approach to quantifying chest wall deformities in pediatric patients without radiation exposure. Our method is highly reliable, even among users with minimal image processing or 3D modeling experience. Our protocol can potentially be used to track treatment progress in children with chest wall deformities.

Combining 3D optical imaging and dual energy absorptiometry to measure three compositional components.

We report on the design of the technique combining 3D optical imaging and dual-energy absorptiometry body scanning to estimate local body area compositions of three compartments. Dual-energy attenuation and body shape measures are used together to solve for the three compositional tissue thicknesses: water, lipid, and protein. We designed phantoms with tissue-like properties as our reference standards for calibration purposes. The calibration was created by fitting phantom values using non-linear regression of quadratic and truncated polynomials. Dual-energy measurements were performed on tissue-mimicking phantoms using a bone densitometer unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the biological compositional compartments. The components for the solid phantom were tested and their high energy/low energy attenuation ratios are in good correspondent to water, lipid, and protein for the densitometer x-ray region. The three-dimensional body shape was reconstructed from the depth maps generated by Microsoft Kinect for Windows. We used open-source Point Cloud Library and freeware software to produce dense point clouds. Accuracy and precision of compositional and thickness measures were calculated. The error contributions due to two modalities were estimated. The preliminary phantom composition and shape measurements are found to demonstrate the feasibility of the method proposed.