Name: 3d ultrasound imaging: fast and cost-effective morphometry of musculoskeletal tissue
Uploaded: 2017-11-27T12:30:00.000+00:00
Duration: 8 min 52 s
Description: Watch this Scientific Journal Video about 3D Ultrasound Imaging: Fast and Cost-effective Morphometry of Musculoskeletal Tissue at JoVE.com

The authors are very grateful to Adam Shortland and Nicola Fry who shared their algorithms for the 3-dimensional ultrasound in 2004, which were the inspiration for the development of the software used in this study.

The authors have nothing to disclose.

A valid and reliable 3DUS technique is presented that allows for the fast analysis of morphometric variables of skeletal muscles. Different 3DUS approaches for soft tissue imaging have been available for approximately a decade42,43, however the 3DUS approaches are still not used commonly. MRI is a &#39;gold standard&#39; for estimation of in vivo muscle volumes (e.g., references16,17,18,19,20). MRI validity has been tested and confirmed in studies comparing either phantoms or cadaveric organs of known volume to MRI-based volume estimates44,45. However, MRI availability for research is limited and scans are time consuming and costly. In addition, experimental subject postures are limited by the bore seize of the MRI scanners. Typical MR images generate insufficient contrast to perform measurements of variables of muscle geometry (fascicle lengths and angles). However, 3D muscle geometry can be assessed also using MRI by using additional techniques, e.g., DTI technique21. Similar to MRI, US imaging provides adequate distinction at interfaces between different types of tissues (i.e.&#160;visible within US images), providing a valid modality for soft tissues volume assessment1,30,44,46,47,48,49. In contrast to MRI, 3DUS images have sufficient contrast to perform analysis on both volume and muscle geometry from the same measurement.
In addition, the technique presented allows combining images of multiple sweeps into one array, for the study of larger muscles. This new 3DUS method provides a potential tool for clinical assessment of muscle morphology. This method can be used also for imaging soft-tissue structures other than muscle (e.g., tendons, internal organs, arteries).
Modifications to Improve Offline Processing Time:
Modifications of the 3DUS approach were mainly aimed at improving processing time and measuring larger muscles. The offline processing time of a 3DUS image depends on voxel array settings, sampling frequency, size of ROI, duration and speed of the sweep, number of sweeps, and the used workstation. Previously, a reconstruction time of &#8776; 2 h was necessary for reconstructing only one sweep yielding 750 US images (30 s at 25 Hz)15,25,30. With the present 3DUS method, the same sweep takes only 50 s reconstruction time (improving the &#39;offline&#39; processing time by 99%). This improvement can be explained by the enhanced filling algorithm that utilizes large vector operations to fill the voxels frame-by-frame, instead of pixel per pixel and increased random access memory (RAM) of workstations to construct larger voxel arrays. With the new 3DUS approach, a typical reconstruction representing a sweep length of 30 cm at a speed of 1 cm/s, with a target voxel size of 0.2 x 0.2 x 0.2 mm3 and a sampling frequency of 25 Hz, takes the following time to reconstruct:
a. Approximately 10 s to identify the synchronization pulse and select relevant US images. 
b. Approximately 120 s to determine the calibration transformation matrix (PrTIm). 
c. Approximately 10 s for the bin-filling stage. 
d. Approximately 30 s for executing the gap-filling steps.
In total, taking 170 s. Note, step b only needs to be performed once, assuming a rigid connection of the MoCap markers to the probe, leaving 50 s for the reconstruction of a single sweep. Combining two single sweep reconstructed voxel arrays takes approximately 10 s.
Limitations and Critical Steps:
There are several 3DUS imaging aspects that should be taken into account:
i. US image quality: Higher spatial resolution of 2D US images provide more pixels to be placed within the voxel array. This would allow the voxel dimensions to decrease, leading to higher voxel density. Several currently available ultrasound machines use spatial compounding to reduce the noisy granular texture, allowing for better artifact-free distinction of the interfaces of tissues. Another option to reduce speckle is edge enhancement. However, it should be noted that this approach is not desirable, since it deforms the image in an attempt to create distinct interfaces, thereby distorting the true anatomical position of the interfaces.
ii. MoCap accuracy: Pixels can only be accurately placed into a voxel, if the position sensor accurately quantifies the coordinates of the probe. With an increase in image resolution, MoCap accuracy becomes more important. The presented 3DUS setup works best with a voxel dimension of 0.2 x 0.2 x 0.2 mm3, using a MoCap system with an accuracy of 0.1 mm, providing ample accuracy to reconstruct the 3DUS voxel array.
iii. Sample frequency: The lowest temporal resolution of either the US images or MoCap data stream determines the sample frequency. This affects the sweep time or the voxel array settings. For instance, doubling the sample frequency from 25 to 50 Hz allows a sweep to be performed in half the time. Alternatively, not changing the sweep speed, provides more images to fill the voxel array, leaving fewer gaps to be filled and thereby potentially increasing the voxel array resolution. However, increasing the voxel array resolution, without increasing the sampling frequency, requires a slower scan, which will increase the potential of movement artifacts.
iv. Image reconstruction time: Fast reconstructions require a powerful workstation with sufficient available RAM. In addition, reconstruction time varies largely based on the voxel array volume and complexity of the gap-filling process.
v. Experimental protocol: Standardization of the experimental protocol, as exemplified in the present study for the VL and GM, is essential for comparison of morphological measurements (e.g., fascicle length, fascicle angle, muscle belly length, tendon length, aponeurosis length) between subjects and monitoring within subjects in longitudinal studies. However, note that the morphology assessed at rest may alter during muscle activation. For example, for the VL experiment, the knee extensor morphology during maximal contraction may demonstrate a high pennation angle and shorter fascicles in 60&#176; knee flexion, in comparison with morphology at rest50. In certain conditions (e.g., spasticity), electromyography (EMG) may be used to verify resting muscle activity levels during examination.
vi. Probe pressure and tissue deformation: If ample ultrasound gel is applied on the ROI, the amount of pressure to remain for full contact between probe and the skin is limited. As guidance, we advise that scanning a ROI should feel like hovering over the skin, and pressure should only be applied to keep in contact with the gel and thereby the skin. However, slight tissue deformation may be inevitable, even with a generous amount of ultrasound gel. Probe size and a curved ROI affect the required amount of pressure or gel used. Larger probe size and a more curved ROI require more pressure and/or more gel, than smaller probes with a similar curved ROI. Another possible solution is to discard the reverberation (i.e.&#160;non-skin-contact) region of the US images. In addition, tissue deformation is most likely to occur in the first tissue layers, such as skin and subcutaneous adipose tissue layers. Note that subjects with little to no subcutaneous adipose tissue are therefore more prone to adverse effects of pressure. In addition, the tissue deformation occurs most likely at the center of the probe, which is typically not the region of overlap with other sweeps.
vii. Imaging and anatomical knowledge: Another important consideration in using any imaging modality is that the knowledge of both the anatomy and the imaging modality is essential to obtain meaningful interpretation. Anatomical variation between subjects and image artifacts needs to be recognized and taken into account in the identification process of anatomical structures. Even with healthy and/or well developed muscles, clear identification can be difficult because it requires anatomical knowledge to differentiate between different components of one muscle or between muscle groups51. However, in atrophied muscle (i.e.&#160;elderly, in the case of pathology, or a cadaver), the clear identification is even more complicated because of a smaller size and decreased image contrast, and therefore less distinct tissue interfaces (Figure 4). We believe that without prior anatomical knowledge, we would have been limited in making correct judgements in designing this 3DUS approach and in performing the 3DUS measurements. For example, for GM experiments, different footplate angles do not necessarily cause expected changes in muscle tendon complex lengths, due to deformation within the foot7. Also detailed anatomical information on curvature of the distal aponeurosis was essential for an adequate selection of the mid-longitudinal plane in all subjects38.
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/55943/55943fig4.jpg" /> 
Figure 4: Variation and quality of reconstructed anatomical cross-sectional 3DUS images of the quadriceps muscle halfway along the thigh. (A) Example of a male human cadaver shows an image of an atrophied state at death (death age: 81 years). Identification of the boundaries of individual heads of the quadriceps muscle is difficult. (B) Example of a sedentary male (aged 30 years). (C) Example of a male athlete rower (aged 30 years). The white squares for scale represent 1 cm x 1 cm. <a href="//cloudflare.jove.com/files/ftp_upload/55943/55943fig4large.jpg" style="font-size: 14px;" target="_blank">Please click here to view a larger version of this figure.</a>
Future Applications:
The 3DUS approach provides an imaging tool that can be used for various purposes and settings in sports and clinics. In clinical interventions effectiveness is related to the physical fitness level52. Using 3DUS for monitoring patients who are at risk of losing muscle mass is important (e.g., references53,54,55) and potentially allows for adjustment of the treatment. Another potential application of 3DUS lies in monitoring the morphological adaptation of muscle in response to intervention (training) and/or injury.
This protocol described a cost- and time-effective method of measuring soft tissue structure of the human body based on freehand 3DUS sweeps. Moreover, assessment of the meaningful morphological parameters of m. vastus lateralis and m. gastrocnemius medialis proved to be valid and reliable.

In healthcare and sports, information on the morphology of muscles is very valuable in diagnostics and/or follow-up evaluations after treatment or training1. Ultrasound (US) imaging is a tool commonly used for visualization of soft tissue structures in muscle diseases2, critical illnesses3,4, cardiovascular diseases5, neurological disorders6,7,8, and effects of physical training6,9,10. US imaging enables quantification of muscle size, fascicle length, and angle of pennation. These morphological variables are important determinants of muscle force and length range of force exertion11,12,13,14,15.
Currently, US imaging measurements are mostly performed in 2D images, with the examiner choosing a presumably, suitable orientation and location of the ultrasound probe. Such 2D methods restrict morphological measurements to one image plane, while the parameter of interest may not be present within this plane. Morphological analysis requires a 3D approach, providing out-of-plane measurements using 3D reference points. Such a 3D morphological representation of soft tissues is known to be provided by Magnetic Resonance Imaging (MRI)16,17,18,19,20. However, MRI is expensive and not always available. Also, visualization of muscle fibers requires special MRI sequences, such as diffusion tensor imaging (DTI)21. A cost-effective alternative to MRI is 3D ultrasound (3DUS) imaging. The 3DUS approach provides several advantages over MRI techniques, e.g., it imposes less space limitations for positioning the subject during an examination. 3DUS imaging is a technique sequentially capturing 2D (B-mode US) images and positioning them into a volume element (voxel) array22,23,24. The process of 3DUS image reconstruction consists of five steps: (1) Capturing a series of freehand 2D US images; (2) Tracking the position of the US probe, using a Motion Capture (MoCap) system; (3) Synchronizing the MoCap position and US images; (4) Calculating the location and orientation of the ultrasound images within the voxel array using a calibrated system of reference; and (5) Placing these images into this voxel array.
The 3DUS approach has been successfully applied for assessment of morphology of skeletal muscle15,25,26,27,28,29. However, previous approaches7,15,25,30 have proved cumbersome, time consuming and technically limited, as only small segments of large muscles could be reconstructed.
To improve the 3DUS approach, a new 3DUS protocol has been developed that allows reconstruction of complete muscles within a short period of time. This protocol article describes the use of 3DUS imaging for morphometry of the m. vastus lateralis (VL) and m. gastrocnemius medialis (GM).

<table><tbody><tr><td>Ultrasound device (Technos MPX)</td><td>Esaote, Italy</td><td>NA</td><td></td></tr><tr><td>Linear array probe (12.5 Mhz, 5 cm)</td><td>Esaote, Italy</td><td>NA</td><td></td></tr><tr><td>Workstation (HP Z440)</td><td>HP, USA</td><td>http://www8.hp.com/us/en/workstations/z440.html</td><td></td></tr><tr><td>Framegrabber (Canopus, ADVC 300)</td><td>Canopus, Japan</td><td>ADVC 300</td><td></td></tr><tr><td>Motion Capture System (Certus)</td><td>NDI, Canada</td><td>http://www.ndigital.com/msci/products/optotrak-certus/</td><td></td></tr><tr><td>Synchronisation device</td><td>VU, NL</td><td>Contact corresponding author</td><td></td></tr><tr><td>Calibration frame</td><td>VU, NL</td><td>Contact corresponding author</td><td></td></tr><tr><td>Thermometer</td><td>Greisinger, Germarny</td><td>GTH 175/PT</td><td></td></tr><tr><td>Examination table</td><td>NA</td><td>NA</td><td>Any examination table</td></tr><tr><td>Inclinometer</td><td>Lafayette instrument, USA</td><td>ACU001</td><td></td></tr><tr><td>Adjustable Footplate</td><td>VU, NL</td><td>Contact corresponding author</td><td></td></tr><tr><td>Torque wrench</td><td>VU, NL</td><td>Contact corresponding author</td><td></td></tr><tr><td>Extendable rod</td><td>VU, NL</td><td>Contact corresponding author</td><td></td></tr><tr><td>Goniometer (Gollehon)</td><td>Lafayette instrument, USA</td><td>1135</td><td></td></tr><tr><td>Triangular shaped beam</td><td>NA</td><td>NA</td><td>Made out a piece of stiff foam</td></tr><tr><td>Lashing straps</td><td>NA</td><td>NA</td><td>Any lashing strap</td></tr><tr><td>Surgical skin marker</td><td>NA</td><td>NA</td><td>Any surgical skin marker</td></tr><tr><td>Ultrasound transmission gel</td><td>Servoson</td><td>NA</td><td>A sticky gel type is recommended</td></tr></tbody></table>

3d ultrasound imaging: fast and cost-effective morphometry of musculoskeletal tissue

The developmental goal of 3D ultrasound imaging (3DUS) is to engineer a modality to perform 3D morphological ultrasound analysis of human muscles. 3DUS images are constructed from calibrated freehand 2D B-mode ultrasound images, which are positioned into a voxel array. Ultrasound (US) imaging allows quantification of muscle size, fascicle length, and angle of pennation. These morphological variables are important determinants of muscle force and length range of force exertion. The presented protocol describes an approach to determine volume and fascicle length of m.&#160;vastus lateralis and m.&#160;gastrocnemius medialis. 3DUS facilitates standardization using 3D anatomical references. This approach provides a fast and cost-effective approach for quantifying 3D morphology in skeletal muscles. In healthcare and sports, information on the morphometry of muscles is very valuable in diagnostics and/or follow-up evaluations after treatment or training.

The described 3DUS technique was used to collect morphological data of the GM and VL in four male human cadavers, age at death 76.8 &#177; 7.9 years (mean &#177; SD). The cadavers were obtained via the donation program of the Department of Anatomy and Neuroscience of the Vrije Universiteit Medical Center (VUmc), Amsterdam, the Netherlands. The bodies were preserved using an embalming method aimed at maintaining the morphological features of the tissue39.
Prior to dissection, a 3DUS image was made of the GM and VL according to the methodology described. During dissection, skin, subcutaneous tissue, and fasciae overlaying the GM and VL were removed. A mid-longitudinal section was cut, taking the orientation of the distal aponeurosis into account. Using a caliper, the fascicle length was measured, halfway between the origin and the distal end of the muscle belly. Subsequently, after tenotomy, the muscle belly was dissected and submerged in a calibrated water column. Using ImageJ, the volumes were measured on photographs of the water column with and without the muscle belly, and muscle volume was calculate from the difference40. Fascicle length and volume were measured three times and the mean and standard deviation values were calculated. Criterion validity between the 3DUS method and dissection measurements was tested using a Pearson&#39;s correlation for average fascicle length and muscle volume. Intra-rater reliability of the 3DUS method derived fascicle length and volume measurements was quantified using a two-way mixed model intra-class correlation coefficient (ICC3,3)41, and after logarithmic transformation of the data, the coefficient of variation (CV) was calculated. The validity of fascicle length and muscle volume measurements were confirmed by significant and high correlations (r = 0.998, p &#60;0.01 and r = 0.985, p &#60;0.01, respectively). Intra-rater reliability of the 3DUS method derived measurements of fascicle length and volume was high (ICC3,3 0.983, CV 7.3%, and ICC3,3 0.998, CV 5.4%, respectively). It is concluded that the 3DUS approach presented is a valid and reliable tool for volume and fascicle length assessment of human VL and GM (Table 1).
<img alt="Table 1" src="/files/ftp_upload/55943/55943table1.jpg" /> 
Table 1:&#160;Cadaver Validation Data. C# is Cadaver number, GM is&#160;m. gastrocnemius medialis, VL is&#160;m. vastus lateralis. &#34;Dissection&#34;shows results from the cadaver dissection, and &#34;3DUS&#34; shows the results from the 3DUS image analysis of the cadavers.

Watch this Scientific Journal Video about 3D Ultrasound Imaging: Fast and Cost-effective Morphometry of Musculoskeletal Tissue at JoVE.com

3D Ultrasound Imaging: Fast and Cost-effective Morphometry of Musculoskeletal Tissue

3D ultrasound imaging (3DUS) allows fast and cost-effective morphometry of musculoskeletal tissues. We present a protocol to measure muscle volume and fascicle length using 3DUS.

The developmental goal of 3D ultrasound imaging (3DUS) is to engineer a modality to perform 3D morphological ultrasound analysis of human muscles. 3DUS ...

3d-ultrasound-imaging-fast-cost-effective-morphometry-musculoskeletal

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JoVE Journal

Medicine

23.0K Views.  Amsterdam Movement Sciences. 3D ultrasound imaging (3DUS) allows fast and cost-effective morphometry of musculoskeletal tissues. We present a protocol to measure muscle volume and fascicle length using 3DUS.

Video: 3D Ultrasound Imaging: Fast and Cost-effective Morphometry of Musculoskeletal Tissue

A Novel Application of Musculoskeletal Ultrasound Imaging

Ultrasound is an attractive modality for imaging muscle and tendon motion during dynamic tasks and can provide a complementary methodological approach for biomechanical studies in a clinical or laboratory setting. Towards this goal, methods for quantification of muscle kinematics from ultrasound imagery are being developed based on image processing. The temporal resolution of these methods is typically not sufficient for highly dynamic tasks, such as drop-landing. We propose a new approach that utilizes a Doppler method for quantifying muscle kinematics. We have developed a novel vector tissue Doppler imaging (vTDI) technique that can be used to measure musculoskeletal contraction velocity, strain and strain rate with sub-millisecond temporal resolution during dynamic activities using ultrasound. The goal of this preliminary study was to investigate the repeatability and potential applicability of the vTDI technique in measuring musculoskeletal velocities during a drop-landing task, in healthy subjects. The vTDI measurements can be performed concurrently with other biomechanical techniques, such as 3D motion capture for joint kinematics and kinetics, electromyography for timing of muscle activation and force plates for ground reaction force. Integration of these complementary techniques could lead to a better understanding of dynamic muscle function and dysfunction underlying the pathogenesis and pathophysiology of musculoskeletal disorders.

We describe a new ultrasound-based vector tissue Doppler imaging technique to measure muscle contraction velocity, strain and strain rate with sub-millisecond temporal resolution during dynamic activities. This approach provides complementary measurements of dynamic muscle function and could lead to a better understanding of mechanisms underlying musculoskeletal disorders.

Ultrasound is an attractive modality for imaging muscle and tendon  motion during dynamic tasks and can provide a complementary methodological  approach ...

Outer-Boundary Assisted Segmentation and Quantification of Trabecular Bones by an Imagej Plugin

Micro-computed tomography (micro-CT) is routinely used to assess bone quantity and trabecular microstructural properties in small animals under different bone loss conditions. However, the standard approach for trabecular analysis of micro-CT images is slice-by-slice semi-automatic hand-contouring, which is labor intensive and error prone. Described here is an efficient method for automatic segmentation of trabecular bones according to the bone's outer boundaries, where trabecular bones can be identified and segmented automatically with accuracy with less operator bias when appropriate segmentation parameters are set. To profile satisfactory segmentation parameters, an image stack of segmentation results is displayed, where all possible combinations of the segmentation parameters are changed one by one in sequence, and segmentation results with associated parameters can easily be visually checked. As a quality-control feature of the plugin, simulated standard objects are quantified where the measured quantities can be compared with theoretical values. Layer-by-layer quantification of trabecular properties and trabecular thicknesses are reported by such a plugin, and the distributions of such properties within the selected regions can be profiled easily. Although layer-by-layer quantification retains more information about trabecular bones and facilitates further statistical analysis of structural changes, such measures are unavailable from the output of current commercial software, where only a single quantified value for each parameter is reported for each sample. Therefore, the described workflows are better approaches for analyzing trabecular bones with accuracy and efficiency.

We present a workflow for segmenting and quantifying trabecular bones for 2D and 3D images based on the bone&#39;s outer boundary using an ImageJ plugin. This approach is more efficient and accurate than the current manual hand-contouring approach, and provides layer-by-layer quantifications, which are not available in current commercial software.

Micro-computed tomography (micro-CT) is routinely used to assess bone quantity and trabecular microstructural properties in small animals under different ...

Bioengineering

Four-Dimensional CT Analysis Using Sequential 3D-3D Registration

Four-dimensional computed tomography (4DCT) provides a series of volume data and visualizes joint motions. However, numerical analysis of 4DCT data remains difficult because segmentation in all volumetric frames is time-consuming. We aimed to analyze joint kinematics using a sequential 3D-3D registration technique to provide the kinematics of the moving bone with respect to the fixed bone semiautomatically using 4DCT DICOM data and existing software. Surface data of the source bones are reconstructed from 3DCT. The trimmed surface data are respectively matched with surface data from the first frame in 4DCT. These trimmed surfaces are sequentially matched until the last frame. These processes provide positional information for target bones in all frames of the 4DCT. Once the coordinate systems of the target bones are decided, translation and rotation angles between any two bones can be calculated. This 4DCT analysis offers advantages in kinematic analyses of complex structures such as carpal or tarsal bones. However, fast or large-scale motions cannot be traced because of motion artifacts.

We analyzed joint kinematics from four-dimensional computed tomography data. The sequential 3D-3D registration method semiautomatically provides the kinematics of the moving bone with respect to the subject bone from four-dimensional computed tomography data.

Four-dimensional computed tomography (4DCT) provides a series of volume data and visualizes joint motions. However, numerical analysis of 4DCT data ...

Analysis of Craniomaxillofacial Malformations in Mice Using Three-dimensional Microcomputed Tomography

To model craniofacial malformations caused by vitamin A deficiency (VAD), we expressed a dominant-negative retinoid receptor mutation in osteoblasts to specifically inhibit RAR transcriptional activity in mice. This approach allowed us to investigate the effects of VAD on cranial hypomineralization, mandibular deformity, and clavicular hypoplasia in clinical cases. In this study, microcomputed tomography (microCT) scanning of the craniomaxillofacial region of mice represented a valuable tool for studying the growth and development of this animal model. The manual estimation of images is both time-consuming and inaccurate. Hence, here, we present a straightforward, efficient, and accurate approach for segmenting and quantifying the microCT images of each craniomaxillofacial bone. MicroCT software was used to slice the mandible, frontal bone, parietal bone, nasal bone, premaxilla, maxilla, interparietal bone, and occipital bone of mice and measure their corresponding lengths and widths. This segmentation method can be applied to study growth and development in developmental biology, biomedicine, and other related sciences and allows researchers to analyze the effects of genetic mutations on individual craniofacial bones.

Here, we describe in depth a method, which is based on microcomputed tomography, to segment and measure 3D models of craniomaxillofacial bones in mice, for better assessment of craniomaxillofacial bone development in mice than what is possible with current methods.

To model craniofacial malformations caused by vitamin A deficiency (VAD), we expressed a dominant-negative retinoid receptor mutation in osteoblasts to ...

Developmental Biology

4D Ultrasound and MALDI Imaging for Cardiac and Vascular Analysis in Mice

Multimodal Study of Murine Cardiovascular Remodeling: Four-Dimensional Ultrasound and Mass Spectrometry Imaging

Cardiovascular disease (CVD) is the leading cause of death in the United States. Damage in&#160;the cardiovascular system can be due to environmental exposure, trauma, drug toxicity, or numerous other factors.&#160;As a result, cardiac tissue and vasculature undergo structural changes and display diminished function. The damage and the resulting remodeling can be detected and quantified with ultrasound (US) imaging at the organ level and mass spectrometry imaging (MSI) at the molecular level. This manuscript describes an innovative methodology for studying murine cardiac pathophysiology, coupling in vivo four-dimensional (4D) ultrasound imaging and analysis with ex vivo matrix-assisted laser desorption/ionization (MADLI) MSI of the heart. 4D ultrasound can provide dynamic volumetric measurements, including radial displacement, surface area strain, and longitudinal strain throughout an entire cardiac cycle. In the vasculature, MSI and ultrasound are used to assess vessel wall compositions, hemodynamics, and vessel wall dynamics. The methodology can be tailored to study a myriad of CV diseases by adjusting functional metrics of interest and/or varying MALDI MSI protocol to target specific molecules. MALDI MSI can be used to study lipids, small metabolites, peptides, and glycans. This protocol outlines the use of MALDI MSI for untargeted lipidomic analysis and the use of ultrasound imaging for cardiovascular hemodynamics and biomechanics.

Here, we describe a protocol to use in vivo four-dimensional ultrasound imaging and ex vivo mass spectrometry imaging to assess biomechanical and biomolecular alterations in the murine cardiovascular system. This technique is applied to analyze cardiac remodeling in surgically induced myocardial infarction and vascular changes in aging animals.

Cardiovascular disease (CVD) is the leading cause of death in the United States. Damage in&#160;the cardiovascular system can be due to environmental ...

Cortical Bone Assessment Using the Ultrasonic BDAT Device

Cortical Bone Assessment Using Ultrasonic Guided Waves: A Reproducibility Study in a Healthy Population

Fragility fractures are still a worldwide health burden in the context of population aging. In particular, the global number of hip fractures is expected to double between 2020 and 2050. Therefore, it is essential to detect patients at risk of fragility fracture at the population scale. The current golden standard is dual X-ray absorptiometry (DXA), providing the areal bone mineral density (aBMD). Ultrasonic devices, usually more portable and cheaper than X-ray devices, represent interesting DXA alternatives as screening tools. However, operator dependency is usually recognized as their main drawback. In this study, the measurement protocol of the bi-directional axial transmission (BDAT) ultrasonic device is presented in detail. The dedicated ultrasonic probe is placed at the one-third distal radius of the non-dominant forearm using conventional coupling gel. The guided interface provides in quasi-real time (about 2 Hz) four parameters of interest: velocities of the first arriving signal (vFAS) and the A0 mode (vA0),&#160;cortical thickness (Ct.Th) and porosity (Ct.Po), as well as four quality parameters. The operator moves the probe slowly at the measurement site, carefully observing the feedback provided by the interface until finding a stable position and starting a series of 10 acquisitions. When at least four consistent series are obtained, the measurement ends, and an automatic report is generated. The measurement usually takes about 5 min to complete. To determine the robustness of this protocol, a reproducibility study was conducted among 3 operators (one expert and two novices) and 14 healthy participants (6 women, 8 men, 21-53 years old). The intraclass correlation coefficients (ICC) were found good for vA0 (0.76), Ct.Po (0.80) or excellent for Ct.Th (0.87) and vFAS (0.91). The standard deviations were found to be less than 10% of the total ranges in clinical practice.

Here, we present the measurement protocol of the bi-directional axial transmission (BDAT) ultrasonic device in detail and test it in a reproducibility study, considering 14 healthy participants and 3 operators. Reliability, measured with the intraclass correlation coefficients (ICC), was good to excellent for four parameters of interest.

Fragility fractures are still a worldwide health burden in the context of population aging. In particular, the global number of hip fractures is expected ...

Obtaining Quality Extended Field-of-View Ultrasound Images of Skeletal Muscle to Measure Muscle Fascicle Length

Muscle fascicle length, which is commonly measured in vivo using traditional ultrasound, is an important parameter defining a muscle&#8217;s force generating capacity. However, over 90% of all upper limb muscles and 85% of all lower limb muscles have optimal fascicle lengths longer than the field-of-view of common traditional ultrasound (T-US) probes. A newer, less frequently adopted method called extended field-of-view ultrasound (EFOV-US) can enable direct measurement of fascicles longer than the field-of-view of a single T-US image. This method, which automatically fits together a sequence of T-US images from a dynamic scan, has been demonstrated to be valid and reliable for obtaining muscle fascicle lengths in vivo. Despite the numerous skeletal muscles with long fascicles and the validity of the EFOV-US method for making measurements of such fascicles, few published studies have utilized this method. In this study, we demonstrate both how to implement the EFOV-US method to obtain high quality musculoskeletal images and how to quantify fascicle lengths from those images. We expect that this demonstration will encourage the use of the EFOV-US method to increase the pool of muscles, both in healthy and impaired populations, for which we have in vivo muscle fascicle length data.

This study describes how to obtain high quality musculoskeletal images using the extended field-of-view ultrasound (EFOV-US) method for the purpose of making muscle fascicle length measures. We apply this method to muscles with fascicles that extend past the field-of-view of common traditional ultrasound (T-US) probes.

Muscle fascicle length, which is commonly measured in vivo using traditional ultrasound, is an important parameter defining a muscle&#8217;s force ...

Use of 3D Robotic Ultrasound for In Vivo Analysis of Mouse Kidneys

Common modalities for in vivo imaging of rodents include positron emission tomography (PET), computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound (US). Each method has limitations and advantages, including availability, ease of use, cost, size, and the use of ionizing radiation or magnetic fields. This protocol describes the use of 3D robotic US for in vivo imaging of rodent kidneys and heart, subsequent data analysis, and possible research applications. Practical applications of robotic US are the quantification of total kidney volume (TKV), as well as the measurement of cysts, tumors, and vasculature. Although the resolution is not as high as other modalities, robotic US allows for more practical high throughput data collection. Furthermore, using US M-mode imaging, cardiac function may be quantified. Since the kidneys receive 20%-25% of the cardiac output, assessing cardiac function is critical to the understanding of kidney physiology and pathophysiology.

Use of 3D Robotic Ultrasound for In Vivo Analysis of Mouse Kidneys

This protocol demonstrates robotic ultrasound (US) as a practical, cost-effective, and quick alternative to traditional non-invasive image modalities.

Common modalities for in vivo imaging of rodents include positron emission tomography (PET), computed tomography (CT), magnetic resonance imaging (MRI), ...

Ultrasound Evaluation of Achilles Tendon Morphology

Measurement of Healthy and Injured Triceps Surae Morphology

Achilles tendon injuries occur throughout the lifespan and can negatively affect quality of life and overall health. Achilles tendinopathy is generally classified as an overuse injury associated with fusiform tendon thickening, neovascularization, and interstitial tendon degeneration. Current literature suggests these structural changes are associated with&#160;symptoms and lower physical activity levels, as well as&#160;symptoms and lower extremity function in the long term. Surgically and non-surgically managed Achilles tendon ruptures result in increased tendon cross-sectional area (CSA) and a lengthened Achilles tendon. Both structural outcomes have clinical implications, as larger CSA positively predicts function, whereas increased tendon lengthening predicts reduced function after Achilles tendon rupture. Given the relationship between structural changes associated with Achilles tendon injuries for both injury severity and injury recovery, it is critical to be able to quantify Achilles tendon structure reliably and accurately. Silbernagel&#39;s group has established a valid and reliable method for efficiently evaluating triceps surae muscle and tendon structure. In this protocol, B-mode musculoskeletal ultrasound imaging is used to measure triceps surae structure, including Achilles tendon thickness and CSA, soleus thickness, and the presence of additional findings (calcifications and bursitis). B-mode extended field-of-view is used to measure Achilles tendon length and gastrocnemius anatomical CSA. Finally, power Doppler is used to identify intratendinous neovascularization. Quantification of triceps surae structure allows for comparison between limbs as well as longitudinal changes in response to exercise and treatment for healthy individuals and those with Achilles tendon injuries. This protocol has been used in many research studies to date and proves valuable in understanding the relationship between tendon structure and injury development, severity, and recovery. As ultrasound devices are becoming more affordable and portable, this protocol proves promising as a clinical tool, given its quick and efficient methods.

Author Spotlight: Exploring the Complexities of Achilles Tendon Injuries &#8212; Research and Future Directions

Ultrasound imaging is becoming more accessible in clinical and research settings, and a consistent protocol will be beneficial for comparison between studies and for clinical interpretations. This protocol for ultrasound evaluation is a valid and reliable method to evaluate Achilles tendon morphology in healthy, tendinopathic, and ruptured tendons.

Achilles tendon injuries occur throughout the lifespan and can negatively affect quality of life and overall health. Achilles tendinopathy is generally ...

3D Optical Imaging for Rapid Body Size and Composition Assessment

Clinical Anthropometrics and Body Composition from 3-Dimensional Optical Imaging

The body size and composition assessment is commonly included in the routine management of healthy athletes as well as of different types of patients to personalize the training or rehabilitation strategy. The digital anthropometric analyses described in the following protocol can be performed with recently introduced systems. These new tools and approaches have the potential to be widely used in clinical settings because they are very simple to operate and enable the rapid collection of accurate and reproducible data. One system consists of a rotating platform with a weight measurement plate, three infrared cameras, and a tablet built into a tower, while the other system consists of a tablet mounted on a holder. After image capture, the software of both systems generates a de-identified three-dimensional humanoid avatar with associated anthropometric and body composition variables. The measurement procedures are simple: a subject can be tested in a few minutes and a comprehensive report (including the three-dimensional scan and body size, shape, and composition measurements) is automatically generated.

Author Spotlight: Advancements in 3D Optical Imaging for Comprehensive Body Composition Assessment in Modern Research

The procedures for body size, shape, and composition assessment through commercially available solutions for three-dimensional optical imaging enable the rapid collection of accurate and reproducible data. Clinicians could implement the acquisition of innovative and useful biomarkers (&#34;e-tape&#34; measurements) in routine evaluations of patients to assist in characterizing&#160;their health status.

The body size and composition assessment is commonly included in the routine management of healthy athletes as well as of different types of patients to ...

3D Ultrasound Imaging: Fast and Cost-effective Morphometry of Musculoskeletal Tissue

Summary

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Measurement of Healthy and Injured Triceps Surae Morphology

Clinical Anthropometrics and Body Composition from 3-Dimensional Optical Imaging