Funding sources: HL084087, HL089885, HL091475, S10RR027946, T32 GM07356

1. Preparation for imaging
<ol>
 <li>Begin by securing an isoflurane anesthetized mouse to an animal-handling platform in the supine position. Place a nose cone over the animal's nose and mouth to deliver 0.5-1% isoflurane to maintain the anesthesia.</li>
 <li>Secure the paws of the mouse to the electrode pads with conducting gel. Ensure appropriate ECG, body temperature at 37 &deg;C and check respiratory rate for physiological assessment during imaging. </li>
 <li>Apply depilatory cream to the chest and upper abdomen of the mouse.</li>
 <li>After 2 minutes, use wet gauze remove to the cream.</li>
</ol>
2. Left parasternal long axis view
<ol>
 <li>Once the mouse has been prepared for imaging, tilt the left side of the platform to rotate the animal handling platform 30 degrees about the anterioposterior axis.</li>
 <li>Orient the transducer in the vertical position and rotate 10 degrees counterclockwise with the notch pointed toward the posterior of the mouse.</li>
 <li>Next, while in the two-dimensional viewing/video "B-mode", lower the transducer over the left parasternal line until the heart comes into view. Once the pulmonary artery comes into view, collect images and store them. </li>
 <li>Still in B-mode, move the transducer left or right until the aortic outflow and apex come into view. Some rotation of the probe may be necessary to ensure proper alignment with the long axis of the heart. </li>
 <li>Use video capture to obtain data for subsequent analysis. Minimize the field of view to ensure the highest frame rate possible for downstream regional strain analyses. Each time a video is captured, the prior 100 frames are saved. </li>
 <li>Switch to the Color Doppler mode by selecting "Color Doppler." Although Color Doppler has been available for over 30 years in humans, this technology has only recently been possible in rodent ultrasound. </li>
 <li>To quickly monitor the direction and velocity of blood flow, the Doppler window overlay digitizes the flow from red, indicating flow toward the probe, to blue, indicating flow away from the probe. Acquire necessary images by image capture.</li>
 <li>Once all Color Doppler data has been obtained, switch the instrument to Pulse-Wave Doppler Mode, the one-dimensional view used to digitally assess blood flow direction and velocity over time.</li>
 <li>Move the probe slightly toward the head of the mouse until the pulmonary artery comes into view. In the context of heart failure, PW/Color Doppler measurements of the pulmonary artery can be used as a surrogate for right heart function. Capture images as desired. </li>
</ol>
3. Left mid-papillary short axis
<ol>
 <li>Short-axis echocardiography provides a view of the entire left ventricle contracting in a concentric fashion, and allows for accurate B- and M-mode based assessment of cardiac function and morphometry.</li>
 <li>In B-mode, from the parasternal long axis view, rotate the transducer orthogonal to the left parasternal long axis view at the level of the papillary muscle. </li>
 <li>Ensure proper location along the length of the left ventricle. Both papillary muscles should be clearly visible and separated, giving a horizontal cross-sectional view. </li>
 <li>With the M-mode, place the sample volume through the center of the ventricle and acquire data.</li>
 <li>If desired, attach, initiate and utilize the 3-dimensional motor to obtain the images necessary for complete 3-dimensional reconstruction.</li>
 <li>Physiology settings, including respiratory rate and ECG, are set for gating 3D image capture in end-diastole</li>
 <li>The 3D imaging motor is initiated for image capture in end-diastole.</li>
 <li>Once the end-diastole 3D capture is complete, physiology settings for respiratory rate and ECG are set for gating the 3D image capture in end-systole</li>
 <li>The 3D imaging motor is initiated for image capture in end-systole.</li>
</ol>
4. Subcostal (four chamber) view
<ol>
 <li>The subcostal view is the best approach for measuring competency and pressure gradients across the mitral valve.</li>
 <li>Tilt the upper left corner of the platform all the way down. Orient the transducer toward the right shoulder of the mouse, maintaining the short axis rotation of the probe.</li>
 <li>In B-mode, lower the transducer over the upper abdomen so that it rests below the diaphragm. Visualize the mitral valve using color Doppler as described before.</li>
</ol>
5. Aortic view
<ol>
 <li>Rotate the animal-handling platform into the left lateral decubitus position. The left side of the platform should be tilted as far as possible. Next, orient the transducer, tilted as far up as possible, along the length of the mouse at the level of the scapula.</li>
 <li>Lower the transducer inferior to the right shoulder along the anterior axillary line. Visualize the aortic arch, and acquire images. </li>
 <li>Raise the head of the mouse, and lower the transducer into the suprasternal notch of the mouse. Visualize blood flow using color Doppler, and acquire images.</li>
</ol>
6. Representative Results
<ol>
 <li>This is a long-axis view of the heart in B-mode showing both the left ventricle and a small portion of the right ventricle. </li>
 <li>Here, a left short axis view of another heart was taken in M-mode. The upper image shows the position of the sample volume line in yellow through the center of the chamber. The bottom image is a one dimensional trace of the above line over time as well as calculations of morphometry in cyan</li>
 <li>This is a view of the aortic arch in B-mode. The closed aortic valve can be seen on the left and the blood vessels supplying the head and upper limbs of the mouse can be seen on the right. </li>
 <li>Radial Strain analysis was performed on a mouse prior to developing heart dysfunction, shown in the top image, and a mouse with global hypokinesis and regional dyssynchrony, shown in the bottom image. Both phenotypes were induced through transverse aortic constriction, a mouse model of increased afterload. </li>
 <li>In the figure, the time is displayed on the x-axis and the radial strain, as a percentage, is shown on the y-axis. Strain analysis allows for regional assessment of cardiac function that may otherwise go unnoticed in conventional techniques such as M-mode, which only directly measures function of the anterior free wall and the posterior wall. </li>
 <li>The anterior free wall is shown in green. The pink line shows the lateral wall is shown in pink. The posterior wall is shown in cyan. The inferior free wall is shown in blue. The posterior septal wall is shown in yellow. The anterior septum is shown in magenta, and the average is shown in black.</li>
</ol>
<img src="/files/ftp_upload/2100/2100fig1.jpg" alt="Figure 1" /> Figure 1. Left parasternal long axis view in B-mode.
<img src="/files/ftp_upload/2100/2100fig2.jpg" alt="Figure 2" /> Figure 2. Left short axis view in M-mode.
<img src="/files/ftp_upload/2100/2100fig3.jpg" alt="Figure 3" /> Figure 3. View of the aortic arch in B-mode.
<img src="/files/ftp_upload/2100/2100fig4.jpg" alt="Figure 4" /> Figure 4. Radial Strain Analysis of two mice 12 weeks post-TAC. Green = ant. free wall. Pink = lateral wall. Cyan = posterior wall. Blue = inf. free wall. Yellow = post. septal wall. Magenta = anterior septum. Black = average A) Mouse with preserved function. B) Mouse with global hypokinesis and regional dyssynchrony.

<ol>
	<li>Patten, R. D., Hall-Porter, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Small+animal+models+of+heart+failure:+development+of+novel+therapies,+past+and+present.">Small animal models of heart failure: development of novel therapies, past and present.</a> Circ Heart Fail. 2, 138-144 (2009).</li><li>Li, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantification+and+MRI+Validation+of+Regional+Contractile+Dysfunction+in+Mice+Post+Myocardial+Infarction+Using+High+Resolution+Ultrasound.">Quantification and MRI Validation of Regional Contractile Dysfunction in Mice Post Myocardial Infarction Using High Resolution Ultrasound.</a> Ultrasound in Medicine &#38; Biology. 33, 894-904 (2007).</li><li>Gardin, J. M., Siri, F. M., Kitsis, R. N., Edwards, J. G., Leinwand, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Echocardiographic+Assessment+of+Left+Ventricular+Mass+and+Systolic+Function+in+Mice.">Echocardiographic Assessment of Left Ventricular Mass and Systolic Function in Mice.</a> Circ Res. 76, 907-914 (1995).</li><li>JG, S. t. e. v. e. n. s. o. n., Weiler, T. B. M., EA, H. o. w. a. r. d., Eyer, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Digital+multigate+Doppler+with+color+echo+and+Doppler+display+-+Diagnosis+of+atrial+and+ventricular+septal+defects.">Digital multigate Doppler with color echo and Doppler display - Diagnosis of atrial and ventricular septal defects.</a> Circulation. 60, (1979).</li><li>Patten, R. D., Aronovitz, M. J., Bridgman, P., Pandian, N. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+pulse+wave+and+color+flow+Doppler+echocardiography+in+mouse+models+of+human+disease.">Use of pulse wave and color flow Doppler echocardiography in mouse models of human disease.</a> J Am Soc Echocardiogr. 15, 708-714 (2002).</li><li>Hoit, B. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Echocardiographic+characterization+of+the+cardiovascular+phenotype+in+rodent+models.">Echocardiographic characterization of the cardiovascular phenotype in rodent models.</a> Toxicol Pathol. 34, 105-110 (2006).</li></ol>

Pistner, Belmonte, Blaxall: Nothing to disclose
Coulthard is a full-time employee of Visualsonics.

Serial high frequency echocardiography has emerged as a powerful tool for non-invasive, high-resolution assessment of cardiac morphology and function, particularly in murine models of heart disease. Maintaining physiological body temperature as well as comparable heart rates between mice by adjusting the anesthesia level prior to acquiring images, is critical to the success of this method. All images should be obtained using the same biomarkers (e.g. parasternal long axis imaging at the papillary muscles). Lastly, ana...

A correction was made to <a href="http://www.jove.com/index/details.stp?id=2100">Murine echocardiography and ultrasound imaging</a>. There was an error in the author, Burns Blaxalls', name and the article title. The authors name has been corrected to:
Burns C. Blaxall
instead of:
Burns Blaxall
The article title was changed to:
Murine Echocardiography and Ultrasound Imaging
instead of:
Murine echocardiography and ultrasound imaging

A correction to an author's name and the article title has been made for the article Murine echocardiography and ultrasound imaging.

Erratum: Murine echocardiography and ultrasound imaging

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		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
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<td>Vevo 2100 Imaging System (120V)</td>
<td>&nbsp;</td>
<td>Visual Sonics</td>
<td>VS-11945</td>
<td>&nbsp;</td>
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<td>Vevo 2100 Imaging Station 1</td>
<td>&nbsp;</td>
<td>Visual Sonics</td>
<td>SA-11982</td>
<td>&nbsp;</td>
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<td>Ultrasound Gel</td>
<td>&nbsp;</td>
<td>Parker Laboratories</td>
<td>01-08</td>
<td>&nbsp;</td>
<tr>
<td>Isoflurane</td>
<td>&nbsp;</td>
<td>Abbott Laboratories</td>
<td>05260-05</td>
<td>&nbsp;</td>
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<td>Vevo Compact Dual Anesthesia System</td>
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murine echocardiography and ultrasound imaging

Rodent models of cardiac pathophysiology represent a valuable research tool to investigate mechanism of disease as well as test new therapeutics.1 Echocardiography provides a powerful, non-invasive tool to serially assess cardiac morphometry and function in a living animal.2 However, using this technique on mice poses unique challenges owing to the small size and rapid heart rate of these animals.3 Until recently, few ultrasound systems were capable of performing quality echocardiography on mice, and those generally lacked the image resolution and frame rate necessary to obtain truly quantitative measurements. Newly released systems such as the VisualSonics Vevo2100 provide new tools for researchers to carefully and non-invasively investigate cardiac function in mice. This system generates high resolution images and provides analysis capabilities similar to those used with human patients. Although color Doppler has been available for over 30 years in humans, this valuable technology has only recently been possible in rodent ultrasound.4,5 Color Doppler has broad applications for echocardiography, including the ability to quickly assess flow directionality in vessels and through valves, and to rapidly identify valve regurgitation. Strain analysis is a critical advance that is utilized to quantitatively measure regional myocardial function.6 This technique has the potential to detect changes in pathology, or resolution of pathology, earlier than conventional techniques. Coupled with the addition of three-dimensional image reconstruction, volumetric assessment of whole-organs is possible, including visualization and assessment of cardiac and vascular structures. Murine-compatible contrast imaging can also allow for volumetric measurements and tissue perfusion assessment.

Watch this Scientific Journal Video about Murine Echocardiography and Ultrasound Imaging at JoVE.com

Murine Echocardiography and Ultrasound Imaging

This video demonstrates use of a rail-mounted high-frequency ultrasound probe to perform echocardiography on an anesthetized mouse. The methods describe both conventional two-dimensional and M-mode measurements of cardiac function in addition to newer, more powerful tools such as color Doppler, strain analysis, as well as general and targeted contrast imaging.

Rodent models of cardiac pathophysiology represent a valuable research tool to investigate mechanism of disease as well as test new therapeutics.1  ...

murine-echocardiography-and-ultrasound-imaging

Research

JoVE Journal

Medicine

35.2K vues.  University of Rochester. Cette vidéo montre l'utilisation d'un rail à haute fréquence sonde échographique pour réaliser une échocardiographie d'une souris anesthésiée. Les méthodes de décrire à la fois des mesures conventionnelles à deux dimensions et en mode M de la fonction cardiaque, en plus de nouvelles, des outils plus puissants tels que le Doppler couleur, analyse des contraintes, ainsi que l'imagerie de contraste générales et ciblées.

Vidéo: Murine Echocardiography and Ultrasound Imaging

Transthoracic Echocardiography in Mice

In recent years, murine models have become the primary avenue for studying the molecular mechanisms of cardiac dysfunction resulting from changes in gene expression. Transgenic and gene targeting methods can be used to generate mice with altered cardiac size and function,1-3 and as a result, in vivo techniques are needed to evaluate their cardiac phenotype. Transthoracic echocardiography, pulse wave Doppler (PWD), and tissue Doppler imaging (TDI) can be used to provide dimensional measurements of the mouse heart and to quantify the degree of cardiac systolic and diastolic performance. Two-dimensional imaging is used to detect abnormal anatomy or movements of the left ventricle, whereas M-mode echo is used for quantification of cardiac dimensions and contractility.4,5 In addition, PWD is used to quantify localized velocity of turbulent flow,6 whereas TDI is used to measure the velocity of myocardial motion.7 Thus, transthoracic echocardiography offers a comprehensive method for the noninvasive evaluation of cardiac function in mice.

Transthoracic echocardiography offers a noninvasive method for the evaluation of cardiac function in mice. A combination of ultrasound and Doppler imaging modalities can be used to obtain dimensional measurements of the heart and intracardiac blood flow, which together provide an assessment of cardiac systolic and diastolic performance.

In recent years, murine models have become the primary avenue for studying the molecular mechanisms of cardiac dysfunction resulting from changes in gene ...

Murine Fetal Echocardiography

Transgenic mice displaying abnormalities in cardiac development and function represent a powerful tool for the understanding the molecular mechanisms underlying both normal cardiovascular function and the pathophysiological basis of human cardiovascular disease. Fetal and perinatal death is a common feature when studying genetic alterations affecting cardiac development 1-3. In order to study the role of genetic or pharmacologic alterations in the early development of cardiac function, ultrasound imaging of the live fetus has become an important tool for early recognition of abnormalities and longitudinal follow-up. Noninvasive ultrasound imaging is an ideal method for detecting and studying congenital malformations and the impact on cardiac function prior to death 4. It allows early recognition of abnormalities in the living fetus and the progression of disease can be followed in utero with longitudinal studies 5,6. Until recently, imaging of fetal mouse hearts frequently involved invasive methods. The fetus had to be sacrificed to perform magnetic resonance microscopy and electron microscopy or surgically delivered for transillumination microscopy. An application of high-frequency probes with conventional 2-D and pulsed-wave Doppler imaging has been shown to provide measurements of cardiac contraction and heart rates during embryonic development with databases of normal developmental changes now available 6-10. M-mode imaging further provides important functional data, although, the proper imaging planes are often difficult to obtain. High-frequency ultrasound imaging of the fetus has improved 2-D resolution and can provide excellent information on the early development of cardiac structures 11.

Fetal and perinatal death is a common feature when studying genetic alterations affecting cardiac development. High-frequency ultrasound imaging has improved 2-D resolution and can provide excellent information on early cardiac development and is an ideal method to detect the impact on cardiac structure and function prior to death.

Transgenic mice displaying abnormalities in  cardiac development and function represent a powerful tool for the understanding  the molecular mechanisms ...

Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction

Fetal intrauterine growth restriction (IUGR) results in abnormal cardiac function that is apparent antenatally due to advances in fetoplacental Doppler ultrasound and fetal echocardiography. Increasingly, these imaging modalities are being employed clinically to examine cardiac function and assess wellbeing in utero, thereby guiding timing of birth decisions. Here, we used a rabbit model of IUGR that allows analysis of cardiac function in a clinically relevant way. Using isoflurane induced anesthesia, IUGR is surgically created at gestational age day 25 by performing a laparotomy, exposing the bicornuate uterus and then ligating 40-50% of uteroplacental vessels supplying each gestational sac in a single uterine horn. The other horn in the rabbit bicornuate uterus serves as internal control fetuses. Then, after recovery at gestational age day 30 (full term), the same rabbit undergoes examination of fetal cardiac function. Anesthesia is induced with ketamine and xylazine intramuscularly, then maintained by a continuous intravenous infusion of ketamine and xylazine to minimize iatrogenic effects on fetal cardiac function. A repeat laparotomy is performed to expose each gestational sac and a microultrasound examination (VisualSonics VEVO 2100) of fetal cardiac function is performed. Placental insufficiency is evident by a raised pulsatility index or an absent or reversed end diastolic flow of the umbilical artery Doppler waveform. The ductus venosus and middle cerebral artery Doppler is then examined. Fetal echocardiography is performed by recording B mode, M mode and flow velocity waveforms in lateral and apical views. Offline calculations determine standard M-mode cardiac variables, tricuspid and mitral annular plane systolic excursion, speckle tracking and strain analysis, modified myocardial performance index and vascular flow velocity waveforms of interest. This small animal model of IUGR therefore affords examination of in utero cardiac function that is consistent with current clinical practice and is therefore useful in a translational research setting.

We describe examination of fetal cardiac function with contemporary functional fetal echocardiography and fetoplacental Doppler ultrasound using the VisualSonics VEVO 2100 microultrasound in a surgically induced model of intrauterine fetal growth restriction in a rabbit.

Fetal intrauterine growth restriction (IUGR) results in abnormal cardiac function that is apparent antenatally due to advances in fetoplacental Doppler ...

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 ...

Diagnostic Ultrasound Imaging of Mouse Diaphragm Function

Function analysis of rodent respiratory skeletal muscles, particularly the diaphragm, is commonly performed by isolating muscle strips using invasive surgical procedures. Although this is an effective method of assessing in vitro diaphragm activity, it involves non-survival surgery. The application of non-invasive ultrasound imaging as an in vivo procedure is beneficial since it not only reduces the number of animals sacrificed, but is also suitable for monitoring disease progression in live mice. Thus, our ultrasound imaging method may likely assist in the development of novel therapies that alleviate muscle injury induced by various respiratory diseases. Particularly, in clinical diagnoses of obstructive lung diseases, ultrasound imaging has the potential to be used in conjunction with other standard tests to detect the early onset of diaphragm muscle fatigue. In the current protocol, we describe how to accurately evaluate diaphragm contractility in a mouse model using a diagnostic ultrasound imaging technique.

Diagnostic ultrasound imaging has proven to be effective in diagnosing various respiratory diseases in human and animal subjects. We demonstrate a comprehensive ultrasound protocol utilized by Dr. Zuo's lab to analyze diaphragm kinetics specifically in mouse models. This is also a non-invasive research technique which can provide quantitative information on mouse respiratory muscle function.

Function analysis of rodent respiratory skeletal muscles, particularly the diaphragm, is commonly performed by isolating muscle strips using invasive ...

High-frequency Ultrasound Imaging of Mouse Cervical Lymph Nodes

High-frequency ultrasound (HFUS) is widely employed as a non-invasive method for imaging internal anatomic structures in experimental small animal systems. HFUS has the ability to detect structures as small as 30 &#181;m, a property that has been utilized for visualizing superficial lymph nodes in rodents in brightness (B)-mode. Combining power Doppler with B-mode imaging allows for measuring circulatory blood flow within lymph nodes and other organs. While HFUS has been utilized for lymph node imaging in a number of mouse&#160; model systems, a detailed protocol describing HFUS imaging and characterization of the cervical lymph nodes in mice has not been reported. Here, we show that HFUS can be adapted to detect and characterize cervical lymph nodes in mice. Combined B-mode and power Doppler imaging can be used to detect increases in blood flow in immunologically-enlarged cervical nodes. We also describe the use of B-mode imaging to conduct fine needle biopsies of cervical lymph nodes to retrieve lymph tissue for histological&#160; analysis. Finally, software-aided steps are described to calculate changes in lymph node volume and to visualize changes in lymph node morphology following image reconstruction. The ability to visually monitor changes in cervical lymph node biology over time provides a simple and powerful technique for the non-invasive monitoring of cervical lymph node alterations in preclinical mouse models of oral cavity disease.

This protocol describes the application of high-frequency ultrasound (HFUS) for imaging mouse cervical lymph nodes. This technique optimizes visualization and quantification of cervical lymph node morphology, volume and blood flow. Image-guided biopsy of cervical lymph nodes and processing of lymph tissue for histological evaluation is also demonstrated.

High-frequency ultrasound (HFUS) is widely employed as a non-invasive method for imaging internal anatomic structures in experimental small animal ...

Murine Echocardiography of Left Atrium, Aorta, and Pulmonary Artery

The present methodology teaches the investigator how to measure and use the LAV as a surrogate of chronic elevations in Left Ventricular diastolic pressure through echocardiography, as well as to obtain measurements of the Aorta and PA diameter in mice.
Mice older than 10 d of age can be analyzed using the present technique. The technique is composed of 3 main steps: set-up, image acquisition, and image analysis. The set-up step consists of getting the mouse anesthetized with 1% isoflurane, shaving it, and taping it in a supine position to a heated EKG board where the image acquisition will take place. The image acquisition step consists of learning to identify the cardiac structures and obtaining all the required images with its correspondent probe and axis in order to be able to calculate volumes and diameters. The image analysis step consists of measuring the previously acquired images with the aid of computer software.
Advantages of the proposed technique include a fast (15 min) procedure that would allow the researcher to evaluate interventions in a non-invasive, non-terminal approach and therefore follow the same mouse over time; each mouse can be used as its own control. This fact plus having the same operator perform all the acquisition and analysis for the entire experiment minimizes the limitation of operator-dependency. The present methodology is useful for mouse researchers in cardiovascular and pulmonary medicine.

The following protocol describes the methodology for the acquisition and analysis of echocardiographic images used to obtain the Left Atrial Volume (LAV), Aorta (Ao) diameter, and Pulmonary Artery (PA) diameter in mice. This technique is a non-invasive, non-terminal procedure that allows assessment of the cardiopulmonary function.

The present methodology teaches the investigator how to measure and use the LAV as a surrogate of chronic elevations in Left Ventricular diastolic ...

Providing Visual Biofeedback Using Brightness Mode Ultrasound During a Golf Swing

Using ultrasound biofeedback in conjunction with verbal cueing can increase muscle thickness more than verbal cueing alone and may augment traditional rehabilitation techniques in an athletic, physically active population. Brightness mode (B-mode) ultrasound can be applied using frame-by-frame analysis synchronized with video to understand muscle thickness changes during these dynamic tasks. Visual biofeedback with ultrasound has been established in static positions for the muscles of the lateral abdominal wall. However, by securing the transducer to the abdomen using an elastic belt and foam block, biofeedback can be applied during more specific tasks prevalent in lifetime sports, such as golf. To analyze muscle activity during a golf swing, muscle thickness changes can be compared. The thickness must increase throughout the task, indicating that the muscle is more active. This methodology allows clinicians to immediately replay ultrasound videos for patients as a visual tool to instruct proper activity of the muscles of interest. For example, ultrasound can be used to target the external and internal obliques, which play an important role in swinging a golf club or any other rotational sport or activity. This methodology aims to increase oblique muscle thickness during the golf swing. Additionally, the timing of muscle contraction can be targeted by instructing the patient to contract the abdominal muscles at specific time points, such as the beginning of the downswing, with the goal of improving muscle firing patterns during tasks.

Brightness mode ultrasound can be used to provide visual biofeedback of the muscles of the lateral abdominal wall during a golf swing. Post-swing visual and verbal instruction can increase the muscle activation and timing of the external and internal obliques.

Using ultrasound biofeedback in conjunction with verbal cueing can increase muscle thickness more than verbal cueing alone and may augment traditional ...

Muscle Function Obtained with Motion Mode Ultrasound and Surface Electromyography during Core Endurance Exercise

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured between fascial borders at a given time point during an exercise. This selected time point produces a one-dimensional image resulting in real-time, live observation of anatomy. Ultrasound used during functional movement can be referred to as dynamic ultrasound; this is feasible and reliable with the use of a linear transducer, elastic belt, and foam block to secure consistent transducer placement. The lateral abdominal wall is commonly investigated using ultrasound due to the overlapping nature of the muscles. Surface electromyography (sEMG) can complement M-mode ultrasound imaging because it measures the electrical representation of muscle activation. There is minimal evidence using M-mode ultrasound and sEMG simultaneously during core exercise. Exercises that challenge the core musculature involve both isometric holds (e.g., side plank), as well as oscillatory extremity movements (e.g., dead bug). In this study, both instruments will be used simultaneously to measure core muscle function during exercise. Ultrasound measurements will be obtained using a linear transducer and ultrasound unit, and sEMG measurements will be acquired from a wireless sEMG system. To make comparisons between participants and exercises, normalization methods using static, exercise starting positions for both instruments will be used. An activation ratio will be used for ultrasound and calculated by dividing the contracted thickness (thickness during a time point of exercise) by the rested (starting position) thickness. Muscle thickness will be measured in centimeters from the superior inferior fascial border to inferior superior fascial border. These methods aim to offer an innovative and practical measurement of muscle function with M-mode ultrasound and sEMG during core endurance exercises.

This protocol uses motion mode ultrasound and surface electromyography simultaneously to measure muscle function of the core. Muscle thickness and activation of the local stabilizers (e.g., transverse abdominis, internal oblique) and global movers (e.g., external oblique) is achievable during specific time points of the side plank and dead bug exercises.

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured ...

A Modified Sonographic Algorithm for Image Acquisition in Life-Threatening Emergencies in the Critically Ill Newborn

The use of routine point-of-care ultrasound (POCUS) is increasing in neonatal intensive care units (NICUs), with several centers advocating for 24 h equipment availability. In 2018, the sonographic algorithm for life-threatening emergencies (SAFE) protocol was published, which allows the assessment of neonates with sudden decompensation to identify abnormal contractility, tamponade, pneumothorax, and pleural effusion. In the study unit (with a consulting neonatal hemodynamics and POCUS service), the algorithm was adapted by including consolidated core steps to support at-risk newborns, aiding clinicians in managing cardiac arrest, and adding views to verify correct intubation. This paper presents a protocol that can be applied in the NICU and the delivery room (DR) in relation to three scenarios: cardiac arrest, hemodynamic deterioration, or respiratory decompensation. 
This protocol can be performed with a state-of-the-art ultrasound machine or an affordable handheld device; the image acquisition protocol is carefully detailed. This method was designed to be learned as a general competence to obtain the timely diagnosis of life-threatening scenarios; the method aims to save time but does not represent a substitute for comprehensive and standardized hemodynamic and radiological analyses by a multidisciplinary team, which might not universally be on call but needs to be involved in the process. From January 2019 to July 2022, in our center, 1,045 hemodynamic consultation/POCUS consults were performed with 25 patients requiring the modified SAFE protocol (2.3%), and a total of 19 procedures were performed. In five cases, trained fellows on call resolved life-threatening situations. Clinical examples are provided that show the importance of including this technique in the care of critical newborns.

Here, we present a protocol that can be applied in the neonatal intensive care unit and the delivery room in relation to three scenarios: cardiac arrest, hemodynamic deterioration, or respiratory decompensation. This protocol can be performed with a state-of-the-art ultrasound machine or an affordable handheld device; an image acquisition protocol is carefully detailed.

The use of routine point-of-care ultrasound (POCUS) is increasing in neonatal intensive care units (NICUs), with several centers advocating for 24 h ...