We thank J. Hagoort for reading and correcting the manuscript.

This protocol follows the guidelines of the local human research ethics committee.
1. Preparation
<ol>
	<li>Schedule the microcirculatory measurement so that it does not coincide with other procedures such as blood sampling. In term neonates it is best performed after feeding. This prevents agitation and will ease the measurement.</li>
	<li>Ensure that a nurse or a parent attends to support and comfort the neonate during the examination, using the principles of Newborn Individualized Developmental Care and Assessment Program12. 
	Note: Although measurements can be performed by a single person, it is highly recommended to have a second person assist. One holds the camera and is focused on the neonate whilst the other operates the computer and software. In our experience, this results in higher quality images and a shorter duration of the procedure.</li>
	<li>If the clinical condition of the neonate permits, place the neonate in supine position. Microcirculatory imaging can be performed in prone position, but this requires more skill and patience.</li>
	<li>Make sure the body temperature of the preterm infant is within appropriate range (36.5 - 37.5 degrees Celsius).</li>
</ol>
2. Procedure
<ol>
	<li>Install the device along the incubator. Make sure the incubator is at the right height.</li>
	<li>Put the disposable cap on the camera.</li>
	<li>Apply gel, oil or saline on the tip of the probe; this will help smoothen the contact between probe and skin.</li>
	<li>Place the camera on the ventromedial side of the infants upper arm. To prevent focus-artefacts, make sure the probe is perpendicular to the skin. This may require repositioning of the infants arm. 
	Note: The ventromedial side of the upper arm is the primary location to measure the cutaneous microcirculation. This location has little lanugo hair and is therefore less prone to artefacts. It is most easily reached if the patient is positioned in supine position.</li>
	<li>To minimize the total length of procedure, gain time by finding the optimal depth of focus (Figure 3) while searching the location with the fewest artefacts. 
	Note: Depth of focus depends primarily on postnatal age rather than gestational age. The average depth of focus in the first week of life is 0 - 80 &#181;m. Hereafter, due to maturing of the skin, the focus depth rapidly increases with average values of 80 - 200 &#181;m between 1 - 4 weeks of postnatal age (Figure 2). In term born neonates the average depth of focus is 80 - 160 &#181;m at birth.</li>
	<li>Stabilize the probe to avoid movement artefacts. To do so, rest the elbow on the incubator window and the wrist beside the neonate. Alternatively, position the probe alongside the neonate on a pillow.</li>
	<li>Avoid pressure artefacts by letting the camera only have the slightest contact with the skin. Pressure artefacts can be recognized during image capturing if there is back-and-forth flow in vessels or if large vessels are non-perfused while there is good flow in small vessels. Also if the flow pattern is identical throughout the whole screen, beware of pressure artefacts.</li>
	<li>Record videos for a minimum duration of 5 sec.</li>
	<li>After a successful capture, move the camera to another spot on the upper arm. 
	Note: It is recommended to capture in total 5 -&#160;10 videos at 3 - 5 different locations, as some artefacts are only recognized at offline analysis, which means that the video in question is not usable for analysis.</li>
	<li>Gently remove the gel, oil or saline from the skin with a small gauze.</li>
</ol>
3. Offline Analysis
<ol>
	<li>Crop the video if there is a significant movement that impedes analysis. Go to the &#39;Tools&#39; section and use the button &#39;Editor&#39;. Select the frame interval eligible for analysis and click the &#39;Crop Video&#39; button. Note: Videos are acceptable if movement is within &#189; of the field view13.</li>
	<li>Select the cropped video and stabilize it. Go to the &#39;Tools&#39; section and use the button &#39;Analysis&#39;. Click the &#39;Stabilize&#39; button. 
	Note: All movies must be stabilized before automatic analysis can be performed.</li>
	<li>Select the stabilized video. Go to the section &#39;Analysis&#39; and click the &#39;Detect&#39; Button. Make sure the options &#39;Capillaries&#39; and &#39;Vessels&#39; are highlighted.</li>
	<li>After detection (Figure 4), click the &#39;CNA&#39; or &#39;De Backer&#39; button for a full microcirculatory report. This report includes the most used outcome parameters like the total vessel density (TVD), perfused vessel density (PVD) and proportion of perfused vessels (PPV). 
	Note: As an alternative, videos can be exported offline to be manually analyzed. This option can be found in the section &#39;Tools&#39;. Select the option &#39;Export&#39; and click the &#39;AVA export&#39; button.</li>
</ol>

<ol>
	<li>Groner, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Orthogonal+polarization+spectral+imaging:+a+new+method+for+study+of+the+microcirculation.">Orthogonal polarization spectral imaging: a new method for study of the microcirculation.</a> Nat Med. 5 (10), 1209-1212 (1999).</li><li>Goedhart, P. T., Khalilzada, M., Bezemer, R., Merza, J., Ince, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sidestream+Dark+Field+(SDF)+imaging:+a+novel+stroboscopic+LED+ring-based+imaging+modality+for+clinical+assessment+of+the+microcirculation.">Sidestream Dark Field (SDF) imaging: a novel stroboscopic LED ring-based imaging modality for clinical assessment of the microcirculation.</a> Opt Express. 15 (23), 15101-15114 (2007).</li><li>Sherman, H., Klausner, S., Cook, W. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Incident+dark-field+illumination:+a+new+method+for+microcirculatory+study.">Incident dark-field illumination: a new method for microcirculatory study.</a> Angiology. 22 (5), 295-303 (1971).</li><li>Trzeciak, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+microcirculatory+perfusion+derangements+in+patients+with+severe+sepsis+and+septic+shock:+relationship+to+hemodynamics,+oxygen+transport,+and+survival.">Early microcirculatory perfusion derangements in patients with severe sepsis and septic shock: relationship to hemodynamics, oxygen transport, and survival.</a> Ann Emerg Med. 49 (1), 88-98 (2007).</li><li>Sakr, Y., Dubois, M. J., De Backer, D., Creteur, J., Vincent, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Persistent+microcirculatory+alterations+are+associated+with+organ+failure+and+death+in+patients+with+septic+shock.">Persistent microcirculatory alterations are associated with organ failure and death in patients with septic shock.</a> Crit Care Med. 32 (9), 1825-1831 (2004).</li><li>De Backer, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microcirculatory+alterations+in+patients+with+severe+sepsis:+impact+of+time+of+assessment+and+relationship+with+outcome.">Microcirculatory alterations in patients with severe sepsis: impact of time of assessment and relationship with outcome.</a> Crit Care Med. 41 (3), 791-799 (2013).</li><li>Buijs, E. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+microcirculatory+impairment+during+therapeutic+hypothermia+is+associated+with+poor+outcome+in+post-cardiac+arrest+children:+A+prospective+observational+cohort+study.">Early microcirculatory impairment during therapeutic hypothermia is associated with poor outcome in post-cardiac arrest children: A prospective observational cohort study.</a> Resuscitation. , (2013).</li><li>Genzel-Boroviczeny, O., Christ, F., Glas, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood+transfusion+increases+functional+capillary+density+in+the+skin+of+anemic+preterm+infants.">Blood transfusion increases functional capillary density in the skin of anemic preterm infants.</a> Pediatr Res. 56 (5), 751-755 (2004).</li><li>Ergenekon, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peripheral+microcirculation+is+affected+during+therapeutic+hypothermia+in+newborns.">Peripheral microcirculation is affected during therapeutic hypothermia in newborns.</a> Arch Dis Child Fetal Neonatal Ed. 98 (2), F155-F157 (2013).</li><li>Schwepcke, A., Weber, F. D., Mormanova, Z., Cepissak, B., Genzel-Boroviczeny, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microcirculatory+mechanisms+in+postnatal+hypotension+affecting+premature+infants.">Microcirculatory mechanisms in postnatal hypotension affecting premature infants.</a> Pediatr Res. , (2013).</li><li>van Elteren, H. A., Ince, C., Tibboel, D., Reiss, I. K., de Jonge, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cutaneous+microcirculation+in+preterm+neonates:+comparison+between+sidestream+dark+field+(SDF)+and+incident+dark+field+(IDF)+imaging.">Cutaneous microcirculation in preterm neonates: comparison between sidestream dark field (SDF) and incident dark field (IDF) imaging.</a> J Clin Monit Comput. , (2015).</li><li>Als, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Individualized+Behavioral+and+Environmental+Care+for+the+Very-Low-Birth-Weight+Preterm+Infant+at+High-Risk+for+Bronchopulmonary+Dysplasia+-+Neonatal+Intensive-Care+Unit+and+Developmental+Outcome.">Individualized Behavioral and Environmental Care for the Very-Low-Birth-Weight Preterm Infant at High-Risk for Bronchopulmonary Dysplasia - Neonatal Intensive-Care Unit and Developmental Outcome.</a> Pediatrics. 78 (6), 1123-1132 (1986).</li><li>Massey, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+microcirculation+image+quality+score:+development+and+preliminary+evaluation+of+a+proposed+approach+to+grading+quality+of+image+acquisition+for+bedside+videomicroscopy.">The microcirculation image quality score: development and preliminary evaluation of a proposed approach to grading quality of image acquisition for bedside videomicroscopy.</a> J Crit Care. 28 (6), 913-917 (2013).</li><li>Weidlich, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Changes+in+microcirculation+as+early+markers+for+infection+in+preterm+infants--an+observational+prospective+study.">Changes in microcirculation as early markers for infection in preterm infants--an observational prospective study.</a> Pediatr Res. 66 (4), 461-465 (2009).</li><li>De Backer, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+to+evaluate+the+microcirculation:+report+of+a+round+table+conference.">How to evaluate the microcirculation: report of a round table conference.</a> Crit Care. 11 (5), R101 (2007).</li><li>Sallisalmi, M., Oksala, N., Pettila, V., Tenhunen, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+sublingual+microcirculatory+blood+flow+in+the+critically+ill.">Evaluation of sublingual microcirculatory blood flow in the critically ill.</a> Acta Anaesthesiol Scand. 56 (3), 298-306 (2012).</li><li>van den Berg, V. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reproducibility+of+microvascular+vessel+density+analysis+in+Sidestream+dark-field-derived+images+of+healthy+term+newborns.">Reproducibility of microvascular vessel density analysis in Sidestream dark-field-derived images of healthy term newborns.</a> Microcirculation. 22 (1), 37-43 (2015).</li></ol>

The authors have nothing to disclose.

In this manuscript we describe and demonstrate the approach for transcutaneous microcirculatory imaging in preterm neonates. Visualizing this method will help researchers overcome two of the biggest challenges in research: reproducibility and the time and labor intensive nature of learning new techniques. This technique can provide useful information of peripheral microcirculation in preterm infants in a non-invasive manner. Serial measurements can help clinicians evaluate the effects of therapeutic interventions. The mi...

Hemodynamic diagnostics in critically ill preterm neonates has always been difficult. Most diagnostic tools used in adults cannot be applied in these tiny preterm infants; and then there is a problem of the sensitivity of the outcome parameters. But most of all, these infants are so vulnerable, that the risks of diagnostic procedures do not outweigh the benefits. As a result, in the field of neonatology, hemodynamics has been neglected and therefore there is a lack of knowledge on this topic.
An interesting option for handling these problems might be visualizing the microcirculation. The introduction of handheld microscopes in the late 1990s made it possible to visualize the microcirculation in a non-invasive manner. Three generations of devices have been introduced: Orthogonal Polarization Spectral (OPS) imaging1, Sidestream Dark Field (SDF) imaging2, and Incident Dark Field (IDF) imaging3. They all use more or less the same technique in which green light with a specific wavelength (548nm) stroboscopic illuminates the microcirculation. The green light is absorbed by oxy- and deoxyhemoglobin and mostly reflected by the surrounding tissue. This property of green light therefore creates visible contrast. The reflected light passes a magnification lens and is projected on a camera sensor. Hereby it is possible to visualize the flowing red blood cells at a depth of approximately one millimeter of mucosal tissue or directly at solid organs. 
Over the past 15 years, the microcirculation has been mainly studied in adults, especially in patients with septic shock4-6. These observational studies found that persistent microcirculatory alterations were associated with organ failure and mortality. This observation cannot be extrapolated directly to (preterm) infants however, as in the adults the microcirculation was measured sublingually. High quality images of the sublingual microcirculation cannot be obtained in preterm infants because they are unable to cooperate. In term infants the buccal microcirculation has been the area of interest7. Fortunately, in preterm infants the thin skin allows transcutaneous microcirculatory imaging. This approach has been applied in neonatal studies focusing on blood transfusion8, therapeutic hypothermia9 and hypotension10.
In this manuscript we present our protocol for transcutaneous microcirculatory imaging using Incident Dark Field imaging in preterm neonates. We will focus on different strategies to acquire the highest quality images. Technical details and differences between the SDF and IDF devices can be found elsewhere11.

<table>
	<tbody>
		<tr>
			<td>Cytocam</td>
			<td>Braedius</td>
			<td>http://www.braedius.com/magnoliaPublic/braedius/products.html</td>
			<td>Other well known handheld microscopes to visualize the microcirculation are MicroScan (Microvision Medical) using SDF technique or the CytoScan (CytoMetrics) using OPS technique</td>
		</tr>
		<tr>
			<td>Disposable Lens Cover</td>
			<td>Glycocheck</td>
			<td>http://www.glycocheck.com/lenscovers.php</td>
			<td></td>
		</tr>
		<tr>
			<td>CCTools</td>
			<td>Braedius</td>
			<td>http://www.braedius.com/magnoliaPublic/braedius/products.html</td>
			<td>Another well known offline analysis programme is AVA (Microvision medical).&#160;</td>
		</tr>
	</tbody>
</table>

transcutaneous microcirculatory imaging in preterm neonates

Microcirculatory imaging (MI) is a relatively new research tool mainly used in the intensive care setting. MI provides a clear view of the smallest capillaries, arterioles and venules. The magnifying effect visualizes the flow pattern of erythrocytes through these vessels.
It's non-invasive character makes it suitable to apply in (preterm) neonates, even in cardiorespiratory unstable patients. In adults and children, MI is mainly performed sublingually, but this is not possible in preterm infants as these cannot cooperate and the size of the probe is problematic. In preterm infants, MI is therefore performed transcutaneously. Their thin skin makes it possible to obtain high quality images of peripheral microcirculation. 
In this manuscript we will demonstrate the method of transcutaneous MI in preterm infants. We will focus on the different techniques and provide tips to optimize image quality. The highlights of software settings, safety and offline analysis are also addressed.

Figures 1 and 2 show representative still images of high-quality MI videos. These examples demonstrate the difference in skin thickness in the same infants between day 1 (Figure 1) and day 28 (Figure 2) of postnatal age. On day 1, there is a bright illumination, adequate focus on the micro vessels and minimal presence of artefacts. On day 28 it is more difficult to find the right balance between focus on the micro vessels and artefacts du...

Watch this Scientific Journal Video about Transcutaneous Microcirculatory Imaging in Preterm Neonates at JoVE.com

Transcutaneous Microcirculatory Imaging in Preterm Neonates

Microcirculatory imaging (MI) is used to monitor peripheral perfusion in critically ill or preterm neonates. This manuscript and video demonstrates the optimal approach for obtaining high-quality images.

Microcirculatory imaging (MI) is a relatively new research tool mainly used in the intensive care setting. MI provides a clear view of the smallest ...

transcutaneous-microcirculatory-imaging-in-preterm-neonates

Research

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Medicine

7.6K Views.  Erasmus MC-Sophia Children's Hospital. Microcirculatory imaging (MI) is used to monitor peripheral perfusion in critically ill or preterm neonates. This manuscript and video demonstrates the optimal approach for obtaining high-quality images.

Video: Transcutaneous Microcirculatory Imaging in Preterm Neonates

The Use of Pharmacological-challenge fMRI in Pre-clinical Research: Application to the 5-HT System

Pharmacological MRI (phMRI) is a new and promising method to study the effects of substances on brain function that can ultimately be used to unravel underlying neurobiological mechanisms behind drug action and neurotransmitter-related disorders, such as depression and ADHD. Like most of the imaging methods (PET, SPECT, CT) it represents a progress in the investigation of brain disorders and the related function of neurotransmitter pathways in a non-invasive way with respect of the overall neuronal connectivity. Moreover it also provides the ideal tool for translation to clinical investigations. MRI, while still behind in molecular imaging strategies compared to PET and SPECT, has the great advantage to have a high spatial resolution and no need for the injection of a contrast-agent or radio-labeled molecules, thereby avoiding the repetitive exposure to ionizing radiations. Functional MRI (fMRI) is extensively used in research and clinical setting, where it is generally combined with a psycho-motor task. phMRI is an adaptation of fMRI enabling the investigation of a specific neurotransmitter system, such as serotonin (5-HT), under physiological or pathological conditions following activation via administration of a specific challenging drug.
The aim of the method described here is to assess brain 5-HT function in free-breathing animals. By challenging the 5-HT system while simultaneously acquiring functional MR images over time, the response of the brain to this challenge can be visualized. Several studies in animals have already demonstrated that drug-induced increases in extracellular levels of e.g. 5-HT (releasing agents, selective re-uptake blockers, etc) evoke region-specific changes in blood oxygenation level dependent (BOLD) MRI signals (signal due to a change of the oxygenated/deoxygenated hemoglobin levels occurring during brain activation through an increase of the blood supply to supply the oxygen and glucose to the demanding neurons) providing an index of neurotransmitter function. It has also been shown that these effects can be reversed by treatments that decrease 5-HT availability16,13,18,7. In adult rats, BOLD signal changes following acute SSRI administration have been described in several 5-HT related brain regions, i.e. cortical areas, hippocampus, hypothalamus and thalamus9,16,15. Stimulation of the 5-HT system and its response to this challenge can be thus used as a measure of its function in both animals and humans2,11.

The goal of this technique is to assess serotonin (5-HT) neurotransmitter function in the live and free-breathing animal with pharmacological magnetic resonance imaging (phMRI) and an intravenous challenge with a selective serotonin reuptake inhibitor (SSRI), fluoxetine.

Pharmacological MRI (phMRI) is a new and promising method to study the effects of substances on brain function that can ultimately be used to unravel ...

Automated Measurement of Microcirculatory Blood Flow Velocity in Pulmonary Metastases of Rats

Because the lung is a major target organ of metastatic disease, animal models to study the physiology of pulmonary metastases are of great importance. However, very few methods exist to date to investigate lung metastases in a dynamic fashion at the microcirculatory level, due to the difficulty to access the lung with a microscope. Here, an intravital microscopy method is presented to functionally image and quantify the microcirculation of superficial pulmonary metastases in rats, using a closed-chest pulmonary window and automated analysis of blood flow velocity and direction. The utility of this method is demonstrated to measure increases in blood flow velocity in response to pharmacological intervention, and to image the well-known tortuous vasculature of solid tumors. This is the first demonstration of intravital microscopy on pulmonary metastases in a closed-chest model. Because of its minimized invasiveness, as well as due to its relative ease and practicality, this technology has the potential to experience widespread use in laboratories that specialize on pulmonary tumor research.

A method is presented to measure microcirculatory blood flow velocity in pulmonary cancer metastases of the pleural surface in rats in an automated fashion, using closed-chest pulmonary intravital microscopy. This model has potential to be used as a widespread tool to perform physiologic research on pulmonary metastases in rodents.

Because the lung is a major target organ of metastatic disease, animal models to study the physiology of pulmonary metastases are of great importance. ...

State of the Art Cranial Ultrasound Imaging in Neonates

Cranial ultrasound (CUS) is a reputable tool for brain imaging in critically ill neonates. It is safe, relatively cheap and easy to use, even when a patient is unstable. In addition it is radiation-free and allows serial imaging. CUS possibilities have steadily expanded. However, in many neonatal intensive care units, these possibilities are not optimally used. We present a comprehensive approach for neonatal CUS, focusing on optimal settings, different probes, multiple acoustic windows and Doppler techniques. This approach is suited for both routine clinical practice and research purposes. In a live demonstration, we show how this technique is performed in the neonatal intensive care unit. Using optimal settings and probes allows for better imaging quality and improves the diagnostic value of CUS in experienced hands. Traditionally, images are obtained through the anterior fontanel. Use of supplemental acoustic windows (lambdoid, mastoid, and lateral fontanels) improves detection of brain injury. Adding Doppler studies allows screening of patency of large intracranial arteries and veins. Flow velocities and indices can be obtained. Doppler CUS offers the possibility of detecting cerebral sinovenous thrombosis at an early stage, creating a window for therapeutic intervention prior to thrombosis-induced tissue damage. Equipment, data storage and safety aspects are also addressed.

Cranial ultrasound (CUS) is a valuable tool for brain imaging in critically ill neonates. This video shows a comprehensive approach for neonatal (Doppler) CUS for both clinical and research purposes, including a bedside demonstration of the technique.

Cranial ultrasound (CUS) is a reputable tool for brain imaging in critically ill neonates. It is safe, relatively cheap and easy to use, even when a ...

Transcutaneous Assessment of Renal Function in Conscious Rodents

Glomerular filtration rate (GFR) is the gold standard to assess overall kidney function. However, traditional methods to evaluate GFR are cumbersome and time-consuming. In addition, serial blood or urine samples are required, with the associated stress for the experimental animals. A recent technique significantly reduces the investment in time and resources, minimizing the invasiveness and the animal stress, but being equally valid as the traditional approaches. The method measures transcutaneously renal function. Using an optical device and the exogenous renal marker fluorescein isothiocyanate (FITC)-sinistrin, this technique is capable of measuring the elimination kinetics of the marker through the skin. With neither blood nor urine samples nor the associated laboratory assays needed, the results of the transcutaneous measurement are almost instantaneously available. The method has been already validated in different species and successfully applied in several models of renal pathology. Moreover, due to its minimally invasive characteristics, it is suitable for sequential measurements within the same animal. Here is provided a detailed protocol to carry out the transcutaneous assessment of renal function in rodents.

Determination of glomerular filtration rate (GFR) is the gold standard to assess overall kidney function. However, traditional procedures to measure this parameter are cumbersome and require a large investment of time. Here we describe a faster and minimally invasive method to determinate GFR transcutaneously.

Glomerular filtration rate (GFR) is the gold standard to assess overall kidney function. However, traditional methods to evaluate GFR are cumbersome and ...

Quantitative Visualization of Leukocyte Infiltrate in a Murine Model of Fulminant Myocarditis by Light Sheet Microscopy

Light-sheet fluorescence microscopy (LSFM), in combination with chemical clearing protocols, has become the gold standard for analyzing fluorescently labelled structures in large biological specimens, and is down to cellular resolution. Meanwhile, the constant refinement of underlying protocols and the enhanced availability of specialized commercial systems enable us to investigate the microstructure of whole mouse organs and even allow for the characterization of cellular behavior in various live-cell imaging approaches. Here, we describe a protocol for the spatial whole-mount visualization and quantification of the CD45+ leukocyte population in inflamed mouse hearts. The method employs a transgenic mouse strain (CD11c.DTR)that has recently been shown to serve as a robust, inducible model for the study of the development of fulminant fatal myocarditis, characterized by lethal cardiac arrhythmias. This protocol includes myocarditis induction, intravital antibody-mediated cell staining, organ preparation, and LSFM with subsequent computer-assisted image post-processing. Although presented as a highly-adapted method for our particular scientific question, the protocol represents the blueprint of an easily adjustable system that can also target completely different fluorescent structures in other organs and even in other species.

Here, we describe a light-sheet microscopy approach to visualize the cardiac CD45+ leukocyte infiltrate in a murine model of aseptic fulminant myocarditis, which is induced by the intratracheal diphtheria toxin treatment of CD11c.DTR mice.

Light-sheet fluorescence microscopy (LSFM), in combination with chemical clearing protocols, has become the gold standard for analyzing fluorescently ...

Application of an Amplitude-integrated EEG Monitor (Cerebral Function Monitor) to Neonates

Amplitude-integrated EEG (aEEG) is an easily accessible technique to monitor the electrocortical activity in preterm and term infants in neonatal intensive care units (NICUs). This method was first used to monitor newborns after asphyxia, providing information about future neurological outcomes. The aEEG is also helpful to select newborns who benefit from cooling. The aEEG monitoring of preterm infants is becoming more widespread, as various studies have shown that neurodevelopmental outcome is related to early aEEG tracings. Here, we demonstrate the application of the aEEG monitoring system and present typical patterns that depend upon gestational age and pathophysiological conditions. Furthermore, we mention pitfalls in the interpretation of the aEEG, as this method requires accurate fixation and localization of the electrodes. Additionally, the raw EEG can be used to detect neonatal seizures or to identify aEEG application problems. In conclusion, aEEG is a safe and generally well-tolerated method for the bedside monitoring of neonatal cerebral function; it can even provide information about long-term outcome.

Application of an Amplitude-integrated EEG Monitor Cerebral Function Monitor to Neonates

Here, we show how to apply amplitude-integrated electroencephalography to monitor cerebral function in neonates.

Amplitude-integrated EEG (aEEG) is an easily accessible technique to monitor the electrocortical activity in preterm and term infants in neonatal ...

Electrophysiological Measurement of Noxious-evoked Brain Activity in Neonates Using a Flat-tip Probe Coupled to Electroencephalography

Pain is an unpleasant sensory and emotional experience. In non-verbal patients, it is very difficult to measure pain, even with pain assessment tools. Those tools are subjective or determine secondary physiological indicators which also have certain limitations particularly when exploring the effectiveness of analgesia. As cortical processing is essential for pain perception, brain activity measures may provide a useful approach to assess pain in infants. Here we present a method to assess nociception with electrophysiological brain activity recordings optimized for the use in newborn infants. To produce highly standardized and reproducible noxious stimuli we applied mechanical stimulation with a flat-tip probe, e.g., PinPrick, which is not skin-breaking and does not cause behavioral distress. The noxious-evoked potential allows the objective measurement of nociception in non-verbal patients. This method can be used in newborn infants as early as 34 weeks of gestational age. Moreover, it could be applied in different situations such as measuring the efficacy of analgesic or anesthetic drugs.

Measuring pain in non-verbal patients is a challenge. In this study we combine EEG recording with stimulation using a flat-tip probe to detect noxious-evoked brain activity in an objective manner.

Pain is an unpleasant sensory and emotional experience. In non-verbal patients, it is very difficult to measure pain, even with pain assessment tools. ...

Phase Contrast Magnetic Resonance Imaging in the Rat Common Carotid Artery

Phase contrast magnetic resonance imaging (PC-MRI) is a noninvasive approach that can quantify flow-related parameters such as blood flow. Previous studies have shown that abnormal blood flow may be associated with systemic vascular risk. Thus, PC-MRI can facilitate the translation of data obtained from animal models of cardiovascular diseases to pertinent clinical investigations. In this report, we describe the procedure for measuring blood flow in the common carotid artery (CCA) of rats using cine-gated PC-MRI and discuss relevant analysis methods. This procedure can be performed in a live, anesthetized animal and does not require euthanasia after the procedure. The proposed scanning parameters yield repeatable measurements for blood flow, indicating excellent reproducibility of the results. The PC-MRI procedure described in this article can be used for pharmacological testing, pathophysiological assessment, and cerebral hemodynamics evaluation.

The overall goal of this procedure is to measure the blood flow in the rat common carotid artery by using noninvasive phase contrast magnetic resonance imaging.

Phase contrast magnetic resonance imaging (PC-MRI) is a noninvasive approach that can quantify flow-related parameters such as blood flow. Previous ...

Quantitative [18F]-Naf-PET-MRI Analysis for the Evaluation of Dynamic Bone Turnover in a Patient with Facetogenic Low Back Pain

Imaging techniques that reflect dynamic bone turnover may aid in characterizing a wide range of bone pathologies. Bone is a dynamic tissue undergoing continuous remodeling with the competing activity of osteoblasts, which produce the new bone matrix, and osteoclasts, whose function is to eliminate mineralized bone. [18F]-NaF is a positron emission tomography (PET) radiotracer that enables visualization of bone metabolism. [18F]-NaF is chemically absorbed into hydroxyapatite in the bone matrix by osteoblasts and can thus noninvasively detect osteoblastic activity, which is occult to conventional imaging techniques. Kinetic modeling of dynamic [18F]-NaF-PET data provides detailed quantitative measures of bone metabolism. Conventional semi-quantitative PET data, which utilizes standardized uptake values (SUVs) as a measure of radiotracer activity, is referred to as a static technique due to its snapshot of tracer uptake in time.&#160; Kinetic modeling, however, utilizes dynamic image data where tracer levels are continuously acquired providing tracer uptake temporal resolution. From the kinetic modeling of dynamic data, quantitative values like blood flow and metabolic rate (i.e., potentially informative metrics of tracer dynamics) can be extracted, all with respect to the measured activity in the image data. When combined with dual modality PET-MRI, region-specific kinetic data can be correlated with anatomically registered high-resolution structural and pathologic information afforded by MRI. The goal of this methodological manuscript is to outline detailed techniques for performing and analyzing dynamic [18F]-NaF-PET-MRI data. The lumbar facet joint is a common site of degenerative arthritis disease and a common cause for axial low back pain.&#160; Recent studies suggest [18F]-NaF-PET may serve as a useful biomarker of painful facetogenic disease.&#160; The human lumbar facet joint will, therefore, be used as a prototypical region of interest for dynamic [18F]-NaF-PET-MRI analysis in this manuscript.

Quantitative [18F]-Naf-PET-MRI Analysis for the Evaluation of Dynamic Bone Turnover in a Patient with Facetogenic Low Back Pain

Imaging techniques that reflect dynamic bone turnover may aid in characterizing a wide range of bone pathologies. We present detailed methodologies for performing and analyzing dynamic [18F]-NaF-PET-MRI data in a patient with facetogenic low back pain using the lumbar facet joints as a prototypical region of interest.

Imaging techniques that reflect dynamic bone turnover may aid in characterizing a wide range of bone pathologies. Bone is a dynamic tissue undergoing ...

Clinical Practice Protocol of Creative Music Therapy for Preterm Infants and Their Parents in the Neonatal Intensive Care Unit

Creative music therapy for preterm infants and their parents (CMT) has emerged as a promising family-integrated early intervention involving communicative musicality to improve infant development, parental well-being, and bonding. It aims at relaxing and nurturing the infant as well as promoting safety and social interaction for the parent-infant dyad. A music therapist specially trained in CMT hums or sings in an infant-directed, improvised, lullaby style continually adjusting to the individual needs, expressions, and breathing pattern of the preterm infant. Based on the principles of family-integrated care, the family is incorporated individually in the therapeutic process, namely by delivering CMT during kangaroo care (KC) and by motivating and facilitating parental vocal interaction with their infant to strengthen the parent-infant bonding. CMT aims at relaxing, stimulating, and coregulating premature infants at a time when many other interventions are still risky and can overwhelm the vulnerable patient group. CMT may be advantageous not by educating and teaching parents, but rather by uncovering the intuitive capacities of parenting that are often overshadowed by the traumatic experience of preterm birth. However, CMT can only be provided when the infants are clinically stable. CMT with parental integration is feasible when parents are available and receptive to participate. This paper presents a detailed protocol on how to use CMT to empower preterm infants and their families.

Creative music therapy for preterm infants and their parents has emerged as a promising family-integrated early intervention. We present a detailed protocol on how to use vocal interaction, humming, or singing to empower preterm infants and their families.

Creative music therapy for preterm infants and their parents (CMT) has emerged as a promising family-integrated early intervention involving communicative ...