Name: in vivo tracking of edema development and microvascular pathology in a model of experimental cerebral malaria using magnetic resonance imaging
Uploaded: 2017-06-08T12:30:00
Description: Watch this Scientific Journal Video about In Vivo Tracking of Edema Development and Microvascular Pathology in a Model of Experimental Cerebral Malaria Using Magnetic Resonance Imaging at JoVE.com

The expert technical assistance of Miriam Reinig is gratefully acknowledged. AH received funding from a postdoctoral stipend of the Medical Faculty of the University of Heidelberg. MP is supported by a memorial stipend from the Else-Kro&#776;ner-Fresenius Foundation. AKM is a recipient of a maternity leave stipend by the DZIF Academy of the German Center for Infection Research (DZIF). JP is the recipient of a Heidelberg Research Center for Molecular Medicine (HRCMM) Career Development Fellowship. We furthermore gratefully acknowledge Julia M. Sattler and Friedrich Frischknecht for providing an exemplary movie of sporozoite movement.

All animal experiments reported in this article were conducted according to the Federation for Laboratory Animal Science Associations (FELASA) category B and the Society of Laboratory Animal Science (GV-SOLAS) standard guidelines and were approved by the local German authorities in Karlsruhe (Regierungspr&#228;sidium Karlsruhe, Germany). Please note that biosavety level 2 applies to mosquito and Plasmodium berghei ANKA sporozoite work.
1. Infection
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	<li>Infect Anopheles stephensi</e...

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C., Renia, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+models+of+cerebral+malaria.">Experimental models of cerebral malaria.</a> Curr Top Microbiol Immunol. 297, 103-143 (2005).</li><li>Zhao, 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=Olfactory+plays+a+key+role+in+spatiotemporal+pathogenesis+of+cerebral+malaria.">Olfactory plays a key role in spatiotemporal pathogenesis of cerebral malaria.</a> Cell Host Microbe. 15 (5), 551-563 (2014).</li><li>Nacer, 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=Experimental+cerebral+malaria+pathogenesis--hemodynamics+at+the+blood+brain+barrier.">Experimental cerebral malaria pathogenesis--hemodynamics at the blood brain barrier.</a> PLoS Pathog. 10 (12), e1004528 (2014).</li><li>Nacer, 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=Neuroimmunological+blood+brain+barrier+opening+in+experimental+cerebral+malaria.">Neuroimmunological blood brain barrier opening in experimental cerebral malaria.</a> PLoS Pathog. 8 (10), e1002982 (2012).</li><li>Pai, 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=Real-time+imaging+reveals+the+dynamics+of+leukocyte+behaviour+during+experimental+cerebral+malaria+pathogenesis.">Real-time imaging reveals the dynamics of leukocyte behaviour during experimental cerebral malaria pathogenesis.</a> PLoS Pathog. 10 (7), e1004236 (2014).</li><li>Shaw, T. 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In this article, we describe a whole-brain MRI protocol to delineate changes in experimental cerebral malaria. We believe that MRI has been under-utilized in malaria research to date and hope that our protocols will aid other investigators. We would like to describe some additional points that may be helpful.
If severely sick mice are imaged, positioning is crucial. Due to increased intracranial pressure, mice are susceptible to death, and thus, the cervical spine should not be stretched. Anes...

Malaria is a significant global health problem.1 Severe malaria is characterized in part by cerebral involvement and is often a poor prognostic factor. Cerebral involvement is common in children under the age of five in areas of high malaria transmission and represents the major cause of malaria related death in that age group.1 While aggressive treatment can be life-saving, the detection of cerebral malaria, especially in early stages, can be difficult. The pathological processes involved in cerebral malaria include microvascular disruption and cerebral edema, which can lead to severe brain swelling. In this article, we present a magnetic resonance imaging (MRI) protocol that allows whole-brain in vivo imaging of experimental cerebral malaria (ECM). Whole-brain high-resolution imaging methods have been widely underutilized in this disease, even though little is known about how ECM initiates in the central nervous system or what specific mechanisms lead to the disease. In vivo MRI, covering the whole brain, represents an important research tool to gain a better understanding of ECM pathology. MRI is able to assess global cerebral brain swelling, which has recently been recognized to be an important predictor of death not only in ECM, but also in human cerebral malaria.2,3 Severe brain swelling occurs in fatal disease and represents one of several pathological features between the ECM models and human disease, a disease that is characterized by both inflammatory and microvascular alterations.4
ECM can be induced in CBA or C57BL mice through infection with lethal Plasmodium berghei ANKA.5 The onset of ECM typically occurs between days 6 and 10 post-infection and results in fitting, ataxia, respiratory distress, and coma, which lead to rapid death.4 The Rapid Murine Coma and Behavior Scale (RMCBS) is a helpful score to evaluate clinical symptoms of ECM. It consists of 10 parameters, each scored from 0 to 2, with a maximum possible score of 20.6 Recently, we showed good agreement between the severity of the RMCBS scores in ECM mice and pathological changes demonstrated by MRI.7 In this protocol, we describe ECM induction in mice and in vivo magnetic resonance imaging of mice with ECM.

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			<td>The MathWorks, Inc.,</td>
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			<td>FDT toolbox&#160;</td>
			<td colspan="2">FMRIB&#39;s Software Library</td>
			<td><a href="http://www.fmrib.ox.ac.uk/fsl/fdt/index.html">http://www.fmrib.ox.ac.uk/fsl/fdt/index.html</a></td>
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in vivo tracking of edema development and microvascular pathology in a model of experimental cerebral malaria using magnetic resonance imaging

Cerebral malaria is a sign of severe malarial disease and is often a harbinger of death. While aggressive management can be life-saving, the detection of cerebral malaria can be difficult. We present an experimental mouse model of cerebral malaria that shares multiple features of the human disease, including edema and microvascular pathology. Using magnetic resonance imaging (MRI), we can detect and track the blood-brain barrier disruption, edema development, and subsequent brain swelling. We describe multiple MRI techniques that can visualize these pertinent pathological changes. Thus, we show that MRI represents a valuable tool to visualize and track pathological changes, such as edema, brain swelling, and microvascular pathology, in vivo.

In C57BL/6 mice, the first clinical symptoms of ECM can be observed between days 6 and 10 after infection with P. berghei ANKA sporozoites. ECM develops in 60 - 80% of infected mice and rapidly progresses to coma and death within 24 to 48 h. In contrast, mice that do not develop ECM die after the second week post-infection from severe anemia due to hyperparasitemia.12
In MRI imaging, the earliest...

Watch this Scientific Journal Video about In Vivo Tracking of Edema Development and Microvascular Pathology in a Model of Experimental Cerebral Malaria Using Magnetic Resonance Imaging at JoVE.com

In Vivo Tracking of Edema Development and Microvascular Pathology in a Model of Experimental Cerebral Malaria Using Magnetic Resonance Imaging

We describe a mouse model of experimental cerebral malaria and show how inflammatory and microvascular pathology can be tracked in vivo using magnetic resonance imaging.

In Vivo Tracking of Edema Development and Microvascular Pathology in a Model of Experimental Cerebral Malaria Using Magnetic Resonance Imaging

Cerebral malaria is a sign of severe malarial disease and is often a harbinger of death. While aggressive management can be life-saving, the detection of ...

The overall goal of this method is to monitor pathological changes of experimental cerebral malaria in vivo. This method can help to answer key questions in the pathogenesis of experimental cerebral malaria as it allows us to visualize in vivo how pathology of the whole brain evolves in space and over time. The technique thereby allows a detailed assessment of brain pathology, and can be used to assess the efficacy of novel treatment strategies in cerebral malaria.Performing the MRI setup will be Manuel Fischer, our lab manager. Begin by collecting female mosquitoes from their cage, 17 to 22 days after the blood meal. Use forceps to place three to four mosquitoes on a glass slide, combined with a drop of cold RPMI medium.Then, place the slide under a microscope. Carefully stretch the mosquito between the head and body with forceps, and use a syringe and needle to isolate the salivary gland. Next, collect the salivary glands from the glass slide by sucking them up with a glass pipette, and transferring them into 1.5 milliliter centrifuge tube.Then, use a small plastic stick to smash the isolated salivary glands within the centrifuge tube for three minutes in order to isolate the sporozoites from the salivary gland tissue. Centrifuge for three minutes at 1, 000 times g and four degrees Celsius to purify the sporozoites from the remaining tissue. Pipette the supernatant, which contains the sporozoites, to a new centrifuge tube, and count the purified sporozoites in a Neubauer hemocytometer.Sporozoites show a typical counterclockwise movement. Next, adjust the concentration of the purified sporozoites to 10, 000 per milliliter by adding phosphate-buffered saline. Finally, place a C57BL/6 mouse in a restrainer, and put its tail into warm water to better visualize the tail vein.Then, inject a total of 1, 000 sporozoites, or 0.1 milliliters, into the tail vein to initiate infection. Begin by bringing the mouse to a 9.4T small animal Magnetic Resonance Imaging, or MRI scanner, that uses a volume resonator for radiofrequency transmission. Then, apply dexpanthenol eye ointment to both eyes.Turn on the temperature-controlled water bath to 42 degrees Celsius in order to maintain the body temperature of the mouse. Then, place a tail vein catheter into the mouse's tail vein. Next, position the mouse for the MRI by placing it prone and with a crunched back on an animal bed equipped with a headlock and tooth bar to minimize head motion.Take care not to straighten the cervical spine of the mouse. Connect a contrast agent injection system filled with 0.3 millimole per kilogram Gd-DTPA to the tail vein catheter. Next, place the 4-Channel Phased Array Surface Receiver head coil onto the head of the mouse.Finally, place a breathing pad onto the back of the mouse and check the respiration on the monitoring device. Turn on the positional laser by pressing F2 on the control panel, and move the mouse until the horizontal positional light is in the middle of the smaller part of the coil, which covers the head of the mouse. Turn off the positional laser by pressing F2 again, and then move the mouse into the final position by pressing F3 on the control panel.Begin by performing a localizing scan to make sure that the mouse brain is in the isocenter of the magnet. Qualitatively assess vasogenic edema by using 3D T2-weighted imaging. Select a multi-slice RARE sequence, and adjust the slice position, making sure that the whole brain, from the nose to the cerebellum is covered.After adjusting the saturation slices, start the sequence, and wait 10 minutes and 48 seconds to acquire the images. Next, perform T2 relaxometry to quantitatively assess vasogenic edema by selecting multi-slice, multiple-spin echo sequence. Adjust the slice position, and start the acquisition of the sequence, which takes eight minutes and 53 seconds.To quantitatively assess both vasogenic edema and cytotoxic edema, carry out diffusion-weighted imaging by selecting a spin-echo EPI diffusion sequence. Adjust the slice position and saturation slice. Then start the sequence and wait seven minutes and 56 seconds until the raw images are acquired.Following that, assess microhemorrhages, using 3D T2 star-weighted imaging. Select a flow-compensated FLASH sequence, adjust the slice position, and start the sequence, which runs for 15 minutes and 40 seconds. Afterwards, assess arterial patency using time of flight angiography by selecting a 3D FLASH sequence.Adjust the slice position, start the sequence, and then wait seven minutes and 16 seconds until the images are acquired. Finally, assess the blood-brain barrier disruption. Select a 3D T1-weighted imaging with a FLASH sequence, adjust the slice position, and start the sequence.Wait one minute and 14 seconds until images without contrast are acquired. Then, inject contrast of 0.3 millimole per kilogram and repeat the measurement. An increase in blood-brain barrier disruption and a fluid increase indicate early vasogenic edema in the olfactory bulb that is already present in mild disease, and starts to spread towards the brain stem as the severity of the disease increases.On T2 maps, the severity of vasogenic edema can be quantified by drawing regions of interest into specific anatomical regions. For each region, a T2 relaxation time that increases with increasing edema can be obtained. Furthermore, brain volume indicative of edema starts to significantly increase in moderately sick mice as compared to baseline, and further increases in severely sick mice.Lastly, microvascular pathology, as evidenced by microhemorrhages and an increase of vessel susceptibility contrast, occurs after the first signs of blood-brain barrier disruption in vasogenic edema. These microhemmorhages predominantly occur in the olfactory bulb. If the whole MRI protocol is obtained, all images including positioning can be obtained within one hour, if it is performed properly.The minimal protocol should include a T2 weighted sequence or T2 relaxometry, and a T2 star-weighted sequence in order to judge the presence of vasogenic edema, microhemmorhage load, and microvascular impairment. After watching this video, you should have a good understanding how whole-brain MRI visualizes pathological changes in experimental cerebral malaria, including such changes as brain swelling, which is difficult to detect ex vivo.

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Magnetic Resonance Derived Myocardial Strain Assessment Using Feature Tracking

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF. Current technologies for CMR are time consuming and difficult to implement in clinical practice. Feature tracking is a technology that can lead to more automization and robustness of quantitative analysis of medical images with less time consumption than comparable methods.
Methods: An automatic or manual input in a single phase serves as an initialization from which the system starts to track the displacement of individual patterns representing anatomical structures over time. The specialty of this method is that the images do not need to be manipulated in any way beforehand like e.g. tagging of CMR images.
Results: The method is very well suited for tracking muscular tissue and with this allowing quantitative elaboration of myocardium and also blood flow.
Conclusions: This new method offers a robust and time saving procedure to quantify myocardial tissue and blood with displacement, velocity and deformation parameters on regular sequences of CMR imaging. It therefore can be implemented in clinical practice.

An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF.

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that ...

Magnetic Resonance Imaging Quantification of Pulmonary Perfusion using Calibrated Arterial Spin Labeling

This demonstrates a MR imaging method to measure the spatial distribution of pulmonary blood flow in healthy subjects 
during normoxia (inspired O2, fraction (FIO2) = 0.21) hypoxia (FIO2 = 0.125), and hyperoxia 
(FIO2 = 1.00). In addition, the physiological responses of the subject are monitored in the MR scan environment. MR images 
were obtained on a 1.5 T GE MRI scanner during a breath hold from a sagittal slice in the right lung at functional residual capacity. An arterial 
spin labeling sequence (ASL-FAIRER) was used to measure the spatial distribution of pulmonary blood flow 1,2 and a multi-echo fast 
gradient echo (mGRE) sequence 3 was used to quantify the regional proton (i.e. H2O) density, allowing the quantification 
of density-normalized perfusion for each voxel (milliliters blood per minute per gram lung tissue). 
With a pneumatic switching valve and facemask equipped with a 2-way non-rebreathing valve, different oxygen concentrations 
were introduced to the subject in the MR scanner through the inspired gas tubing. A metabolic cart collected expiratory gas via expiratory tubing. Mixed expiratory O2 and CO2 concentrations, oxygen consumption, carbon dioxide production, respiratory exchange ratio, 
respiratory frequency and tidal volume were measured. Heart rate and oxygen saturation were monitored using pulse-oximetry. 
Data obtained from a normal subject showed that, as expected, heart rate was higher in hypoxia (60 bpm) than during normoxia (51) or hyperoxia (50) and the arterial oxygen saturation (SpO2) was reduced during hypoxia to 86%. Mean ventilation was 8.31 L/min BTPS during hypoxia, 7.04 L/min during normoxia, and 6.64 L/min during hyperoxia. Tidal volume was 0.76 L during hypoxia, 0.69 L during normoxia, and 0.67 L during hyperoxia. 
Representative quantified ASL data showed that the mean density normalized perfusion was 8.86 ml/min/g during hypoxia, 8.26 ml/min/g during normoxia and 8.46 ml/min/g during hyperoxia, respectively. In this subject, the relative dispersion4, an index of global heterogeneity, was increased in hypoxia (1.07 during hypoxia, 0.85 during normoxia, and 0.87 during hyperoxia) while the fractal dimension (Ds), another index of heterogeneity reflecting vascular branching structure, was unchanged (1.24 during hypoxia, 1.26 during normoxia, and 1.26 during hyperoxia). 
Overview. This protocol will demonstrate the acquisition of data to measure the distribution of pulmonary perfusion noninvasively under conditions of normoxia, hypoxia, and hyperoxia using a magnetic resonance imaging technique known as arterial spin labeling (ASL). 
Rationale: Measurement of pulmonary blood flow and lung proton density using MR technique offers high spatial resolution images which can be quantified and the ability to perform repeated measurements under several different physiological conditions. In human studies, PET, SPECT, and CT are commonly used as the alternative techniques. However, these techniques involve exposure to ionizing radiation, and thus are not suitable for repeated measurements in human subjects.

A MR imaging method to study the distribution of pulmonary blood flow under a variety of physiological conditions, in this case exposure to three different inspired oxygen concentrations: hypoxia, normoxia, and hyperoxia, is described. This technique utilizes human pulmonary physiology research techniques in an MR scanning environment.

This demonstrates a MR imaging method to measure the spatial distribution of pulmonary blood flow in healthy subjects 
during normoxia (inspired O2, ...

Multi-modal Imaging of Angiogenesis in a Nude Rat Model of Breast Cancer Bone Metastasis Using Magnetic Resonance Imaging, Volumetric Computed Tomography and Ultrasound

Angiogenesis is an essential feature of cancer growth and metastasis formation. In bone metastasis, angiogenic factors are pivotal for tumor cell proliferation in the bone marrow cavity as well as for interaction of tumor and bone cells resulting in local bone destruction. Our aim was to develop a model of experimental bone metastasis that allows in vivo assessment of angiogenesis in skeletal lesions using non-invasive imaging techniques.
For this purpose, we injected 105 MDA-MB-231 human breast cancer cells into the superficial epigastric artery, which precludes the growth of metastases in body areas other than the respective hind leg1. Following 25-30 days after tumor cell inoculation, site-specific bone metastases develop, restricted to the distal femur, proximal tibia and proximal fibula1. Morphological and functional aspects of angiogenesis can be investigated longitudinally in bone metastases using magnetic resonance imaging (MRI), volumetric computed tomography (VCT) and ultrasound (US).
MRI displays morphologic information on the soft tissue part of bone metastases that is initially confined to the bone marrow cavity and subsequently exceeds cortical bone while progressing. Using dynamic contrast-enhanced MRI (DCE-MRI) functional data including regional blood volume, perfusion and vessel permeability can be obtained and quantified2-4. Bone destruction is captured in high resolution using morphological VCT imaging. Complementary to MRI findings, osteolytic lesions can be located adjacent to sites of intramedullary tumor growth. After contrast agent application, VCT angiography reveals the macrovessel architecture in bone metastases in high resolution, and DCE-VCT enables insight in the microcirculation of these lesions5,6. US is applicable to assess morphological and functional features from skeletal lesions due to local osteolysis of cortical bone. Using B-mode and Doppler techniques, structure and perfusion of the soft tissue metastases can be evaluated, respectively. DCE-US allows for real-time imaging of vascularization in bone metastases after injection of microbubbles7.
In conclusion, in a model of site-specific breast cancer bone metastases multi-modal imaging techniques including MRI, VCT and US offer complementary information on morphology and functional parameters of angiogenesis in these skeletal lesions.

In the pathogenesis of bone metastasis, angiogenesis is a crucial process and therefore represents a target for imaging and therapy. Here, we present a rat model of site-specific breast cancer bone metastasis and describe strategies to non-invasively image angiogenesis in vivo using magnetic resonance imaging, volumetric computed tomography and ultrasound.

Angiogenesis is an essential feature of cancer growth and metastasis formation. In bone metastasis, angiogenic factors are pivotal for tumor cell ...

In vivo 19F MRI for Cell Tracking

In vivo 19F MRI allows quantitative cell tracking without the use of ionizing radiation. It is a noninvasive technique that can be applied to humans. Here, we describe a general protocol for cell labeling, imaging, and image processing. The technique is applicable to various cell types and animal models, although here we focus on a typical mouse model for tracking murine immune cells. The most important issues for cell labeling are described, as these are relevant to all models. Similarly, key imaging parameters are listed, although the details will vary depending on the MRI system and the individual setup. Finally, we include an image processing protocol for quantification. Variations for this, and other parts of the protocol, are assessed in the Discussion section. Based on the detailed procedure described here, the user will need to adapt the protocol for each specific cell type, cell label, animal model, and imaging setup. Note that the protocol can also be adapted for human use, as long as clinical restrictions are met.

In vivo 19F MRI for Cell Tracking

We describe a general protocol for in vivo cell tracking using MRI in a mouse model with ex vivo labeled cells. A typical protocol for cell labeling, image acquisition processing and quantification is included.

In vivo 19F MRI allows quantitative cell tracking without the use of ionizing radiation. It is a noninvasive technique that can be applied to humans. ...

Noninvasive Assessment of Cardiac Abnormalities in Experimental Autoimmune Myocarditis by Magnetic Resonance Microscopy Imaging in the Mouse

Myocarditis is an inflammation of the myocardium, but only ~10% of those affected show clinical manifestations of the disease. To study the immune events of myocardial injuries, various mouse models of myocarditis have been widely used. This study involved experimental autoimmune myocarditis (EAM) induced with cardiac myosin heavy chain (Myhc)-&#945; 334-352 in A/J mice; the affected animals develop lymphocytic myocarditis but with no apparent clinical signs. In this model, the utility of magnetic resonance microscopy (MRM) as a non-invasive modality to determine the cardiac structural and functional changes in animals immunized with Myhc-&#945; 334-352 is shown. EAM and healthy mice were imaged using a 9.4 T (400 MHz) 89 mm vertical core bore scanner equipped with a 4 cm millipede radio-frequency imaging probe and 100 G/cm triple axis gradients. Cardiac images were acquired from anesthetized animals using a gradient-echo-based cine pulse sequence, and the animals were monitored by respiration and pulse oximetry. The analysis revealed an increase in the thickness of the ventricular wall in EAM mice, with a corresponding decrease in the interior diameter of ventricles, when compared with healthy mice. The data suggest that morphological and functional changes in the inflamed hearts can be non-invasively monitored by MRM in live animals. In conclusion, MRM offers an advantage of assessing the progression and regression of myocardial injuries in diseases caused by infectious agents, as well as response to therapies.

This study demonstrates the successful establishment of magnetic resonance microscopy imaging as a non-invasive tool to assess the cardiac abnormalities in mice affected with autoimmune myocarditis. The data indicate that the technique can be used to monitor the disease-progression in live animals.

Myocarditis is an inflammation of the myocardium, but only ~10% of those affected show clinical manifestations of the disease. To study the immune events ...

Tracking the Mammary Architectural Features and Detecting Breast Cancer with Magnetic Resonance Diffusion Tensor Imaging

Breast cancer is the most common cause of cancer among women worldwide. Early detection of breast cancer has a critical role in improving the quality of life and survival of breast cancer patients. In this paper a new approach for the detection of breast cancer is described, based on tracking the mammary architectural elements using diffusion tensor imaging (DTI). 
The paper focuses on the scanning protocols and image processing algorithms and software that were designed to fit the diffusion properties of the mammary fibroglandular tissue and its changes during malignant transformation. The final output yields pixel by pixel vector maps that track the architecture of the entire mammary ductal glandular trees and parametric maps of the diffusion tensor coefficients and anisotropy indices. 
The efficiency of the method to detect breast cancer was tested by scanning women volunteers including 68 patients with breast cancer confirmed by histopathology findings. Regions with cancer cells exhibited a marked reduction in the diffusion coefficients and in the maximal anisotropy index as compared to the normal breast tissue, providing an intrinsic contrast for delineating the boundaries of malignant growth. Overall, the sensitivity of the DTI parameters to detect breast cancer was found to be high, particularly in dense breasts, and comparable to the current standard breast MRI method that requires injection of a contrast agent. Thus, this method offers a completely non-invasive, safe and sensitive tool for breast cancer detection.

We describe how to obtain parametric and vector maps of the diffusion tensor of the breast using magnetic resonance imaging. The protocol and final output following imaging processing are tailored for tracking breast architectural features and detecting breast malignancy.

Breast cancer is the most common cause of cancer among women worldwide. Early detection of breast cancer has a critical role in improving the quality of ...

Simultaneous PET/MRI Imaging During Mouse Cerebral Hypoxia-ischemia

Dynamic changes in tissue water diffusion and glucose metabolism occur during and after hypoxia in cerebral hypoxia-ischemia reflecting a bioenergetics disturbance in affected cells. Diffusion weighted magnetic resonance imaging (MRI) identifies regions that are damaged, potentially irreversibly, by hypoxia-ischemia. Alterations in glucose utilization in the affected tissue may be detectable by positron emission tomography (PET) imaging of 2-deoxy-2-(18F)fluoro-&#7429;-glucose ([18F]FDG) uptake. Due to the rapid and variable nature of injury in this animal model, acquisition of both modes of data must be performed simultaneously in order to meaningfully correlate PET and MRI data. In addition, inter-animal variability in the hypoxic-ischemic injury due to vascular differences limits the ability to analyze multi-modal data and observe changes to a group-wise approach if data is not acquired simultaneously in individual subjects. The method presented here allows one to acquire both diffusion-weighted MRI and [18F]FDG uptake data in the same animal before, during, and after the hypoxic challenge in order to interrogate immediate physiological changes.

The method presented here uses simultaneous positron emission tomography and magnetic resonance imaging. In the cerebral hypoxia-ischemia model, dynamic changes in diffusion and glucose metabolism occur during and after injury. The evolving and irreproducible damage in this model necessitates simultaneous acquisition if meaningful multi-modal imaging data are to be acquired.

Dynamic changes in tissue water diffusion and glucose metabolism occur during and after hypoxia in cerebral hypoxia-ischemia reflecting a bioenergetics ...

Using Multi-fluorinated Bile Acids and In Vivo Magnetic Resonance Imaging to Measure Bile Acid Transport

Along with their traditional role as detergents that facilitate fat absorption, emerging literature indicates that bile acids are potent signaling molecules that affect multiple organs; they modulate gut motility and hormone production, and alter vascular tone, glucose metabolism, lipid metabolism, and energy utilization. Changes in fecal bile acids may alter the gut microbiome and promote colon pathology including cholerrheic diarrhea and colon cancer. Key regulators of fecal bile acid composition are the small intestinal Apical Sodium-dependent Bile Acid Transporter (ASBT) and fibroblast growth factor-19 (FGF19). Reduced expression and function of ASBT decreases intestinal bile acid up-take. Moreover, in vitro data suggest that some FDA-approved drugs inhibit ASBT function. Deficient FGF19 release increases hepatic bile acid synthesis and release into the intestines to levels that overwhelm ASBT. Either ASBT dysfunction or FGF19 deficiency increases fecal bile acids and may cause chronic diarrhea and promote colon neoplasia. Regrettably, tools to measure bile acid malabsorption and the actions of drugs on bile acid transport in vivo are limited. To understand the complex actions of bile acids, techniques are required that permit simultaneous monitoring of bile acids in the gut and metabolic tissues. This led us to conceive an innovative method to measure bile acid transport in live animals using a combination of proton (1H) and fluorine (19F) magnetic resonance imaging (MRI). Novel tracers for fluorine (19F)-based live animal MRI were created and tested, both in vitro and in vivo. Strengths of this approach include the lack of exposure to ionizing radiation and translational potential for clinical research and practice.

Using Multi-fluorinated Bile Acids and In Vivo Magnetic Resonance Imaging to Measure Bile Acid Transport

Tools to diagnose bile acid malabsorption and measure bile acid transport in vivo are limited. An innovative approach in live animals is described that utilizes combined proton (1H) plus fluorine (19F) magnetic resonance imaging; this novel methodology has translational potential to screen for bile acid malabsorption in clinical practice.

Along with their traditional role as detergents that facilitate fat absorption, emerging literature indicates that bile acids are potent signaling ...

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 ...

Cardiac Magnetic Resonance Imaging at 7 Tesla

CMR at an ultra-high field (magnetic field strength B0&#160;&#8805; 7 Tesla) benefits from the signal-to-noise ratio (SNR) advantage inherent at higher magnetic field strengths and potentially provides improved signal contrast and spatial resolution. While promising results have been achieved, ultra-high field CMR is challenging due to energy deposition constraints and physical phenomena such as transmission field non-uniformities and magnetic field inhomogeneities. In addition, the magneto-hydrodynamic effect renders the synchronization of the data acquisition with the cardiac motion difficult. The challenges are currently addressed by explorations into novel magnetic resonance technology. If all impediments can be overcome, ultra-high field CMR may generate new opportunities for functional CMR, myocardial tissue characterization, microstructure imaging or metabolic imaging. Recognizing this potential, we show that multi-channel radio frequency (RF) coil technology tailored for CMR at 7 Tesla together with higher order B0 shimming and a backup signal for cardiac triggering facilitates high fidelity functional CMR. With the proposed setup, cardiac chamber quantification can be accomplished in examination times similar to those achieved at lower field strengths. To share this experience and to support the dissemination of this expertise, this work describes our setup and protocol tailored for functional CMR at 7 Tesla.

The sensitivity gain inherent to ultrahigh field magnetic resonance holds promise for high spatial resolution imaging of the heart. Here, we describe a protocol customized for functional cardiovascular magnetic resonance (CMR) at 7 Tesla using an advanced multi-channel radio-frequency coil, magnetic field shimming and a triggering concept.

CMR at an ultra-high field (magnetic field strength B0&#160;&#8805; 7 Tesla) benefits from the signal-to-noise ratio (SNR) advantage inherent at higher ...