<meta charset="utf8"></head><body>使用具有自门控功能的 3T UTE MRI 进行高分辨率肺部成像的方案

<ol><li>Raju, S., Ghosh, S., Mehta, A. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Chest+ct+signs+in+pulmonary+disease%3A+A+pictorial+review%5BTitle%5D)+AND+%22Chest%22%5BJournal%5D)">Chest ct signs in pulmonary disease: A pictorial review.</a> Chest. 151 (6), 1356-1374 (2017).</li>
<li>Biederer, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((MRI+of+the+lung+%282%2F3%29.+Why%2C+when%2C+how%5BTitle%5D)+AND+%22Insights+Imaging%22%5BJournal%5D)">MRI of the lung (2/3). Why, when, how.</a> Insights Imaging. 3 (4), 355-371 (2012).</li>
<li>Biederer, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((MRI+of+the+lung+%283%2F3%29-current+applications+and+future+perspectives%5BTitle%5D)+AND+%22Insights+Imaging%22%5BJournal%5D)">MRI of the lung (3/3)-current applications and future perspectives.</a> Insights Imaging. 3 (4), 373-386 (2012).</li>
<li>Johnson, K. M., Fain, S. B., Schiebler, M. L., Nagle, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Optimized+3D+ultrashort+echo+time+pulmonary+MRI%5BTitle%5D)+AND+%22Magn+Reson+Med%22%5BJournal%5D)">Optimized 3D ultrashort echo time pulmonary MRI.</a> Magn Reson Med. 70 (5), 1241-1250 (2013).</li>
<li>Ma, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Ultra-short+echo-time+pulmonary+MRI%3A+Evaluation+and+reproducibility+in+COPD+subjects+with+and+without+bronchiectasis%5BTitle%5D)+AND+%22J+Magn+Reson+Imaging%22%5BJournal%5D)">Ultra-short echo-time pulmonary MRI: Evaluation and reproducibility in COPD subjects with and without bronchiectasis.</a> J Magn Reson Imaging. 41 (5), 1465-1474 (2015).</li>
<li>Roach, D. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Ultrashort+echo-time+magnetic+resonance+imaging+is+a+sensitive+method+for+the+evaluation+of+early+cystic+fibrosis+lung+disease%5BTitle%5D)+AND+%22Ann+Am+Thorac+Soc%22%5BJournal%5D)">Ultrashort echo-time magnetic resonance imaging is a sensitive method for the evaluation of early cystic fibrosis lung disease.</a> Ann Am Thorac Soc. 13 (11), 1923-1931 (2016).</li>
<li>Tibiletti, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Multistage+three-dimensional+UTE+lung+imaging+by+image-based+self-gating%5BTitle%5D)+AND+%22Magn+Reson+Med%22%5BJournal%5D)">Multistage three-dimensional UTE lung imaging by image-based self-gating.</a> Magn Reson Med. 75 (3), 1324-1332 (2016).</li>
<li>Weick, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Dc-gated+high-resolution+three-dimensional+lung+imaging+during+free-breathing%5BTitle%5D)+AND+%22J+Magn+Reson+Imaging%22%5BJournal%5D)">Dc-gated high-resolution three-dimensional lung imaging during free-breathing.</a> J Magn Reson Imaging. 37 (3), 727-732 (2013).</li>
<li>Fischer, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Self-gated+non-contrast-enhanced+functional+lung+imaging+%28SENCEFUL%29+using+a+quasi-random+fast+low-angle+shot+%28FLASH%29+sequence+and+proton+MRI%5BTitle%5D)+AND+%22NMR+Biomed%22%5BJournal%5D)">Self-gated non-contrast-enhanced functional lung imaging (SENCEFUL) using a quasi-random fast low-angle shot (FLASH) sequence and proton MRI.</a> NMR Biomed. 27 (8), 907-917 (2014).</li>
<li>Tibiletti, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Respiratory+self-gated+3D+UTE+for+lung+imaging+in+small+animal+MRI%5BTitle%5D)+AND+%22Magn+Reson+Med%22%5BJournal%5D)">Respiratory self-gated 3D UTE for lung imaging in small animal MRI.</a> Magn Reson Med. 78 (2), 739-745 (2017).</li>
<li>Jiang, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Motion+robust+high+resolution+3D+free-breathing+pulmonary+MRI+using+dynamic+3D+image+self-navigator%5BTitle%5D)+AND+%22Magn+Reson+Med%22%5BJournal%5D)">Motion robust high resolution 3D free-breathing pulmonary MRI using dynamic 3D image self-navigator.</a> Magn Reson Med. 79 (6), 2954-2967 (2018).</li>
<li>Higano, N. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Retrospective+respiratory+self-gating+and+removal+of+bulk+motion+in+pulmonary+UTE+MRI+of+neonates+and+adults%5BTitle%5D)+AND+%22Magn+Reson+Med%22%5BJournal%5D)">Retrospective respiratory self-gating and removal of bulk motion in pulmonary UTE MRI of neonates and adults.</a> Magn Reson Med. 77 (3), 1284-1295 (2016).</li>
<li>Metze, P., et al. Non-uniform self-gating in 2D lung imaging. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aMetze%2C+P+%22Front+Phys%22">Front Phys</a>. 10, (2022).</li>
<li>Gandhi, D. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Comparison+of+weighting+algorithms+to+mitigate+respiratory+motion+in+free-breathing+neonatal+pulmonary+radial+UTE-MRI%5BTitle%5D)+AND+%22Biomed+Phys+Eng+Express%22%5BJournal%5D)">Comparison of weighting algorithms to mitigate respiratory motion in free-breathing neonatal pulmonary radial UTE-MRI.</a> Biomed Phys Eng Express. 10 (3), 035030(2024).</li>
<li>Fauveau, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Performance+of+spiral+UTE-MRI+of+the+lung+in+post-covid+patients%5BTitle%5D)+AND+%22Magn+Reson+Imaging%22%5BJournal%5D)">Performance of spiral UTE-MRI of the lung in post-covid patients.</a> Magn Reson Imaging. 96, 135-143 (2023).</li>
<li>Metz, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Comparison+of+diagnostic+quality+of+3D+ultrashort-echo-time+techniques+for+pulmonary+magnetic+resonance+imaging+in+free-breathing%5BTitle%5D)+AND+%22Acta+Radiologica%22%5BJournal%5D)">Comparison of diagnostic quality of 3D ultrashort-echo-time techniques for pulmonary magnetic resonance imaging in free-breathing.</a> Acta Radiologica. 64 (5), 1851-1858 (2023).</li>
<li>Periaswamy, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Comparison+of+ultrashort+TE+lung+MRI+and+HRCT+lungs+for+detection+of+pulmonary+nodules+in+oncology+patients%5BTitle%5D)+AND+%22Indian+J+Radiol+Imaging%22%5BJournal%5D)">Comparison of ultrashort TE lung MRI and HRCT lungs for detection of pulmonary nodules in oncology patients.</a> Indian J Radiol Imaging. 32 (04), 497-504 (2022).</li>
<li>Darçot, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Comparison+between+magnetic+resonance+imaging+and+computed+tomography+in+the+detection+and+volumetric+assessment+of+lung+nodules%3A+A+prospective+study%5BTitle%5D)+AND+%22Frontiers+in+Medicine%22%5BJournal%5D)">Comparison between magnetic resonance imaging and computed tomography in the detection and volumetric assessment of lung nodules: A prospective study.</a> Frontiers in Medicine. 9, 858731(2022).</li>
<li>Dournes, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((3D+ultrashort+echo+time+MRI+of+the+lung+using+stack-of-spirals+and+spherical+k-space+coverages%3A+Evaluation+in+healthy+volunteers+and+parenchymal+diseases%5BTitle%5D)+AND+%22J+Magn+Reson+Imaging%22%5BJournal%5D)">3D ultrashort echo time MRI of the lung using stack-of-spirals and spherical k-space coverages: Evaluation in healthy volunteers and parenchymal diseases.</a> J Magn Reson Imaging. 48 (6), 1489-1497 (2018).</li>
<li>Campbell-Washburn, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((2019+American+Thoracic+Society+Bear+Cage+winning+proposal%3A+Lung+imaging+using+high-performance+low-field+magnetic+resonance+imaging%5BTitle%5D)+AND+%22Am+J+Respir+Crit+Care+Med%22%5BJournal%5D)">2019 American Thoracic Society Bear Cage winning proposal: Lung imaging using high-performance low-field magnetic resonance imaging.</a> Am J Respir Crit Care Med. 201 (11), 1333-1336 (2020).</li>
<li>Robison, R. K., Anderson, A. G., Pipe, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Three-dimensional+ultrashort+echo-time+imaging+using+a+FLORET+trajectory%5BTitle%5D)+AND+%22Magn+Reson+Med%22%5BJournal%5D)">Three-dimensional ultrashort echo-time imaging using a FLORET trajectory.</a> Magn Reson Med. 78 (3), 1038-1049 (2017).</li>
<li>Willmering, M. M., Robison, R. K., Wang, H., Pipe, J. G., Woods, J. C. Implementation of the FLORET sequence for lung imaging. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aWillmering%2C+MM+%22Magn+Reson+Med%22">Magn Reson Med</a>. 82 (3), 1091-1100 (2019).</li>
<li>Chan, R. W., Ramsay, E. A., Cunningham, C. H., Plewes, D. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Temporal+stability+of+adaptive+3D+radial+MRI+using+multidimensional+golden+means%5BTitle%5D)+AND+%22Magn+Reson+Med%22%5BJournal%5D)">Temporal stability of adaptive 3D radial MRI using multidimensional golden means.</a> Magn Reson Med. 61 (2), 354-363 (2009).</li>
<li>Yu, J., Xue, Y., Song, H. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Comparison+of+lung+T2%2A+during+free-breathing+at+1.5+T+and+3.0+T+with+ultrashort+echo+time+imaging%5BTitle%5D)+AND+%22Magn+Reson+Med%22%5BJournal%5D)">Comparison of lung T2* during free-breathing at 1.5 T and 3.0 T with ultrashort echo time imaging.</a> Magn Reson Med. 66 (1), 248-254 (2011).</li>
<li>Otsu, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+threshold+selection+method+from+gray-level+histograms%5BTitle%5D)+AND+%22IEEE+Trans+Syst+Man+Cybern%22%5BJournal%5D)">A threshold selection method from gray-level histograms.</a> IEEE Trans Syst Man Cybern. 9 (1), 62-66 (1979).</li>
<li>Martin Uecker, F. O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Berkely+advanced+reconstruction+toolbox%5BTitle%5D)+AND+%22Proc+Intl+Soc+Magn+Reson+Med%22%5BJournal%5D)">Berkely advanced reconstruction toolbox.</a> Proc Intl Soc Magn Reson Med. 23, 2486(2015).</li>
<li><a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=%22Bart+Toolbox+for+Computational+Magnetic+Resonance+Imaging%22">Bart Toolbox for Computational Magnetic Resonance Imaging</a>. , (2024).</li>
<li>Munidasa, S. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aMunidasa%2C+S+%22Treatment+monitoring+of+pediatric+cystic+fibrosis+lung+disease+using+free+breathing+lung+MRI%22">Treatment monitoring of pediatric cystic fibrosis lung disease using free breathing lung MRI</a>. , Doctor of Philosophy thesis, University of Toronto. (2024).</li>
<li>Zhu, X., Chan, M., Lustig, M., Johnson, K. M., Larson, P. E. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Iterative+motion-compensation+reconstruction+ultra-short+TE+%28IMOCO+UTE%29+for+high-resolution+free-breathing+pulmonary+MRI%5BTitle%5D)+AND+%22Magn+Reson+Med%22%5BJournal%5D)">Iterative motion-compensation reconstruction ultra-short TE (IMOCO UTE) for high-resolution free-breathing pulmonary MRI.</a> Magn Reson Med. 83 (4), 1208-1221 (2020).</li>
<li>Tan, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Motion-compensated+low-rank+reconstruction+for+simultaneous+structural+and+functional+UTE+lung+MRI%5BTitle%5D)+AND+%22Magn+Reson+Med%22%5BJournal%5D)">Motion-compensated low-rank reconstruction for simultaneous structural and functional UTE lung MRI.</a> Magn Reson Med. 90 (3), 1101-1113 (2023).</li>
<li>Bhattacharya, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Oxygen-enhanced+functional+lung+imaging+using+a+contemporary+0.55+T+MRI+system%5BTitle%5D)+AND+%22NMR+Biomed%22%5BJournal%5D)">Oxygen-enhanced functional lung imaging using a contemporary 0.55 T MRI system.</a> NMR Biomed. 34 (8), e4562(2021).</li>
<li>Kim, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Feasibility+of+dynamic+T2%2A-based+oxygen-enhanced+lung+MRI+at+3T%5BTitle%5D)+AND+%22Magn+Reson+Med%22%5BJournal%5D)">Feasibility of dynamic T2*-based oxygen-enhanced lung MRI at 3T.</a> Magn Reson Med. 91 (3), 972-986 (2024).</li>
<li>Klimeš, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((3D+phase-resolved+functional+lung+ventilation+MR+imaging+in+healthy+volunteers+and+patients+with+chronic+pulmonary+disease%5BTitle%5D)+AND+%22Magn+Reson+Med%22%5BJournal%5D)">3D phase-resolved functional lung ventilation MR imaging in healthy volunteers and patients with chronic pulmonary disease.</a> Magn Reson Med. 85 (2), 912-925 (2021).</li>
</ol>

<table><tbody><tr><td>Chest MRI Coil</td><td>Siemens, GE, Philips,, Other Clinical MRI Imaging Coil Vendor</td><td>N/A</td><td>A 26 - 32 channel Chest coil should be used</td></tr><tr><td>High Performance Workstation</td><td>HP, Apple, or other Computer Hardware company</td><td>N/A</td><td>A computer with a minimum of 64 GB of Memory is needed for image reconstruction</td></tr><tr><td>Matlab</td><td>Mathworks</td><td>R2016A or newer</td><td>A Matlab license is needed to run the provided computer code</td></tr><tr><td>MRI Phantom</td><td>Siemens, GE, Philips, or Other MRI Phantom Vendor</td><td>N/A</td><td>Any Phantom can be used to test the MRI sequence prior to its use in human subjects.</td></tr><tr><td>MRI Scanner</td><td>Siemens, GE, Philips, or Other Clinical MRI Scanner Vendor</td><td>N/A</td><td>The protocol was developed on a 3T scanner, but 1.5T or 0.55T would also work with minimal adaptation</td></tr></tbody></table>

pulmonary structural mri using free-breathing, self-gated ultra-short echo time imaging

<meta charset="utf8"></head><body>作者聚焦：使用计算高效的重建方法优化肺 MRI 方案

使用自由呼吸、自门控超短回声时间成像的肺部结构 MRI 

High quality MRI of the lungs is challenged by low tissue density, fast MRI signal relaxation, and respiratory and cardiac motion. For these reasons, ...

pulmonary-structural-mri-using-free-breathing-self-gated-ultra-short

Research

JoVE Journal

Medicine

Pulmonary Structural MRI using Free-Breathing, Self-Gated Ultra-short Echo Time Imaging

283 次观看.  University of Kansas Medical Center. 我的研究集中在用于肺结构和功能成像的 MRI 方法的开发和应用。我们想了解如何最好地对肺部进行成像，然后使用这些技术来了解肺部健康和疾病。肺部 MRI 是一个快速发展的领域。研究人员正在研究收集不同气体制剂 MRI 的新方法，以及使用传统 MRI 对肺结构和功能进行成像的新方法。结构 MRI 已经取得了长足的进步，出现了各种减轻运动和?...

视频: 作者聚焦：使用计算高效的重建方法优化肺 MRI 方案

Contrast Enhanced Vessel Imaging using MicroCT

Microscopic computed tomography (microCT) offers high-resolution volumetric imaging of the anatomy of living small animals. However, the contrast between different soft tissues and body fluids is inherently poor in micro-CT images 1. Under these circumstances, visualization of blood vessels becomes a nearly impossible task. To overcome this and to improve the visualization of blood vessels exogenous contrast agents can be used. Herein, we present a methodology for visualizing the vascular network in a rodent model. By using a long-acting aqueous colloidal polydisperse iodinated blood-pool contrast agent, eXIA 160XL, we optimized image acquisition parameters and volume-rendering techniques for finding blood vessels in live animals. Our findings suggest that, to achieve a superior contrast between bone and soft tissue from vessel, multiple-frames (at least 5-8/ frames per view), and 360-720 views (for a full 360&deg; rotation) acquisitions were mandatory. We have also demonstrated the use of a two-dimensional transfer function (where voxel color and opacity was assigned in proportion to CT value and gradient magnitude), in visualizing the anatomy and highlighting the structure of interest, the blood vessel network. This promising work lays a foundation for the qualitative and quantitative assessment of anti-angiogenesis preclinical studies using transgenic or xenograft tumor-bearing mice.

Contrast enhanced small animal vessel imaging by microCT is a rapid, cost-effective and high-throughput technique for serial in situ examination for tumor development, for analyzing the network of blood vessels that nourish them, and for following the response of tumors to preclinical therapeutic intervention(s).

增强容器成像MicroCT

Microscopic computed tomography (microCT) offers high-resolution volumetric imaging of the anatomy of living small animals. However, the contrast between ...

科研

医学

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.

使用校准动脉自旋标记磁共振肺灌注显像定量

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

MRI-guided Disruption of the Blood-brain Barrier using Transcranial Focused Ultrasound in a Rat Model

Focused ultrasound (FUS) disruption of the blood-brain barrier (BBB) is an increasingly investigated technique for circumventing the BBB1-5. The BBB is a significant obstacle to pharmaceutical treatments of brain disorders as it limits the passage of molecules from the vasculature into the brain tissue to molecules less than approximately 500 Da in size6. FUS induced BBB disruption (BBBD) is temporary and reversible4 and has an advantage over chemical means of inducing BBBD by being highly localized. FUS induced BBBD provides a means for investigating the effects of a wide range of therapeutic agents on the brain, which would not otherwise be deliverable to the tissue in sufficient concentration. While a wide range of ultrasound parameters have proven successful at disrupting the BBB2,5,7, there are several critical steps in the experimental procedure to ensure successful disruption with accurate targeting. This protocol outlines how to achieve MRI-guided FUS induced BBBD in a rat model, with a focus on the critical animal preparation and microbubble handling steps of the experiment.

Microbubble-mediated focused ultrasound disruption of the blood-brain barrier (BBB) is a promising technique for non-invasive targeted drug delivery in the brain1-3. This protocol outlines the experimental procedure for MRI-guided transcranial BBB disruption in a rat model.

MRI引导下的破坏血脑屏障在大鼠模型经颅聚焦超声

Focused ultrasound (FUS) disruption of the blood-brain barrier (BBB) is an increasingly investigated technique for circumventing the BBB1-5. The BBB is a ...

MRI and PET in Mouse Models of Myocardial Infarction

Myocardial infarction is one of the leading causes of death in the Western world. The similarity of the mouse heart to the human heart has made it an ideal model for testing novel therapeutic strategies.
In vivo magnetic resonance imaging (MRI) gives excellent views of the heart noninvasively with clear anatomical detail, which can be used for accurate functional assessment. Contrast agents can provide basic measures of tissue viability but these are nonspecific. Positron emission tomography (PET) is a complementary technique that is highly specific for molecular imaging, but lacks the anatomical detail of MRI. Used together, these techniques offer a sensitive, specific and quantitative tool for the assessment of the heart in disease and recovery following treatment.
In this paper we explain how these methods are carried out in mouse models of acute myocardial infarction. The procedures described here were designed for the assessment of putative protective drug treatments. We used MRI to measure systolic function and infarct size with late gadolinium enhancement, and PET with fluorodeoxyglucose (FDG) to assess metabolic function in the infarcted region. The paper focuses on practical aspects such as slice planning, accurate gating, drug delivery, segmentation of images, and multimodal coregistration. The methods presented here achieve good repeatability and accuracy maintaining a high throughput.

We describe how to perform MRI and PET imaging of the mouse heart. The protocol is tailored to assess treatment efficacy in models of myocardial infarction and heart failure.

MRI和PET心肌梗死小鼠模型

Myocardial infarction is one of the leading causes of death in the Western world. The similarity of the mouse heart to the human heart has made it an ...

Quantitative Mapping of Specific Ventilation in the Human Lung using Proton Magnetic Resonance Imaging and Oxygen as a Contrast Agent

Specific ventilation imaging (SVI) is a functional magnetic resonance imaging technique capable of quantifying specific ventilation &#8213; the ratio of the fresh gas entering a lung region divided by the region&#8217;s end-expiratory volume &#8213; in the human lung, using only inhaled oxygen as a contrast agent. Regional quantification of specific ventilation has the potential to help identify areas of pathologic lung function. Oxygen in solution in tissue shortens the tissue&#8217;s longitudinal relaxation time (T1), and thus a change in tissue oxygenation can be detected as a change in T1-weighted signal with an inversion recovery acquired image. Following an abrupt change between two concentrations of inspired oxygen, the rate at which lung tissue within a voxel equilibrates to a new steady-state reflects the rate at which resident gas is being replaced by inhaled gas. This rate is determined by specific ventilation. To elicit this sudden change in oxygenation, subjects alternately breathe 20-breath blocks of air (21% oxygen) and 100% oxygen while in the MRI scanner. A stepwise change in inspired oxygen fraction is achieved through use of a custom three-dimensional (3D)-printed flow bypass system with a manual switch during a short end-expiratory breath hold. To detect the corresponding change in T1, a global inversion pulse followed by a single shot fast spin echo sequence was used to acquire two-dimensional T1-weighted images in a 1.5&#160;T MRI scanner, using an eight-element torso coil. Both single slice and multi-slice imaging are possible, with slightly different imaging parameters. Quantification of specific ventilation is achieved by correlating the time-course of signal intensity for each lung voxel with a library of simulated responses to the air/oxygen stimulus. SVI estimations of specific ventilation heterogeneity have been validated against multiple breath washout and proved to accurately determine the heterogeneity of the specific ventilation distribution.

Specific ventilation imaging is a functional magnetic resonance imaging technique that allows for quantification of regional specific ventilation in the human lung, using inhaled oxygen as a contrast agent. Here, we present a protocol to collect and analyze specific ventilation imaging data.

以质子磁共振成像和氧为造影剂对人肺特异性通气进行定量定位

Specific ventilation imaging (SVI) is a functional magnetic resonance imaging technique capable of quantifying specific ventilation &#8213; the ratio of ...

使用超极化氙 129 MRI 评估肺功能

Quantitative Measure of Lung Structure and Function Obtained from Hyperpolarized Xenon Spectroscopy

Hyperpolarized Xenon-129 (HXe) magnetic resonance imaging (MRI) provides tools for obtaining 2- or 3-dimensional maps of lung ventilation patterns, gas diffusion, Xenon uptake by lung parenchyma, and other lung function metrics. However, by trading spatial for temporal resolution, it also enables tracing of pulmonary Xenon gas exchange on a ms timescale. This article describes one such technique, chemical shift saturation recovery (CSSR) MR spectroscopy. It illustrates how it can be used to assess capillary blood volume, septal wall thickness, and the surface-to-volume ratio in the alveoli. The flip angle of the applied radiofrequency pulses (RF) was carefully calibrated. Single-dose breath-hold and multi-dose free-breathing protocols were employed for administering the gas to the subject. Once the inhaled Xenon gas reached the alveoli, a series of 90&#176; RF pulses was applied to ensure maximum saturation of the accumulated Xenon magnetization in the lung parenchyma. Following a variable delay time, spectra were acquired to quantify the regrowth of the Xenon signal due to gas exchange between the alveolar gas volume and the tissue compartments of the lung. These spectra were then analyzed by fitting complex pseudo-Voigt functions to the three dominant peaks. Finally, the delay time-dependent peak amplitudes were fitted to a one-dimensional analytical gas-exchange model to extract physiological parameters.

作者聚焦:利用自由呼吸超极化氙 129 MRI 推进肺病研究

The manuscript presents a detailed protocol for using hyperpolarized Xenon-129 chemical shift saturation recovery (CSSR) to trace pulmonary gas exchange, assess the apparent alveolar septal wall thickness, and measure the surface-to-volume ratio. The method has the potential to diagnose and monitor lung diseases.

通过超偏振氙光谱法获得的肺结构和功能的定量测量

Hyperpolarized Xenon-129 (HXe) magnetic resonance imaging (MRI) provides tools for obtaining 2- or 3-dimensional maps of lung ventilation patterns, gas ...

超极化 129Xe MRI 研究肺功能的标准化工作流程

Acquiring Hyperpolarized 129Xe Magnetic Resonance Images of Lung Ventilation

Hyperpolarized 129Xe MRI comprises a unique array of structural and functional lung imaging techniques. Technique standardization across sites is increasingly important given the recent FDA approval of 129Xe as an MR contrast agent and as interest in 129Xe MRI increases among research and clinical institutions. Members of the 129Xe MRI Clinical Trials Consortium (Xe MRI CTC) have agreed upon best practices for each of the key aspects of the 129Xe MRI workflow, and these recommendations are summarized in a recent publication. This work provides practical information to develop an end-to-end workflow for collecting 129Xe MR images of lung ventilation according to the Xe MRI CTC recommendations. Preparation and administration of 129Xe for MR studies will be discussed and demonstrated, with specific topics including choice of appropriate gas volumes for entire studies and for individual MR scans, preparation&#160;and delivery of individual 129Xe doses, and best practices for monitoring subject safety and 129Xe tolerability during studies. Key MR technical considerations will also be covered, including pulse sequence types and optimized parameters, calibration of 129Xe flip angle and center frequency, and 129Xe MRI ventilation image analysis.

作者聚焦:使用 129Xe MRI 推进肺部成像的标准化和最佳实践

Hyperpolarized 129Xe magnetic resonance imaging (MRI) is a method for studying regionally resolved aspects of pulmonary function. This work presents an end-to-end standardized workflow for hyperpolarized 129Xe MRI of lung ventilation, with specific attention to pulse sequence design, 129Xe dose preparation, scan workflow, and best practices for subject safety monitoring.

使用自由呼吸、自门控超短回声时间成像的肺部结构 MRI

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增强容器成像MicroCT

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MRI和PET心肌梗死小鼠模型

以质子磁共振成像和氧为造影剂对人肺特异性通气进行定量定位

通过超偏振氙光谱法获得的肺结构和功能的定量测量

通过超偏振氙光谱法获得的肺结构和功能的定量测量

通过超偏振氙光谱法获得的肺结构和功能的定量测量

获取肺通气的超极化 ¹²⁹Xe 磁共振图像

获取肺通气的超极化 ¹²⁹Xe 磁共振图像

使用自由呼吸、自门控超短回声时间成像的肺部结构 MRI

副本

摘要

探索更多视频

增强容器成像MicroCT

使用校准动脉自旋标记磁共振肺灌注显像定量

MRI引导下的破坏血脑屏障在大鼠模型经颅聚焦超声

MRI和PET心肌梗死小鼠模型

以质子磁共振成像和氧为造影剂对人肺特异性通气进行定量定位

通过超偏振氙光谱法获得的肺结构和功能的定量测量

通过超偏振氙光谱法获得的肺结构和功能的定量测量

通过超偏振氙光谱法获得的肺结构和功能的定量测量

获取肺通气的超极化 129Xe 磁共振图像

获取肺通气的超极化 129Xe 磁共振图像

获取肺通气的超极化 ¹²⁹Xe 磁共振图像

获取肺通气的超极化 ¹²⁹Xe 磁共振图像