Bu eser Bakanlığı Bilim ve teknoloji, Tayvan, grant MOST-105-2314-B-039-044-MY2 sayısı altında gelen hibe tarafından desteklenmiştir.

Kurumsal Bakım ve kullanım Komiteleri (IACUC) Çin Tıp Üniversitesi'nin tüm prosedürleri onayladı.
1. hayvan hazırlık ve izleme
<ol><li>Cüzdan, anahtarlar, kredi kartı, vb gibi tüm manyetik olarak duyarlı nesneler MRI tarama için hayvan hazırlık başlıyor önce tarayıcı oda dışında bırakın.</li>
	<li>Başlangıçta bir indüksiyon kutusuna gerektiği gibi 3-5 min için %5 isoflurane (ISO) ve oksijen (2 L/dak) karışımı kullanarak fare (2 aylık erkek Sprague-Dawley (SD) fare, 280-350 g) anestezi.</li>
	<li>Hayvan yaslanmış ve bir kuyruk veya ayak çimdik yanıt sergiler, ISO yönetim durdurma ve hayvan tarama odasına aktar.</li>
	<li>Fare kafa ilk yüzükoyun MRI yatakta yerleştirin ve anestezi korumak için bir burun konisi aygıtı üzerinden % 2-3 ISO teslim.</li>
	<li>Solunum solunum yastık algılayıcıyı hayvanın gövde altında yerleştirerek izlemek.</li>
	<li>Sensör bir solunum sistemi ve solunum hızı arasında 40-50 vuruş / dakika (bpm) için onay bağlayın.</li>
	<li>PC-MRI toplama, cine geçitli bir elektrot doğru forepaw koyun ve sol arka pençe, sırasıyla (Şekil 1a).</li>
	<li>Elektrokardiyografi (EKG) kabloları birlikte twist.</li>
	<li>Bir kafa tutucu kulak bar ve bir ısırık bar ile kafa hareketi kısıtlamak için hayvan güvenliğini sağlamak için kullanın.</li>
	<li>Sistem veya gazlı bez yastıkları ısıtma sıcak bir hava içinde iken mıknatıs vücut ısısını korumak için kullanın.</li>
	<li>R-dalga ECG monitörde (Şekil 1b) açık olduğundan emin olun ve hayvanın tarayıcıya yerleştirin. Görüntü birimi bobin tarafından alınan hayvanın boyun üst yüzey bobin yerleştirmek için gerek yoktur.</li>
</ol>2. Mr'ı edinme
<ol><li>% 2 – 3 ISO tüm görüntüleme işlemi sırasında anestezi korumak için kullanın. Sürekli olarak fizyolojik tepkiler ve tutmak kadar sürekli izlemek.</li>
	<li>Hayvan tarayıcının içinde yerleştirilir ve fizyolojik olarak kararlı olmaya devam ediyor sonra MRI taramaları başlatın. Bu çalışmada 630 mT/m bir degrade gücü ile 7 T küçük bir hayvan MRI sistemi kullanmak, ama diğer alan güçlü küçük hayvan MRG sistemlerinde kullanılabilir.</li>
	<li>MRI tarayıcı konsol monitörden "Localizer" serisi seçin ve izci görüntüler koronal, Aksiyel, oluşturmak için herhangi bir hızlı görüntü alma sırası, Örneğin, hızlı spin eko kullanarak tüm üç yönelimleri boyunca ve sagittal görüntüleri elde . Bunlar amacı izci görüntüleri görüntüleme uçaklar belirlemektir.</li>
	<li>Hayvanın baş ve boyun ortasına mıknatıs merkezinde olduğundan emin olun. Doğru konumuna ulaşılıncaya kadar gerekirse, hayvanın pozisyonunu ayarlayýn. Hayvan yeniden konumlandırdıysanız izci görüntüleri elde etmek için tarama tekrarlamak.</li>
	<li>"Saat uçuş (TOF) Anjiyo" serisi MRI tarayıcı konsol monitörden seçin ve ilk CCA tam anatomik yerini tespit etmek için bir 2D TOF anjiyo elde etmek. Aşağıdaki Tarama parametreleri kullanın: tekrarı zaman (TR) / echo zaman (TE) 22/4,87 ms, fiske vurmak açı = 90 °, görüş alanı (FOV) = 40 × 40 mm2, matris boyutu = 256 × 256, dilim kalınlığı uyarma (NEX) sayısı ile 0.6 mm = = 1. Not: TOF sırasının adı işportacı özgü olabilir. Kullanıcı konsol monitör bu parametreler ekleyebilirsiniz.</li>
	<li>Doygunluk band "açık" ve venöz sinyalleri önlemek için üst yerleştirilir emin olun. Not: Doygunluk grup için genellikle TOF dizisi ile geliyor. Doygunluk grup monitörde görünmüyorsa, hizmet kişi bildirin.</li>
	<li>TOF anjiyo kullanarak CCA bulmak sonra PC-MRI CCA ortasına görüntü boyutunda hedef ve öyle ki dilim kan akımı (Şekil 2a) yönüne dik orient.</li>
	<li>Solunum ve ECG çoğunluğuna net sinyal (Şekil 1b), monitör bilgisayarda gösterilen MRI sisteme bağlı ve "" "tetik modu" Mr tarayıcı konsol monitörden olmak tetikleyici modülü ayarlamak emin olun.</li>
	<li>Bilgisayardan izleme (Şekil 1b) PC-MRI tarama işlemini başlatmadan önce hayvanın fizyolojik yanıt istikrarlı olduğunu onaylayın. Perdeleme seçimleri "Tarih" monitör bilgisayar ve konsol monitör MRI inceden inceye gözden geçirmek içinde olduğundan emin olun. Not: Bu çalışmada kullanılan sistem izleme Fizyoloji işportacı tarafından sağlanır. En hayvan tarayıcılar için sağlanan ve işportacı özgü benzer Fizyoloji izleme sistemleri vardır.</li>
	<li>PC-MRI dizisi dizi MRI tarayıcı konsol monitörden seçin ve aşağıdaki parametreleri kullanarak geçişli PC-MRI taramaları gerçekleştirmek: TR/TE=15.55/4.51 ms (minimum TR ve TE), fiske vurmak açı 30 ° FOV = 40 × 40 mm2, matris boyutu = 192 × 192, dilim = kalınlığı 2 mm, (VENC) kodlama hızı = 120 cm/s =, = NEX ile 8. Tek yönlü VENC uçak aracılığıyla yönde kazanılır. Not: Tarama zamanı yaklaşık 8,5 min, ama gerçek tarama zamanı nedeniyle kardiyak döngüleri varyasyon hayvanlar arasında biraz farklı olabilir.</li>
	<li>CCA, başka bir konuma gibi çatallanma 4' değiştirilecek bölgedir faiz (ROI) 2.6-2,9 resim alma, yineleyin.</li>
	<li>Hayvan tarayıcıdan çıkarın ve tarama tamamlandığında onun kurtarma kafes dönmek.</li>
	<li>Hayvan vücut ısısını korumak için Isıtma lambası ile sıcak. Lamba en az 15 cm aşırı ısınmayı önlemek için hayvan uzakta tutmak.</li>
	<li>Ne zaman hayvan taşımak başlar ve bir yanıt bir kuyruk veya ayak çimdik olarak sergileyen, Isıtma lambası dön.</li>
</ol>3. veri işleme
<ol><li>MRG veri Digital Imaging and Communications Tıp (DICOM) biçimi veya diğer bir işportacı özgü biçimde kaydedin. İki tür ile Cine seriyi oluşturmak: bir büyüklük görüntüyü (anatomi) ve faz görüntü (Şekil 2b). Not: bazı tarayıcılar büyüklüğü görüntü × faz veya karmaşık farkı (farklı degradeler hız kodlama ile iki satın almalar arasında karmaşık çıkarma) olabilir, görüntü üçüncü türü oluşturulur. Üçüncü resim satıcı bağımlıdır.</li>
	<li>Görüntü verileri önceden işlemek. Gizli faz hız harita içine görüntü ve faz-ofset hata 5düzeltin. Not: Faz görüntü sinyal şiddeti gerçek hız değerleri yerine rasgele bir Bay birimi var, ama Bay sinyal şiddeti hız için doğrusal olarak orantılıdır. Faz görüntüden yüksek MRI sinyal genellikle VENC değeri olarak atanır ve minimum sinyal VENC ters değeri atanır. Matlab komut dosyası örneği için tamamlayıcı kod dosyasına 1 bakın veÇalıştır"düğmesine basın.</li>
	<li>ROI dikkatle CCA sınırını izleyerek betimlemek. Arter dilate ve çeşitli kardiyak aşamalarında oluşturmak gibi her zaman dilimi için ROIs betimlemek. Kan akımı arter yatırım getirisi, yani, hız × alan üzerinde entegre ederek hesaplayın. Her arter sonuçlandı kan akışının mL/s biriminde yapıldı. Matlab komut dosyası örneği için tamamlayıcı kod dosyasına 2 bakın veÇalıştır"düğmesine basın.</li>
</ol>

<ol>
	<li>Zakszewski, E., Schmit, B., Kurpad, S., Budde, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusion+imaging+in+the+rat+cervical+spinal+cord.">Diffusion imaging in the rat cervical spinal cord.</a> J Vis Exp. (98), (2015).</li><li>Wise, R. G., Al-Shafei, A. I., Carpenter, T. A., Hall, L. D., Huang, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+measurement+of+blood+and+myocardial+velocity+in+the+rat+heart+by+phase+contrast+MRI+using+sparse+q-space+sampling.">Simultaneous measurement of blood and myocardial velocity in the rat heart by phase contrast MRI using sparse q-space sampling.</a> J Magn Reson Imaging. 22 (5), 614-627 (2005).</li><li>Skardal, K., Espe, E. K., Zhang, L., Aronsen, J. M., Sjaastad, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-Directional+Evaluation+of+Mitral+Flow+in+the+Rat+Heart+by+Phase-Contrast+Cardiovascular+Magnetic+Resonance.">Three-Directional Evaluation of Mitral Flow in the Rat Heart by Phase-Contrast Cardiovascular Magnetic Resonance.</a> PLoS One. 11 (3), e0150536 (2016).</li><li>Peng, S. L., 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=Phase-contrast+magnetic+resonance+imaging+for+the+evaluation+of+wall+shear+stress+in+the+common+carotid+artery+of+a+spontaneously+hypertensive+rat+model+at+7T:+Location-specific+change,+regional+distribution+along+the+vascular+circumference,+and+reproducibility+analysis.">Phase-contrast magnetic resonance imaging for the evaluation of wall shear stress in the common carotid artery of a spontaneously hypertensive rat model at 7T: Location-specific change, regional distribution along the vascular circumference, and reproducibility analysis.</a> Magn Reson Imaging. 34 (5), 624-631 (2016).</li><li>Yu, H. Y., Peng, H. H., Wang, J. L., Wen, C. Y., Tseng, W. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantification+of+the+pulse+wave+velocity+of+the+descending+aorta+using+axial+velocity+profiles+from+phase-contrast+magnetic+resonance+imaging.">Quantification of the pulse wave velocity of the descending aorta using axial velocity profiles from phase-contrast magnetic resonance imaging.</a> Magn Reson Med. 56 (4), 876-883 (2006).</li><li>Peng, S. L., 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=Optimization+of+phase-contrast+MRI+for+the+quantification+of+whole-brain+cerebral+blood+flow.">Optimization of phase-contrast MRI for the quantification of whole-brain cerebral blood flow.</a> J Magn Reson Imaging. 42 (4), 1126-1133 (2015).</li><li>Peng, S. L., Shih, C. T., Huang, C. W., Chiu, S. C., Shen, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimized+analysis+of+blood+flow+and+wall+shear+stress+in+the+common+carotid+artery+of+rat+model+by+phase-contrast+MRI.">Optimized analysis of blood flow and wall shear stress in the common carotid artery of rat model by phase-contrast MRI.</a> Sci Rep. 7 (1), 5253 (2017).</li><li>Bozgeyik, Z., Berilgen, S., Ozdemir, H., Tekatas, A., Ogur, E. <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+the+effects+of+sildenafil+citrate+(viagra)+on+vertebral+artery+blood+flow+in+patients+with+vertebro-basilar+insufficiency.">Evaluation of the effects of sildenafil citrate (viagra) on vertebral artery blood flow in patients with vertebro-basilar insufficiency.</a> Korean J Radiol. 9 (6), 477-480 (2008).</li><li>Swampillai, J., Rakebrandt, F., Morris, K., Jones, C. J., Fraser, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acute+effects+of+caffeine+and+tobacco+on+arterial+function+and+wave+travel.">Acute effects of caffeine and tobacco on arterial function and wave travel.</a> Eur J Clin Invest. 36 (12), 844-849 (2006).</li><li>Neff, K. W., Horn, P., Schmiedek, P., Duber, C., Dinter, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=2D+cine+phase-contrast+MRI+for+volume+flow+evaluation+of+the+brain-supplying+circulation+in+moyamoya+disease.">2D cine phase-contrast MRI for volume flow evaluation of the brain-supplying circulation in moyamoya disease.</a> AJR Am J Roentgenol. 187 (1), W107-W115 (2006).</li><li>Stalder, A. F., 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=Quantitative+2D+and+3D+phase+contrast+MRI:+optimized+analysis+of+blood+flow+and+vessel+wall+parameters.">Quantitative 2D and 3D phase contrast MRI: optimized analysis of blood flow and vessel wall parameters.</a> Magn Reson Med. 60 (5), 1218-1231 (2008).</li><li>Dall'Armellina, 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=Improved+method+for+quantification+of+regional+cardiac+function+in+mice+using+phase-contrast+MRI.">Improved method for quantification of regional cardiac function in mice using phase-contrast MRI.</a> Magn Reson Med. 67 (2), 541-551 (2012).</li><li>Peng, S. L., Ravi, H., Sheng, M., Thomas, B. P., Lu, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Searching+for+a+truly+&amp;#34;iso-metabolic&amp;#34;+gas+challenge+in+physiological+MRI.">Searching for a truly &amp;#34;iso-metabolic&amp;#34; gas challenge in physiological MRI.</a> J Cereb Blood Flow Metab. 37 (2), 715-725 (2017).</li><li>Liu, P., 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=Quantitative+assessment+of+global+cerebral+metabolic+rate+of+oxygen+(CMRO2)+in+neonates+using+MRI.">Quantitative assessment of global cerebral metabolic rate of oxygen (CMRO2) in neonates using MRI.</a> NMR Biomed. 27 (3), 332-340 (2014).</li><li>Xu, F., Ge, Y., Lu, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noninvasive+quantification+of+whole-brain+cerebral+metabolic+rate+of+oxygen+(CMRO2)+by+MRI.">Noninvasive quantification of whole-brain cerebral metabolic rate of oxygen (CMRO2) by MRI.</a> Magn Reson Med. 62 (1), 141-148 (2009).</li><li>Lotz, J., Meier, C., Leppert, A., Galanski, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiovascular+flow+measurement+with+phase-contrast+MR+imaging:+basic+facts+and+implementation.">Cardiovascular flow measurement with phase-contrast MR imaging: basic facts and implementation.</a> Radiographics. 22 (3), 651-671 (2002).</li><li>Pelc, N. J., Herfkens, R. J., Shimakawa, A., Enzmann, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phase+contrast+cine+magnetic+resonance+imaging.">Phase contrast cine magnetic resonance imaging.</a> Magn Reson Q. 7 (4), 229-254 (1991).</li><li>Kim, 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=Accelerated+phase-contrast+cine+MRI+using+k-t+SPARSE-SENSE.">Accelerated phase-contrast cine MRI using k-t SPARSE-SENSE.</a> Magn Reson Med. 67 (4), 1054-1064 (2012).</li><li>Valvano, G., 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=Accelerating+4D+flow+MRI+by+exploiting+low-rank+matrix+structure+and+hadamard+sparsity.">Accelerating 4D flow MRI by exploiting low-rank matrix structure and hadamard sparsity.</a> Magn Reson Med. 78 (4), 1330-1341 (2017).</li></ol>

İfşa etmek bir şey yoktur.

PC-MRI kan akımı non-invaziv ve boyuna değerlendirilmesi için kapsamlı bir yaklaşım olacaktır. Biz PC-Mr sıçan CCA'ı gerçekleştirmek için bir protokol mevcut. Bu yordam herhangi bir hayvan MRI tarayıcı gerçekleştirmek kolay ve iyi tekrarlanabilirlik gösterir.
PC-Mr tekniği insan 10,11 hem de hayvan çalışmaları 4,12artan popülerlik kazanmıştır. Bu ça...

Manyetik rezonans görüntüleme (MRG) iç vücut yapıları ve Fizyoloji ayrıntılı bilgiler sağlar ve giderek preklinik hayvan çalışmaları ve klinik tanı için kullanılıyor çok yönlü bir yaklaşımdır. Hayvan modelleri çok önemli klinik dolaylı 1daha iyi anlamak için önemlidir. Hayvan modelleri oldukça anestezi gereksinimleri ve fizyolojik parametreler ile ilgili olarak insanlardan farklı olarak, MRI yordamlar kadar hayvanlar için duruma getirilmesi önem varsayar.
Faz kontrast MRI (PC-MRI) kan akımı gibi akışı ile ilgili parametreleri ölçmek için akan spin hızı kullanır MRI özel bir türüdür. PC-MRI ile hayvan modellerini kullanarak ana arterlerde akışı desen eşleme, kardiyovasküler patolojileri 2ışık yardımcı olur. Ayrıca, PC-MRI non-invaziv kan akımı patofizyolojik koşulları 3doğal değişiklikler izleyebilirsiniz. Bu gözlemler PC-MRI insan kalp-damar hastalıkları hayvan modellerinde kullanılan değerli bir yaklaşım olduğunu göstermektedir.
Bu raporda, miktar kan akımı sıçan ortak karotid arter (CCA) için bir yöntem açıklanmaktadır. Baş ve boyun oksijenli kan ile iki CCAs vermeniz ve karotid arter hastalığı inme önemli bir nedenidir. Bu nedenle, CCA içinde erken patoloji tespit çok önemli. Bu yordamı yaklaşık olarak 15 dk süresince ve potansiyel olarak hemodinami değişikliği, böyle ateroskleroz veya kontur ile koşulları uygulanabilir.

<table border="0" cellpadding="0" cellspacing="0" width="875">
	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">7T small animal MRI system</td>
			<td style="width:123px;">Bruker</td>
			<td style="width:344px;"></td>
			<td style="width:193px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Isoflurane&#160;</td>
			<td>Baxter</td>
			<td>1001936040</td>
			<td>anesthetic</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">ECG lead&#160;</td>
			<td>3M</td>
			<td>2269T</td>
			<td style="width:193px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Matlab</td>
			<td>MathWorks</td>
			<td></td>
			<td>sofeware for image processing</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Monitoring and gating system</td>
			<td>SA instruments, Inc</td>
			<td>Model 1030</td>
			<td style="width:193px;"></td>
		</tr>
	</tbody>
</table>

phase contrast magnetic resonance imaging in the rat common carotid artery

Faz kontrast manyetik rezonans görüntüleme (PC-MRI) kan akımı gibi akışı ile ilgili parametreleri ölçmek invaziv olmayan bir yaklaşımdır. Önceki çalışmalar anormal kan akımı sistemik vasküler riski ile ilişkili olabilir göstermiştir. Böylece, PC-MRI ilgili klinik araştırmalar için kardiyovasküler hastalıkların hayvan modellerden alınan verileri tercümesi kolaylaştırabilir. Bu raporda, biz ortak karotid arter (CCA) kan akımını ölçmek için cine-gated PC-MRI kullanarak fareler açıklayınız ve ilgili analiz yöntemleri tartışmak. Bu yordam bir imzalat, canlı hayvan gerçekleştirilebilir ve ötenazi işlemden sonra gerektirmez. Önerilen tarama parametreleri için kan akımı, sonuç mükemmel tekrarlanabilirlik gösteren tekrarlanabilir ölçümler verim. Bu makalede açıklanan PC-MRI yordam farmakolojik test, patofizyolojik değerlendirme ve serebral hemodinami değerlendirme için kullanılabilir.

Doğru dilim geometri PC-MRI deney başarısı sağlamak için çok önemli. Uçak doğru görüntü konumlandırma bir "yuvarlak" arter şekli (Şekil 3a) görüntüler ve arter ile daha az dik olduğunda bükülme, yani, arttıkça elde edilen arter geometri oval, kısmi hacmin daha büyük lider olur etkileri (Şekil 3b). Şiddetli kısmi ses efektleri kan akışı 6,<sup class="xref...

Watch this Scientific Journal Video about Phase Contrast Magnetic Resonance Imaging in the Rat Common Carotid Artery at JoVE.com

Phase Contrast Magnetic Resonance Imaging in the Rat Common Carotid Artery

Bu yordamı genel amacı fare ortak karotid arter kan akışında noninvaziv faz kontrast manyetik rezonans görüntüleme kullanarak ölçmek etmektir.

Faz kontrast manyetik rezonans görüntüleme sıçan ortak karotis arter

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

phase-contrast-magnetic-resonance-imaging-rat-common-carotid

Research

JoVE Journal

Medicine

9.4K Görüntüleme.  Chang Gung Memorial Hospital. Bu yordamı genel amacı fare ortak karotid arter kan akışında noninvaziv faz kontrast manyetik rezonans görüntüleme kullanarak ölçmek etmektir.

Video: Phase Contrast Magnetic Resonance Imaging in the Rat Common Carotid Artery

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.

Özellik Takibi Manyetik Rezonans Türetilmiş Miyokard Gerinim Değerlendirmesi

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 ...

Tıp

Training a Sophisticated Microsurgical Technique: Interposition of External Jugular Vein Graft in the Common Carotid Artery in Rats

Neointimal hyperplasia is one the primary causes of stenosis in arterialized veins that are of great importance in arterial coronary bypass surgery, in peripheral arterial bypass surgery as well as in arteriovenous fistulas.1-5 The experimental procedure of vein graft interposition in the common carotid artery by using the cuff-technique has been applied in several research projects to examine the aetiology of neointimal hyperplasia and therapeutic options to address it. 6-8 The cuff prevents vessel anastomotic remodeling and induces turbulence within the graft and thereby the development of neointimal hyperplasia.
Using the superior caval vein graft is an established small-animal model for venous arterialization experiment.9-11 This current protocol refers to an established jugular vein graft interposition technique first described by Zou et al., 9 as well as others.12-14 Nevertheless, these cited small animal protocols are complicated.
To simplify the procedure and to minimize the number of experimental animals needed, a detailed operation protocol by video training is presented. This video should help the novice surgeon to learn both the cuff-technique and the vein graft interposition. Hereby, the right external jugular vein was grafted in cuff-technique in the common carotid artery of 21 female Sprague Dawley rats categorized in three equal groups that were sacrificed on day 21, 42 and 84, respectively. Notably, no donor animals were needed, because auto-transplantations were performed. The survival rate was 100 % at the time point of sacrifice. In addition, the graft patency rate was 60 % for the first 10 operated animals and 82 % for the remaining 11 animals. The blood flow at the time of sacrifice was 8&plusmn;3 ml/min. In conclusion, this surgical protocol considerably simplifies, optimizes and standardizes this complicated procedure. It gives novice surgeons easy, step-by-step instruction, explaining possible pitfalls, thereby helping them to gain expertise fast and avoid useless sacrifice of experimental animals.

Neointimal hyperplasia is the primary cause of stenosis in arterialized veins. We propose a new protocol whereby the right external jugular vein is grafted using the cuff technique in the common carotid artery of Sprague Dawley rats. The survival rate was 100 % at the time point of sacrifice.

Sıçanlarda Common Karotid Arter interpozisyon Harici Juguler Ven Greft: Gelişmiş Mikrocerrahi Tekniği Eğitimi

Neointimal hyperplasia is one the primary causes of stenosis in arterialized veins that are of great importance in arterial coronary bypass surgery, in ...

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.

Manyetik Rezonans Görüntüleme, Volumetrik Bilgisayarlı Tomografi ve Ultrason Kullanımı Meme Kanseri Kemik metastazı bir Nude Rat Model Angiogenezis Multi-modal Görüntüleme

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

A Murine Model of Stent Implantation in the Carotid Artery for the Study of Restenosis

Despite the considerable progress made in the stent development in the last decades, cardiovascular diseases remain the main cause of death in western countries. Beside the benefits offered by the development of different drug-eluting stents, the coronary revascularization bears also the life-threatening risks of in-stent thrombosis and restenosis. Research on new therapeutic strategies is impaired by the lack of appropriate methods to study stent implantation and restenosis processes. Here, we describe a rapid and accessible procedure of stent implantation in mouse carotid artery, which offers the possibility to study in a convenient way the molecular mechanisms of vessel remodeling and the effects of different drug coatings.

A model of stent implantation in mouse carotid artery is described. Compared to other similar methods, this procedure is very rapid, simple and accessible, offering the possibility to study in a convenient way the vascular wall reaction to different drug-eluting stents and the molecular mechanisms of restenosis.

Restenoz Çalışmaları Karotis Arter Stent İmplantasyonu bir murin Modeli

Despite  the considerable progress made in the stent development in the last decades,  cardiovascular diseases remain the main cause of death in western ...

Adult Mouse Venous Hypertension Model: Common Carotid Artery to External Jugular Vein Anastomosis.

The understanding of the pathophysiology of brain arteriovenous malformations and arteriovenous fistulas has improved thanks to animal models. A rat model creating an artificial fistula between the common carotid artery (CCA) and the external jugular vein (EJV) has been widely described and proved technically feasible. This construct provokes a consistent cerebral venous hypertension (CVH), and therefore has helped studying the contribution of venous hypertension to formation, clinical symptoms, and prognosis of brain AVMs and dural AVFs. Equivalent mice models have been only scarcely described and have shown trouble with stenosis of the fistula. An established murine model would allow the study of not only pathophysiology but also potential genetic therapies for these cerebrovascular diseases.
We present a model of arteriovenous fistula that produces a durable intracranial venous hypertension in the mouse. Microsurgical anastomosis of the murine CCA and EJV can be difficult due to diminutive anatomy and frequently result in a non-patent fistula. In this step-by-step protocol we address all the important challenges encountered during this procedure. Avoiding excessive retraction of the vein during the exposure, using 11-0 sutures instead of 10-0, and making a carefully planned end-to-side anastomosis are some of the critical steps. Although this method requires advanced microsurgical skills and a longer learning curve that the equivalent in the rat, it can be consistently developed.
This novel model has been designed to integrate transgenic mouse techniques with a previously well-established experimental system that has proved useful to study brain AVMs and dural AVFs. By opening the possibility of using transgenic mice, a broader spectrum of valid models can be achieved and genetic treatments can also be tested. The experimental construct could also be further adapted to the study of other cerebrovascular diseases related with venous hypertension such as migraine, transient global amnesia, transient monocular blindness, etc.

We describe a method for creating a reliable model of cerebral venous hypertension in the adult mouse. This model has been widely described and tested in the rat. This new counterpart in the mice opens the possibility of using genetic modified animals and thereby broadens the applications of the model.

Yetişkin Fare Venöz Hipertansiyon Modeli: Dış Boyun Ven Anastomoza Ortak Karotis Arter.

The understanding of the pathophysiology of brain arteriovenous malformations and arteriovenous fistulas has improved thanks to animal models. A rat model ...

Vascular Balloon Injury and Intraluminal Administration in Rat Carotid Artery

The carotid artery balloon injury model in rats has been well established for over two decades. It remains an important method to study the molecular and cellular mechanisms involved in vascular smooth muscle dedifferentiation, neointima formation and vascular remodeling. Male Sprague-Dawley rats are the most frequently employed animals for this model. Female rats are not preferred as female hormones are protective against vascular diseases and thus introduce a variation into this procedure. The left carotid is typically injured with the right carotid serving as a negative control. Left carotid injury is caused by the inflated balloon that denudes the endothelium and distends the vessel wall. Following injury, potential therapeutic strategies such as the use of pharmacological compounds and either gene or shRNA transfer can be evaluated. Typically for gene or shRNA transfer, the injured section of the vessel lumen is locally transduced for 30 min with viral particles encoding either a protein or shRNA for delivery and expression in the injured vessel wall. Neointimal thickening representing proliferative vascular smooth muscle cells usually peaks at 2 weeks after injury. Vessels are mostly harvested at this time point for cellular and molecular analysis of cell signaling pathways as well as gene and protein expression. Vessels can also be harvested at earlier time points to determine the onset of expression and/or activation of a specific protein or pathway, depending on the experimental aims intended. Vessels can be characterized and evaluated using histological staining, immunohistochemistry, protein/mRNA assays, and activity assays. The intact right carotid artery from the same animal is an ideal internal control. Injury-induced changes in molecular and cellular parameters can be evaluated by comparing the injured artery to the internal right control artery. Likewise, therapeutic modalities can be evaluated by comparing the injured and treated artery to the control injured only artery.

This protocol uses a balloon catheter to cause an intraluminal injury on the rat carotid artery and henceforth elicit neointimal hyperplasia. This is a well-established model for studying the mechanisms of vascular remodeling in response to injury. It is also widely used to determine the validity of potential therapeutic approaches.

Sıçan Karotis Arter Vasküler Balon Yaralanma ve intraluminal İdaresi

The carotid artery balloon injury model in rats has been well established for over two decades. It remains an important method to study the molecular and ...

Dynamic Contrast Enhanced Magnetic Resonance Imaging of an Orthotopic Pancreatic Cancer Mouse Model

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) has been limitedly used for orthotopic pancreatic tumor xenografts due to severe respiratory motion artifact in the abdominal area. Orthotopic tumor models offer advantages over subcutaneous ones, because those can reflect the primary tumor microenvironment affecting blood supply, neovascularization, and tumor cell invasion. We have recently established a protocol of DCE-MRI of orthotopic pancreatic tumor xenografts in mouse models by securing tumors with an orthogonally bent plastic board to prevent motion transfer from the chest region during imaging. The pressure by this board was localized on the abdominal area, and has not resulted in respiratory difficulty of the animals. This article demonstrates the detailed procedure of orthotopic pancreatic tumor modeling using small animals and DCE-MRI of the tumor xenografts. Quantification method of pharmacokinetic parameters in DCE-MRI is also introduced. The procedure described in this article will assist investigators to apply DCE-MRI for orthotopic gastrointestinal cancer mouse models.

The goal of this protocol is to apply dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) for orthotopic pancreatic tumor xenografts in mice. DCE-MRI is a non-invasive method to analyze microvasculature in a target tissue, and useful to assess vascular response in a tumor following a novel therapy.

Ortotopik Pankreas Kanseri Fare Modeli Dinamik Kontrast Geliştirilmiş Manyetik Rezonans Görüntüleme

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) has been limitedly used for orthotopic pancreatic tumor xenografts due to severe ...

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.

Fare Serebral Hipoksi-iskemi sırasında Eşzamanlı PET / MR Görüntüleme

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

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.

7 Tesla, kardiyak manyetik rezonans görüntüleme

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 ...

In Vivo Gene Transfer to the Rabbit Common Carotid Artery Endothelium

The goal of this method is to introduce a transgene into the endothelium of isolated segments of both rabbit common carotid arteries. The method achieves focal endothelial-selective transgenesis, thereby allowing an investigator to determine the biological roles of endothelial-expressed transgenes and to quantify the in vivo transcriptional activity of DNA sequences in large artery endothelial cells. The method uses surgical isolation of rabbit common carotid arteries and an arteriotomy to deliver a transgene-expressing viral vector into the arterial lumen. A short incubation period of the vector in the lumen, with subsequent aspiration of the lumen contents, is sufficient to achieve efficient and durable expression of the transgene in the endothelium, with no detectable transduction or expression outside of the isolated arterial segment. The method allows assessment of the biological activities of transgene products both in normal arteries and in models of human vascular disease, while avoiding systemic effects that could be caused either by targeting gene delivery to other sites (e.g. the liver) or by the alternative approach of delivering genetic constructs to the endothelium by germ line transgenesis. Application of the method is limited by the need for a skilled surgeon and anesthetist, a well-equipped operating room, the costs of purchasing and housing rabbits, and the need for expertise in gene-transfer vector construction and use. Results obtained with this method include: transgene-related alterations in arterial structure, cellularity, extracellular matrix, or vasomotor function; increases or reductions in arterial inflammation; alterations in vascular cell apoptosis; and progression, retardation, or regression of diseases such as intimal hyperplasia or atherosclerosis. The method also allows measurement of the ability of native and synthetic DNA regulatory sequences to alter transgene expression in endothelial cells, providing results that include: levels of transgene mRNA, levels of transgene protein, and levels of transgene enzymatic activity.

In Vivo Gene Transfer to the Rabbit Common Carotid Artery Endothelium

This method is to introduce a transgene into the endothelium of rabbit carotid arteries. Introduction of the transgene allows the assessment of the biological role of the transgene product either in normal arteries or disease models. The method is also useful for measuring activity of DNA regulatory sequences.

Vivo Gen transferi için tavşan ortak Karotid arter endotel

The goal of this method is to introduce a transgene into the endothelium of isolated segments of both rabbit common carotid arteries. The method achieves ...