Name: phase contrast magnetic resonance imaging in the rat common carotid artery
Uploaded: 2018-09-05T15:30:00.000+00:00
Duration: 7 min 2 s
Description: Watch this Scientific Journal Video about Phase Contrast Magnetic Resonance Imaging in the Rat Common Carotid Artery at JoVE.com

この作品は、省の科学と技術、台湾、MOST-105-2314-B-039-044-MY2 の許可番号の下からの補助金によって支えられました。

制度的ケアおよび使用委員会 (IACUC) 中国医科大学は、すべてのプロシージャを承認しました。
1. 動物の準備と監視
<ol><li>動物用 MRI スキャンを開始する前にスキャナーの部屋の外などの財布、鍵、クレジット カードなど磁気の影響受けやすいオブジェクトはすべてを残します。</li>
	<li>最初麻酔ラット (2 ヶ月歳雄 Sprague-dawley (SD) ラット, 280-350 g) に応じて、3-5 分間 5% イソフルラン (ISO) と酸素 (2 L/分) の混合物を使用して誘導ボックス。</li>
	<li>動物はリカンベントと尻尾や足指のピンチに応答を示さない、ISO 管理を中止し、動物をスキャニング ルームに転送します。</li>
	<li>先頭の腹臥位での MRI ベッドでラットを置き、麻酔を維持するための鼻の円錐形のデバイスを介して 2 〜 3% の ISO を提供します。</li>
	<li>動物の胴体の下で呼吸器枕センサーを配置することによって呼吸を監視します。</li>
	<li>呼吸器系と 40-50 ビート/分 (bpm) の間の呼吸のチェック センサーを接続します。</li>
	<li>シネ ゲート PC MRI 買収、右の前足に 1 つの電極を配置し、左後肢足、それぞれ (図 1 a)。</li>
	<li>心電図検査 (ECG) ケーブルを一緒にねじる。</li>
	<li>頭部の動きを制限するのには、動物を保護するのに耳バーと一口バー ヘッド ホルダーを使用します。</li>
	<li>磁石の中に体温を維持するために暖かい空気暖房システムやガーゼのパッドを使用します。</li>
	<li>R 波が (図 1 b)、心電図モニターを明確ことを確認し、スキャナーに動物を配置します。ボリューム コイルによって画像を取得するように動物の首の上に表面コイルを配置する必要はありません。</li>
</ol>2. MRI 買収
<ol><li>イメージ作成手順の全体の間に麻酔を維持するために 2-3% の ISO を使用します。生理反応および可能な限り一定に維持を継続的に監視します。</li>
	<li>動物はスキャナー内部に配置し、生理学的安定を続けている一度 MRI スキャンを開始します。本研究では 630 mT/m、勾配の強さで 7 T 小動物の MRI 装置を使用、小動物 MRI システムの他の電界強度を使用できます。</li>
	<li>MRI スキャナーのコンソール モニターから「ローカライザー」シーケンスを選択し、高速アクイジション ・ シーケンスがすべて例えば、高速スピンエコー法を使用してコロナ軸、を作成するすべての 3 つの向きに沿ってスカウト画像と矢状面画像を取得.これらの目的のスカウト画像撮像面を決定することです。</li>
	<li>動物の頭と首の中心は磁石の中心にことを確認します。正しい位置に到達するまで、必要に応じて動物の位置を調整します。動物が移動した場合は、スカウトの画像を得るためにスキャンを繰り返します。</li>
	<li>MRI スキャナーのコンソール モニターから「飛行時間 (tof 型) 血管造影」シーケンスを選択し、CCA の正確な解剖学的位置を確認するために最初の 2D TOF 血管造影を取得します。次のスキャン パラメーターを使用: 繰り返し時間 (TR)/時間 (TE) をエコー = 22/4.87 ms、反転の角度 90 °、視野 (FOV) を = = 40 × 40 mm2、マトリックス サイズ = 256 × 256、スライス厚 0.6 mm、励起 (NEX) の数 = 1。 注: TOF シーケンスの名前は、ベンダー固有かもしれません。ユーザーは、これらのパラメーターを監視コンソールに挿入できます。</li>
	<li>飽和帯が「オン」、静脈の信号からの干渉を避けるために上に配置ことを確認します。 メモ: 彩度バンドのそれ通常付属 TOF シーケンス。飽和帯は、モニターに表示されない、サービス担当者に連絡してください。</li>
	<li>TOF 血管造影を用いた CCA が見つかったら、CCA のセンターに PC MRI のイメージ面をターゲットし、スライスが (図 2 a) の血流の方向と直角になるように合わせます。</li>
	<li>呼吸と心電図のゲートの両方のモニター コンピューター (図 1 b) に明確なシグナルを示す MRI 装置に接続され MRI スキャナーのコンソール モニターから"on" 「トリガー モード」にするトリガー モジュールを設定を確認します。</li>
	<li>(図 1 b) 監視コンピューターから PC MRI スキャンを開始する前に、動物の生理が安定していることを確認します。ゲート選択をモニター コンピューターおよび MRI スキャナーのコンソール モニターの両方で「オン」を確認します。 注: 本研究で使用されるシステムを監視する生理学は、ベンダーによって提供されます。ほとんどの動物のスキャナーと同様生理モニタリング システムが提供およびベンダー固有です。</li>
	<li>MRI スキャナーのコンソール モニターから PC MRI シーケンスのシーケンスを選択し、次のパラメーターを使用してゲート PC MRI スキャンを実行: TR/TE=15.55/4.51 ms (最小値 TR と TE)、反転角度 = 30 °、FOV = 40 × 40 mm2、マトリックス サイズ 192 × 192、スライスを =厚さ 2 mm、(VENC) のエンコード速度を = = 120 cm/s、NEX = 8。単一指向性 VENC を面内方向で取得されます。 注: スキャン時間は約 8.5 分ですが実際のスキャン時間は心臓周期の変化による動物の間で異なる場合があります。</li>
	<li>利益 (率 ROI) の領域が分岐4など、CCA の別の場所に変更する場合は、画像集録の 2.6-2.9 手順を繰り返します。</li>
	<li>スキャナーから動物を削除し、スキャンが完了するとその回復ケージにそれを返します。</li>
	<li>体温を維持するために加熱ランプ、動物、暖かい。過熱を防ぐためには、動物からランプ、少なくとも 15 cm を保ちます。</li>
	<li>動物が移動を開始して尻尾や足指のピンチに応答を展示、加熱ランプが消えます。</li>
</ol>3. データ処理
<ol><li>デジタル画像と通信医学 (DICOM) 形式または他のベンダー固有の書式で MRI データを保存します。シネ画像の 2 種類のシリーズを生成: (解剖画像) の大きさの画像と位相画像 (図 2 b)。 注: いくつかのスキャナーの大きさ × 相イメージまたは複雑な違い (異なる流速エンコーディング グラデーションと 2 つの買収の間で複雑な減算) ことができる、画像の 3 番目のタイプが生成されます。3 番目のイメージは、ベンダーによって異なります。</li>
	<li>イメージ データの事前処理します。ひそかな位相速度マップにイメージし、位相オフセット エラー 5を修正します。 注: 位相画像が真の速度値の代わりに信号強度の任意氏ユニットが、MR 信号強度は速度に正比例。位相画像から最大の MRI 信号が通常 VENC の値として割り当てられ、最小信号 VENC の反対の値が割り当てられます。Matlab スクリプトの例の補足コード ファイル 1 を参照してくださいし、「実行」のボタンを押します。</li>
	<li>CCA の境界をトレースして慎重に投資収益率を描きます。動脈が拡張、心臓のさまざまなフェーズ中に構築、各時間枠の Roi を描きます。動脈投資収益率、すなわち速度 × エリアを統合することによって血流量を計算します。各動脈の結果血流は mL/秒の単位であった。Matlab スクリプトの例の補足コード ファイル 2 を参照してくださいし、「実行」のボタンを押します。</li>
</ol>

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開示するものがあります。

PC MRI は、血流の非侵襲的・縦断的評価の包括的なアプローチです。ラット CCA の PC MRI を実行するためのプロトコルを提案します。この手順は、任意の動物の MRI スキャナーを実行するは簡単です、良い再現性を示します。
PC MRI 技術は人間10,11として動物実験4,12の増加する人気を得?...

磁気共鳴画像 (MRI) は、体内構造と生理に関する詳細情報を提供し、前臨床動物実験、臨床診断のためにますます使用されている汎用性の高いアプローチです。動物モデルがかなり臨床的意義1の理解を深めるために不可欠です。麻酔の要件および生理学的なパラメーターに関して人間と動物モデルはかなり異なる、このような動物の mri 検査手順の最適化は、重要性を想定しています。
位相コントラスト MRI (PC-MRI) は、血流などの流れ関連パラメーターの定量化に流れるスピンの速度を使用して MRI の特殊なタイプです。PC-MRI、モデル動物を用いた主要な動脈の流れパターンのマッピングに助けることができる心臓血管病理2に光を当てる必要があります。また、PC mri 検査は非侵襲的病態生理学的条件3の血流固有の交替を監視できます。PC MRI が心血管疾患の動物モデルで使用することができます貴重なアプローチであることが示唆されました。
本報告では、ラットの総頸動脈 (CCA) における血流量の定量化手法について述べる。2 つの CCAs 供給酸素を含んだ血液を頭頸部と頚動脈疾患は脳卒中の主な原因。したがって、CCA の初期病理を検出は極めて重要です。この手順は、約 15 分の期間を持って、潜在的血行動態変化、このような動脈硬化や脳卒中との状況に適用できます。

<table><tbody><tr><td>7T small animal MRI system</td><td>Bruker</td><td></td><td></td></tr><tr><td>Isoflurane&amp;nbsp;</td><td>Baxter</td><td>1001936040</td><td>anesthetic</td></tr><tr><td>ECG lead&amp;nbsp;</td><td>3M</td><td>2269T</td><td></td></tr><tr><td>Matlab</td><td>MathWorks</td><td></td><td>sofeware for image processing</td></tr><tr><td>Monitoring and gating system</td><td>SA instruments, Inc</td><td>Model 1030</td><td></td></tr></tbody></table>

phase contrast magnetic resonance imaging in the rat common carotid artery

位相コントラスト mri (PC-) は、血流などの流れ関連パラメーターを定量化することができる非侵襲的アプローチです。以前の研究では、異常血流が全身の血管リスクと関連しているかもしれない示されています。したがって、PC MRI は、適切な臨床研究に心血管疾患の動物モデルから得られたデータの翻訳を促進できます。このレポートでは、シネ ゲート PC MRI を用いたラットの総頸動脈 (CCA) の血流を測定する手順を説明し、関連する分析方法について説明します。この手順では、ライブ、麻酔動物で行うことが、手順の後に安楽死を必要としません。スキャンに提案されたパラメーターは、再現性のある測定結果の優れた再現性を示す血流をもたらします。この資料に記載されている PC mri 検査の手順は、薬理学的試験、病態生理学的評価、および脳循環動態の評価に使用できます。

ジオメトリを正しいスライス PC MRI 実験の成功を確保するために極めて重要です。「ラウンド」動脈の形状 (図 3 a) をもたらす正確な平面位置と湾曲が増加、すなわち、それが動脈の小さい垂直のとき結果動脈ジオメトリと卵形、リード部分の大きいボリュームになります。効果 (図 3 b)。重度の部分容積効果血流<sup ...

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

この手順の全体的な目標は、非侵襲的位相コントラスト磁気共鳴イメージングを用いたラットの総頸動脈の血流を測定することです。

ラットの総頸動脈で位相コントラスト磁気共鳴イメージング

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

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Medicine

9.4K ビュー.  Chang Gung Memorial Hospital. この手順の全体的な目標は、非侵襲的位相コントラスト磁気共鳴イメージングを用いたラットの総頸動脈の血流を測定することです。

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

Focal Cerebral Ischemia Model by Endovascular Suture Occlusion of the Middle Cerebral Artery in the Rat

Stroke is the leading cause of disability and the third leading cause of death in adults worldwide1. In human stroke, there exists a highly variable clinical state; in the development of animal models of focal ischemia, however, achieving reproducibility of experimentally induced infarct volume is essential. The rat is a widely used animal model for stroke due to its relatively low animal husbandry costs and to the similarity of its cranial circulation to that of humans2,3. In humans, the middle cerebral artery (MCA) is most commonly affected in stroke syndromes and multiple methods of MCA occlusion (MCAO) have been described to mimic this clinical syndrome in animal models. Because recanalization commonly occurs following an acute stroke in the human, reperfusion after a period of occlusion has been included in many of these models. In this video, we demonstrate the transient endovascular suture MCAO model in the spontaneously hypertensive rat (SHR). A filament with a silicon tip coating is placed intraluminally at the MCA origin for 60 minutes, followed by reperfusion. Note that the optimal occlusion period may vary in other rat strains, such as Wistar or Sprague-Dawley. Several behavioral indicators of stroke in the rat are shown. Focal ischemia is confirmed using T2-weighted magnetic resonance images and by staining brain sections with 2,3,5-triphenyltetrazolium chloride (TTC) 24 hours after MCAO.

Surgical induction of ischemic brain damage in the rat is a widely used model for stroke research. Here we demonstrate the induction of focal cerebral ischemia by occlusion of the middle cerebral artery. Visualization of the resulting infarct by histological staining and magnetic resonance imaging is also shown.

ラット中大脳動脈の血管縫合閉塞による局所脳虚血モデル

Stroke is the leading cause of disability and the third leading cause of death in adults worldwide1. In human stroke, there exists a highly variable ...

神経科学

Optimized System for Cerebral Perfusion Monitoring in the Rat Stroke Model of Intraluminal Middle Cerebral Artery Occlusion

The translational potential of pre-clinical stroke research depends on the accuracy of experimental modeling. Cerebral perfusion monitoring in animal models of acute ischemic stroke allows to confirm successful arterial occlusion and exclude subarachnoid hemorrhage. Cerebral perfusion monitoring can also be used to study intracranial collateral circulation, which is emerging as a powerful determinant of stroke outcome and a possible therapeutic target. Despite a recognized role of Laser Doppler perfusion monitoring as part of the current guidelines for experimental cerebral ischemia, a number of technical difficulties exist that limit its widespread use. One of the major issues is obtaining a secure and prolonged attachment of a deep-penetration Laser Doppler probe to the animal skull. In this video, we show our optimized system for cerebral perfusion monitoring during transient middle cerebral artery occlusion by intraluminal filament in the rat. We developed in-house a simple method to obtain a custom made holder for twin-fibre (deep-penetration) Laser Doppler probes, which allow multi-site monitoring if needed. A continuous and prolonged monitoring of cerebral perfusion could easily be obtained over the intact skull.

Cerebral perfusion monitoring has been demonstrated to improve accuracy in ischemic stroke models. Technical difficulties often limit the use of this essential tool for cerebrovascular research. In this video, an optimized system is shown to obtain a single or multi-site hemodynamic monitoring during intraluminal middle cerebral artery occlusion in rats.

腔内中大脳動脈閉塞のラット脳卒中モデルにおける脳血流モニタリングのための最適化されたシステム

The translational potential of pre-clinical stroke research depends on the accuracy of experimental modeling. Cerebral perfusion monitoring in animal ...

医学

Diffusion Imaging in the Rat Cervical Spinal Cord

Magnetic resonance imaging (MRI) is the state of the art approach for assessing the status of the spinal cord noninvasively, and can be used as a diagnostic and prognostic tool in cases of disease or injury. Diffusion weighted imaging (DWI), is sensitive to the thermal motion of water molecules and allows for inferences of tissue microstructure. This report describes a protocol to acquire and analyze DWI of the rat cervical spinal cord on a small-bore animal system. It demonstrates an imaging setup for the live anesthetized animal and recommends a DWI acquisition protocol for high-quality imaging, which includes stabilization of the cord and control of respiratory motion. Measurements with diffusion weighting along different directions and magnitudes (b-values) are used. Finally, several mathematical models of the resulting signal are used to derive maps of the diffusion processes within the spinal cord tissue that provide insight into the normal cord and can be used to monitor injury or disease processes noninvasively.

The goal of this protocol is to obtain high-quality diffusion weighted magnetic resonance imaging (DWI) of the rat spinal cord for noninvasive characterization of tissue microstructure. This protocol describes optimizations of the MRI sequence, radiofrequency coil, and analysis methods to enable DWI images free from artifacts.

ラット頸部脊髄の拡散イメージング

Magnetic resonance imaging (MRI) is the state of the art approach for assessing the status of the spinal cord noninvasively, and can be used as a ...

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.

マウス脳低酸素性虚血の間に同時PET / MRIイメージング

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

A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia

MRI provides a sensitive and specific imaging tool to detect acute ischemic stroke by means of a reduced diffusion coefficient of brain water. In a rat model of ischemic stroke, differences in quantitative T1 and T2 MRI relaxation times (qT1 and qT2) between the ischemic lesion (delineated by low diffusion) and the contralateral non-ischemic hemisphere increase with time from stroke onset. The time dependency of MRI relaxation time differences is heuristically described by a linear function and thus provides a simple estimate of stroke onset time. Additionally, the volumes of abnormal qT1 and qT2 within the ischemic lesion increase linearly with time providing a complementary method for stroke timing. A (semi)automated computer routine based on the quantified diffusion coefficient is presented to delineate acute ischemic stroke tissue in rat ischemia. This routine also determines hemispheric differences in qT1 and qT2 relaxation times and the location and volume of abnormal qT1 and qT2 voxels within the lesion. Uncertainties associated with onset time estimates of qT1 and qT2 MRI data vary from &plusmn; 25 min to &plusmn; 47 min for the first 5 hours of stroke. The most accurate onset time estimates can be obtained by quantifying the volume of overlapping abnormal qT1 and qT2 lesion volumes, termed 'Voverlap' (&plusmn; 25 min) or by quantifying hemispheric differences in qT2 relaxation times only (&plusmn; 28 min). Overall, qT2 derived parameters outperform those from qT1. The current MRI protocol is tested in the hyperacute phase of a permanent focal ischemia model, which may not be applicable to transient focal brain ischemia.

A protocol for stroke onset time estimation in a rat model of stroke exploiting quantitative magnetic resonance imaging (qMRI) parameters is described. The procedure exploits diffusion MRI for delineation of the acute stroke lesion and quantitative T1 and T2 (qT1 and qT2) relaxation times for timing of stroke.

恒久的な脳虚血における脳卒中発症時間推定のための磁気共鳴イメージ投射プロトコル

MRI provides a sensitive and specific imaging tool to detect acute ischemic stroke by means of a reduced diffusion coefficient of brain water. In a rat ...

Quantitative MRI of Endothelial Permeability and (Dys)function in Atherosclerosis

Cardiovascular diseases are the leading causes of death worldwide. A permeable/leaky and dysfunctional endothelium is considered the earliest marker of vascular damage and thought to drive atherosclerosis. A method to identify these changes in vivo would be desirable in the clinic. Magnetic resonance imaging (MRI)-based tools and other technologies have enabled a profound understanding of the role of the endothelium in cardiovascular diseases and risk in vivo. There is, however, a need for reproducible and simple approaches for extracting quantifiable data reflective of endothelial damage from a single imaging study. A non-invasive, easy-to-implement, and quantitative MRI workflow was developed to acquire and analyze images that allow the quantification of two imaging biomarkers of arterial endothelial damage (leakiness/permeability and dysfunction). Here, the protocol describes the application of this method in the brachiocephalic artery of atherosclerotic ApoE-/- mice using a clinical MRI scanner. First, late gadolinium enhancement (LGE) and Modified Look-Locker Inversion Recovery (MOLLI) T1 mapping protocols to quantify endothelial leakage using an albumin-binding probe are described. Second, anatomic, and quantitative blood flow sequences to measure endothelial dysfunction, in response to acetylcholine are described. Importantly, the method outlined here allows the acquisition of high-spatial-resolution 3D images with large volumetric coverage enabling accurate segmentation of vessel wall structures to improve inter- and intra-observer variability and to increase reliability and reproducibility. Additionally, it provides quantitative data without the need for high-temporal resolution for complex kinetic modeling, making it model-independent and even allowing for imaging of highly mobile vessels (coronary arteries). Therefore, the approach simplifies and expedites data analysis. Finally, this method can be implemented on different scanners, can be extended to image different arterial beds, and is clinically applicable for use in humans. This method could be used to diagnose and treat patients with atherosclerosis by adopting a precision-medicine approach.

Quantitative MRI of Endothelial Permeability and Dysfunction in Atherosclerosis

We have developed an accurate, non-invasive, and easy-to-use method to quantify endothelial permeability and dysfunction in the arteries using Magnetic Resonance Imaging (MRI), named qMETRIC. This technique enables assessing vascular damage and cardiovascular risk associated with atherosclerosis in preclinical models and humans.

Cardiovascular diseases are the leading causes of death worldwide. A permeable/leaky and dysfunctional endothelium is considered the earliest marker of ...

生物工学

Ferric Chloride-induced Canine Carotid Artery Thrombosis: A Large Animal Model of Vascular Injury

Occlusive arterial thrombosis leading to cerebral ischemic stroke and myocardial infarction contributes to ~13 million deaths every year globally. Here, we have translated a vascular injury model from a small animal into a large animal (canine), with slight modifications that can be used for pre-clinical screening of prophylactic and thrombolytic agents. In addition to the surgical methods, the modified protocol describes the step-by-step methods to assess carotid artery canalization by angiography, detailed instructions to process both the brain and carotid artery for histological analysis to verify carotid canalization and cerebral hemorrhage, and specific parameters to complete an assessment of downstream thromboembolic events by utilizing magnetic resonance imaging (MRI). In addition, specific procedural changes from the previously well-established small animal model necessary to translate into a large animal (canine) vascular injury are discussed.

Here, we present the modifications necessary to a well characterized and commonly used small animal ferric chloride-induced (FeCl3) carotid artery injury model for use in a large animal vascular injury model. The resulting model can be utilized for pre-clinical trial assessment of both prophylactic and thrombolytic pharmacological and mechanical interventions.

塩化第二鉄によるイヌ総頚動脈血栓症: 血管損傷の大動物モデル

Occlusive arterial thrombosis leading to cerebral ischemic stroke and myocardial infarction contributes to ~13 million deaths every year globally. Here, ...

Middle Cerebral Artery Occlusion Allowing Reperfusion via Common Carotid Artery Repair in Mice

The ischemic stroke is a major cause of adult long-term disability and death worldwide. The current treatments available are limited, with only tissue plasminogen activator (tPA) as an approved drug treatment to target ischemic strokes. Current research in the field of ischemic stroke focuses on better understanding the pathophysiology of stroke, to develop and investigate novel pharmaceutical targets. Reliable experimental stroke models are crucial for the progression of potential treatments. The middle cerebral artery occlusion (MCAO) model is clinically relevant and the most frequently used surgical model of ischemic stroke in rodents. However, the outcomes of this model, such as lesion volume, are associated with high levels of variability, particularly in mice. The alternative MCAO model described here allows the reperfusion of the common carotid artery (CCA) and the increased perfusion of the middle cerebral artery (MCA) territory, using a tissue pad with fibrinogen-based sealant to repair the vessel, and the improved welfare of the mice by avoiding external carotid artery (ECA) ligation. This reduces the reliance on the Circle of Willis, which is known to be highly anatomically variable in mice. Representative data show that using this alternative surgical approach decreases the variability in lesion volumes between the traditional MCAO approach and the alternative approach described here.

Intraluminal filament occlusion of the middle cerebral artery is the most frequently used in vivo model of experimental stroke in rodents. An alternative surgical approach to allow common carotid artery repair is performed here, which allows the reperfusion of the common carotid artery and a full reperfusion to the middle cerebral artery territory.

マウスにおける一般的な頸動脈の修理で再灌流を許可する中大脳動脈閉塞

The ischemic stroke is a major cause of adult long-term disability and death worldwide. The current treatments available are limited, with only tissue ...

Cardiac Magnetic Resonance Imaging

Source: Frederick W. Damen and <a href="https://www.jove.com/author/Craig+J._Goergen">Craig J. Goergen</a>, Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
In this video, high field, small-bore magnetic resonance imaging (MRI) with physiological monitoring is demonstrated to acquire gated cine loops of the murine cardiovascular system. This procedure provides a basis for assessing left-ventricular function, visualizing vascular networks, and quantifying motion of organs due to respiration. Comparable small animal cardiovascular imaging modalities include high-frequency ultrasound and micro-computed tomography (CT); however, each modality is associated with trade-offs that should be considered. While ultrasound does provide high spatial and temporal resolution, imaging artifacts are common. For example, dense tissue (i.e., the sternum and ribs) can limit imaging penetration depth, and hyperechoic signal at the interface between gas and liquid (i.e., pleura surrounding the lungs) can blur contrast in nearby tissue. Micro-CT in contrast does not suffer from as many in-plane artifacts, but does have lower temporal resolution and limited soft-tissue contrast. Furthermore, micro-CT uses X-ray radiation and often requires the use of contrast agents to visualize vasculature, both of which are known to cause side effects at high doses including radiation damage&#160; and renal injury. Cardiovascular MRI provides a nice compromise between these techniques by negating the need for ionizing radiation and providing the user with the ability to image without contrast agents (although contrast agents are often used for MRI).
This data was acquired with a triggering Fast Low Angle SHot (FLASH) MRI sequence that was gated off of the R-peaks in the cardiac cycle and expiratory plateaus in respiration. These physiological events were monitored through subcutaneous electrodes and a pressure-sensitive pillow that was secured against the abdomen. To ensure the mouse was properly warmed, a rectal temperature probe was inserted and used to control the output of a MRI-safe heating fan. Once the animal was inserted into the bore of the MRI scanner and navigation sequences were run to confirm positioning, the gated FLASH imaging planes were prescribed and data acquired. Overall, high field MRI is a powerful research tool that can provide soft tissue contrast for the study of small animal disease models.

Cardiac MRI: Principle and Imaging

心臓磁気共鳴イメージング

Source: Frederick W. Damen and Craig J. Goergen, Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
In this video, high ...

Education

JoVE Science Education

工学

生物医学工学

 Phase Contrast Magnetic Resonance Imaging to Assess Blood Flow in the Arteries of a Rat

<a href='https://app.jove.com/v/57304/phase-contrast-magnetic-resonance-imaging-rat-common-carotid'>Source: Chiu, S., et al. Phase Contrast Magnetic Resonance Imaging in the Rat Common Carotid Artery. J. Vis. Exp. (2018).</a>This video demonstrates phase contrast magnetic resonance imaging (PC-MRI) to measure blood flow in the common carotid artery of a rat. After securing an anesthetized rat on the MRI bed and ensuring stable physiological parameters, the common carotid artery is scanned to capture images at defined intervals. Blood flow is then computed from these images to evaluate changes throughout the cardiac cycle.

Source: Chiu, S., et al. Phase Contrast Magnetic Resonance Imaging in the Rat Common Carotid Artery. J. Vis. Exp. (2018).This video demonstrates phase ...