Abstract
Rodent models of cardiac pathophysiology represent a valuable research tool to investigate mechanism of disease as well as test new therapeutics.1 Echocardiography provides a powerful, non-invasive tool to serially assess cardiac morphometry and function in a living animal.2 However, using this technique on mice poses unique challenges owing to the small size and rapid heart rate of these animals.3 Until recently, few ultrasound systems were capable of performing quality echocardiography on mice, and those generally lacked the image resolution and frame rate necessary to obtain truly quantitative measurements. Newly released systems such as the VisualSonics Vevo2100 provide new tools for researchers to carefully and non-invasively investigate cardiac function in mice. This system generates high resolution images and provides analysis capabilities similar to those used with human patients. Although color Doppler has been available for over 30 years in humans, this valuable technology has only recently been possible in rodent ultrasound.4,5 Color Doppler has broad applications for echocardiography, including the ability to quickly assess flow directionality in vessels and through valves, and to rapidly identify valve regurgitation. Strain analysis is a critical advance that is utilized to quantitatively measure regional myocardial function.6 This technique has the potential to detect changes in pathology, or resolution of pathology, earlier than conventional techniques. Coupled with the addition o
f three-dimensional image reconstruction, volumetric assessment of whole-organs is possible, including visualization and assessment of cardiac and vascular structures. Murine-compatible contrast imaging can also allow for volumetric measurements and tissue perfusion assessment.
心脏的病理生理的啮齿类动物模型代表一个有价值的研究工具，调查机制，疾病以及测试新疗法1超声心动图提供了强大的，非侵入性工具，连续评估一个活生生的动物的心脏形态学和功能。，但是，使用这种技术对小鼠对由于这些动物的体积小，心率加快，独特的挑战。直到最近，很少超声系统能够执行质量超声心动图对小鼠，和那些普遍缺乏的图像分辨率和帧速率要获得真正的定量测量。新发布的系统，如VisualSonics Vevo2100为研究者提供新的工具，以谨慎和非侵入性的调查小鼠的心脏功能。该系统生成高分辨率的图像，并提供与人类患者所使用的类似的分析能力。虽然彩多普勒已超过30年在人类的，这个宝贵的技术最近才得以在啮齿类动物超声。4,5彩多普勒超声心动图，具有广阔的应用前景，包括能够
快速评估船只在通过阀门的流量方向性，并迅速查明瓣关闭不全。应变分析是一个重要的的进步，是利用定量测量区域的心肌功能。6这项技术有可能检测病理变化，或病理的决议，较常规技术。再加此外，整个器官的三维图像重建容积评估是可能的，包括心脏和血管结构的可视化和评估。鼠兼容相衬成像，还可以让体积测量和组织灌注的评估。
Protocol
1. Preparation for imaging
1. Begin by securing an isoflurane anesthetized mouse to an animal-handling platform
in the supine position. Place a nose cone over the animal's nose and mouth to
deliver 0.5-1% isoflurane to maintain the anesthesia.
2. Secure the paws of the mouse to the electrode pads with conducting gel. Ensure
appropriate ECG, body temperature at 37 °C and check respiratory rate for
physiological assessment during imaging.
3. Apply depilatory cream to the chest and upper abdomen of the mouse.
4. After 2 minutes, use wet gauze remove to the cream.
1。成像的制备
1. 异氟醚麻醉鼠标的动物仰卧位处理平台的开始。放置一个以上的动物提供0.5-1％异氟
醚维持麻醉的鼻子和嘴巴的鼻锥。
2. 鼠标的爪子安全进行凝胶电极片。确保适当的心电图，身体的温度在37℃，呼吸频
率，在成像检查生理评估。
3. 脱毛霜鼠标的胸部和上腹部。
4. 2分钟后，用湿纱布取出的奶油。
2. Left parasternal long axis view
1. Once the mouse has been prepared for imaging, tilt the left side of the platform to
rotate the animal handling platform 30 degrees about the anterioposterior axis.
2. Orient the transducer in the vertical position and rotate 10 degrees counterclockwise
with the notch pointed toward the posterior of the mouse.
3. Next, while in the two-dimensional viewing/video "B-mode", lower the transducer
over the left parasternal line until the heart comes into view. Once the pulmonary artery comes into view, collect images and store them.
4. Still in B-mode, move the transducer left or right until the aortic outflow and apex
come into view. Some rotation of the probe may be necessary to ensure proper
alignment with the long axis of the heart.
5. Use video capture to obtain data for subsequent analysis. Minimize the field of
view to ensure the highest frame rate possible for downstream regional strain
analyses. Each time a video is captured, the prior 100 frames are saved.
6. Switch to the Color Doppler mode by selecting "Color Doppler." Although Color
Doppler has been available for over 30 years in humans, this technology has only recently been possible in rodent ultrasound.
7. To quickly monitor the direction and velocity of blood flow, the Doppler window
overlay digitizes the flow from red, indicating flow toward the probe, to blue,
indicating flow away from the probe. Acquire necessary images by image capture. 8. Once all Color Doppler data has been obtained, switch the instrument to Pulse-Wave
Doppler Mode, the one-dimensional view used to digitally assess blood flow direction and velocity over time.
9. Move the probe slightly toward the head of the mouse until the pulmonary artery
comes into view. In the context of heart failure, PW/Color Doppler measurements of the pulmonary artery can be used as a surrogate for right heart function. Capture images as desired.
2。左胸骨旁长轴
1. 一旦鼠标已经准备成像，左侧倾斜的平台，对anterioposterior轴30度旋转的动物处
理平台。
2. 东方的垂直位置传感器和旋转10度逆时针的缺口对准鼠标后。
3. 下一步，而在二维观看/视频“B模式”，降低左胸骨旁线传感器，直到心脏映入眼帘。
一旦肺动脉映入眼帘，采集图像，并将其储存。
4. 不过在B模式下，移动传感器的左或右，直到主动脉流出和Apex映入眼帘。一些可
能是必要的，以确保正确对齐的心脏长轴旋转探头。
5. 使用视频采集，以供后续分析获得的数据。最小化的视野，以确保最高的帧速率可能
对下游区域应变分析。每个视频捕获时，前100帧将被保存。
6. 切换选择“彩多普勒彩多普勒模式。”虽然彩多普勒已超过30年在人类的，这项
技术最近才得以在啮齿类动物超声。
7. 快速监视的方向和血流速度，多普勒窗口覆盖的数字化从红的流量，流向探头，蓝
表示，说明流量远离探头。获得必要的图像，通过图像采集。
8. 已获得，一旦所有的彩多普勒数据，仪器开关脉冲波多普勒模式下，一维的观点，
用于数字评估血流方向和速度随着时间的推移。
9. 走向探针头鼠标稍微直到肺动脉映入眼帘。在心力衰竭的情况下，PW /彩多普勒测
量肺动脉可作为右心功能的替代品。捕捉所需的图像。
3. Left mid-papillary short axis
1. Short-axis echocardiography provides a view of the entire left ventricle contracting in
a concentric fashion, and allows for accurate B- and M-mode based assessment of
cardiac function and morphometry.
2. In B-mode, from the parasternal long axis view, rotate the transducer orthogonal to
the left parasternal long axis view at the level of the papillary muscle.
3. Ensure proper location along the length of the left ventricle. Both papillary muscles
should be clearly visible and separated, giving a horizontal cross-sectional view.
4. With the M-mode, place the sample volume through the center of the ventricle and
acquire data.
5. If desired, attach, initiate and utilize the 3-dimensional motor to obtain the images
necessary for complete 3-dimensional reconstruction.
6. Physiology settings, including respiratory rate and ECG, are set for gating 3D image
capture in end-diastole
7. The 3D imaging motor is initiated for image capture in end-diastole.
8. Once the end-diastole 3D capture is complete, physiology settings for respiratory
rate and ECG are set for gating the 3D image capture in end-systole
9. The 3D imaging motor is initiated for image capture in end-systole.
3。左乳头中短轴
tilt
1. 短轴超声心动图提供了一个同心时尚承包整个左心室，并允许准确的B型和M - 心脏
功能和形态学基础的评估模式。
2. 在B模式中，从胸骨旁长轴切面，左胸骨旁乳头肌水平长轴正交旋转传感器。
3. 确保适当的位置沿长度左心室。这两个乳头肌应清晰可见，分开，给人一种水平的横
断面。
4. 与M -模式，将通过心室中心的样本量和采集数据。
5. 如果需要的话，附加，启动和利用三维电机，以获得完整的三维重建所需的图像。
6. 生理学设置，包括呼吸频率及心电图，浇注的三维图像采集舒张末期
7. 三维成像电机启动在舒张末期图像捕捉。
8. 一旦舒张末期3D捕捉完成后，呼吸频率及心电图的生理设置被设置为浇注在年底收
缩的三维图像捕捉
9. 三维成像电机启动最终收缩捕捉的图像。
4. Subcostal (four chamber) view
1. The subcostal view is the best approach for measuring competency and pressure
gradients across the mitral valve.
2. Tilt the upper left corner of the platform all the way down. Orient the transducer
toward the right shoulder of the mouse, maintaining the short axis rotation of the probe.
3. In B-mode, lower the transducer over the upper abdomen so that it rests below the
diaphragm. Visualize the mitral valve using color Doppler as described before.
4。肋下（四腔）查看
1. 肋下的看法是最好的方法能力和压力梯度测量二尖瓣。