Vevo lazr multi modality imaging platform

Rats were anesthetized using 3% isoflurane, and echocardiography was performed using a FUJIFILM VisualSonics Vevo LAZR Multimodality Imaging Platform with a Transducer LZ250 transducer. The left ventricle internal diameter was determined.

For echocardiography, zebrafish were anaesthetized with 0.02% MS-222 and fixed on a sponge in the supine position. The echocardiography was performed using the Vevo LAZR Multi-modality Imaging Platform (FUJIFILM VisualSonics) under B-mode (50 MHz, 77 fps) at 20°C as previously described (González-Rosa et al. 2014 (link), Hein et al. 2015 (link), Wang et al. 2017 (link)). Ejection fraction (EF, which indicates the volumetric output of blood from the heart) and fractional shortening (FS, which indicates the systolic function of the heart) were acquired using a plug-in of Vevo LAB (Vevo Strain) under B-mode images. The window was set to be 300 frames long, starting with diastalsis.

The hearts of wild-type AB strain zebrafish aged 15 months were cryoinjured, and then 6 fish (3 female and 3 male) were maintained in untreated fish water or in fish water containing 50 µM metformin. Each fish was anesthetized in water containing 0.01 % tricaine for ~ 3 min, after which it was placed ventral side up in a 0.5 cm × 5 cm groove cut in the middle of a piece of damp sponge in a beaker. Echocardiography was acquired using a Vevo LAZR Multi-modality Imaging Platform (FUJIFILM VisualSonics) in B-mode (50 MHz, 77 fps), with an ultrasound transducer fixed above the ventral side of the zebrafish and parallel to the longitudinal axis (LAX) plane. Color Doppler (40 MHz, 25 kHz PRF) was used to precisely measure the direction of blood inflow from the atrium. The whole imaging procedure took no more than 10 min. The fish was then returned to fresh fish water where it could recover from the anesthetic. Each fish was maintained in fish water until the next time point when echocardiography was conducted again. B-mode images were analyzed using a Vevo LAB (Vevo Strain) plug-in, and the window was set to be 300 frames long, starting with the end-diastole. Ventricular chamber dimensions were obtained from B-mode images in the LAX view, and systolic function was measured as fractional shortening and ejection fraction.