Visualsonics ms400

At the 14th day after irradiation, echocardiography was used for heart wall dimension measurements and to measure left ventricular ejection fraction (LVEF) by a well-trained investigator. The study measured the LV diastole and systole according to the main laws of the American Society of Echocardiography (Lang et al., 2015 (link)). Echocardiography was performed with a high-frequency transducer probe (VisualSonics MS400, FUJIFILM VisualSonics, Inc. Toronto, Canada, with a frequency range of 18–38 MHZ). Initially, the rats were anesthetized with 3% isofurane (80% oxygen) and placed supinely on an electrical heating pad (37°C). During examination, the isofurane concentration was reduced to a minimum (1–2%) to obtain constant and comparable heart rates shown by ECG. Additionally, prewarmed ultrasound gel was applied to reduce cold stimulation to small animals. Interventricular septum and para-sternal short-axis images were acquired. Conventional indicators were measured from the LV M-mode in short-axis view for three consecutive cardiac cycles and then averaged; these indicators included the LV wall thickness, diameter, fractional shortening (FS [LV end-diastolic diameter−LV end-systolic diameter]/LV end-diastolic diameter×100), and ejection fraction (EF [LV end-diastolic volume−LV end-systolic volume]/LV end-diastolic volume×100).

A high-frequency, high-resolution digital imaging platform (Vevo^® 2100 Imaging System, FUJIFILM Visual Sonics Inc., Toronto, ON, Canada) was used on anesthetized mice (isoflurane in O₂; 3% for induction and 1.5% for maintenance; Forene, Abbvie, North Chicago, IL, USA)) to assess pulse wave velocity measurements of the abdominal aorta (aPWV). Body temperature was maintained at 36–38 °C and mice were continuously monitored and isoflurane concentrations were titrated (1–2%) during imaging to maintain heart rates at 500 ± 50 beats/min (bpm). PWV measurements were performed with a 24 MHz transducer (Visual Sonics MS400, FUJIFILM Visual Sonics, Inc., Toronto, ON, Canada) using the method developed by Di Lascio et al. [23 (link)]. In brief, a 24 MHz transducer was placed on the abdomen of the animal and B-mode images of 700 frames per second of the abdominal aorta and carotid artery were obtained using the EKV imaging mode to measure aortic diameter (D). A PW Doppler tracing was obtained to measure aortic flow velocity (V). Velocity was plotted against the natural logarithm of the diameter, and the slope of the linear part of the resulting ln(D)-V loop was used to calculate PWV values using MATLAB v2014 (Mathworks, Natick, MA, USA).

A high-frequency, high-resolution digital imaging platform (Vevo^® 2100 Imaging System, FUJIFILM VisualSonics Inc., Toronto, ON, Canada) was used on anesthetized mice (induction with 1.5% in O₂, 1l/min and maintenance with 3.5% in O₂, 1 L/min, Forene, Abbvie, Lake Bluff, IL, USA). to assess pulse wave velocity measurements of the abdominal aorta (aPWV). Body temperature was maintained at 36–38 °C and mice were continuously monitored, and isoflurane concentrations were titrated (1–2%) during imaging to maintain heart rates at 500 ± 50 beats/minute (bpm). PWV measurements were performed with a 24-MHz transducer (VisualSonics MS400, FUJIFILM VisualSonics, Inc., Toronto, ON, Canada) using the method developed by Di Lascio et al., (2014) [57 (link)]. In short, a 24-MHz transducer was positioned on the abdomen of the animal. B-mode images of 700 frames-per-second of the abdominal aorta and carotid artery were obtained using the EKV imaging mode to measure the aortic diameter (D). A pulse wave doppler tracing was obtained to measure aortic flow velocity (V). Velocity was plotted against the natural logarithm of the diameter, and the slope of the linear part of the resulting ln(D)-V loop was used to calculate PWV values using Matlab v2014 (MathWorks).