Abstract 13699: Synchrotron Radiation Pulmonary Micro-Angiography for Measurement of Pulmonary Arterial Flow Velocity in a High Pulmonary Flow Rat Model
Background: High pulmonary flow (HPF) is frequently complicated by irreversible vascular remodeling. Visualization of the micro-vasculature and the measurement of pulmonary blood flow (PBF) velocity in HPF rats would provide insights regarding the correlation between high PBF and vascular remodeling. Previously, we established a method for visualizing pulmonary microvasculature in rat model by using synchrotron radiation pulmonary micro-angiography (SRPA). In this study, we aimed to establish the PBF measurement with SRPA and validate its reliability compared with the echocardiographic data of HPF rats.
Method: SRPA was performed at the Photon Factory of the High Energy Accelerator Research Organization (Tsukuba, Japan). As an HPF rat model, a fistula between the abdominal aorta and IVC was created in Wistar rats. After 8 weeks, pulmonary micro-angiography was performed. The dynamic changes of density detected by SRPA at the right lower pulmonary artery (PA) were measured by the density measurement software Gray-val (Library Inc. Japan). The PBF velocity was calculated by the transit time of contrast medium in the PA. Echocardiography was Also performed by Vevo®2100 (VisualSonics Inc. Canada) to evaluate the peak pulmonary flow velocity and cardiac function.
Result: The velocity of the PA measured by SRPA in HPF rats was significantly increased compared with the control (82.3 ± 8.5 mm/sec vs. 46.1 ± 4.3 mm/sec, p<0.05). The Peak velocity of the main PA measured by echocardiography was also significantly increased in HPF rats compared with the control (1572 ± 105.8 mm/sec vs. 1128.3 ± 34.2 mm/sec). The left ventricular ejection fraction was significantly decreased in HPF rats (64.0 ± 2.0 vs. 70.9 ± 0.3%) and the left ventricular systolic diameter was significantly increased in HPF rats (4.8 ± 0.1 vs. 4.19 ± 0.2mm).
Conclusion: In this study, increased PBF in the HPF rat model was detected by both echocardiography and SRPA. SRPA was useful for measuring the PBL velocity, especially at distal vasculature. This newly developed technology may help to investigate the mechanism of vascular remodeling associated with HPF. Further study about pathological change in pulmonary arterioles and endothelial cell injury is necessary.
- © 2012 by American Heart Association, Inc.