Abstract 11454: Measurement of Pulmonary Arterial Flow Velocity in a High Flow Pulmonary Hypertension Rat Model Using Synchrotron Radiation Pulmonary Micro-Angiography
Background: High flow pulmonary hypertension (HFPH) in congenital heart disease is frequently complicated by irreversible vascular remodeling. Visualization of the micro-vasculature and the measurement of PBF velocity in HFPH rats would provide insights regarding the correlation between high PBF and vascular remodeling. In this study, we aimed to establish a method for utilizing synchrotron radiation pulmonary micro-angiography(SRPA) and measure the PBF velocity in an in-vivo HFPH rat model.
Method: SRPA was performed at the Photon Factory of the High Energy Accelerator Research Organization(Tsukuba, Japan). The advantages of synchrotron radiation derived X-rays are high spatial resolution due to increased photon density and straightness of beam. High density resolution is obtained with a high-sensitivity HARP (high-gain Avalanche Rushing amorphous Photoconductor) camera. The minimum identified diameter was 100 um. As an HFPH rat model, a fistula between the abdominal aorta and IVC was created. After 8 weeks, pulmonary micro-angiography was performed by transvenous infusion via the right jugular vein. The dynamic changes in density at the right main pulmonary artery (RPA), the superior branch to the inferior lobe (A6) and pulmonary arterioles (PA) were measured by the computer-imaging program ImageJ. The PBF velocity was calculated by the transit time of the contrast medium between points.
Result: The velocity of the proximal pulmonary artery (between RPA and A6) in HFPH rats was 111.5±23.5 mm/sec, and 117.0±13.5 mm/sec in the control. The velocity of the distal pulmonary artery (between A6 and PA) was significantly increased in HFPH rats as 71.7±23.2mm/sec, compared with the control as 9.4±2.6mm/sec.(p<0.05)
Conclusion: These results demonstrate the effectiveness of SRPA for visualizing the microvasculature in an in-vivo HFPH rat model. This newly developed technology may help investigate the mechanism of vascular remodeling associated with HFPH.
- © 2011 by American Heart Association, Inc.