Visualization of intracerebral arteries by synchrotron radiation microangiography.

BACKGROUND AND PURPOSE Small cerebral vessels are a major site for vascular pathology leading to cerebral infarction and hemorrhage. However, such small cerebral vessels are difficult to visualize by using conventional methods. The goal of our study was the development of methodology allowing visualization of small cerebral arteries in rodents, suitable for experimental models. MATERIALS AND METHODS Using barium sulfate as a contrast material, we obtained microangiographic images of physiologic and pathologic changes consequent to cerebral infarction in mouse brain by monochromatic synchrotron radiation (SR). To achieve high-resolution and high-contrast images, we used a new x-ray camera with a pixel size of 4.5 microm, and we set the energy level at 37.5 keV, just above the K absorption of barium. RESULTS Small intracerebral arteries ( approximately 30 microm in diameter) were clearly visualized, as well as the cortical branches (50-70 microm in diameter) at the brain surface. The limit of detection appeared to be vessels approximately 10 microm in diameter. Compared with the noninfarcted side, the number of intracerebral arteries was dramatically decreased in the middle cerebral artery area affected by stroke. CONCLUSIONS These results indicate the potential of SR for evaluating pathologic changes in small cerebral arteries and for monitoring the impact of pro- and antiangiogenic therapeutic strategies.