Abstract
Quantitative three dimensional analysis is possible, in principle, by PIXE tomography. But, the inherent problems in quantitation, restrictions on the sample geometry and preparation, and specimen damage due to high fluences make this method unsuitable for many biological samples. The specimen under investigation, a murine artery, was around a millimeter in diameter and the induced atherosclerotic lesion was spread few hundreds of micrometers across the length of the artery. Since no tomographic experiments were possible, we chose to do the 3D quantitative analysis by means of PIXE Stacking. Herein, thin serial sections of the specimen are prepared and measured by conventional ion beam techniques. The resultant two dimensional quantitative element maps are stacked and aligned to reconstruct a quantitative volume of the specimen. Although the reconstructed dimension has poorer spatial resolution as compared with the measured dimensions, new information can still be gained from it. The three dimensional element distribution of the atherosclerotic lesion shows calcification on the outer surface of the artery, which otherwise would not have been easily visible in the two dimensional analysis.
