Dual-Modality Micro-CT with Poly-Capillary X-ray Optics

Tuesday, January 10, 2006 - 9:00am - 9:45am
EE/CS 3-180
Erik Ritman (Mayo Clinic)
Conventional attenuation-based x-ray micro-CT is limited in terms of the image contrast it can convey for differentiating different
tissue components, spaces and functions. Multi-modality imaging (e.g., radionuclide emission and/or x-ray scatter) can expand the
information that can be obtained about those tissue aspects, but a challenge is accurate co-registration of the multiple images needed
for the CT image data to be used to enhance the other modality's specificity. Poly-capillary optics consist of bundles of hollow glass
capillaries (nominally 25µm in lumen diameter) which can bend x-rays or gamma rays by virtue of reflection of the photons within those
capillaries. This approach serves both to exclude unwanted radiation (i.e., collimates the radiation) and to allow passage of radiation
along accurately described paths - either parallel or focused. As both x-rays from an external x-ray source and from gamma ray emitters
and x-ray scatterers within an object can be imaged with this approach, the images from these three modalities are perfectly
co-registered. This allows use of the x-ray image to provide for attenuation correction of the internally generated radiation, as well
as restricting that emission to specific anatomic structures and spaces by virtue of a priori physiological knowledge.