  In pathology protocols, each tissue block can generate a large number of
sections making it impractical to analyze every section. X-ray microscopy that
provides a rapid survey of intact tissue blocks can help pinpoint the relevant
structures in 3D space for subsequent analysis, and thus reduce workload and
enable further automation downstream. Unlike dedicated virtual histology
studies by traditional micro computed tomography (CT), routine scout imaging is
constrained by a time window of minutes and minimal sample handling to avoid
interfering with the pathology protocols. Traditional micro CT was not able to
meet the requirements due to lengthy study times or sample alteration by the
introduction of x-ray contrast agents. A form of x-ray tomosynthesis used in
security screening was found to be efficient for rapid microscopy of unstained
samples. When compared to a commercial micro CT scanner, it provided a 10-fold
increase in imaging speed and a 4.8-fold increase in contrast-to-noise ratio.
We report the results from a variety of human and animal tissue samples, where
it served as an integral step of pathology protocols. In cases of vascular
disease, it provided quantitative measurements of calcification in intact
samples, which were difficult to obtain by standard pathology procedures. The
prospect of continuous and automated screening of many samples in an
assembly-line approach is discussed.
