MS for Srdjan Coric


Title:

Parallel Beam Backprojection: An FPGA Implementation Optimized for
Medical Imaging

Abstract:

Medical image processing in general and computerized tomography (CT)
in particular can benefit greatly from hardware acceleration.  This
application domain is marked by computationally intensive algorithms
requiring the rapid processing of large amounts of data.  To date,
reconfigurable hardware has not been applied to this important area.
For efficient implementation and maximum speedup, fixed-point
implementations are required.  The associated quantization errors must
be carefully balanced against the requirements of the medical
community.  Specifically, care must be taken so that very little error
is introduced compared to floating-point implementations and the
visual quality of the images is not compromised.

An FPGA implementation of the parallel-beam backprojection algorithm
used in CT for which all of the above requirements are met is
presented in this thesis.  A number of quantization issues arising in
backprojection are explored with concentration on minimizing error
while maximizing efficiency.  The presented implementation shows
significant speedup over software versions, and is more flexible than
an ASIC implementation.  Furthermore, this FPGA implementation can
easily be adapted to medical sensors with different dynamic ranges as
well as to tomographic scanners employed in a wider range of
application areas including nondestructive evaluation and baggage
inspection in airport terminals.