Backprojection project is supported by Mecury Computer Systems, Inc.

Professor Miriam Leeser Northeastern University, Associate Professor
Professor Eric Miller Northeastern University, Associate Professor
Marc Trepanier Mecury Computer System, Product Planning System Engineer
Srdjan Coric Northeastern University, Graduate Student
Haiqian Yu Northeastern University, Graduate Student


Implement backprojection in reconfigurable hardware.


Backprojection is the most common algorithm used in the tomographic reconstruction of a clinical data. An everyday example of tomographic is the medical x-ray CAT scan: a person is x-rayed from various angles and the two-dimensional density of the person can be "reconstructed" by using backprojection. However, the restoration is computation consuming. Our goal is using hardware to implement backprojection algorithm thus greatly decrease the processing time.

For more information about backprojection & tomography, see Here.

Hardware Description

Phase I:

Annapolis Wildstar with 3 Xilinx Virtex FPGA Processing Element-XCV1000 and 40 Mbyte of Synchronous ZBT SRAM

Phase II:

Annapolis Firebird with Xilinx Virtex FPGA Processing Elements-XCV2000E and 32Mbyte of Synchronous ZBT SRAM.

Data Flow Diagram

Basically, what we do here is to accumulate the corresponding backprojection value of different angle for each pixel. The detailed algorithm can be found here.
Click Here for the hardware data flow

 Detailed Information

Simple architecture & Advanced architecture using Wildstar (Finished)

Simple architecutre & Advanced architecutre using Firebird (Current)

Some Result

Backprojection result: Software floating point vs. Hardware fixed point

Processing acceleration:
    Using Simple Architecture & Using Advanced Architecture


S. Coric, M. Leeser, E. Miller, M. Trepanier, "Parallel-Beam Backprojection: An FPGA Implementation Optimized for Medical Imaging", Tenth ACM Int. Symposium on FPGA, Monterey, CA, USA. Feb.24-26, 2002

Last modified Mar. 27, 2002 by Haiqian Yu