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Optimizing the acquisition time profile for a planar integral measurement system with a spinning slat collimator
Author(s) -
Earl R. D.,
Zeng G. L.,
Zhang B.
Publication year - 2005
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.2008447
Subject(s) - collimator , weighting , dwell time , planar , iterative method , iterative reconstruction , optics , spinning , computer science , algorithm , physics , computer vision , acoustics , engineering , clinical psychology , computer graphics (images) , medicine , mechanical engineering
This article considers a hypothetical imaging device with a spinning slat collimator that measures parallel‐planar‐integral data from an object. This device rotates around the object 180° and stops at N positions uniformly distributed over this 180°. At each stop, the device spins on its own axis 180° and acquires measurements at M positions uniformly distributed over this 180°. For a fixed total imaging time, an optimal distribution of the scanning time among the data measurement locations is searched by a nonlinear programming method: Nelder‐Mead's simplex method. The optimal dwell time is approximately proportional to the weighting factor in the backprojector of the reconstruction algorithm. By using an optimal dwell‐time profile, the reconstruction signal‐to‐noise ratio has a gain of 23%–24% for the filtered backprojection algorithm and a gain of 10%–18% for the iterative algorithms, compared with the situation when a constant dwell‐time profile is used.