Affiliations: CT/Micro-CT Laboratory, Department of Radiology,
University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242, USA | Department of Mathematics & Computer Science,
University of Missouri – St. Louis, 8001 Natural Bridge Road, St. Louis, MO
63121-4499, USA. Tel.: +1 319 356 2930; Fax: +1 319 356 2220; E-mail:
[email protected]
Abstract: The section sensitivity profile (SSP) was well understood in the
case of single-row-detector spiral CT. With the introduction of
multi-row-detector spiral CT and the transition into cone-beam spiral CT, a
revisit to the SSP issue becomes necessary. In this paper, the SSP of
multi-row-detector spiral CT is formulated for the half-scan interpolation
method at any transverse position. Based on the SSP formula, numerical
simulation is performed to quantify the characteristics of the SSP with the
number of detector rows up to 40. It is shown that the SSP varies as a function
of the pitch and the number of detector rows. Given an appropriate selection of
the pitch and the number of detector rows, the SSP does not change very much
over the field of view in terms of the mean, the slice thickness, and the
skewness of the SSP. Although in general applications the SSP at the gantry
iso-center can be used as the representative of the SSP family, for more
accurate analyses the spatial variation of the SSP must be taken into
account.
