PT  - JOURNAL ARTICLE
AU  - Scott D. Metzler
AU  - Roberto Accorsi
AU  - John R. Novak
AU  - Ahmet S. Ayan
AU  - Ronald J. Jaszczak
TI  - On-Axis Sensitivity and Resolution of a Slit-Slat Collimator
DP  - 2006 Nov 01
TA  - Journal of Nuclear Medicine
PG  - 1884--1890
VI  - 47
IP  - 11
4099  - http://jnm.snmjournals.org/content/47/11/1884.short
4100  - http://jnm.snmjournals.org/content/47/11/1884.full
SO  - J Nucl Med2006 Nov 01; 47
AB  - A slit-slat collimator combines a slit along the axis of rotation with a set of axial septa, offering both magnification in the transaxial direction and complete sampling with just a circular orbit. This collimator has a sensitivity that increases for points near the aperture slit. The literature treats this collimator as having the same sensitivity as a single-pinhole collimator, ignoring the effect of the axial septa. Herein, the sensitivity and resolution of this collimator are reevaluated. Methods: Experimental and Monte Carlo methods are used to determine the sensitivity and resolution in both the transaxial and axial directions as a function of distance from the slit (h). Eight configurations are tested, varying the slit width, septal spacing, and septal height. Results: Both the experimental and the Monte Carlo sensitivities agree reasonably with an analytic form that is the geometric mean of the pinhole and parallel-beam formulas, disagreeing with previous literature. Transaxial resolution is consistent with the pinhole-resolution formula. Axial resolution is consistent with the parallel-beam resolution formula. Conclusion: The sensitivity of this collimator is proportional to h−1 and has resolution in the transaxial direction that is consistent with pinhole resolution and in the axial direction that is consistent with parallel-beam resolution.