Comparative modulation transfer functions of the EMI and Delta scanners.

Spatial resolution of the EMI and Delta computed tomographic scanners has been measured by recording the response to a nylon and water sunburst phantom (Siemens star) and calculating the modulation transfer function at radii corresponding to various spatial frequencies. The resolution appears to be related primarily to the size of the matrix element, and exhibits an upper cut-off frequency somewhat in excess of 3 cycles/cm.