PROBLEM TO BE SOLVED: To provide a random coincidence count estimating method and a random coincidence count estimating device which can apply time-of-flight (TOF) mask to estimation of random coincidence counts.SOLUTION: A random coincidence count estimating method includes: obtaining time-of-flight (TOF) list mode count data that includes TOF information; converting the obtained TOF list mode count data into four-dimensional (4D) raw sinogram count data including random count values without using the TOF information; low-pass filtering the 4D interpolated sinogram count data obtained by interpolating the 4D raw sinogram count data; converting the low-pass filtered 4D interpolated sinogram count data into filtered 4D raw sinogram count data; and generating five-dimensional (5D) TOF raw sinogram count data from the filtered 4D raw sinogram count data by effectively applying a TOF mask filter for filtering paired vanishing points to the filtered 4D raw sinogram count data.
RANDOM COINCIDENCE COUNT ESTIMATING METHOD AND RANDOM COINCIDENCE COUNT ESTIMATING DEVICE