Patent ID: 8369928

Claim:
A method comprising: scanning a subject with a combined magnetic resonance imaging (MRI)/positron emission tomography (PET) scanner having a PET imaging modality and an MR imaging modality; using an analog to digital converter to discrete time sample a signal from a photo detector; cancelling one or more poles of the signal with a digital infinite impulse response filter implemented with fixed-point arithmetic inside a field programmable gate array to subtract the tail of an integrated energy signal to eliminate high frequency components that may interfere with the MR imaging modality to obtain a modified signal; and using the modified signal to generate an image of the subject, wherein the infinite impulse response filter z-transform for the field programmable gate array implemented single pole/zero digital filter is described mathematically by the equation H ⁡ ( z ) = K 1 - K 2 1 - K 3 ⁢ z - 1 for an idealized model of a single exponential defined detector signal, wherein z represents the complex variable e sT , K 1 represents a digital constant coefficient associated with the input, K 2 represents a digital constant coefficient, K 3 represents the coefficient associated with the past input and output samples.