a computed tomography imaging method includes receiving an analog beam intensity signal from a computed tomography scanner and converting the signal into a series of digital representations of the signal at successive points in time using a predetermined sample rate . indications that a portion of the scanner has reached a certain position relative to the beam are received asynchronously with respect to the sample rate . the value of at least one of the digital representations is adjusted in response to the indications to obtain a corrected digital representation of the analog signal .