An imaging system (100) includes a subject support (114) that supports a subject in an examination region (106). The imaging system further includes a detector (112) that detects a signal traversing the examination region, generating an output indicative of the examination region. The imaging system further includes a subject motion sensing system (118) that includes an optical system (206, 208, 214) that detects motion of the subject in the examination region and generates motion data indicative thereof. The imaging system further includes a console (122) that controls at least one of data acquisition or reconstruction based on the motion data.