Data from one or more sensors measuring parameters associated with the operating state of a phantom during a scan 47 is input to a computer model 48, which is used to produce reference image data. This is compared with the acquired image 49 in order to return a pass/fail score, indicating acceptability of imaging system calibration. Synchronization 45 may occur before image acquisition. The measured parameters may be, for example, phantom fluid flow rate, pressure, pH or concentration of a dissolved compound such as glucose, or temperature and are used with Computational Flow Dynamics (CFD) to produce the ground truth model for comparison. A predetermined threshold level may be based on ISO standards. Adjustments may be made until a pass score is returned. The method may be used with scanners using e.g. MRI or PET techniques, and may be applicable to a diffusion or perfusion phantom.
