Semi-automatical Validation of SPECT/CT Scanners

Hybrid scanners, which enable the performance of single photon emission tomography (SPECT) and X-ray computerized tomography (CT) in one procedure, have considerable potential as an all-rounder in the nuclear medicine departments. However, challenges remain in validating the accuracy of such hybrid systems. In this paper, a systematic validation method with minimum user interaction is proposed, which has been successfully used on a data-set from a SPECT/Spiral-CT hybrid camera. This method focuses on measuring the distance between the centers of gravity of the SPECT hot spot and its counterpart in the CT image. A novel adaptive threshold method is proposed to automatically segment SPECT hot spots, while the corresponding CT structures are segmented by the semi-automatic random walk method, based on a fast multigrid solver. Accuracy and reproducibility of the validation method have been confirmed by experiments with 21 clinical data-sets.