THE SMART-SCAN-TECHNIQUE IN SPIRAL COMPUT ED-TOMOGRAPHY - A NEW METHOD FOR DOSE REDUCTION

Purpose: In this article a new method - the Smart-Scan-Technique - for dose reduction during spiral computed tomography is described. This t echnique allones a dynamical adaptation of the tube current according to the measured local density structure form and absorption values of the object of interest. Its clinical applicability for dose reduction is investigated. In addition, changes in image quality are evaluated. Methods: Specially designed, water filled plexiglas-phantoms, an Alder son-Rando phantom, and 20 patients were used to simulate possible meas ures of patients within the thoracic and abdominal region. For those t wo regions the dose reduction, the modulation transfer function, and t he pixel noise were measured. Results: Depending on patient geometry d ose reduction up to 20% could be achieved with the Smart-Scan-Techniqu e. This technique also enabled a decrease of the modulation transfer f unction and an increase of the pixel noise by 8%. Conclusion: Relevant dose reductions can be achieved by applying the Smart-Scan-Technique in spiral computed tomography.