The Smart-Scan-Technique in spiral computed 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 technique 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 Alderson-Rando phantom, and 20 patients were used to simulate possible measures of patients within the thoracic and abdominal region. For those two regions the dose reduction, the modulation transfer function, and the pixel noise were measured. Results: Depending on patient geometry dose reduction up to 20% could be achieved with the Smart-Scan-Technique. This technique also enabled a decrease of the modulation transfer function 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.