A system to investigate and adjust profile pattern of computed tomography dose index along the longitudinal-axis

Abstract

The purpose of this study to develop software to extract and investigate the rofiles of the tube current and volume computed tomography dose index (CTDI_vol) along the longitudinal axis (z-axis). The tube current and CTDI_vol were extracted from the Digital Imaging and Communications in Medicine (DICOM) header of every image along the longitudinal axis. We evaluated the profiles of the tube current and CTDI_vol from eight computed tomography (CT) scanners. If the CTDI_vol did not fluctuate along the fluctuation of the tube currents, then the system will adjust the CTDI_vol with tube currents. It is found that TCM is not always activated. If TCM is activated, the profiles of TCM vary from one scanner to another. The Siemens and Philip scanners have adjusted the CTDI_vol profile with tube current, but the Toshiba scanner has not. By developed software, CTDI_vol profile of the Toshiba can be easily adjusted. In conclusion, software to investigate the profile pattern of CTDI_vol along the longitudinal axis has been successfully developed. The software is easy to use and works quickly. From this study, medical staff must be careful when using the CTDI_vol along longitudinal axis contained in each DICOM header.