Correções em leituras de volumes e densidades determinados em tomografia computadorizada
Brazilian Journal of Radiation Sciences
With the increasing use of 3D reconstruction techniques, to assist in diagnosis, dedicated programs are being widely used. For this they must be calibrated in order to encounter the values of the true volumes and CT number of the human tissues. The aim is to indicate correction values for volumes and CT number, read in a 3D reconstruction system using DICOM images of Computed Tomography. This work utilized a PMMA thorax phantom associated with the DICOM image and the program found by a program
... found by a program of a tomograph. To generate the CT number correction the Catphan phantom was used and compared its values to that of the manufacturer values associated with the line of linearity. The physical volume of the PMMA phantom found was 10445.2 cm³ and CT number of (123.5 ± 33.4) HU. For the volumes found according to the structures of interest, the values are 11040.0 cm³, 10242.5 cm³ and 10257.3 cm³ and the correction values are -6.6%, +1.9% and +1.0% respectively for tissues: pulmonary, bony and soft tissues. For the CT numbers found in this program were (106.6 ± 55.5) HU, (117.9 ± 90.9) HU and (109.8 ± 25.7) HU and corrections of +15.9%, +4.8% and 12.5% respectively for tissues: pulmonary, bone and soft tissues. The procedure performed can be used in other 3D reconstruction programs and where there are tools for CT number readings, observing the necessary corrections.