Measurement of the volume of oral tumors by three-dimensional spiral computed tomography

Objective: To determine the precision and accuracy of in vitro measurements of the volume of oral tumors with three-dimensional (3D) spiral computed t omography (CT) and their precision in vivo. Methods: Two simulated tumors made of modelling compound mixed with contras t medium were positioned medial to the mandibles of five cadaver heads and examined with subsecond spiral CT. Two observers delineated the simulated t umors twice in axial, coronal and sagittal views and then measured the volu me from multiplanar reconstructed images. The software tools automatically displayed the simulated tumors in 3D-reconstructed images with the volumetr ic measurements. The simulated tumors were removed and their volume measure d by water displacement. The volume of 15 oral tumors associated with the m andible were measured in vivo With the same imaging methods and the precisi on analysed. Results: There were no statistically significant differences between or wit hin observers or between imaging and physical measurements in vitro, nor be tween inter- and intra-observer measurements in who (P>0.05). Conclusion: Volumetric measurements from 3D-reconstructed CT are reliable a nd accurate in vitro and reliable in vivo. The method is potentially useful for the management of oral neoplasms.