The purpose of this study was to determine the precision and accuracy of facial soft tissue measurement using personal computer (PC)-based multiplanar reconstructed (MPR) computed tomography (CT) images and to evaluate the effect of the various CT scanning protocols on the facial soft tissue thickness measurement. Thirteen different CT imaging protocols were used to image a cadaver head. MPR reformations and three-dimensional (3D) reconstructions viewed on a laptop PC were used to make measurements at six specific sites on each set of images. These measurements were compared to physical measurements at the same sites. Increasing the slice thickness resulted in decreased image quality. Within the same slice thickness, increasing the pitch ratio in the spiral mode, resulted in decreasing image quality. The image quality of conventional CT scanning was relatively poorer than that of the spiral CT scanning. However, the mean deviation from the physical measurement was within 0.43 mm in every instance. This mean deviation was quite small and clinically acceptable for measuring the soft tissue thickness of the facial area. PC-based MPR CT images of the face using routine scanning CT protocols can be used to accurately measure soft tissue thickness in the facial region. However, for more fine and accurate data collection, scanning protocols with slice thicknesses less than 5 mm, and a spiral/helical mode pitch less than 2:1 are recommended.
Bibliographical noteFunding Information:
The Authors acknowledge the capable technical assistance of Scot Heery, RTR, of the Department of Radiology at The University of Iowa Hospital and Clinics. We also thank Mary Hendrix, PhD, Head of the Department of Anatomy and Cell Biology at The University of Iowa, who provided the cadaver material for our study. We further wish to thank Mr. John Dyson, Director of the Medical Instrument Shop at The University of Iowa, for modifying his digital caliper by reducing the shaft diameter to permit insertion into the punch holes. This work was supported in part by Yonsei University Dental College Research Fund of 2003.
All Science Journal Classification (ASJC) codes
- Pathology and Forensic Medicine