RATIONALE AND OBJECTIVES: The purpose of this study was to determine the accuracy (validity) and precision (reliability) of spiral computed tomographic (CT) images by using film- and computer graphics-based measurements of simulated neoplastic lesions associated with the mandible. MATERIALS AND METHODS: Four cadaver heads, each with two simulated tumors containing contrast medium positioned medial to the mandibles, were examined by using a subsecond spiral CT scanner. Data were transferred to film and to a computer workstation. With computer graphics, data were analyzed by using multiplanar reconstructed images. Linear measurements of the length, width, and depth of simulated tumors were made by two observers, twice each, on the film scans by using manual calipers and on the multiplanar reconstructed images by using computerized measurements. The soft tissues were then removed from the cadavers and the same measurements made by using the same calipers. RESULTS: No statistically significant differences between computer graphics- or film-based measurements and physical measurements (P > .05) or between inter- and intraobserver measurements (P > .05) were found. CONCLUSION: The authors found high reproducibility of measurements for all dimensions. Spiral CT allows accurate computer graphics- and film-based measurements of neoplastic lesions associated with the mandible.
RATIONALE AND OBJECTIVES: The purpose of this study was to determine the accuracy (validity) and precision (reliability) of spiral computed tomographic (CT) images by using film- and computer graphics-based measurements of simulated neoplastic lesions associated with the mandible. MATERIALS AND METHODS: Four cadaver heads, each with two simulated tumors containing contrast medium positioned medial to the mandibles, were examined by using a subsecond spiral CT scanner. Data were transferred to film and to a computer workstation. With computer graphics, data were analyzed by using multiplanar reconstructed images. Linear measurements of the length, width, and depth of simulated tumors were made by two observers, twice each, on the film scans by using manual calipers and on the multiplanar reconstructed images by using computerized measurements. The soft tissues were then removed from the cadavers and the same measurements made by using the same calipers. RESULTS: No statistically significant differences between computer graphics- or film-based measurements and physical measurements (P > .05) or between inter- and intraobserver measurements (P > .05) were found. CONCLUSION: The authors found high reproducibility of measurements for all dimensions. Spiral CT allows accurate computer graphics- and film-based measurements of neoplastic lesions associated with the mandible.