Comparative localized linear accuracy of small-field cone-beam CT and multislice CT for alveolar bone measurements

ObjectivesTo compare the accuracy of cone-beam computerized tomography (CBCT) and multislice CT (MSCT) for linear jaw bone measurements.Study designAn ex vivo formalin-fixed human maxilla was imaged with both CBCT (Accuitomo 3D; Morita, Kyoto, Japan) and MSCT (4-slice Somatom VolumeZoom and 16-slice Somatom Sensation 16; Siemens, Erlangen, Germany). The MSCT images were reconstructed using different reconstruction filters to optimize bone visualization (U70u and U90u for VolumeZoom, H30s and H60s for Sensation 16). Before scanning, triplets of small gutta-percha markers were glued onto the soft tissues overlying the maxillary bone on the top and on both sides of the alveolar ridge to define a set of reproducible linear measurements in 11 planes. Image measurements were performed by 2 observers. The gold standard was determined by means of physical measurements with a caliper by 3 observers.ResultsThe accuracy of the linear measurements was 0.35 ± 1.31 mm (U70u) and 0.06 ± 1.23 mm (U90u) for the Somatom VolumeZoom, 0.24 ± 1.20 mm (H60s) and 0.54 ± 1.14 mm (H30s) for the Sensation 16, and −0.09 ± 1.64 mm for the Accuitomo 3D. Statistical analysis with 2-way analysis of variance showed no significant inter- or intraobserver disagreement for the physical or the radiologic measurements. There was also no significant difference for the measurements on the different reconstruction filters.ConclusionBoth CBCT and MSCT yield submillimeter accuracy for linear measurements on an ex vivo specimen.