Comparative dose measurements by spiral tomography for preimplant diagnosis: The Scanora machine versus the Cranex Tome radiography unit

Objective. The purpose of this study was to determine the dose profile of t he Cranex Tome radiography unit and compare it with that of the Scanora mac hine. Study design. The radiation dose delivered by the Cranex Tome radiography u nit during the cross-sectional mode was determined. Single tooth gaps in re gions 3 (16) and 30 (46) were simulated. Dosimetry was carried out with 2 p hantoms, a head and neck phantom and a full-body phantom loaded with 142 th ermoluminescent dosimeters (TLD) and 280 TLD, respectively; all locations c orresponded to radiosensitive organs or tissues. The recorded local mean or gan doses were compared with those measured in another study evaluating the Scanora machine. Results. Generally, dose values from the Cranex Tome radiography unit reach ed only 50% to 60% of the values measured for the Scanora machine. The effe ctive dose was calculated as 0.061 mSv and 0.04 mSv for tooth regions 3 (16 ) and 30 (46), respectively. Corresponding values for the Scanora machine w ere 0.117 mSv and 0.084 mSv. Conclusion. Cross-sectional imaging in the molar region of the upper and th e lower jaw can be performed with the Cranex Tome unit, which delivers only approximately half of the dose that the Scanora machine delivers.