Objective

  To assess the influence of anatomical location on computed tomography (CT) numbers in mid- and full field of view (FOV) cone beam computed tomography (CBCT) scans.

 Study Design

  Polypropylene tubes with varying concentrations of dipotassium hydrogen phosphate (K2HPO4) solutions (50-1200mg/mL) were imaged within the incisor, premolar, and molar dental sockets of a human skull phantom. CBCT scans were acquired using the NewTom 3G and NewTom 5G units. The CT numbers of the K2HPO4 phantoms were measured, and the relationship between CT numbers and K2HPO4 concentration was examined. The measured CT numbers of the K2HPO4 phantoms were compared between anatomical sites.

  Results

  At all six anatomical locations, there was a strong linear relationship between CT numbers and K2HPO4 concentration (R 2 >0.93). However, the absolute CT numbers varied considerably with the anatomical location.

 Conclusion

  The relationship between CT numbers and object density is not uniform through the dental arch on CBCT scans.

 Source: Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology

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