Рентгенология & Радиология, 2018, LVII 151-158

Cone beam computed tomography linear measurements of simulated lesions

  1. Kishkilova, E. Tasheva-Terzieva

Abstract.

CBCT has gained its importance in Maxillofacial diagnostics. Although acquisition of rentgenographic images with CBCT is proved to be technically easy, there is a need of a better understanding of the method’s potential and especially the factor affecting the image quality. We found subject of linear measurements accuracy to be quite debatable. We used 48 simulated lesions in the lower and upper jaws of 6 pigs heads. The heads were initially scanned with soft tissue with HD and normal resolution (protocols STP HD and STPno). After removing the soft tissues we rescanned the heads with the same resolutions (STA HD and STA no). The direct measurement of the diameter and depth of simulated lesions was made by digital caliper (Fi). The rentgenographic measurements were performed on each sign (diameter and depth) for each hole and each scanning protocol. After comparing the two types of measurement, we noticed that concerning the diameter in most cases the rentgenographic measurement was underestimated compared to direct measurement, and for the depths of simulated lesions rentgenographic measurement was overestimated compared to direct measurement. Based on our findings we formulated a safety zone for surgical procedures in the maxillo facial region, separately for horizontal and vertical measurements.

Key words: CONE BEAM COMPUTED TOMOGRAPHY. SIMULATED LESIONS. LINEAR MEASUREMENTS. SAFETY ZONE