Imaging Sci Dent.  2022 Mar;52(1):53-60. 10.5624/isd.20210172.

Fractal dimension analysis on CBCT scans for detecting low bone mineral density in postmenopausal women

• Carvalho BF
• Castro JGKd
• Melo NSd
• Souza Figueiredo PTd
• Moreira-Mesquita CR
• Paula APd
• Sindeaux R
• Leite AF

• KMID: 2527655
• DOI: http://doi.org/10.5624/isd.20210172

Abstract

Purpose
The aim of this study was to compare the fractal dimension (FD) measured at 2 bone sites (second cervical vertebra and mandible) on cone-beam computed tomography (CBCT). The research question was whether FD could serve as an accessory tool to refer postmenopausal women for densitometric analysis. Therefore, the reliability and accuracy of FD were evaluated.
Materials and Methods
In total, 103 postmenopausal women were evaluated, of whom 52 had normal bone mineral density and 51 had osteoporosis, according to dual X-ray absorptiometry of the lumbar spine and hip. On the CBCT scans, 2 regions of interest were selected for FD analysis: 1 at the second cervical vertebra and 1 located at the mandible. The correlations between both measurements, intra- and inter-observer agreement, and the accuracy of the measurements were calculated. A P value less than 0.05 was considered to indicate statistical significance for all tests.
Results
The mean FD values were significantly lower at the mandibular region of interest in osteoporotic patients than in individuals with normal bone mineral density. The areas under the curve were 0.644 (P=0.008) and 0.531 (P=0.720) for the mandibular and vertebral sites, respectively.
Conclusion
FD at the vertebral site could not be used as an adjuvant tool to refer women for osteoporosis investigation. Although FD differed between women with normal BMD and osteoporosis at the mandibular site, it demonstrated low accuracy and reliability.

Keyword

Osteoporosis; Cone-Beam Computed Tomography; Fractals; Dual-Energy X-ray Absorptiometry