Standardization of mineral density maps of physiologic and pathologic biominerals in humans using cone-beam CT and micro-CT scanners

Sudarshan Srirangapatanam; Misun Kang; Yianni Ellenikiotis; Andrew Jheon; Sunil Kapila; Hubert S Swana; Marshall L Stoller; Youngho Seo; Sunita P Ho

doi:10.1016/j.dental.2022.03.010

Standardization of mineral density maps of physiologic and pathologic biominerals in humans using cone-beam CT and micro-CT scanners

Dent Mater. 2022 Jun;38(6):989-1003. doi: 10.1016/j.dental.2022.03.010. Epub 2022 Apr 13.

Authors

Sudarshan Srirangapatanam¹, Misun Kang², Yianni Ellenikiotis³, Andrew Jheon³, Sunil Kapila³, Hubert S Swana⁴, Marshall L Stoller⁵, Youngho Seo⁶, Sunita P Ho⁷

Affiliations

¹ Department of Urology, School of Medicine, University of California, San Francisco, CA, USA; College of Medicine, University of Central Florida, FL, USA.
² Department of Preventive and Restorative Dentistry, School of Dentistry, University of California, San Francisco, CA, USA.
³ Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, CA, USA.
⁴ College of Medicine, University of Central Florida, FL, USA.
⁵ Department of Urology, School of Medicine, University of California, San Francisco, CA, USA.
⁶ Department of Radiology and Biomedical Imaging, School of Medicine, University of California, San Francisco, CA, USA; Department of Nuclear Engineering, University of California Berkeley, Berkeley, CA, USA.
⁷ Department of Urology, School of Medicine, University of California, San Francisco, CA, USA; Department of Preventive and Restorative Dentistry, School of Dentistry, University of California, San Francisco, CA, USA. Electronic address: Sunita.Ho@ucsf.edu.

PMID: 35428494
DOI: 10.1016/j.dental.2022.03.010

Abstract

Objectives: The lack of standardized X-ray imaging remains a challenge for comparative studies on spatial scans acquired from different clinic-specific X-ray scanners. The central objectives of this study are: 1) to delineate mineral density (MD) values, and 2) generate spatial MD maps of various physiologic and pathologic biominerals, and 3) propose a standardization protocol within the safe-operating zone of a CT scanner that underpins normalization of absorbed dose to shape and density of tissues.

Methods: A systematic approach to propose a standardization protocol for CT imaging in vivo included: 1) estimation of pathologic MD ranges by performing a comparative meta-analysis on 2009-2019 data from the PubMed database; 2) calibration of cone-beam CT (CBCT) and micro-CT scanners with phantoms of known mineral densities (0, 250, 500, 750 and 3000 mg/cc) and shapes (cylinders and polyhedrons); 3) scanning craniofacial bones (N = 5) and dental tissues (N = 5), and ectopic minerals from humans (N = 3 each, pulp, salivary gland, kidney and prostrate stones, and penile and vascular plaques); 4) underscoring the effect of shape-factor (surface area-to-volume ratio) on MD of biominerals.

Results: Higher MDs of physiologic and pathologic cortical bones (504-1009 mg/cc) compared to trabecular bone (82-212 mg/cc) were observed. An increase in shape-factor increased the CBCT error in MD measurement and revealed that the scanner resolution is dependent on the absorbed dose and shape-factor of detectable features.

Significance: CT scanners should be calibrated with phantoms containing segments of known shape-factors and mineral densities to identify safe-operating zones. The calibrated approach will narrow the gap between length-scale dependent measurements, and will permit spatiotemporal quantitative and reliable detection of pathologies.

Keywords: Computed tomography; Craniofacial and dental tissues; Mineral density; Skeletal bone; X-ray imaging.

Publication types

Meta-Analysis
Research Support, Non-U.S. Gov't

MeSH terms

Bone and Bones*
Cone-Beam Computed Tomography* / methods
Humans
Minerals
Reference Standards
X-Ray Microtomography / methods

Substances

Minerals