Phantomless estimation of bone mineral density on computed tomography: a scoping review

Abstract

Background

Age-related conditions like osteoporosis have become more familiar with increasing global life expectancy. Osteoporosis is characterized by reduced bone mineral density and structural weakening of bone tissue that leads to a higher risk of fracture. Dual-energy X-ray absorptiometry is the current standard for diagnosing osteoporosis. Computed tomography provides an alternative for diagnosis, but traditional QCT involves the use of phantoms, which does not allow retrospective or opportunistic assessments of BMD. This study aims to provide an overview of the evidence and feasibility for emerging phantomless techniques for the estimation of BMD on CT.

Methods

A scoping review was conducted to evaluate the feasibility and effectiveness of phantomless BMD estimation using CT. A comprehensive search of Scopus and PubMed databases focused on literature published between 2010 and 2024. Search terms included combinations of “phantomless”, “BMD estimation”, and “CT”. Studies emphasizing accuracy, reliability, and clinical feasibility were included. The review identified 26 relevant studies examining methods of phantomless BMD estimation. The majority of the studies used internal anatomical references to calibrate BMD measurements. These methods demonstrated accuracy comparable to traditional phantom-based techniques. Limitations of the technique included variability in scanner types and inconsistencies caused by patient-specific factors like body composition and contrast agents.

Conclusion

Phantomless BMD estimation methods are a feasible approach to detecting osteoporosis. The possibility to be integrated into routine CT workflows make them an attractive option for opportunistic screening. Further research is necessary to refine methods, ensure consistent results across different clinical settings, and address outstanding issues such as scanner variability and the effects of contrast agents.

Key Points

• Phantomless CT BMD estimation methods are a feasible approach to detecting osteoporosis.

• Phantomless is an attractive option for opportunistic diagnosis and screening.

• Further studies need to address scanner variability and effects of contrast agents.

Citation Format

• Waqar A, Bazzocchi A, Aparisi Gómez MP. Phantomless estimation of bone mineral density on computed tomography: a scoping review. Rofo 2025; 197: 1262–1278

Zusammenfassung

Hintergrund

Altersbedingte Erkrankungen wie Osteoporose sind mit der zunehmenden globalen Lebenserwartung häufiger geworden. Osteoporose ist durch eine verringerte Knochenmineraldichte und strukturelle Schwächung des Knochengewebes gekennzeichnet, was zu einem höheren Frakturrisiko führt. Die Dual-Energy-Röntgenabsorptiometrie ist der aktuelle Standard zur Diagnose von Osteoporose. Die Computertomografie bietet eine alternative Methode zur Diagnose, jedoch erfordert das traditionelle QCT die Verwendung von Phantomen, was retrospektive oder opportunistische Bewertungen der Knochenmineraldichte (BMD) nicht zulässt. Diese Studie zielt darauf ab, einen Überblick über die Evidenz und Machbarkeit aufkommender phantomloser Techniken zur Schätzung der BMD in der CT zu geben.

Methode

Eine Scoping-Übersicht wurde durchgeführt, um die Machbarkeit und Wirksamkeit der phantomlosen BMD-Schätzung mittels CT zu bewerten. Eine umfassende Suche in den Datenbanken Scopus und PubMed konzentrierte sich auf Literatur, die zwischen 2010 und 2024 veröffentlicht wurde. Die Suchbegriffe umfassten Kombinationen von „phantomlos“, „BMD-Schätzung“ und „CT“. Studien, die Genauigkeit, Zuverlässigkeit und klinische Machbarkeit betonten, wurden eingeschlossen. Die Übersicht identifizierte 26 relevante Studien, die Methoden der phantomlosen BMD-Schätzung untersuchten. Die Mehrheit der Studien verwendete interne anatomische Referenzen zur Kalibrierung der BMD-Messungen. Diese Methoden zeigten eine vergleichbare Genauigkeit zu traditionellen phantom-basierten Techniken. Zu den Einschränkungen der Technik gehörten die Variabilität der Scanner-Typen und die Inkonsistenzen, die durch patientenspezifische Faktoren wie Körperzusammensetzung und Kontrastmittel verursacht wurden.

Schlussfolgerung

Phantomlose BMD-Schätzungsmethoden sind ein machbarer Ansatz zur Erkennung von Osteoporose. Die Möglichkeit, in routinemäßige CT-Workflows integriert zu werden, macht sie zu einer attraktiven Option für opportunistisches Screening. Weitere Forschung ist notwendig, um Methoden zu verfeinern, konsistente Ergebnisse in verschiedenen klinischen Umgebungen sicherzustellen und verbleibende Probleme, wie die Scanner-Variabilität und die Auswirkungen von Kontrastmitteln, zu adressieren.

Kernaussagen

• Phantomlose CT-BMD-Schätzmethoden sind ein machbarer Ansatz zur Erkennung von Osteoporose.

• Phantomlos ist eine attraktive Option für opportunistische Diagnose und Screening.

• Weitere Studien müssen die Scanner-Variabilität und die Auswirkungen von Kontrastmitteln berücksichtigen.

Keywords

osteoporosis - phantomless - BMD - internal calibration - opportunistic

Publication History

Received: 13 December 2024

Accepted after revision: 25 January 2025

Article published online:
05 March 2025

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