Ultraschall Med 2020; 41(02): 138-145
DOI: 10.1055/a-1074-0722
Original Article

Safety Indices of Ultrasound: Adherence to Recommendations and Awareness During Routine Obstetric Ultrasound Scanning

Sicherheitsindizes im Ultraschall: Einhaltung der Empfehlungen und Aufmerksamkeit beim Routine-Ultraschall in der Geburtshilfe
Lior Drukker
1   Nuffield Department of Women's & Reproductive Health, Oxford-University, Oxford, United Kingdom of Great Britain and Northern Ireland
Richard Droste
2   Institute of Biomedical Engineering, Oxford-University, Oxford, United Kingdom of Great Britain and Northern Ireland
Pierre Chatelain
2   Institute of Biomedical Engineering, Oxford-University, Oxford, United Kingdom of Great Britain and Northern Ireland
J. Alison Noble
2   Institute of Biomedical Engineering, Oxford-University, Oxford, United Kingdom of Great Britain and Northern Ireland
Aris T. Papageorghiou
1   Nuffield Department of Women's & Reproductive Health, Oxford-University, Oxford, United Kingdom of Great Britain and Northern Ireland
› Author Affiliations


Purpose To analyze bioeffect safety indices and assess how often operators look at these indices during routine obstetric ultrasound.

Materials and Methods Automated analysis of prospectively collected data including video recordings of full-length ultrasound scans coupled with operator eye tracking was performed. Using optical recognition, we extracted the Mechanical Index (MI), Thermal Index in soft tissue (TIs), and Thermal Index in bone (TIb) values and ultrasound mode. This allowed us to report the bioeffect safety indices during routine obstetric scans and assess adherence to professional organization recommendations. Eye-tracking analysis allowed us to assess how often operators look at the displayed bioeffect safety indices.

Results A total of 637 ultrasound scans performed by 17 operators were included, of which 178, 216, and 243 scans were first, second, and third-trimester scans, respectively. During live scanning, the mean and range were 0.14 (0.1 to 3.0) for TIb, 0.2 (0.1 to 1.2) for TIs, and 0.9 (0.1 to 1.3) for MI. The mean and standard deviation of TIb were 0.15 ± 0.03, 0.23 ± 0.09, 0.32 ± 0.24 in the first, second, and third trimester, respectively. For B-mode, the highest TIb was 0.8 in all trimesters. The highest TIb was recorded for pulsed-wave Doppler mode in all trimesters. The recommended exposure times were maintained in all scans. Analysis of eye tracking suggested that operators looked at bioeffect safety indices in only 27 (4.2 %) of the scans.

Conclusion In this study, recommended bioeffect indices were adhered to in all routine scans. However, eye tracking showed that operators rarely assessed safety indices during scanning.


Ziel Analyse der Bioeffekt-Sicherheitsindizes und Bewertung, wie häufig Anwender diese Indizes beim Routine-Ultraschall in der Geburtshilfe betrachten.

Material und Methoden Durchführung einer automatisierten Analyse prospektiv gesammelter Daten einschließlich der Videoaufnahmen von Ultraschalluntersuchungen in voller Länge, gekoppelt mit einem Eye-Tracking des Anwenders. Mithilfe optischer Erkennung wurden die Werte des mechanischen Index (MI), thermischen Index im Weichteilgewebe (TIs) und thermischen Index im Knochen (TIb) sowie der Ultraschallmodus extrahiert. Dadurch konnten wir die Bioeffekt-Sicherheitsindizes bei geburtshilflichen Routineuntersuchungen angeben und die Einhaltung der Empfehlungen der Berufsorganisation beurteilen. Die Analyse des Eye-Trackings ermöglichte es uns zu beurteilen, wie oft die Anwender die angezeigten Bioeffekt-Sicherheitsindizes betrachten.

Ergebnis Insgesamt wurden 637 Ultraschalluntersuchungen von 17 Anwendern eingeschlossen, von denen 178 im ersten, 216 im zweiten und 243 Untersuchungen im dritten Schwangerschaftstrimenon durchgeführt wurden. Bei der Live-Untersuchung lagen Mittelwert und Bereich des TIb bei 0,14 (0,1 bis 3,0), des TIs bei 0,2 (0,1 bis 1,2) und des MI bei 0,9 (0,1 bis 1,3). Mittelwert und Standardabweichung des TIb betrugen 0,15 ± 0,03 im ersten, 0,23 ± 0,09 im zweiten und 0,32 ± 0,24 im dritten Trimenon. Für den B-Modus lag der höchste TIb in allen Trimenons bei 0,8. Der höchste TIb wurde für den gepulsten Doppler-Modus in allen Trimenons gemessen. Die empfohlenen Expositionszeiten wurden bei allen Scans eingehalten. Die Analyse des Eye-Trackings ergab, dass die Anwender nur bei 27 Scans (4,2 %) auf die Bioeffekt-Sicherheitsindizes achteten.

Schlussfolgerung In dieser Studie wurden die empfohlenen Bioeffekt-Indizes bei allen Routine-Scans eingehalten. Die Eye-Tracking-Methode zeigte jedoch, dass die Anwender die Sicherheitsindizes während der Untersuchung nur selten analysieren.

Publication History

Received: 11 September 2019

Accepted: 02 December 2019

Article published online:
27 February 2020

© Georg Thieme Verlag KG
Stuttgart · New York

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