Download PDF
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
› Further Information
Also available at
    Permissions and Reprints

Abstract

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.

Zusammenfassung

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.

Key words

ultrasound safety - doppler ultrasound - thermal index - output display standard - eye tracking


Publication History

Received: 11 September 2019

Accepted: 02 December 2019

Article published online:
27 February 2020

© Georg Thieme Verlag KG
Stuttgart · New York

 

  • References

  • 1 Ang Jr ES, Gluncic V, Duque A. et al. Prenatal exposure to ultrasound waves impacts neuronal migration in mice. Proc Natl Acad Sci USA 2006; 103: 12903-12910
    CrossrefPubMedGoogle Scholar
  • 2 Abramowicz JS. Ultrasound and autism: association, link, or coincidence?. J Ultrasound Med 2012; 31: 1261-1269
    CrossrefPubMedGoogle Scholar
  • 3 Hoglund Carlsson L, Saltvedt S, Anderlid BM. et al. Prenatal ultrasound and childhood autism: long-term follow-up after a randomized controlled trial of first- vs second-trimester ultrasound. Ultrasound Obstet Gynecol 2016; 48: 285-288
    CrossrefPubMedGoogle Scholar
  • 4 Torloni MR, Vedmedovska N, Merialdi M. et al. Safety of ultrasonography in pregnancy: WHO systematic review of the literature and meta-analysis. Ultrasound Obstet Gynecol 2009; 33: 599-608
    CrossrefPubMedGoogle Scholar
  • 5 Salvesen KA. Ultrasound in pregnancy and non-right handedness: meta-analysis of randomized trials. Ultrasound Obstet Gynecol 2011; 38: 267-271
    PubMedGoogle Scholar
  • 6 Holt R, Abramowicz JS. Quality and Safety of Obstetric Practices Using New Modalities- Ultrasound, MR, and CT. Clin Obstet Gynecol 2017; 60: 546-561
    CrossrefPubMedGoogle Scholar
  • 7 Nelson TR, Fowlkes JB, Abramowicz JS. et al. Ultrasound biosafety considerations for the practicing sonographer and sonologist. J Ultrasound Med 2009; 28: 139-150
    CrossrefPubMedGoogle Scholar
  • 8 Kollmann C, Jenderka KV, Moran CM. et al. EFSUMB Clinical Safety Statement for Diagnostic Ultrasound – (2019 revision). Ultraschall in Med 2019; DOI: 10.1055/a-1010-6018.
    Article in Thieme ConnectPubMedGoogle Scholar
  • 9 Ter HaarG. Guidelines and recommendations for the safe use of diagnostic ultrasound: the user's responsibilties. In The Safe use of Ultrasound in Medical Diagnosis 3rd edition, ter Haar G (eds). London: British Institute of Radiology; 2012: 142-157
    PubMedGoogle Scholar
  • 10 Barnett SB, Ter Haar GR, Ziskin MC. et al. International recommendations and guidelines for the safe use of diagnostic ultrasound in medicine. Ultrasound Med Biol 2000; 26: 355-366
    CrossrefPubMedGoogle Scholar
  • 11 Marsal K. The output display standard: has it missed its target?. Ultrasound Obstet Gynecol 2005; 25: 211-214
    CrossrefPubMedGoogle Scholar
  • 12 Sheiner E, Abramowicz JS. Clinical end users worldwide show poor knowledge regarding safety issues of ultrasound during pregnancy. J Ultrasound Med 2008; 27: 499-501
    PubMedGoogle Scholar
  • 13 American Institute of Ultrasound in Medicine. American Institute of Ultrasound in Medicine. Official Statement: Recommended Maximum Scanning Times for Displayed Thermal Index (TI) Values. 2016 https://www.aium.org/officialStatements/65 [Accessed May 2nd, 2019]
    PubMedGoogle Scholar
  • 14 Safety Group of the British Medical Ultrasound Society. Guidelines for the safe use of diagnostic ultrasound equipment. 2009 https://www.bmus.org/static/uploads/resources/BMUS-Safety-Guidelines-2009-revision-FINAL-Nov-2009.pdf [Accessed May 2nd, 2019]
    PubMedGoogle Scholar
  • 15 Royal College of Obstetricians and Gynaecologists. Royal College of Obstetricians and Gynaecologists, Small-for-Gestational-Age Fetus, Investigation and Management (Green-top Guideline No. 31). https://www.rcog.org.uk/globalassets/documents/guidelines/gtg_31.pdf [Accessed February 18th, 2019]
    PubMedGoogle Scholar
  • 16 Sarris I, Ioannou C, Ohuma EO. et al. Standardisation and quality control of ultrasound measurements taken in the INTERGROWTH-21st Project. BJOG 2013; 120 (Suppl. 02) 33-37
    CrossrefPubMedGoogle Scholar
  • 17 Abramowicz JS. Benefits and risks of ultrasound in pregnancy. Semin Perinatol 2013; 37: 295-300
    CrossrefPubMedGoogle Scholar
  • 18 Alldred SK, Takwoingi Y, Guo B. et al. First trimester ultrasound tests alone or in combination with first trimester serum tests for Down’s syndrome screening. Cochrane Database Syst Rev 2017; 3: CD012600
    PubMedGoogle Scholar
  • 19 Salvesen K, Lees C, Abramowicz J. et al. ISUOG statement on the safe use of Doppler in the 11 to 13 +6-week fetal ultrasound examination. Ultrasound Obstet Gynecol 2011; 37: 628
    CrossrefPubMedGoogle Scholar
  • 20 Rempen A, Chaoui R, Hausler M. et al. Quality Requirements for Ultrasound Examination in Early Pregnancy (DEGUM Level I) between 4+0 and 13+6 Weeks of Gestation. Ultraschall in Med 2016; 37: 579-583
    Article in Thieme ConnectPubMedGoogle Scholar
  • 21 von Kaisenberg C, Chaoui R, Hausler M. et al. Quality Requirements for the early Fetal Ultrasound Assessment at 11–13+6 Weeks of Gestation (DEGUM Levels II and III). Ultraschall in Med 2016; 37: 297-302
    Article in Thieme ConnectPubMedGoogle Scholar
  • 22 Kollmann C, Jenderka KV, Moran CM. et al. EFSUMB Clinical Safety Statement for Diagnostic Ultrasound – (2019 revision). Ultraschall in Med 2019; DOI: 10.1055/a-1010-6018.
    Article in Thieme ConnectPubMedGoogle Scholar
  • 23 European Research Council (ERC). Advanced Grant Perception Ultrasound by Learning Sonographic Experience.. https://erc.europa.eu/projects-figures/erc-funded-projects/results?search_api_views_fulltext=Sonographic+
    PubMedGoogle Scholar
  • 24 Chatelain P, Sharma H, Drukker L. et al. Evaluation of Gaze Tracking Calibration for Longitudinal Biomedical Imaging Studies. IEEE Trans Cybern 2020; 50: 153-163
    CrossrefPubMedGoogle Scholar
  • 25 Brysbaert M. Arabic number reading: On the nature of the numerical scale and the origin of phonological recoding. Journal of Experimental Psychology: General 1995; 124: 434-452
    CrossrefPubMedGoogle Scholar
  • 26 Bromley B, Spitz J, Fuchs K. et al. Do clinical practitioners seeking credentialing for nuchal translucency measurement demonstrate compliance with biosafety recommendations? Experience of the Nuchal Translucency Quality Review Program. J Ultrasound Med 2014; 33: 1209-1214
    CrossrefPubMedGoogle Scholar
  • 27 Sheiner E, Abramowicz JS. Acoustic output as measured by thermal and mechanical indices during fetal nuchal translucency ultrasound examinations. Fetal Diagn Ther 2009; 25: 8-10
    CrossrefPubMedGoogle Scholar
  • 28 Nemescu D, Berescu A, Onofriescu M. et al. Safety Indices during Fetal Echocardiography at the Time of First-Trimester Scan Are Machine Dependent. PLoS One 2015; 10: e0127570
    CrossrefPubMedGoogle Scholar
  • 29 Deane C, Lees C. Doppler obstetric ultrasound: a graphical display of temporal changes in safety indices. Ultrasound Obstet Gynecol 2000; 15: 418-423
    CrossrefPubMedGoogle Scholar
  • 30 Toms DA. The mechanical index, ultrasound practices, and the ALARA principle. J Ultrasound Med 2006; 25: 560-561 ; author reply 561–562
    CrossrefPubMedGoogle Scholar
  • 31 Abramowicz JS, Kossoff G, Marsal K. et al. Safety Statement, 2000 (reconfirmed 2003). International Society of Ultrasound in Obstetrics and Gynecology (ISUOG). Ultrasound Obstet Gynecol 2003; 21: 100
    CrossrefPubMedGoogle Scholar
  • 32 Sande RK, Matre K, Eide GE. et al. The effects of reducing the thermal index for bone from 1.0 to 0.5 and 0.1 on common obstetric pulsed wave Doppler measurements in the second half of pregnancy. Acta Obstet Gynecol Scand 2013; 92: 790-796
    CrossrefPubMedGoogle Scholar
  • 33 Houston LE, Allsworth J, Macones GA. Ultrasound is safe... right?: resident and maternal-fetal medicine fellow knowledge regarding obstetric ultrasound safety. J Ultrasound Med 2011; 30: 21-27
    CrossrefPubMedGoogle Scholar
  • 34 Retz K, Kotopoulis S, Kiserud T. et al. Measured acoustic intensities for clinical diagnostic ultrasound transducers and correlation with thermal index. Ultrasound Obstet Gynecol 2017; 50: 236-241
    PubMedGoogle Scholar
  • 35 Drukker L, Droste R, Chatelain P. et al. Routine third-trimester growth scans: how common is expected value bias?. Ultrasound Obstet Gynecol 2019; DOI: 10.1002/uog.21929.
    CrossrefPubMedGoogle Scholar