Safety in Diagnostic Ultrasound Educational Activities Using Nonpregnant Participants

Background. The American Institute of Ultrasound in Medicine has long advocated the prudent use of medical ultrasound and has developed safety recommendation statements. These include the following: (1) ultrasound should be used by qualified health professionals to provide medical benefit to patients¹; (2) ultrasound exposures should be as low as reasonably achievable (ALARA) within the goals of the study^2,3; (3) the participant should be informed of the anticipated exposure conditions and how these compare with normal diagnostic practice²; (4) repetitive and prolonged exposures on a single participant should be justified and consistent with prudent and conservative use²; and (5) infection control policies and procedures must be followed.^4,5

Statement. Ultrasound examinations conducted for the purpose of education and training require adherence to prudent and conservative use guidelines. Specifically, the guidelines below should be followed:

1. Demonstration scans on live, nonpregnant participants should be performed in a manner consistent with the ALARA principle, including limiting the thermal index (TI; (≤0.7 for neonatal transcranial and neonatal spinal examinations, ≤1.0 for ophthalmic examinations, or ≤1.5 for all other examinations)^3,6 and mechanical index (MI; ≤0.23 for ophthalmic examinations, <0.4 specifically for contrast-aided and lung examinations, ≤1.4 for intestine examinations, and ≤1.9 for other examinations such as liver ultrasound). ^4,6–8
2. If higher exposure conditions or contrast agents are needed for the training, then either (a) a tissue-mimicking phantom should be used, or (b) the live participant should only be scanned once per day similar to the exposures experienced during clinical practice. The use of contrast agents should be in accordance with the product label and recommendations of relevant professional organizations, and dosage should be the minimum required to produce diagnostic-quality images. ^9–12 In some cases, this might be considerably less than the dose specified in the product label.
3. All participants should provide appropriate informed consent for the ultrasound study after a discussion of the risks and benefits, including safety and potential biological effects. If an injectable contrast agent is used, the discussion and consent should also include details about vascular access, possible adverse reactions such as cardiopulmonary reactions consistent with labeling, and possible bioeffects of contrast imaging.⁶ Female participants should provide a statement to the best of their knowledge that they are not pregnant.
4. All equipment must be used in a manner consistent with its US Food and Drug Administration (FDA)-cleared indications for use. In particular, only equipment that has been FDA-cleared for ophthalmic indications should be used to scan the eye during training due to the sensitivity of the eye to heating, as reflected by lower FDA-recommended maximum output levels (MI ≤0.23 and TI ≤1.0).⁴

References

1. American Institute of Ultrasound in Medicine. Prudent clinical use and safety of diagnostic ultrasound. American Institute of Ultrasound in Medicine website. https://www.aium.org/officialStatements/34. Approved May, 2019.

2. American Institute of Ultrasound in Medicine. Safety in training and research. American Institute of Ultrasound in Medicine website. https://www.aium.org/officialStatements/36. Approved May 19, 2020.

3. American Institute of Ultrasound in Medicine. As low as reasonably achievable (ALARA) principle. American Institute of Ultrasound in Medicine website.  https://www.aium.org/officialStatements/39. Approved May 19, 2020

4. American Institute of Ultrasound in Medicine. Statement on mammalian biological effects in tissues with gas body contrast agents. American Institute of Ultrasound in Medicine website. https://www.aium.org/officialStatements/25. Approved March 25, 2015.

5. American Institute of Ultrasound in Medicine. Guidelines for cleaning and preparing external- and internal-use ultrasound transducers and equipment between patients as well as safe handling and use of ultrasound coupling gel. American Institute of Ultrasound in Medicine website. https://www.aium.org/officialStatements/57. Approved March 27, 2020.

6. American Institute of Ultrasound in Medicine. Recommended maximum scanning times for displayed thermal index (TI) values. American Institute of Ultrasound in Medicine website. https://www.aium.org/officialStatements/65. Approved October 30, 2016.

7. US Food and Drug Administration. Marketing clearance of diagnostic ultrasound systems and transducers. US Food and Drug Administration website. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/marketing-clearance-diagnostic-ultrasound-systems-and-transducers. Current as of June 27, 2019.

8. American Institute of Ultrasound in Medicine. Statement on mammalian biological effects in tissues with naturally occurring gas bodies. American Institute of Ultrasound in Medicine website. https://www.aium.org/officialStatements/6. Approved March 25, 2015.

9. American Institute of Ultrasound in Medicine. Statement on mammalian biological effects in tissues without gas bodies. American Institute of Ultrasound in Medicine website.  https://www.aium.org/officialStatements/63. Approved March 25, 2015.

10. Sidhu PS, Cantisani V, Dietrich CF, et al. The EFSUMB guidelines and recommendations for the clinical practice of contrast-enhanced ultrasound (CEUS) in non-hepatic applications:  update 2017 (long version). Ultraschall Med 2018; 39:e2–e44.

11. Claudon M, Dietrich CF, Choi BI, et al. Guidelines and good clinical practice recommendations for contrast enhanced ultrasound (CEUS) in the liver—update 2012: a WFUMB-EFSUMB initiative in cooperation with representatives of AFSMB, AIUM, ASUM, FLAUS and ICUS. Ultraschall Med 2013; 34:11–29.

12. American Institute of Ultrasound in Medicine. AIUM practice parameter for the performance of contrast-enhanced ultrasound examinations. J Ultrasound Med 2020; 9999:1–9.