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FDA Webinar: Marketing Clearance of Diagnostic Ultrasound

Systems and Transducers: Final Guidance

Moderator: Irene Aihie

August 22, 2019

1:00 pm ET

Coordinator: Welcome and thank you for standing by. At this time all participants are in a 

listen-only mode until the question-and-answer session. Today’s conference 

is being recorded. If you have any objections, you may disconnect at this 

time. I would now introduce your conference host, Ms. Irene Aihie. Ma’am, 

you may begin.

Irene Aihie: Hello and welcome to today’s FDA Webinar. I am Irene Aihie of CDRH’s 

Office of Communications and Education. On June 27, 2019, the FDA issued 

the final guidance document Marketing Clearance of Diagnostic Ultrasound 

Systems and Transducers.

The guidance provides detailed recommendations for manufacturers seeking 

marketing clearance of diagnostic ultrasound systems and transducers. In 

addition to outlining regulatory approaches for certain diagnostic ultrasound 

devices, this guidance document describes the types of modifications to a 

diagnostic ultrasound device for which FDA does not intend to enforce the 

requirements for a new pre-market notification 510(k).
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Today (Shahram Vaezy), Biomedical Engineer in the Office of (unintelligible) 

Diagnostics and Radiological Health here in CDRH will present an overview 

of this guidance document. Following the presentation, we will open the lines 

for your questions related to information provided through the presentation.

Additionally, there are other interests such as minor experts here with us to 

assist with the Q&A portion of our Webinar. Now I give you Shahram .

Shahram Vaezy: Hello. My name is Shahram Vaezy. I’m a Biomedical Engineer in the 

Division of Radiologic Health, also health and technology 7 (OHT 7) in the 

Office of Product Evaluation and Quality (OPEQ) in the Center for Division 

of Radiologic Health (CDRH). Our division is responsible for the regulatory 

review of diagnostic ultrasound devices that are primarily used in the 

radiology departments.

This Webinar is intended to provide an introduction to the recently-issued 

FDA guidance document: Marketing Clearance of Diagnostic Ultrasound 

Systems and Transducers. This guidance document was issued in the draft 

form on October 2, 2017, and in the final form, after addressing public 

comments on the draft, on June 27, 2019. 

The agenda for today’s Webinar is to provide a background on ultrasound 

regulation in the United States. It is important to understand the overall 

context of ultrasound regulation in such a fast-growing industry. I will 

provide the highlights and scope of the final guidance document to draw your 

attention to the significant changes as compared to the previous guidance 

document.

The significant changes are:
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• A compliance, or enforcement, policy under which the FDA does not 

intend to enforce compliance with the pre-market notification (510(k))

requirements. In other words, certain devices would not need 510(k) 

clearance prior to marketing. 

• A transducer element check feature to be implemented in diagnostic 

ultrasound systems to ensure proper probe performance for acquiring 

images or signals with sufficient accurate visualization of the anatomy 

and/or physiology of the tissues under interrogation.

A routine update of the current consensus standard and the guidance standards

referenced in the ultrasound guidance document. 

We will wrap-up with key takeaways of the final guidance document for 

preparing pre-market notifications. 

Some examples of the compliance policy applications will be discussed.

After the completion of the presentation, there will be some time for Q&A.

The objectives of this presentation are as follows: 

First, I will provide an overview of the regulatory history of diagnostic 

ultrasound devices in the United States, a synopsis of the various FDA 

guidance documents for diagnostic ultrasound devices. 

Next, I will briefly present on the significant growth of the ultrasound industry 

and the associated regulatory considerations. It is important to understand 

how the FDA could adjust to the technological advancements of the industry.

I will present on the major differences between the previous guidance 

document issued in 2008 and the recent final guidance document issued on 
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June 27, 2019. Hopefully, this information will help us become familiar with 

the new regulatory evaluation.

Okay, let’s get started with a brief background on the regulation of diagnostic 

ultrasound devices. 

First and foremost, it is important to understand that diagnostic ultrasound devices are considered 

pre-amendment medical devices. In other words, there were diagnostic ultrasound devices 

marketed prior to the 1976 medical device amendments to the federal Food, Drug and Cosmetic 

Act which is known as the Act. Therefore, device manufacturers may seek regulatory clearance 

of their devices based on demonstrating substantial equivalence of their device to those marketed 

legally prior to 1976. Such a device would be considered a Class 2 medical device. 

Importantly, most diagnostic ultrasound devices are considered belonging to Class 2 and receive 

marketing clearance from the FDA to the through the premarket notification also known as the 

510(k) process, 510(k) being the section of the Food, Drug and Cosmetic Act where this 

requirement is defined.

The FDA issued the first diagnostic ultrasound guidance in mid-1980. Several 

other guidance documents were issued following the 1980 guidance. The last 

guidance document before the current one was issued on September 9, 2008.

Finally on June 27, 2019, the FDA issued a revised guidance document 

entitled “Marketing Clearance of Diagnostic Ultrasound Systems and 

Transducers, Guidance for Industry and Food and Drug Administration Staff.” 

And now for the recently-published guidance document. 
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While the majority of this guidance document is similar to the previous 

version, there are some noteworthy differences that need to be highlighted. 

These are as follows:

Perhaps the most significant highlight of the recent guidance is a compliance policy, otherwise 

referred to as enforcement policy. Based on this policy, the FDA does not intend to enforce 

compliance with the 510(k) requirements for certain modified ultrasound and transducer devices 

that have already obtained an initial 510(k) clearance when certain conditions apply. Let me 

provide a bit of background for this policy and elaborate on its implications. 

The medical ultrasound industry has experienced a tremendous growth and 

technological advancements. The advancements have been in multiple fronts. 

There are significant advances in the engineering aspects, both hardware and 

software of diagnostic ultrasound devices.

We have seen advances in transducer technology, signal processing, 

visualization and overall extraction of information from basic echo 

information gathered from tissues. 2D arrays, elastography and 3D

visualization are examples of these advancements.

There are significant advances in the clinical applications of ultrasound as 

well. Examples are in musculoskeletal, neural and contrast imaging. Also 

there are significant advances in the development of application-specific 

systems primarily in the form of point-of-care, portable devices. These 

systems are primarily based on technologies and devices that have been 

applied in the clinical conditions for a number of years.

So we have a technology at a certain point in its maturity that we have a 

number of well-established modes of operation, in well-defined parameter 
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ranges, that have been evaluated by the FDA for many years. Furthermore, 

there’s a rich track record for these technologies, making them very known 

from both engineering and clinical perspectives.

A reasonable regulatory adjustment to these changes would be to update our 

approach through regulation of ultrasound devices. The recent guidance is in the spirit of a least 

burdensome approach to allow manufacturers with an established track record of ultrasound 

device development to make certain modifications to their devices more quickly without the 

need to submit another 510(k). This enforcement policy is intended to further promote and 

protect the public health by allowing the availability of a wide range of versatile ultrasound 

devices for clinical care.

Another significant highlight of the recent guidance document is the 

recommendation for manufacturers to incorporate a transducer element check in the probes. This 

feature was introduced a result of our continued surveillance of the industry. We have seen 

numerous examples of probe performance issues due to transducer aging, damage or other 

problems. The transducer element check was introduced to ensure continued safety and 

effectiveness of the probe. We will get into the details of this feature in just a few slides. 

Clearly the recent guidance document includes updated consensus standards, and updated FDA 

guidance documents.

So as a summary, the recently-issued guidance document:

• supersedes the previous guidance document issued in 2008. The title of that document 

was very similar to the recent one, as noted here. 

As described on the previous slide, there are a number of specific types of modifications for 

diagnostic ultrasound device for which FDA does not intend to enforce the requirements for a 

new pre-market notification 510(k). The 2008 guidance had specified a new 510(k) for these 

types of modifications. We will get into these types of modifications in just a few slides. 

And the new guidance document includes a new transducer element check that applies to all 

ultrasound devices covered in this guidance. Therefore, whether a 510(k) would be required or 
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not, manufacturers should start implementing this new feature in their diagnostic ultrasound 

systems. 

Okay, let’s go over the compliance policy. The compliance or enforcement 

policy is that FDA does not intend to enforce compliance with the 510(k) 

requirements for certain modified ultrasound devices.

Clearly the manufacturer has a 510(k) clearance for the new device that has 

now been modified and is the subject device in question. In order to qualify 

for this compliance policy, a number of conditions should apply to the 

modified ultrasound device.

I will list these conditions in this and the following slide, the full descriptions 

of these conditions are provided in Section 5.1.2 of the guidance document. 

The conditions are as follows: 

Intended use of the modified device is not changed. The intended use remains to be diagnostic 

use via obtaining echo signals, new clinical applications are not introduced unless the 

manufacturer has clearance for such use or another device,no disease- or treatment-specific 

indications, no use of contract agents. and the device remains to be for prescription use. 

Reusable ultrasound bronchoscopes are excluded and no intracardiac or intravascular indications 

should be introduced.

The device is not a reusable device subject to requirements for the submission 

of reprocessing labeling and validation data. As a specific example, sterile

use should not be introduced if not previously cleared. 

The modes of operation for the modified device are well-established. Our current thinking on 

the modes of operations that are well-established are provided in Table 2 of the guidance 
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document. Pretty much no surprises here. For example, adding any or a combination of the 

basic modes such as A-mode, B-mode. and Doppler will qualify for the compliance policy. 

Example of the modes not included are shear wave elastography, acoustic attenuation mapping, 

transmission-based imaging and sound speed measurement.

The modifications should not lead to acoustic outputs that exceed the 

recommended maximum output levels. This is simply a safety consideration. I would like to 

take this opportunity to point-out that, as always, acoustic output levels beyond those specified in 

the guidance document and what have historically been used by manufacturers may be utilized in 

an ultrasound system. However, those devices would not be qualified for the compliance policy 

and the manufacturers should submit a Q-submission to discuss their plans for such a 

development. This is described in Section 5.2.4 of the guidance document,where the 510(k) 

submissions are described.

The modifications do not result in ultrasound parameters outside well-known

ranges specified in the guidance document. These parameters are a center 

frequency of 1 to 20 MHz, peak rarefactional pressure of up to 7 MPa, number 

of cycles in pulse up to 100, excluding the CW Doppler and coded excitation

modes of operation and pulse repetition frequency of 100 Hz to 20 kHz.

Continuing with the conditions for a device that would qualify for the 

compliance policy, the modifications of the device do not utilize novel

mechanical or thermal effect for imaging or measurements. This is to ensure 

that the safety and effectiveness of the device are reviewed appropriately.

There is currently a fairly good understanding of the mechanical and thermal 

effects induced using acoustic output level specified in the guidance document with reasonable 

levels of acoustic dose. However, at higher levels, such as those that could be used for Acoustic 

Radiation Force Impulse (ARFI) imaging,there might be biological effects that should be 

analyzed. Similar to what I mentioned on the acoustic output levels, the cases where the level of 
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thermal or mechanical effects could be increased as a result of certain modifications, 

manufacturers are encouraged to discuss their plans with the FDA via a Q-submission.

As for measurements and analyses that may be introduced as a result of a 

certain device modification, they should be clearly described for the users and 

the users should be able to adjust the associated control parameters with such 

measurements and analysis.

This is considered an important component of these measurements. It should 

be possible to reverse the newly-introduced image processing method. Also,

it should be possible to change or adjust assumptions used in a measurements,

and very importantly the device operator should be informed fully on the 

algorithms used for these measurements and analyses.

Clearly if a manufacturer does not plan to provide controls for these 

measurements, then the device would not qualify for the compliance policy 

and a 510(k) should be submitted to the FDA to allow the FDA to review the 

safety and effectiveness of the measurements and analyses.

As I have stated in the highlights of the new guidance document, 

manufacturers should include a transducer element check for all probes with 

the device. This is an important feature that I will discuss in detail in the next 

couple of slides.

Similar to the recommendations in the previous guidance document, the 

transducer surface temperature should fall within a well-defined range, and 

appropriate transducer covers should be recommended to users.

And now to the transducer element check that I alluded to earlier. 
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First and foremost let me say, this feature is introduced as a result of our postmarket analysis. There have been reports of transducer malfunctions that have 

gone unnoticed by the operators, not due to the operator error, but primarily 

due to the complexity of the image formation processes that may not 

conducive to revealing transducer malfunction.

Therefore, it’s our thinking that a transducer element check would provide a 

method to ensure the safety and effectiveness of the probe to provide the 

image quality originally intended. 

Importantly the transducer element check applies to all diagnostic ultrasound 

devices regardless of whether they would qualify for the compliance policy or 

not.

The characteristics of the transducer element check are as follows:

First, the transducer element check should be integrated an integrated test. 

Basically, the manufacturers should implement this feature as part of each 

probe.

The integrated tests of transducer performance should be performed each time 

a transducer is connected to the main system or activated. Please note that 

this feature is not meant to slow-down the busy workflow of scanning for the 

operators. Manufacturers are encourage to design innovative methods of 

performing this test while maintaining, or improving, the existing workflow 

structure and timeframes.

The transducer performance test should be accessible by competent technical 

personnel such as operators or service personnel. This recommendation is 
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based on the necessity to keep the operators informed about the transducer 

performance and image quality.

We certainly appreciate that the different performance specifications may be 

necessary for transducers based on the application and system configuration. 

However, each device should include some level of testing. For example, an 

impedance check of each transducer element may provide a preliminary 

evaluation of the element integrity and function.

Next, of great importance, in the spirit of keeping the operators informed on 

the transducer function, and maintaining image quality, device manufacturers 

should implement methods to communicate their results of the transducer 

performance test to the operators.

This information should clearly identify regions of the image that could be 

potentially compromised by transducer malfunction. This integrated test of 

transducer element check should also generate a report on the performance of 

the probe under test for documentation.

The report should generally include a list of elements, or smallest available 

patches of elements that have been compromised. Finally, the transducer 

element check should be available to the operators to initiate any time a 

particular probe is suspected of failure.

As I mentioned earlier, these characteristics have been included to ensure 

continued safe and effective operation of the probes monitored by the folks 

who are working with these systems on a daily basis. 

And now on the update of consensus standards that are recognized by the 

FDA and have been referenced in the new guidance document.
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These standards are:

Referred to as of the Output Display Standard in the previous guidance 

document. It’s IEC 60601-2-37 on the basic safety and essential performance 

of ultrasonic medical diagnostic and monitoring equipment, the 2015 update,

IEC 62359 ultrasonic field characterizations for the determination of thermal 

and mechanical indices related to medical diagnostic ultrasonic fields, the 

2017 update.

IEC 62127-1 ultrasonic hydrophones, Part 1 for measurement and 

characterization of medical ultrasonic fields up to 40 MHz, 2013 issue date 

and a Part 2 of the same standard IEC 62127-1 ultrasonic hydrophones Part 2 

for calibration for ultrasonic fields up to 40 MHz, annex 1, issued in 2013.

IEC 60601-1 for basic safety and essential performance of medical electrical 

equipment, electrical safety, the 2012 update and finally IEC 60601-1-2 for 

basic safety and essential performance of medical electrical equipment for 

electromagnetic disturbances, the 2014 update.

An important note is that there is an FDA guidance document on the

appropriate use of the voluntary consensus standards in pre-market 

submissions. I will provide a link in the next slide.

As for the update of the FDA guidance documents they are, as I just 

mentioned, there’s an update on the appropriate use of voluntary consensus 

standards in pre-market submissions for medical devices, issues dated 

September 14, 2018.
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An important guidance document is deciding when to submit a 510(k) for a 

software change to an existing device, dated October 25, 2017. The new 

ultrasound document is consistent with the policies outlined in this guidance 

document.

A very important guidance document is: Request for feedback and

meeting for medical device submissions, the Q-submission program that I 

alluded to earlier. This is dated May 7, 2019. This guidance document 

provides information on the mechanisms to seek FDA feedback on various 

topics related to the regulatory pathway of a medical device. This is a free 

program. Early interaction with the FDA is highly encouraged to allow the 

FDA to provide regulatory feedback on device development. 

The FDA guidance document Reprocessing medical devices in healthcare 

settings, validation methods and labeling, dated March 17, 2015, provides 

information on cleaning and disinfection of medical devices.

Also, the FDA guidance document Submission and review of sterility 

information in pre-market notifications, the 510(k) submissions for devices 

labeled as sterile, dated January 21, 2016. The reference to the FDA guidance 

document on electromagnetic compatibility, has also been updated.The latest 

guidance document was issued on July 11, 2016. 

Last but not least, the FDA guidance document content of pre-market 

submissions for management of cybersecurity in medical devices, dated 

October 2014, is a new guidance document referenced in the ultrasound 

guidance document. 

So, for key takeaways, the recent guidance document enables manufacturers 

with an established track record of ultrasound device development to make certain modifications 
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without the need to submit another 510(k). In addition to providing a less-burdensome approach 

for manufacturers, this policy will help reduce burden of review of modifications with 

established history of safety and effectiveness. 

A new transducer element check is included in the guidance document as a 

mechanism for users to test possible degradations due to aging, and ensure 

continued safety and effectiveness.

Now as for the transition period, the guidance document is effective 

immediately but please note that the guidance document represents FDA 

recommendations, manufacturers should address these recommendations.

As for other forms to discuss the guidance document, there will be 

presentations at professional societies. 

We can go over some examples of the compliance policy applications. We’ll 

provide a brief list of these examples. 

First example, adding continuous wave (CW) and pulsed wave (PW) Doppler interrogation 

methods to the mode of operation of a device. Suppose the device had only B mode previously 

and the manufacturer has added CW and PW. These are the modes of operation that are listed in 

Table 2 of the guidance document as I mentioned earlier. 

A second example, adding an algorithm that measures the volume of an organ

on its scientifically well-established image segmentation and volume calculation methods. The 

scientific basis of the algorithm should be disclosed to the users for optimal usage of the 

measurement. This is an example of adding a measurement or analysis. Remember that this 

addition would require that the algorithm of volume measurement be provided to the users. Also 

the controls for the algorithm should should be provided.
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Another example would be adding a new transducer with similar indications 

for use and similar acoustic output as one already cleared in the system. The new transducer 

may have a new clinical application. This is an important point. if the particular clinical 

application has been or the indication has been cleared for another transducer manufactured by 

the same manufacturer. The previous – an interesting point - guidance document allows for the 

addition of transducers without a 510(k) only if the indications for use of the transducer were a 

subset of the main system indication. The new guidance allows the addition of a new transducer

with a new indication if such an indication had prior clearance on another system of the 

manufacturer. 

Finally adding a B-mode noise reduction filter for general imaging use to a 

system. Similar to where examples of the volume calculations, the 

characteristics of the algorithm used for the noise reduction should be 

provided in the labeling material.

There is a line to the guidance document. 

I would like to thank you for your attention and we can now move to the 

Q&A.

Coordinator: We will now begin our formal question-and-answer session and if you would 

like to ask your question, please press star 1 on your touch-tone phone. You 

will be announced prior to asking your question. If you would like to 

withdraw your question, you may press star 2. One moment for the first 

question. 

Shahram Vaezy: While we are waiting for the questions, I can discuss one of the questions that 

we have received after the guidance document was issued. The question has 

been on the transducer element check which is a new component of the 

guidance document. The question has been on the development of these 
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features that may take some time by manufacturers and the question is how 

can this be done for the submissions that are underway if you will?

We have basically, as I mentioned before, what’s recommended in the 

guidance document is really just a recommendation and we hope to see that 

manufacturers plan to implement these features. We would like to see a plan 

for transducer element check in future submissions in the future devices, so, as 

always, we are open to discussions on how to implement such transducer 

element check in your device. 

Irene Aihie: We’ll now take our first question.

Coordinator: The first question is coming from (Chris Phillips). Your line is open.

(Chris Phillips): Hi, I have a question related to the guidance. In the previous version of the 

guidance, there was a suggested template for the 510(k) submissions related to 

ultrasound devices and that doesn’t appear to be the case in this new revision 

of the guidance. Is it suggested that we go back to using the standard 510(k) 

order and template or is it hoped that we continue to use the ultrasound

guidance from previous as a template for our submissions?

Shahram Vaezy: I’m sorry, if you could elaborate on what you mean by the template for the 

510(k).

(Chris Phillips): So there was a recommended order that aligned with the previous guidance 

that we had been utilizing so that we had the right pieces in place whether we 

were talking about Class 1 or Class 3 ultrasound systems and the right places 

to put indications for use. Essentially our 510(k) used to be aligned with the 

order of the previous guidance. Is it hoped that we default back to the 
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standard 510(k) template essentially at this point, or is there a specific 

ultrasound template?

Shahram Vaezy: There is no specific ultrasound template. As you note in the new guidance 

document, the 510(k) Section has been made pretty similar to what we had in 

the previous guidance document. The only new element there is the 

transducer element check and if you want to use your already-setup template 

for 510(k) submission, that would be fine.

(Chris Phillips): Okay, thank you very much.

Shahram Vaezy: Thank you.

Coordinator: And once again if you do have a question, please press star 1 on your touchtone phone. The next question is coming from (Gina). Your line is open.

(Gina): Hi. I’ve got a quick question. I deal with the non-OEM service and repair 

community and I want to know if they replaced the arrays in an OEM device, 

does that require the non-OEM supplier to file for a 510(k) for that transducer 

now?

Shahram Vaezy: That’s a very good question and the response hinges on whether the 

replacement of the transducer would have any bearing on the safety and 

effectiveness of the probe. So and that has to be definitely tested and 

documented by the facility that’s doing this whether it’s a repair or a 

remanufacturing.

If there is any impact on the safety and effectiveness of the probe, this would 

be considered a remanufacturing and for remanufacturing the sponsors need to 

submit a 510(k) if there is no bearing on the safety and effectiveness and 
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basically the performance of the probe, then it would be considered a repair 

and a 510(k) is not required.

(Gina): Okay, thank you.

Shahram Vaezy: Thank you.

Coordinator: We have no further questions at this time. I will now turn the call back to Ms. 

Irene Aihie. 

Irene Aihie: Thank you. This is Irene Aihie. We appreciate your participation and 

thoughtful questions. Today’s presentation and transcript will be made 

available on the CDRH Learn Webpage at www.fda.gov/training/cdrhlearn by 

Friday, August 30. If you have additional questions about today’s 

presentation, please use the contact information provided at the end of the 

slide presentation.

As always we appreciate your feedback. Following the conclusion of today’s 

live Webinar, please complete a short 13-question survey about your FDA 

CDRH Webinar experience. The survey can be found at 

www.fda.gov/cdrhwebinar immediately following the conclusion of today’s 

live Webinar. Again, thank you for participating and this concludes today’s 

Webinar.

Coordinator: This will conclude today’s conference. All parties may disconnect at this 

time.

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