Radiopaedia Blog

Part 2 of a 5-part series on the advantages of a freehand technique over a needle-guide system for ultrasound-guided biopsies. If you haven't read the rest of this post, please start at part 1

Planning and scanning

When using the needle guide, many users identify only one spot to scan and then insert the needle through the guide portal to the side of the transducer. Therefore, they may not have adequately examined the actual route through which the needle will pass to see if it will encounter any structures unsafe to puncture. The needle is fixed at a fairly shallow angle to the transducer and may be harder to see. I will discuss this more in Part 3.

To optimize the freehand technique, you should look for TWO spots. One should be over the direct route of the needle (somewhere outside where the transducer will be while you are guiding the needle) and this should be marked before prepping the skin. The other point will be the position you will be using to view while inserting the needle. You don’t need to mark this because it might change, but you at least need to know that there is at least one good viewing point.

For freehand biopsies, unlike using the needle guide, there is no limitation to where you view, other than you need to be able to be within the plane of the needle. Of course, the closer your transducer is to perpendicular to your needle, the more easily visible it should be because of basic principles of ultrasound reflection. So, a position farther away from the needle may actually give you a better chance of finding it quickly and seeing more of it.

Prepping

While we like to think that our procedures are “sterile,” they are better termed “clean.” I don’t want anyone to suggest that I am being capricious about spreading nosocomial infections, because I religiously follow hand washing protocols. However, I believe the perception that we need true sterility suggests a glorification that what we are doing is just short of a surgical procedure. Actually, we use a needle not really much larger than one used to draw blood, for which a lab tech may only use a quick alcohol swab swipe. I use a needle that does not even require a scalpel nick. If you prep your transducer and skin thoroughly with betadine and use sterile gloves, you should not induce an infection. I am not aware that I have ever done that.

Anesthesia

Adequate local anesthesia is one of the most important aspects to optimizing the patient’s experience. So, I focus strongly on this part of the procedure. I am fascinated by the consistency (incorrectly, I believe) with which residents perform local anesthesia for ultrasound-guided biopsies whether the guide is used or not. This even includes thyroid FNAs. If someone else has instructed them before I observe their first procedure, they typically inject the lidocaine by taking the transducer in their left hand and placing it on the skin. They then take the lidocaine syringe in their right hand and insert it vertically into the skin as though they were placing the needle through an invisible guide portal! It is always awkward to use the syringe at that angle with one hand and then reliably achieve anesthesia at the skin. Clearly, this is a technique “learned” from doing deep biopsies with the guide. So, when using the guide many also attempt to achieve local anesthesia (often less effectively) through the needle portal rather than doing it as I describe below.

Instead, I inject in two stages. At the first stage, I hold the syringe in both hands (with no transducer) and insert the needle subcutaneously tangential to the skin. I then inject and raise a wheal. With the vertical (needle-guide-like technique), it is difficult to verify that you are truly numbing the skin and superficial tissues. I have observed a number of instances where the needle-guide approach to local anesthesia has led to unnecessary pain while doing the biopsy to the point where patients have asked to terminate the procedure. I instruct the resident that the first step should be to numb the skin, because it will be less painful when you inject the deeper tissues, I also point out that you don’t need a transducer to see the skin, which is often a liberating concept for them. They can then fully control the needle, the location of and the volume of lidocaine injected. Note that I believe that you should do it this way even if you DO use the needle guide.

Then, after a moment to allow anesthesia to take effect while I continue setting up the tray, I begin a second stage. I use the transducer to locate the proposed needle track and achieve deeper local anesthesia. Since I am trying to get deep to the skin, I take the transducer in my left hand and pick up the syringe with my right hand with my thumb on the plunger, insert and watch with ultrasound. As soon as I get to the depth I want, I can inject to cover the entire tract I will be traversing.

In part 3 of this series, I will discuss more about planning the procedure to design the best approach and about the added flexibility you have with a freehand approach.

In this series: 

Lincoln L. Berland, MD is Professor Emeritus of the Abdominal Imaging Section of University of Alabama at Birmingham. 

Twitter: @linkberland

NB: Opinions expressed are those of the author alone, and are not those of his employer nor of Radiopaedia.org. 

 

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In many cases it’s just best to adequately describe your findings, but every radiologist knows about the myriad of classification and grading systems out there. 

Radiopaedia.org often comes to the rescue if you come across an obscure classification and even for often used ones if you just can’t remember its details or considerations. 

However, it’s also good to know if a classification is still being used or when it was last updated. And on a historical note it’s just nice to find out how it developed and who came up with it.

Over the last months a team of our editors (Piotr Gołofit, Varun Babu, Praveen Jha, Matthew Morgan, Frank Gaillard, Jeremy Jones and yours truly) worked together on “Operation Bookworm” to provide just that information for almost 170 classifications and gradings at Radiopaedia.org, also giving these articles a small facelift where needed. That’s about a third of our articles on classifications and gradings.

Some examples:

We believe that these additions are very relevant to everyday clinical practice and welcome everyone to help keeping them up to date and add this information in the remaining articles. 

This project is a great example of ongoing critical appraisal of existing content at Radiopaedia.org, illustrating the dynamic and cooperative nature of a community based encyclopaedia that everyone can use and contribute to for free and forever.

We hope you enjoy it!

Tim Luijkx is a Radiopaedia senior editor, and radiology registrar at the Meander Medical Center in Amersfoort, the Netherlands

Twitter: @TimLuijkx

NB: Opinions expressed are those of the author alone, and are not those of his employer nor of Radiopaedia.org. 

 

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I had no choice. I began doing ultrasound-guided biopsies in 1979 during my fellowship and there was no such thing as a biopsy guide. We had to figure out how to do it freehand ourselves and gradually, with the help of colleagues at other institutions, refined the technique. When the needle guide was developed, I found it limiting and awkward and became concerned about some of its risks as I saw others struggling with it.

Before you dismiss this as the ravings of an over-the-hill radiologist who can’t learn new tricks, my yield and adverse effect rate has been comparable (I think better), our technologists generally have preferred working with me on biopsies because my freehand technique is quicker and less uncomfortable for the patient. I have even gotten some of my colleagues to sometimes adopt my approach despite their being taught the dogma that the guide is mandatory for deep abdominal biopsies.

Can you really set the needle guide on the shelf?

There has been a myth in our department that I am the only one who CAN do all ultrasound-guided biopsies freehand (which I think is an excuse for others not to try). Anyone who really knows me understands that is absurd. I am totally uncoordinated and I cannot conceivably have some unattainable innate fine-motor skill for this. The technique I will describe can be done by anyone with basic guided-biopsy skills if you are willing to be bold. But why bother? Because I believe that this approach decreases the time to do procedures, decreases patient risk, increases flexibility and decreases cost.

Of course, I am only referring to deep abdominal and pelvic transcutaneous biopsies here. There is no question that there are situations, such as endovaginal or transrectal biopsies where a specialized needle guide is necessary. Also, I will save discussing principles of biopsies, needle choice, optimizing and saving the specimen, patient communications, timeouts, etc. for now, Instead, I will focus on why and how to do freehand biopsies and how the needle guide and the freehand techniques compare.

 

Typical ultrasound guide (light blue arrow) with expected needle trajectory (yellow arrows). Images adapted from: D. Plut, S. Ponorac, D. Vidmar-Bracika “Diagnostic value of ultrasound-guided fine-needle aspiration cytology in diagnostics of solid renal lesions” ECR 2013 (view poster here

 

What about small and subtle lesions? 

Isn’t it necessary to use the guide for small lesions? The needle guide reliably takes you right to the lesion and assures a successful specimen, right? Can you needle guide-users say that is your consistent experience? What about the difficult-to-reach lesions? Can you see the subtle lesions as well after you put on the sheath with the gel inside? I will discuss these situations more later.

Why bother to learn how NOT use the guide?

Why did we need the guide? When I began doing biopsies, real-time ultrasound was truly primitive and deserved its moniker: “ultrasmoke.” Finding the needle was a serious challenge. Even holding the large transducer and awkward needles were limiting. We needed help! The inventors of the needle guides had great ideas and so help arrived. However, today, the needle is much easier to see and the needle systems we use are much lighter and more efficient. Nevertheless, many still believe that they are nearly obligated to use the “time-tested” help that I think we no longer need. 

Using the needle guide makes sense, right? It decreases the time to do the procedure because the needle goes right to the lesion, it increases precision and minimizes the need for repeat biopsies…except, in my experience, it doesn’t. It seems to be such an imperative for some that I have even seen the guide used for large lesions bulging the skin, for which you really don’t even need ultrasound or for fine needle aspirations of superficial thyroid nodules. This series is about how not to be the person that does that.

In part 2 of this series, I will start describing planning, prepping and administering local anesthesia for freehand biopsies and contrast those techniques to using the needle guide.

In this series: 

Lincoln L. Berland, MD is Professor Emeritus of the Abdominal Imaging Section of University of Alabama at Birmingham. 

Twitter: @linkberland

NB: Opinions expressed are those of the author alone, and are not those of his employer nor of Radiopaedia.org. 

 

 

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20th Sep 2016 09:30 UTC

Radiopaedia.org Rapids

We are excited to launch Radiopaedia.org Rapids project. Click through to access six packets of 30 plain films to help prepare for the FRCR 2B rapid reporting exam or just test your skills. 

Did you spot the solitary pulmonary nodule? 

Take a look at the corresponding CT, which shows the pulmonary nodule much more clearly. This patient had a confirmed pathological diagnosis of lung adenocarcinoma. 

Case courtesy of Dr Henry Knipe, Radiopaedia.org, rID: 29787

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20th Sep 2016 01:46 UTC

Cone beam CT project

A quick project aimed at creating a cone beam CT article and additional of new cases. 

  • Type: topic cluster creation
  • Results:
    • create new cone beam CT article
    • addition of two new cases
  • Duration: 1-2 weeks
  • Team: Matthew Lukies, David Gai, Jeremy Jones, Ian Bickle, Henry Knipe,
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