Radiopaedia Blog

 

As part of a recent 5 part blog by Lincoln Berland MD titled You Don’t Need the Ultrasound Biopsy Guide!, we ran a survey to explore a few facets of use of guides. Specifically we sought to examine if use: 

  1. varies from region to region
  2. is related to when an individual learned to perform biopsies
  3. is related to number of biopsies performed

Before looking into these questions specifically, let's get an overview of respondents. 

We received 307 responses, with the majority of individuals not using a guide (72% never/almost never). Respondents reported performing a variable number of procedures a month, roughly evenly split between 2-10, 20-30 and >30. Most (80%) had been performing these procedures for less than 10 years. Of the 307 responses, 280 provided country information (from 70 different countries). 

 

 

Does use depend on the country or region you live in?

The fact that generally guides are not used, and that in many countries only 1 response was received, makes it difficult to be specific. Grouped into regions however there does seem to be a trend for greatest use in Europe and the Middle East, with the average response being somewhere between "not often" to "sometimes". The Americas (both north and south) and Asia reported guides used on average "not often", whereas Africa and Oceania (Australia and New Zealand) reported "never / almost never" (see below). 

 

 

Does use depend on when you trained?

The data was very skewed towards relatively junior radiologists with the vast majority being under 20 years experience, and most with fewer than 10 years. As such although the highest use was in the most experienced respondents, the number of responses was too low to infer any actual trend. 

 

Does use depend on how many biopsies you perform?

The strongest correlation seems to be with how often biopsies are performed. Radiologists performing on average more than 30 biopsies a month had the lowest average frequency of use (only 0.39; 0 = "never" and 1 = "rarely"). 

 

 

Conclusion

As a result of these relatively low numbers, anything other than simple descriptive statistics above are not really possible and statistical significance is unlikely to be met (even if one believed that the respondents were a truly random sample of radiologists across the globe, which clearly they are not). 

Having said that, I think that one can safely state that the use of ultrasound guides is not the default and that many (almost certainly most) radiologists rarely if ever use guides. It also feels that there is likely a strong influence on the number of procedures performed, with more experienced radiologists finding that the guides are unnecessary and perhaps hinder. 

Regional variation is probably more granular that we can assess, largely depending on what is the norm for the department in which you trained or are currently working. 

Thanks again to Lincoln Berland for his thought provoking series on the topic. 

 

  • part 1 - introduction
  • part 2 - planning and preparation
  • part 3 - approach and visualisation
  • part 4 - the biopsy
  • part 5 - additional benefits & conclusion
  • survey results

 

A. Prof Frank Gaillard is a neuroradiologist at the Royal Melbourne Hospital, Melbourne, Australia, and is the Founder and Editor of Radiopaedia.org. 

NB: Opinions expressed are those of the author alone, and are not those of his employer, or of Radiopaedia.org

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Part 5 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

Why “Do No Harm” is easier with a freehand technique

One of the observations that persuaded me not to use the guide is watching what happens to the needle when someone else is using the needle guide. If there is some difficulty seeing the needle or lesion, there is a strong tendency to want to move the transducer to see better while looking at the screen to find the needle. But the needle is already inside the patient! So if you are looking at the screen while you are moving the transducer, the needle may be bending and torquing while you aren’t watching. I have squirmed while seeing needles bend over 30-45 degrees! How could that not be traumatic to the tissues? It can even causing laceration at the organ surface or even internally, with significant lateral pressure on the end of the needle. That virtually can’t happen with a freehand technique. If you have to reposition with freehand, you partially withdraw and reinsert at a different angle, but I believe that is considerably less traumatic than the bending and angling that may occur with the needle guide.

Time and cost

All of the trickiness of setting up to use the guide takes time — sometimes a lot. I believe that I routinely have been able to perform procedures about 30-50% faster than someone using the guide (which is one big reason the technologists and nursers looked forward to my procedures days). The added cost of the device is obvious. However, there are additional costs of increased room time are real. I have also seen biopsies unnecessarily delayed because not all of the components needed were in stock or in the room or the device that attaches to the transducer actually broke and someone goes to find a replacement. Sometimes the device perforates the sheath and the user feels obligated to re-sterilize and start over… all totally avoidable problems if you don’t use this device.

Conclusion

If you believe that you cannot “walk” (biopsy) without a “crutch” (guide), then you don’t want to try to “walk” and do not develop and maintain the muscles and skills you need. I believe that no one would argue that doing biopsies requires fine eye-hand coordination and other visual and motor skills whether or not you use the guide. However, I believe that using the guide limits those skills from being thoroughly and frequently exercised, without you consciously realizing it. This may limit both your desire and ability to manage ultrasound-guided biopsies, particularly in challenging situations.

So, I recommend that if you have been accustomed to using the guide, try to toss the crutch aside from time to time, first in easier cases until you feel comfortable with your newly developing level of skill and I think that you, your technologists and patients will all be better off for the effort.

Survey

We have conducted a survey to get some insight into use of ultrasound biopsy guides and the results are now available! Read on... 

 

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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Part 4 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

Geometry

When planning the procedure, you need to visualize the geometry of the transducer and needle in your head and take care to view the true plane of the transducer. You must make sure that when you insert the needle, that it is in the plane of the transducer and that as you manipulate both the transducer and needle that you coordination the planes. The human eye is also remarkably good at estimating angles and you will be surprised how close you are to the proper angle when you start doing these. Yes, these are skills you may need to hone, but ones that help for other procedures and ones that virtually anyone who does procedures using needle guides can master…. really. 

Positioning

First, positioning the patient and yourself is crucial, although many do not adequately account for their own positioning as well as they do the patient’s positioning. You need to be able to brace your scanning arm and sometimes the arm with which you are doing the biopsy, so you may need to elevate the table or move the patient. So, once the patient and you are properly positioned, you should brace yourself with your hand, arm and/or elbow resting on something immobile. I bring the lesion into optimal view, but before I actually insert the needle, I try to place my eyes directly within the plane of biopsy itself. If you are looking AT the plane rather than WITHIN the plane, you may not appreciate a subtle deflection of the needle from the viewing plane.

Finally — insert the needle

Once you see the lesion and you are properly braced, nothing is going to move (at least very much). If you are seeing the lesion and you know that you are inserting the needle in the plane of viewing, then you know that when you insert the needle, that it will be in the plane of viewing or very close. Here is the key that is nearly impossible for novices to accomplish psychologically: You should be looking at the needle and transducer as you insert, NOT the screen. Once you take your eyes off the needle and plane and turn your head (or even just your eyes) to look at the screen, you lose your eye-hand coordination and are likely to inadvertently incorrectly angle the needle or transducer. I have even sometimes stood in front of the screen or held my hand over it so the resident cannot see it as she/he inserts the needle. 

If you are looking at the needle while you insert it, it will be close to the right place. So, upon initial insertion, I don’t usually go all the way down to the lesion unless it is large and the orientation wouldn’t be a problem. I want to get it through the surface of the organ and within range of being able to see it. One other point, though, particularly for novices, is that you shouldn’t incrementally edge the needle into the patient millimeter by millimeter because you are scared to hurt something. If you have planned properly, you know that your route is safe and you will cause the patient considerably less discomfort if you insert swiftly through the sensitive peritoneum, liver capsule or other tissue plane rather than stretch and tent those surfaces as you insert slowly.

Readjust

Once the needle is inserted, you can find it with subtle readjustments of the transducer and quickly figure out how to reposition, if necessary. You just need to appreciate that the screen and real geometry are nearly the same so that you intuitively know which way you need to re-angle the needle. So, yes, you may need to withdraw the tip to a more superficial position and reinsert. There are many different types of needles that you may use, so I won’t discuss actually acquiring or saving the specimens. Using the freehand technique is independent of these factors.

In the final 5th part of this series, I will discuss why the freehand technique is often less traumatic than using the needle guide and is cheaper and faster.

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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Part 3 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

In part 1 and part 2 of this series, I discussed issues related to planning, scanning, prepping and local anesthesia. In this part, I will first describe more about locating your ideal sites (not a single site). As I mentioned, I always mark the spot of insertion and find at least one point for viewing. This planning stage is usually the longest part of the procedure, other than the consent and timeout. The longer you plan, the faster the actual procedure goes.

Preferred subcostal approach

Generally, for liver lesion biopsies and some abdominal mass biopsies, if the lesion is high in the abdomen, I prefer inserting the needle subcostally, rather then intercostally, although I don’t adhere to that rigidly if it simply isn’t possible. Since you are penetrating the diaphragm/potential pleural space for an intercostal approach, you may be concerned about seeding the pleura with tumor or infection. In these cases, you want to at least attempt to plan a subcostal approach.

So, particularly with superficial lesions high in the liver, the best subcostal approach may require a very steep angle, sometimes with the needle almost parallel to the surface of the abdomen. It is often impossible to use a guide to achieve this because the footprint of the transducer plus the guide is too long, the guide does not allow such an angle and the lesion may not be visible for the position you have selected for insertion. Additionally, with a steep angle, often a fair amount of pressure is necessary and the sharp edges of the guide may be uncomfortable as they dig into the patient. Your position may also be awkward. Any of this sounding familiar to you guide-users?

More needle length available

One other issue that guide-users may not appreciate is that because of the required step-off of the needle portal to the skin, you cannot insert the needle hub all the way to the skin as you can freehand. This may require you to select a longer needle, which is more awkward to use.

Watch from anywhere

Freehand, you can position the needle optimally and then place the transducer intercostally, subxiphoid or elsewhere - wherever you can see the lesion and needle. You are no longer limited when picking your insertion point to accommodate for the fixed geometry of the guide. You can actually do biopsies that you might otherwise abandon because you can’t figure out how to do them with the needle guide. I have been invited in to help salvage these types of difficult procedures and simply have removed the guide. I have been able to acquire the tissue within a few minutes while the first radiologist had struggled for over 1/2 hour trying to use the guide with a difficult angle

See the lesion and needle better

Also, if when you start the procedure, and you are using the guide, you may find that you cannot see the lesion as well as you did when you marked the spot. There is a reason for this. If you use the guide, you likely will have a plastic sheath and gel inside the sheath. There may be a few gas bubbles trapped in the gel. The presence of the sheath and the gel actually degrades your visualization of the lesion and needle. Without the guide, sheath and gel, your visualization should be comparable to when you localized the lesion when you started.

In part 4 of this series, I will discuss the final stages of planning and actually performing the biopsy.

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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I have recently submitted an editorial to the AJNR on my opinion that we should not be using disk-osteophyte-complex (DOC) term because it is a cop-out in not using the gradient echo T2W image to distinguish disk from osteophyte (disk bright, osteophyte dark). My surgeons say knowing whether the cervical disease is a disk versus an osteophyte is very important to them (diskectomy for disk versus posterior decompression for big osteophyte etc). Can I hear from other voices as to why DOC has become a default term for all DJD pathology in the cervical spine?

 

David M. Yousem is Director of Neuroradiology and a Professor of Radiology at the Johns Hopkins Hospital School of Medicine 

Twitter: @dyousem1

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

 

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