Mastering ultrasound-guided biopsies

RE: Mastering ultrasound-guided biopsies

Sarah Keir — Tue, 08 Jul 2025 21:06:48 GMT

Anthony and David have summarised liver biopsies well.

- FNAs for diffuse disease are only suitable to diagnose lymphoma, or hepatic lipidosis in cats (which in the UK is secondary disease). For diffuse disease (liver homogenous, normal or abnormal, or only increased liver enzymes) then you need laproscopic or laparotomy biopsies. I've given up doing Tru-cuts now as risky on cats and not large enough on dogs as we understand so many more of them have copper hepatitis and so all dog livers should have live copper quantification (or second best is semi-quantitive staining).

- FNAs for focal lesions is useful and you just need to practice. If you'd like to get more practical ultrasound tips, I teach ultrasound - either in practices or stand alone courses (https://www.vetartis.co.uk/attendance-abdominal-ultrasound-course-beginners-improvers/ ). Contact me if you'd like to know more.

Here is an example phantom you can easily make to practice.

RE: Mastering ultrasound-guided biopsies

David Mills — Tue, 08 Jul 2025 11:16:15 GMT

Cadavers are good for practice too if you can get consent (some forms have the option) - with the added bonus of harvesting actual cells that you can stain up and sense check.

RE: Mastering ultrasound-guided biopsies

William Easson — Tue, 08 Jul 2025 10:35:22 GMT

Thankyou for that advice; I got fairly confident with surgical biopsies of the liver before I spent 10years in night work. Now I'm back in the daylight hours. Good to know that FNABs/TruCut don't replace the surgical biopsy, but could perhaps be offered for an out-of-reach lesion or if surgery were contraindicated. I did a fair amount of utrasound-guided centesis, so will cook up some jelly and grapes!

Thankyou!

RE: Mastering ultrasound-guided biopsies

Anthony Dennison — Mon, 07 Jul 2025 12:23:49 GMT

Speaking to most pathologists, they will often say liver biopsies should be surgically taken to get a few portal triads to get appropriate information - a Trucut biopsy doesn't often give you that. I've been told to only Tru-cut if I can't surgically biopsy.

Trick is to try and fill the screen with where you're sampling - just general FNAs of Liver and Spleen are easiest. Either use a probe cover, or just fill a latex glove with ultrasound gel and cover the probe with this so you can put spirit on the skin prior to sampling. Doing an FNAB through gel creates quite a lot of artefact that affects results, putting the probe directly on to spirit will cause the rubber on the probe to perish and fall off.

Take care when inserting the needle through the skin that you don't nick the probe and damage the rubber covering on the probe. Angle the needle at about 45% to the skin, about in line with the middle of the probe and you'll see it appear in your field.

For more specific lesion sampling, best way to practice is to put grapes/other fruit in Jelly and set it. You can use the probe to detect the grape, focus on the screen for the needle positioning but can also check your work by looking through the jelly.

As with every ultrasound technique, it's very hard to read about it and then do it - the only way is practice. Start with the larger solid organs, and as you progress sampling smaller specific lesions becomes easier.

Also, you don't need to worry about coags when doing an FNAB really.