Introduction
Claims about ultrasound visibility are easy to make and hard to verify. The most useful evidence comes from research groups with no commercial interest in the outcome. SonoCoat® has been evaluated in four peer-reviewed publications by independent teams across three countries. Here is what each study set out to do, and where the coating appears in it.
Echogenic coatings are judged on one thing: whether a clinician can still see the instrument when the imaging conditions turn against them. Four independent research groups have put SonoCoat® through that test, in settings ranging from endoscopic ultrasound to prostate brachytherapy. The studies below were designed, run and published by those teams, not by us.
1. The NICE study: ranked first among ten EUS-FNA needles
Tang, Vilmann et al. Gastrointestinal Endoscopy, 2016
The EUS Needle Identification Comparison and Evaluation study compared ten 22-gauge endoscopic ultrasound fine-needle aspiration (EUS-FNA) needles: eight commercially available devices including SonoTip Pro Control, Expect Slimline, EchoTip Ultra, ClearView and EZ Shot 2, plus two prototype needles coated with SonoCoat®. Standardized, unedited videos were assessed by 43 EUS endoscopists and 17 radiologists, all blinded and unfamiliar with the devices. One SonoCoat®-coated prototype was rated best overall, ranking 10% to 40% higher than every other needle (P < .01), with no meaningful difference between how endoscopists and radiologists scored it. The authors also noted that the two needles coated with echogenic polymers were the only ones where the entire needle, rather than the tip alone, remained visible.
2. Prostate brachytherapy: fewer artifacts, clearer needles
Brost, Stish, Lee, Urban and Deufel. Medical Physics, 2023
A team at the Mayo Clinic applied SonoCoat® to 17-gauge titanium high-dose-rate (HDR) brachytherapy needles in three coating thicknesses (27, 40 and 64 µm) over a 2.5 cm region from the tip. The needles were imaged with a transrectal probe in a tissue-equivalent prostate phantom and in a cadaveric male pelvis, under conditions that deliberately reproduced the hardest cases: multiple stacked needles, acoustic shadowing and angled implants. The 64 µm coating reduced reverberation artifacts by 31 ± 14% and comet tail artifacts by 40% to 70%, and improved needle contrast at angles up to 30°. Artifact reduction increased with coating thickness. The coated needles stayed high-contrast and well defined even when acoustically shadowed by other needles, which is the situation where digitizing needle positions normally fails.
3. Liver biopsy: an echogenic sheath for any needle
Hopstaken, de Jong and Fütterer. CardioVascular and Interventional Radiology, 2021
Radboud University Medical Center tested three Sono-Sheath™ prototypes, each a polymeric sheath carrying a different version of the SonoCoat® coating at the tip, against a conventional liver biopsy needle with a sandblasted echogenic tip. Imaging was performed in a human cadaver at two insertion angles (30° and 60°) and two depths (5 and 10 cm), with videos blinded and scored on Likert scales by five independent radiologists, alongside quantitative contrast measurement in a phantom. All three prototypes outranked the control needle at 60° and 5 cm depth, and matched it elsewhere. The radiologists reported more confidence taking a biopsy with the echogenic sheaths. The phantom analysis showed a statistically significant effect of the sheath on echogenic intensity (P = .004).
4. A systematic review of 33 echogenic needles
Hovgesen, Wilhjelm, Vilmann and Kalaitzakis. Journal of Ultrasound in Medicine, 2022
This systematic review from the Technical University of Denmark and Herlev University Hospital followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. It screened the published literature and identified 24 papers reporting visibility measures for 33 different echogenic needles. The authors grouped the needles by surface characteristic, coated versus dimpled versus standard, and ranked them. Echogenic needles outperformed standard needles, particularly at steep angles. Among the echogenic group, coated needles appeared to be better visualized in vivo than non-coated, dimpled designs, with SonoCoat® outranking the EchoTip® in the study it appeared in. The authors are careful here: no single paper compared all the leading needles head to head, so they draw no definitive winner. They do argue that smooth echogenic coatings are worth developing further, because added surface roughness raises concerns around needle tract seeding.
The pattern across all four
Four teams, four specialties, four imaging setups, and one finding that keeps returning: the advantage of the coating grows as the imaging gets worse. Steep insertion angles. Greater depth. Acoustic shadowing from neighboring instruments. A conventional needle performs perfectly well right up until the moment a procedure becomes difficult, and these studies measured exactly that moment.
Equally worth noting is the range of substrates and formats involved. A 22-gauge stainless steel FNA needle, a 17-gauge titanium brachytherapy needle and a polymer sheath are three very different objects, coated in thicknesses from 27 to 64 µm, imaged with three different probe types. The technology held up across all of them.
What the evidence does not tell you
None of these publications reports a clinical outcome. They measure visibility, contrast and artifact suppression in phantoms, cadavers and blinded video assessments. That is the honest limit of published evidence for any coating: it establishes that the technology works, and it says nothing about whether it works on your device, at your wall thickness, at the insertion angles your procedure demands.
Nor do these studies measure complication rates, procedure times or first-pass success in living patients. And every device in these four papers belongs to someone else. A different geometry, a different substrate, a different clinical depth, a different probe.
Whether SonoCoat® earns its place on your instrument is therefore a question the literature cannot settle for you. It has only one answer: coat your device and put it under ultrasound. It is a short study, it runs on your own testing parameters, and it produces the one dataset that these four papers cannot give you.
- Tang SJ, Vilmann AS, Saftoiu A, et al. EUS needle identification comparison and evaluation study (with videos). Gastrointest Endosc. 2016;84(3):424-433. doi:10.1016/j.gie.2016.04.038
- Brost EE, Stish BJ, Lee CU, Urban MW, Deufel CL. Improving ultrasound-based brachytherapy needle conspicuity by applying an echogenic coating. Med Phys. 2023;50(3):1418-1427. doi:10.1002/mp.16138
- Hopstaken JS, de Jong L, Fütterer JJ. Increased needle visibility in ultrasound-guided percutaneous liver biopsy by an echogenic sheath: a proof of concept study in a human cadaver. Cardiovasc Intervent Radiol. 2021;44(6):959-967. doi:10.1007/s00270-021-02783-8
- Hovgesen CH, Wilhjelm JE, Vilmann P, Kalaitzakis E. Echogenic surface enhancements for improving needle visualization in ultrasound: a PRISMA systematic review. J Ultrasound Med. 2022;41(2):311-325. doi:10.1002/jum.15713

Put SonoCoat® on your device and see for yourself
Our engineering team sets up a feasibility study on your substrate and geometry, using the imaging parameters and insertion angles you specify. You get the visibility data for your own product.





