Introduction Liquid embolic agents (LEAs) play a major role in the treatment of cerebral arteriovenous malformations (AVMs) and dural arteriovenous fistulas (DAVFs). Injection under subtracted fluoroscopy (Blank Road Map, RM) is the preferred technique, especially when using ethylene-vinyl-copolymer based agents. Optimal visual control during injection is crucially important to avoid catheter entrapment or non-target embolization and is strongly dependent on Road Map (RM) quality. Available LEAs differ in their radiopacity the main factor for visual control. We present a comparison study of radiographic visibility of various LEAs using a novel injectable angiographic phantom.

Methods An injectable angiographic phantom was designed with parallel tubings between 313 and 1000 micron. Under RM, eight radiopaque liquid agents were injected: Onyx^®18,34 (Medtronic, Dublin, Ireland), SQUID^®12,18 (Emboflu, Fribourg, Switzerland), PHIL^®25,30 (MicroVention, Tustin, CA, USA), Trufill^® (NBCA) (Cordis Neurovascular, Miami, FL, USA) 30% dilution and Omnipaque^®300 (GE Healthcare, Chicago, IL, USA). The phantom was imaged using an Artis Zeego system (Siemens Healthineers, Erlangen, Germany) with consistent settings (‘RM Glue’, RM K40 EA3, 15 p/s). Image analysis was performed with ImageJ (NIH, Bethesda, Maryland) and Matlab (MathWorks, Inc., Natick, MA). Contrast resolution (CR) was evaluated as a contrast to noise ratio (CNR) and calculated as mean peak signal minus mean background signal divided by the standard deviation of the background signal.

Results Omnipaque^®300 and Trufill demonstrated significantly the highest CNR (CNR 11.3–11.4 at 500 micron and CNR 34.1–34.2 at 1000 micron). Onyx^®18 and Onyx^®34 (8.5–8.8 at 500 micron and 28.1–28.2 at 1000 micron) both showed significantly higher CNR than all SQUID^® and PHIL^® concentrations. There was no significant difference between SQUID ^®12, SQUID^®18, and PHIL^®30 (CNR 6–6.4 at 500 micron and CNR 17.8–19 at 1000 micron). PHIL^®25 (CNR 4.8 at 500 micron and CNR 15.4 at 1000 micron) demonstrated the lowest CNR for all measurements. CNR results were consistent across 1000 and 500 micron tubing sizes with minor variation at 313 micron.

• Download figure
• Open in new tab
• Download powerpoint

Abstract O-015 Figure 1

Conclusions There is significant variability in CR for the various LEAs under the RM conditions used in this study. Significantly different CR between most LEAs (except Trufill^®) and iodinated contrast media was evident and should be considered prior to injection. Knowledge and understanding of different visualization performance among various LEAs are important to avoid non-target vessel embolization. Subsequent studies are needed to further establish this method for improving image quality and increase patient’s safety during EVT of cerebral AVMs and DAVFs.

Disclosures J. Mason: 1; C; Balt.