Facial Artery Visualization Techniques

The Journal of Cosmetic Dermatology recently published an article examining different techniques used to visualize the arteries in the face as a response to an increase in filler-associated complications due to intra-arterial injection.¹ The researchers reviewed different medical imaging methods for facial arteries from the 20 years of literature—with special action paid to literature from the last 5 years.

The most commonly used methods for imaging are high-resolution ultrasonography (US) and magnetic resonance angiography (MRA), according to the study.

US is non-invasive and can be used with color doppler or spectral analysis to help with visualization of small arteries. This combination provides depth measurements and detailed analysis of the vessels, however, US is limited and cannot visualize a wide area or create a 3D structure of the vessels. Additionally, the quality of imagining is dependent on the operator. 

“US guidance might however be a very useful tool for the treatment of intravascular STF [soft tissue filler] injections, as the obstructed vessel might be retrieved and injected with hyaluronidase in case that HA is used as an STF,” study authors wrote. 

According to the authors, conventional angiography (CA) while using a contrast medium is the most precise evaluation technique. For CA, a catheter is inserted into the groin through an artery and then threaded through the circulatory system to the facial artery. Procedure risks include bleeding at puncture site, damage to vessel wall, and thrombus formation, but more serious adverse events (SAEs) include 1 in 200 patients suffering from a cerebral attack during CA. 

While using MRA, clinicians can use an IV contrast to make the vessels more pronounced, creating the need for an IV gadolinium injection, which can create more potential risk to a patient. Different MRA methods, such as Time of Flight (TOF), Phase Contrast (PC), and Fast Spin Echo Imaging (FSE), can be used to obtain images, with TOF being the most time effective out of the options. Until recently, TOF MRA was not successful for visualization of all facial blood vessels due to the twists and turns of the arteries, according to the study.

According to the authors, MRA would be the method of choice for harmless facial arterial network visualization. 

The combined technique of infrared (IR) facial heating and MRA (3D TOF MOTSA) was recently suggested. The images may be captured on a 1.5 or 3 Tesla (T) full body MR system, with a dedicated head coil. Additionally, a flexible wrap-around surface coil may be mounted on top of the head coil to increase the signal reception from the facial vessels.

“Before the 3D TOF MRA examination, which is known to be flow-dependent, the patient is positioned with closed eyes in front of an IR light source (300 W with an UV filter) during 10 minutes. This should induce vasodilatation and enhance vascular flow,” the authors wrote.

The patient is asked to stay completely still and a multislab technique is used to reduce the saturation of the blood signal. The MRA shows the facial (F); angular (A); superior (SL) and inferior labial (IL); lateral nasal (LN); dorsal nasal (DN); supratrochlear (STr); supraorbital (SO); and superficial temporal (ST) artery.

Periorbital artifacts may disrupt the imaging of the periorbital vessels, including patients with dental wires. There is evidence that calcium hydroxylapatite-based dermal fillers (CaHA) are visible on a MRI immediately following injection and 1.5 T MRA are more susceptible to motion artifacts because of the longer examination time. One case report demonstrated no signal on the MRI after 2.5 years because of the biodegradability of CaHA.² 

No AEs due to IR combination are mentioned in the study. 3D PC MRA can be used, but the structures of the arteries and veins make it a less suitable choice, according to the study. Additionally, the MRA images may be repeatedly projected on to the patient’s face to prepare for STF injections. 

Currently, there are no cohort studies aimed at the anatomy of the arteries in the face, however, there is evidence that small vessels may become more tortuous with age. It would be best practice to repeat MRI after extensive modifications to the face like trauma, tumor surgery, or deep plane lifts. 

Reimbursement for such MRI’s depend on the country and insurance coverage.

More research is needed to further examine facial arteries noninvasively, without the use of radiation or contrast.

References:

1. Mespreuve M, Waked K, Hendrickx B. Visualization techniques of the facial arteries. Journal of Cosmetic Dermatology. 2021;20(2):386-390. doi:https://doi.org/10.1111/jocd.13477

2. Pavicic T. Complete biodegradable nature of calcium hydroxylapatite after injection for malar enhancement: an MRI study. Clin Cosmet Investig Dermatol. 2015;8:19-25. doi:10.2147/CCID.S72878