Injectable facial fillers: imaging features, complications, and diagnostic pitfalls at MRI and PET CT

Imaging Nasal Obstruction: An Objective Evaluation for a Subjective Complaint

Nasal obstruction (NO) is a common clinical symptom characterized by a subjective sensation of insufficient airflow through the nasal cavity and may result from various factors, including changes in nasal anatomy, inflammatory conditions, tumoral lesions, and other etiologies. While a thorough medical history and physical examination can often identify its cause, imaging is usually necessary to fully understand the problem. Computed tomography (CT) is the primary imaging modality used to evaluate the nasal cavity and paranasal sinuses, allowing for the identification of potential causes and structural abnormalities. However, when soft tissue characterization is required, magnetic resonance imaging (MRI) is also useful. Understanding the anatomical and pathological basis of NO is crucial for accurate diagnosis and appropriate management. Imaging techniques provide valuable information for identifying the underlying causes of NO and guiding treatment decisions. This article reviews the normal anatomy of the nasal cavity and adjacent paranasal sinuses as well as the several conditions that may affect breathing comfort (tumors, inflammatory diseases, bony and cartilaginous anatomical variants, and "nonobstructive" mucosal thickenings), showing their normal presentation on CT and MRI.

Imaging characteristics of incidentally detected cosmetic surgery-derived foreign bodies on CT images in the maxillofacial region

OBJECTIVES

This study examined the imaging characteristics of cosmetic surgery-derived foreign bodies in the maxillofacial region through a retrospective review of cosmetic material foreign bodies incidentally detected on computed tomography (CT) images in routine clinical practice.

METHODS

We retrospectively investigated cases of cosmetic surgery-derived foreign bodies other than dental materials in the maxillofacial region, using 5 years of CT image data stored on an imaging server. The imaging findings of these foreign bodies were investigated, along with patient age, patient sex, whether the foreign bodies were associated with the disease targeted by the CT scan, and the availability of cosmetic surgery information prior to examination.

RESULTS

Foreign bodies were more common in women (19/21 cases), and affected patients displayed a wide age range (20-84 years). Four types of cosmetic surgery-derived foreign bodies in the maxillofacial region were detected by CT examination: nasal prostheses (nasal region), lifting sutures and injectable facial fillers (both in the buccal region), and silicone chin implants (chin region).

CONCLUSIONS

A cosmetic surgery-derived foreign body should be suspected when a foreign body is identified without a dental source of infection. In addition, cosmetic surgery-derived foreign bodies may be present in numerous patients, regardless of age or sex.

Soft Tissue Calcifications in the Head and Neck Region

This article provides an overview of the soft tissue calcifications in the head and neck region as noted on dental imaging, with particular focus on the radiographic appearance of these entities..

18F-FDG PET-CT Scans in Oncology Patients Treated with Hyaluronic Acid Filler: Not Always a Pitfall

The use of hyaluronic acid (HA) fillers in oncology patients undergoing PET-CT scans is a topic of debate due to potential interference with imaging accuracy. A 54-year-old female, postmelanoma metastasectomy in the parotid region with subsequent facial nerve palsy (FNP), received HA filler injections for facial symmetry and functional restoration. Follow-up PET-CT scans showed no interference or artifacts attributable to HA injection, allowing for accurate imaging results. This case suggests that HA fillers administered in oncology patients may not universally pose challenges or disrupt PET-CT imaging interpretation. Due to the possible false positives induced by fillers, the inclusion of aesthetic treatments in patients' anamnesis is a crucial step to accurately interpret PET-CT images. Although maintaining high level of caution in interpreting PET-CT results after filler injection is essential, our case emphasizes the safety of this procedure in oncology patients undergoing follow-up PET-CT scans.

Imaging Features and Complications of Facial Cosmetic Procedures

Facial aesthetic procedures have become increasingly popular and complex, making knowledge of facial anatomy crucial for achieving desired outcomes without complications. Some of the most common procedures include blepharoplasty, bichectomy, face-lifts, facial implants, thread lifting, and fillers. Blepharoplasty and bichectomy are surgical procedures that respectively aim to restore youthful contours to the periorbita and create a slimmer lower face by removing Bichat fat from the maxillofacial region. Facial implants are used for aesthetic augmentation of the skeletal structure and restoration of facial contour by using biomaterials or autogenous bone grafts. Face-lift surgeries involve incisions and removal of excess skin, and thread lifts involve less invasive procedures performed by inserting threads beneath the skin, with the aim to lift the skin and thus reduce wrinkles and sagging. Fillers improve wrinkles and loss of facial volume, with biologic types made from animal, human, or bacterial sources (such as hyaluronic acid), while synthetic fillers include substances such as paraffin, silicone, calcium hydroxyapatite, polymethylmethacrylate microspheres, polyacrylamide hydrogel, hydroxyethyl-ethyl methacrylate, and poly-l-lactic acid. Synthetic fillers can be classified as rapidly resorbable (<12 months), slowly resorbable (<24 months), or permanent. Imaging modalities such as US, CT, and MRI can help identify and analyze each type of facial aesthetic procedure or filler, as well as their possible complications such as foreign-body granuloma, noninflammatory nodule, late intermittent persistent edema, filler migration, infection, or complications after removal of the buccal fat pad. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center The online slide presentation from the RSNA Annual Meeting is available for this article.

Personalization of Minimally-Invasive Aesthetic Procedures with the Use of Ultrasound Compared to Alternative Imaging Modalities

Ultrasonography is a well-tolerated procedure that aids in the targeted esthetic therapies of special cutaneous regions, as well as in the prevention (vascular mapping, identification of previous filler, and others) and management of potential complications (vascular occlusion, external vascular compression, product misplacement or migration, inflammatory reactions, and others). It has lately been promoted as the first-line imaging tool to address injectables. In this article, we aim to review the evolving role of ultrasonography in cosmetic filler procedures, from the fundamental ultrasound characterization of cosmetic fillers to the ultrasound-enhanced detection and management of cosmetic filler complications, including ultrasound's role in hyaluronidase-guided injections for cosmetic filler dissolution. Furthermore, the paper explores the integral role played by ultrasound in enhancing the precision, efficacy, and safety of additional minimally invasive aesthetic techniques such as mesotherapy, radiofrequency, cryolipolysis, and polydioxanone procedures.

Cosmetic Filler and PET Positivity: The Risk of a False Positive

OBJECTIVE

To discuss a case of hyaluronic acid filler displaying as PET avid resulting in a false positive for local recurrence and review of the literature of how filler presents on PET.

STUDY DESIGN

Case report and literature review.

METHODS

Retrospective case review of a patient with angiosarcoma with PET-MRI positivity after hyaluronic acid filler injection. Review of the literature was performed.

RESULTS

A 49-year-old female with low grade angiosarcoma of the right cheek pT1N0M0 was treated with wide local excision and staged reconstruction with cervicofacial advancement flap with subsequent adjuvant radiation therapy. Surveillance PET/MRI scans were conducted every 3 months. After one year without recurrence, HA injectable filler was offered to correct resultant right facial soft tissue defect. The patient proceeded with HA filler and was counseled on the risk of local increased SUV on imaging. Her PET/MRI 3 months later revealed postsurgical changes in the right premaxillary soft tissues with associated low-grade hypermetabolism with max SUV 1.8, which elevated from prior max SUV 0.9. Contralateral left maxillary soft tissues revealed max SUV 0.8. Biopsy was initially favored for concern of local recurrence until the potential for filler to be associated with elevated SUV was discussed. Further evaluation with MRI showed diffusely increased T2 signal with some trace enhancement in the region of PET activity, confirming that findings were consistent with HA filler augmentation per the neuroradiologist team.

CONCLUSIONS

Fillers, including hyaluronic acid, are associated with elevated SUV on PET-CT. Otolaryngologists should be aware of these features to improve patient counseling, avoid unnecessary procedures, and reduce patient anxiety. Laryngoscope, 133:2951-2953, 2023.

In Vivo MRI Tracking of Degradable Polyurethane Hydrogel Degradation In Situ Using a Manganese Porphyrin Contrast Agent

BACKGROUND

A noninvasive method to track implanted biomaterials is desirable for real-time monitoring of material interactions with host tissues and assessment of efficacy and safety.

PURPOSE

To explore quantitative in vivo tracking of polyurethane implants using a manganese porphyrin (MnP) contrast agent containing a covalent binding site for pairing to polymers.

STUDY TYPE

Prospective, longitudinal.

ANIMAL MODEL

Rodent model of dorsal subcutaneous implants (10 female Sprague Dawley rats).

FIELD STRENGTH/SEQUENCE

A 3-T; two-dimensional (2D) T1-weighted spin-echo (SE), T2-weighted turbo SE, three-dimensional (3D) spoiled gradient-echo T1 mapping with variable flip angles.

ASSESSMENT

A new MnP-vinyl contrast agent to covalently label polyurethane hydrogels was synthesized and chemically characterized. Stability of binding was assessed in vitro. MRI was performed in vitro on unlabeled hydrogels and hydrogels labeled at different concentrations, and in vivo on rats with unlabeled and labeled hydrogels implanted dorsally. In vivo MRI was performed at 1, 3, 5, and 7 weeks postimplantation. Implants were easily identified on T1-weighted SE, and fluid accumulation from inflammation was distinguished on T2-weighted turbo SE. Implants were segmented on contiguous T1-weighted SPGR slices using a threshold of 1.8 times the background muscle signal intensity; implant volume and mean T1 values were then calculated at each timepoint. Histopathology was performed on implants in the same plane as MRI and compared to imaging results.

STATISTICAL TESTS

Unpaired t-tests and one-way analysis of variance (ANOVA) were used for comparisons. A P value <0.05 was considered to be statistically significant.

RESULTS

Hydrogel labeling with MnP resulted in a significant T1 reduction in vitro (T1 = 517 ± 36 msec vs. 879 ± 147 msec unlabeled). Mean T1 values of labeled implants in rats increased significantly by 23% over time, from 1 to 7 weeks postimplantation (651 ± 49 msec to 801 ± 72 msec), indicating decreasing implant density.

DATA CONCLUSION

Polymer-binding MnP enables in vivo tracking of vinyl-group coupling polymers.

EVIDENCE LEVEL

1.

TECHNICAL EFFICACY

Stage 1.

Imaging of large volume subcutaneous deposition using MRI: exploratory clinical study results

Subcutaneous (SC) delivery is a preferred route of administration for biotherapeutics but has predominantly been limited to volumes below 3 mL. With higher volume drug formulations emerging, understanding large volume SC (LVSC) depot localization, dispersion, and impact on the SC environment has become more critical. The aim of this exploratory clinical imaging study was to assess the feasibility of magnetic resonance imaging (MRI) to identify and characterize LVSC injections and their effect on SC tissue as a function of delivery site and volume. Healthy adult subjects received incremental injections of normal saline up to 5 mL total volume in the arm and up to 10 mL in the abdomen and thigh. MRI images were acquired after each incremental SC injection. Post-image analysis was performed to correct imaging artifacts, identify depot tissue location, create 3-dimensional (3D) SC depot rendering, and estimate in vivo bolus volumes and SC tissue distention. LVSC saline depots were readily achieved, imaged using MRI, and quantified via subsequent image reconstructions. Imaging artifacts occurred under some conditions, necessitating corrections applied during image analysis. 3D renderings were created for both the depot alone and in relation to the SC tissue boundaries. LVSC depots remained predominantly within the SC tissue and expanded with increasing injection volume. Depot geometry varied across injection sites and localized physiological structure changes were observed to accommodate LVSC injection volumes. MRI is an effective means to clinically visualize LVSC depots and SC architecture allowing assessment of deposition and dispersion of injected formulations.Trial Registration: Not applicable for this exploratory clinical imaging study.

Thermosensitive Biodegradable Hydrogels for Local and Controlled Cerebral Delivery of Proteins: MRI-Based Monitoring of In Vitro and In Vivo Protein Release

Hydrogels have been suggested as novel drug delivery systems for sustained release of therapeutic proteins in various neurological disorders. The main advantage these systems offer is the controlled, prolonged exposure to a therapeutically effective dose of the released drug after a single intracerebral injection. Characterization of controlled release of therapeutics from a hydrogel is generally performed in vitro, as current methods do not allow for in vivo measurements of spatiotemporal distribution and release kinetics of a loaded protein. Importantly, the in vivo environment introduces many additional variables and factors that cannot be effectively simulated under in vitro conditions. To address this, in the present contribution, we developed a noninvasive in vivo magnetic resonance imaging (MRI) method to monitor local protein release from two injected hydrogels of the same chemical composition but different initial water contents. We designed a biodegradable hydrogel formulation composed of low and high concentration thermosensitive polymer and thiolated hyaluronic acid, which is liquid at room temperature and forms a gel due to a combination of physical and chemical cross-linking upon injection at 37 °C. The in vivo protein release kinetics from these gels were assessed by MRI analysis utilizing a model protein labeled with an MR contrast agent, i.e. gadolinium-labeled albumin (74 kDa). As proof of principle, the release kinetics of the hydrogels were first measured with MRI in vitro. Subsequently, the protein loaded hydrogels were administered in male Wistar rat brains and the release in vivo was monitored for 21 days. In vitro, the thermosensitive hydrogels with an initial water content of 81 and 66% released 64 ± 3% and 43 ± 3% of the protein loading, respectively, during the first 6 days at 37 °C. These differences were even more profound in vivo, where the thermosensitive hydrogels released 83 ± 16% and 57 ± 15% of the protein load, respectively, 1 week postinjection. Measurement of volume changes of the gels over time showed that the thermosensitive gel with the higher polymer concentration increased more than 4-fold in size in vivo after 3 weeks, which was substantially different from the in vitro behavior where a volume change of 35% was observed. Our study demonstrates the potential of MRI to noninvasively monitor in vivo intracerebral protein release from a locally administered in situ forming hydrogel, which could aid in the development and optimization of such drug delivery systems for brain disorders.

A Rare Case of Migration of Hyaluronic Acid Gluteal Injection to the Medial Thigh Presenting as a Soft Lump

Introduction Hyaluronic acid (HA) is a widely accepted agent most commonly used as a dermal filler in facial aesthetic/cosmetic medicine. More recently, HA has been utilized for gluteal augmentation. The common side effects of HA injection are often minor and self-limiting. HA migration is a very rare complication.

Case Report We describe a rare case of HA buttock injection migration in a transgender patient, appearing as a superficial lump on right thigh representing a diagnostic dilemma. We highlight the need of a clinical suspicion and discuss the appropriate investigations for guided management of such patients.

Conclusion It is essential for reporting radiologist to be aware of the commonly used injectable fillers, their complications, and imaging findings to avoid misdiagnosis and guide optimal patient management.

Liquid silicone filler migration following illicit gluteal augmentation

The illicit use of fillers has significantly increased, especially among transgender women (transwomen) attempting to fulfill unmet gender affirmation needs. We present a case of liquid silicone filler migration to the distal lateral thigh, multiple years following an illicit gluteal augmentation, and mimicking a neoplasm. Initial clinical and imaging findings were inconclusive necessitating advanced imaging, an orthopedic oncology surgical consultation, and finally an ultrasound-guided biopsy. Knowledge of the increasing use of fillers, their complications, and imaging findings is critical as these patients commonly choose not to disclose this history. A radiologist suggesting this diagnosis may assist the clinician, who is often unaware of this history which could help prevent unnecessary imaging and invasive procedures.

FDG-PET findings associated with various medical procedures and treatments

[¹⁸F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) is a well-established modality with high sensitivity for the diagnosis and staging of oncologic patients. FDG is taken up by the glucose transporter of the cell membrane and becomes trapped within the cell. In addition to malignant neoplasms, active inflammatory lesions and some kinds of benign tumors also accumulate FDG. Moreover, the degree of uptake into normal organs and tissues depends on various physiological conditions, which is affected by various medical procedures, treatments, and drugs. To avoid misleading interpretations, it is important to recognize possible situations of unexpected abnormal accumulation that mimic tumor lesions. In this review, we present various FDG findings associated with surgical or medical procedures and treatments. Some findings reflect the expected physiological reaction to treatment, and some show inflammation due to prior procedures. Occasionally, FDG-PET visualizes other disorders that are unrelated to the malignancy, which may be associated with the adverse effects of certain drugs that the patient is taking. Careful review of medical records and detailed interviews of patients are thus necessary.

Imaging feature of cosmetic fillers in cone-beam computed tomography and its dental consideration

Background

As the application of cone-beam computed tomography (CBCT) in head and neck area increases for dental treatment purposes, cosmetic filler materials are incidentally observed. Since the materials are very diverse, unnecessary referrals or additional examination may be performed when clinicians are unfamiliar with the imaging findings. Thus, this study aimed to introduce the imaging characteristics of cosmetic fillers and grafts shown in dental CBCT with dental considerations that the clinician should be aware of.

Methods

CBCT obtained for dental purpose presenting cosmetic material were selected. The location of the material was identified as buccal, retroantral, parotid space, nose, zygoma, and symphysis. The material was classified as single or multiple, and grouped according to morphology: speckle, round, eggshell, linear, and amorphous. The radiopacity was classified as similar to soft tissue, between soft and hard tissue, similar to hard tissue, and metal.

Results

Twenty-one patients were reviewed, and all patients were female with mean age of 50.5 years. The buccal space was the most frequent location for multiple filler materials. The symphysis was the next frequent location and only single material were shown in this location. Cases having multiple filler showed diverse shapes while all single materials showed round shape. Fillers showing radiopacity of hard tissue were similar to diseases producing soft tissue calcifications. Metal-density material distributed in spaces induced white and dark streak artifacts in the CBCT image. All single materials presented radiopacity between soft and hard tissue and attached to the bone surface causing mandibular bone resorption.

Conclusions

Cosmetic materials displayed various imaging features in CBCT acquired during dental procedure. Clinicians should consider that cosmetic material may cause mandibular bone resorption and imaging artifacts on CBCT. Knowledge of the imaging characteristics of cosmetic fillers may help correct diagnosis.

Does hyaluronidase injected in periocular area change skin ultrastructure: standardized in vitro analysis

BACKGROUND

Treatment with hyaluronic acid (HA) fillers as a strategy for rejuvenation has experienced a significant growth in recent years, accompanied by a parallel increase in its complications, the treatment of which, such as hyaluronidase, we must be aware of.

PATIENTS/METHODS

14 patients (28 eyes) had indication for upper blepharoplasty surgery in the Hospital Universitario y Politécnico La Fe. After surgery, periocular skin of one eye of each patient was infiltrated with 300 U of hyaluronidase (14 cases) while the skin of the fellow eye was preserved untreated (14 controls). All samples were studied by the Pathology department and finally 6 variables (skin structure alteration, degeneration of elastic fibers, deposits, collagen fibers destructuring, inflammation, other findings) were analyzed.

RESULTS

No differences in skin structure, elastic fibers and collagen dermal fibers were found between hyaluronidase treated skin and controls. A significant association between ex vivo application of hyaluronidase in periocular skin and the presence of amorphous extracellular deposits within the dermis was found.

CONCLUSIONS

Hyaluronidase applied ex vivo to periocular skin led to presence of deposits within the extracellular matrix compared to control eyelid skin but elastin and collagen dermis structure remained unaltered.

Drug Delivery from Hyaluronic Acid–BDDE Injectable Hydrogels for Antibacterial and Anti-Inflammatory Applications

Hyaluronic acid (HA) injectable biomaterials are currently applied in numerous biomedical areas, beyond their use as dermal fillers. However, bacterial infections and painful inflammations are associated with healthcare complications that can appear after injection, restricting their applicability. Fortunately, HA injectable hydrogels can also serve as drug delivery platforms for the controlled release of bioactive agents with a critical role in the control of certain diseases. Accordingly, herein, HA hydrogels were crosslinked with 1 4-butanediol diglycidyl ether (BDDE) loaded with cefuroxime (CFX), tetracycline (TCN), and amoxicillin (AMX) antibiotics and acetylsalicylic acid (ASA) anti-inflammatory agent in order to promote antibacterial and anti-inflammatory responses. The hydrogels were thoroughly characterized and a clear correlation between the crosslinking grade and the hydrogels’ physicochemical properties was found after rheology, scanning electron microscopy (SEM), thermogravimetry (TGA), and differential scanning calorimetry (DSC) analyses. The biological safety of the hydrogels, expected due to the lack of BDDE residues observed in ¹H-NMR spectroscopy, was also corroborated by an exhaustive biocompatibility test. As expected, the in vitro antibacterial and anti-inflammatory activity of the drug-loaded HA-BDDE hydrogels was confirmed against Staphylococcus aureus by significantly decreasing the pro-inflammatory cytokine levels.

Infraorbital Hyaluronic Acid Filler: Common Aesthetic Side Effects with Treatment and Prevention Options

Background

Infraorbital hollows can give a fatigued or aged appearance, which can be treated by volumizing the segmented transition from the tear trough to the cheek with hyaluronic acid filler. Due to thin skin and the complex anatomy of the infraorbital area, both short- and long-term side effects (SEs) from this treatment are very common. While some patients are clear surgical candidates vs filler candidates, in real-world practice, many, if not most, patients are on a continuum where either procedure is appropriate, and the treatment decision is individualized based on each person’s risk vs benefit profile.

Objectives

Common aesthetic SEs from hyaluronic acid filler treatment in the infraorbital area will be reviewed, including their etiology, prevention, detection, and treatment.

Methods

The author’s experience from injecting the infraorbital areas of more than 800 patients in private clinical practice and observations from both short- and long-term follow-ups over 8 years is leveraged to provide detailed guidance.

Results

Recommendations on injection techniques, patient selection, and patient education are presented along with algorithms for the prevention and management of bruising, short- and long-term swelling, bumps, and blue discoloration (which is usually secondary to swelling from the filler rather than just the filler alone placed or migrating too superficially).

Conclusions

For nearly all patients, complete dissolution of filler with hyaluronidase is not required to address the issue, and the guidelines provided here will assist clinicians in the management of SEs to increase patient satisfaction with their treatment and aesthetic outcome.

Level of Evidence: 5

Clinical and radiographic features of facial cosmetic materials: A systematic review

Purpose

The aim of this study was to systematically screen the literature for studies reporting cosmetic material in the oral and maxillofacial complex to shed light on the types of cosmetic materials, their radiographic appearance, and possible complications.

Materials and Methods

Five electronic databases were reviewed for eligible studies. The general search terms were “cosmetic,” “filler,” “face,” and “radiograph.” Demographics, material types, clinical and radiographic presentation, and complications were recorded.

Results

Thirty-one studies with 53 cases met the inclusion criteria. The mean age was 52.6±15.4 years with a 4 : 3 female-to-male ratio. The most common material was calcium hydroxyapatite (CaHa) (n=14, 26.4%), found incidentally. The materials were generally located within the upper cheek and zygoma (n=35, 66.0%), radiographically well-defined (n=44, 83%), and had no effects on the surrounding structures (n=27, 50.9%). The internal structure was radiopaque (calcification, hyperdensity) for gold wires, CaHa, bone implants, and secondary calcification or ossification. Outdated cosmetic materials or non-conservative techniques were infiltrative, had effects on the surrounding structures, and presented with clinical signs, symptoms, or complications.

Conclusion

Conventional radiography, cone-beam computed tomography, and multi-detector computed tomography are useful to differentiate several cosmetic materials. Their magnetic resonance imaging appearance was highly variable. The infrequent inclusion of cosmetic materials in the differential diagnosis implies that medical and dental specialists may be unfamiliar with the radiographic appearance of these materials in the face.

MRI Visualization and Distribution Patterns of Foreign Modeling Agents: A Brief Pictorial Review for Clinicians

Since the ancient Egyptians, people have always been worried about their physical appearance. Nowadays, for some cultures like Latin American, physical appearance depends on the context, and the concept of beauty is to have wider hips and more prominent buttocks. One way to achieve these goals is to inject foreign modelants that include some oils to modify certain body regions. Until today, the search continues to find a modelling agent that is nonteratogenic, noncarcinogenic, and not susceptible to infection and can stay at the spot where it was injected (not migration). This review is aimed at providing a brief, comprehensive assessment of the use of modeling agents and summarizes some key imaging features of filler-related complications. The topics of this review are historical data, epidemiology, classification of dermal fillers (xenografts, hyaluronic acid derivatives, autografts, homografts, synthetic materials), adverse reactions, imaging method used in the detection of injectable fillers, MRI patterns observed in complications of injectable fillers, and histological findings of immune response, treatment, and conclusions. We present several classifications of injectable fillers based on composition, degradation, and complications. Additionally, readers will find some representative cases of the most common locations of injectable fillers demonstrating their infiltrative MRI patterns.

Radiographic Features of Facial Cosmetic Material: Report of Two Cases

Recently, the use of noninvasive facial cosmetic procedures has been widely disseminated. In the face, cosmetic fillers, threads, and implants are used to reduce or delay the effects of aging or adjust facial defects caused by trauma or disease. The dentist or dental specialist may encounter these materials in the radiographic images of their patients. There are few reports in the dental literature describing the radiographic appearance of some materials along with the diseases they mimic. As the procedures and materials advance and evolve, dentists and dental specialists must be aware of their radiographic appearance to avoid errors in diagnosis. This is a report of two cases that include panoramic radiography and CBCT scan. Among these cases, there is an unusual appearance of a cosmetic filler due to a subperiosteal injection method. Moreover, it will discuss common types of cosmetic materials used in the face and their imaginological appearance. This is the key to dentists and dental specialists due to increasing use of facial cosmetic materials and a parallel increase in the use of cone beam CT and chances to encounter such findings.

Covalently Crosslinked Hydrogels via Step-Growth Reactions: Crosslinking Chemistries, Polymers, and Clinical Impact

Hydrogels are an important class of biomaterials with the unique property of high-water content in a crosslinked polymer network. In particular, chemically crosslinked hydrogels have made a great clinical impact in past years because of their desirable mechanical properties and tunability of structural and chemical properties. Various polymers and step-growth crosslinking chemistries are harnessed for fabricating such covalently crosslinked hydrogels for translational research. However, selecting appropriate crosslinking chemistries and polymers for the intended clinical application is time-consuming and challenging. It requires the integration of polymer chemistry knowledge with thoughtful crosslinking reaction design. This task becomes even more challenging when other factors such as the biological mechanisms of the pathology, practical administration routes, and regulatory requirements add additional constraints. In this review, key features of crosslinking chemistries and polymers commonly used for preparing translatable hydrogels are outlined and their performance in biological systems is summarized. The examples of effective polymer/crosslinking chemistry combinations that have yielded clinically approved hydrogel products are specifically highlighted. These hydrogel design parameters in the context of the regulatory process and clinical translation barriers, providing a guideline for the rational selection of polymer/crosslinking chemistry combinations to construct hydrogels with high translational potential are further considered.

A nonthrombotic pulmonary embolus caused by polyalkylimide dermal filler: A case report and literature review of medication management

BACKGROUND

This report presents the case of a patient who developed a nonthrombotic embolus attributed to a polyalkylimide dermal filler, and it also charts pharmacotherapeutic strategies for polyalkylimide complications reported in the literature.

CASE SUMMARY

A 31-year-old female presented to a community teaching hospital with dyspnea, hemoptysis, and fever. A thorough history revealed that the patient received intragluteal injections of a polyalkylimide dermal filler (Bio-Alcamid) 4 days before hospitalization, although it was initially and incorrectly diagnosed as silicone embolism syndrome. High-dose intravenous steroids and antibiotics were ineffective, and the patient was transferred to a higher level of care for surgical management. Therein, the patient developed additional complications, including multiple thromboembolic events and the need for long-term enteral nutrition. After a 63-day stay in the intensive care unit and a 13-day stay in an inpatient postacute facility, the patient's postdischarge care transitions included 3 subsequent emergency department visits related to enteral feeding tube malfunction.

PRACTICE IMPLICATIONS

Polyalkylimide is a hydrogel polymer derived from acrylic acid that is used as a dermal filler. Postinjection complications include dermal filler migration and abscess formation. Surgical resection of the filler and prophylactic antibiotics have, anecdotally, been used with success. Comparatively, silicone dermal filler complications may be treated with high-dose intravenous corticosteroids. Although silicone and polyalkylimide are both classified as permanent dermal fillers, the management of their complications differs, especially with regard to medications. This case underscores the necessity for clinicians to accurately identify the type of dermal filler used in order to recommend effective medication management to treat complications. Unlike silicone dermal filler treatment, corticosteroids may actually exacerbate polyalkylimide dermal filler complications. Beta-lactam antibiotics for at least 14 days may be reasonable to treat the cutaneous infectious complications arising from polyalkylimide dermal filler use.

Penile girth augmentation by injectable fillers: a comprehensive review of imaging features and inflammatory complications

Despite the extensive controversy and debate of penile girth augmentation, high demands for such procedures are increasing. Penile inflammation is not common sequel after penile filler augmentation, but when it occurs, it has serious complications that sometimes necessitate emergency surgical intervention. Imaging with a variety of modalities, including ultrasonography, magnetic resonance imaging, and ascending urethrogrphy plays a paramount role in the detection and assessment of these conditions. Inflammatory conditions after penile girth augmentation using injectable fillers are ranging from local granuloma to penile abscess formation or diffuse cellulitis that may extend to the scrotum, perineum or deep pelvic organs. Rapid diagnosis and evaluation of extensions are important to avoid associated morbidity and permanent deformity. Our purpose is to provide a practical review of relevant penile anatomy, imaging appearance and injection technique of different types of subcutaneous fillers used in penile girth augmentation, and inflammatory complications that may occur after these procedures. Brief descriptions of patient clinical information and imaging features of inflammatory complications will be included and correlated in actual cases.

A Potential Filling Material for Wound Healing and Shaping: Acellular Dermal Matrix Combined with Autologous Dermis

BACKGROUND

The currently used subcutaneous fillers are not effective enough. The use of autologous tissues or cells will reduce immune rejection and increase the stability of the fillers, while increasing the absorbability of filling materials. To establish a durable and safe filling material, we herein combined acellular dermal matrix (ADM) with autologous dermal cells and tested the performance of this matrix in wound healing and shaping.

METHODS

To prepare the ADM, stratified skin was obtained from the back of two New Zealand rabbits and decellularized to obtain ADM. The ADM was ultrasonically mixed with as-prepared autologous dermis in vitro. The mixture was injected as a subcutaneous filler into the back area of 20 New Zealand rabbits. In this procedure, different concentration ratios of the mixture were injected, and the volume change of the filler was measured and categorized into five groups. At 4 months and 8 months after filling, samples were obtained for quantitative evaluation of the thickness and vessel density, as well as qualitative evaluation of colonization.

RESULTS

Examination of the ADM conformed that the matrix had no cells. ADM and the prepared autologous dermis were evenly mixed, and the filler was gradually absorbed. The comprehensive evaluation of ADM and autologous dermis mixture showed that group C had the best filling effect with the least infiltration of inflammatory cells and the highest vascular density compared to A, B, D and E groups in the study.

CONCLUSION

When combined at the ratio of 50%:50%, the autologous dermis combined and acellular dermal matrix showed better performance compared to the other four different ratios in this study. This implies that this combination is potentially safer, effective and stable as a filling material compared to ADM or dermal matrix alone.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Case Report of 18F-FDG PET/CT Features of Polyacrylamide Hydrogel Mammoplasty

ABSTRACT

A 57-year-old woman with a history of previous bilateral breast polyacrylamide hydrogel injection presented for 18F-FDG PET/CT imaging to investigate recurrent retroperitoneal liposarcoma. Incidental symmetrical FDG-positive accumulation was noted in the bilateral axillae tracking between the interpectoral planes. The finding is consistent with a chronic inflammatory process secondary to the migration of the polyacrylamide hydrogel injections.

Ultrasound detection of cosmic filler injection of lips in camel beauty pageants: first report in veterinary medicine

This study was carried out in Saudi Arabia during the events of the 4th King Abdulaziz Camel Festival, Saudi Arabia. It was designed to describe the most frequent locations of injected cosmetic fillers in the head region as well as the ultrasound features of the injected material. Apparently healthy camels (Camelus dromedarius) (n = 11,626) were thoroughly examined for injection of cosmetic fillers in the head region. In parallel, 30 non-injected camels were used as controls. The lips of camels suspected of having been injected with fillers were subjected to high-resolution ultrasound examination. Of the 11,626 camels, 58 were found to have been injected with cosmetic fillers, 45 in the upper lip and 13 in both the upper and lower lip. None of the injected camels had a history of recent illness. In addition, in all the injected camels, no dermal lip lesions were seen by the naked eye. Swelling of the upper and/or lower lips was visually inspected and palpated by hand in 52 of the camels. Drooping and swinging of the injected lips were observed in all injected camels. Hardness was detected in the tip of the upper lips of 26 of the injected camels and multiple hard nodules were palpated in the injected lips of 44 camels. Swelling of the edges of the upper and lower lips was detected in 41 of the injected camels. Ultrasonographic features of the injected lips are described in detail. Blood samples were collected from both groups. In none of the injected camels did the hemato-biochemical profiles differ significantly than the control group. In conclusion, results clearly indicate the usefulness and convenience of ultrasound as a diagnostic tool to locate the presence of injected fillers and to help monitor the extension and complications of the deposits.

Quantitative magnetic resonance imaging: differentiating soft tissue implants and fillers used in cosmetic and reconstructive surgery

OBJECTIVE

To evaluate the value of synthetic magnetic resonance imaging (MRI) and T2 mapping in distinguishing between different types of fillers in soft tissues.

MATERIALS AND METHODS

Ex vivo fillers of buttock soft tissues (silicone, collagen, and different types of hyaluronic acid) were scanned using a synthetic MRI sequence at 1.5 and 3 T and an optimized T2 mapping sequence to measure the T2 relaxation times of the fillers ex vivo. Three patients addressed to assess complications with buttock fillers underwent MRI with the standard morphological sequences and an additional synthetic MRI sequence; T2 mapping was not performed for the patients. Two patients had silicone fillers, whereas the exact filler composition for the third patient was unknown.

RESULTS

Measurements of T1 and T2 relaxation times of ex vivo fillers at 1.5 and 3 T using synthetic MRI showed that the silicone, collagen, and hyaluronic acid had distinct relaxation time characteristics. In vivo, the synthetic MRI correctly identified silicone in the two patients with known silicone fillers, showing low T1 and T2 values, whereas in the third patient with an unknown filler type, the synthetic MRI suggested a collagen filler, with intermediate relaxation time values.

CONCLUSION

Quantitative sequences have the potential to differentiate between filler types in a noninvasive fashion.

Injectable fillers: imaging features and related complications

Background

Injectable fillers are currently widely used in the clinical practice; there are many indications for injectable fillers including facial and gluteal rejuvenation, management of post-traumatic facial disfiguring, and pathological volumetric loss secondary to certain disease medications like human immune deficiency virus (HIV) medications.

Radiologists should be familiar with the specific imaging features of the injectable fillers, characteristic anatomical locations, and possible complications to avoid diagnostic pitfalls especially when incidentally discovered while imaging of other pathological process like neoplastic work up or granulomatous lesions follow-up.

Results

The study included 48 patients (45 females and 3 males): 44 patients with facial injectable fillers and four patients with pelvic injectable fillers.

Of the 48 patients, 37 patients showed unremarkable fillers features with normal morphological features and anatomical distribution, and eleven patients showed complications: six patients showed one complication, and five patients showed more than one complications.

Dedicated fillers imaging study was done in 22 patients, while in the other 26 patients, imaging was done for other reasons, and fillers were notified and documented.

Magnetic resonance imaging (MRI) was done for 46 patients; two patients were subjected to combine ultra-sonographic and CT examinations with no clinical indication for MRI study assessment.

Conclusion

Magnetic resonance imaging (MRI) is an effective tool for evaluation of facial and gluteal region fillers with delineation of their imaging features and related potential complications.

Differentiation between fillers and neoplastic or granulomatous lesions could be accurately done with MRI.

A case series: 3-dimensional computed tomographic study of the superior orbital vessels: Superior orbital arcades and their relationships with the supratrochlear artery and supraorbital artery

BACKGROUND

Vascular complications from periorbital intravascular filler injection are major safety concerns.

OBJECTIVE

To thoroughly describe the superior orbital vessels near the orbital rim and propose considerations for upper eyelid and forehead injections.

METHODS

Fifty-one cadaver heads were infused with lead oxide contrast media through the external carotid artery, internal carotid artery, and facial and superficial temporal arteries. Computed tomography (CT) images were obtained after contrast agent injection, and 3-dimensional CT scans were reconstructed by using a validated algorithm.

RESULTS

Eighty-six qualified hemifaces clearly showed the origin, depth, and anastomoses of the superior orbital vessels, which consistently deployed 2 distinctive layers: deep and superficial. Of all hemifaces, 59.3% had deep superior orbital vessels near the orbital rim, including 44.2% with deep superior orbital arcades and 15.1% with deep superior orbital arteries, which originated from the ophthalmic artery. Additionally, 97.7% of the hemifaces had superficial superior orbital arcades, for which 4 origins were identified: ophthalmic artery, superior medial palpebral artery, angular artery, and anastomosis between the angular and ophthalmic arteries.

LIMITATIONS

The arterial depth estimated from 3-dimensional CT needs to be confirmed by standard cadaver dissection.

CONCLUSION

This study elucidated novel arterial systems and proposed considerations for upper eyelid and forehead injections.

STOP Facial Aging Method™: A New Protocol for Facial Rejuvenation

BACKGROUND: There is currently no standardized and reproducible injection technique to address facial aging at all anatomical levels. OBJECTIVE: The Sebban Technique One-point (STOP) Facial Aging Method™ for hyaluronic acid (HA) fillers aims to provide predictive results using a single point of entry. METHODS: STOP combines two complementary techniques: Deep One-point (DOP) and Superficial One-point (SOP). DOP targets the deep plane to restructure the facial architecture, while SOP targets the superficial and deeper hypodermic planes to add volume and provide optimal tissue hydration. The injection procedure involves one DOP phase and two SOP phases using an HA filler appropriate for the treatment indication and injection depth. STOP has been investigated in a retrospective, open-label observational case series. RESULTS: Data from 10 women, aged 41 to 59 years, with varying stages of facial aging were retrospectively examined. Eight had received DOP with bolus injections of a cohesive HA filler and nine had received SOP using an HA filler with good elasticity to target the deep or superficial hypodermis. The mean total volume of HA filler injected (all HA fillers combined) was 5.46mL (range: 4.0-7.0mL) for the whole face. Physician and patient satisfaction with the treatment was high and all subjects stated that they would recommend the treatment to their friends. The STOP protocol was well-tolerated and no complications were observed during the DOP or SOP phases. CONCLUSIONS: STOP is a reproducible and safe technique for global facial rejuvenation with a single cannular point of entry.

Delayed sclerosing granulomatous reaction to dermal filler injection of poly-hydroxyethyl-methacrylate suspended in hyaluronic acid: Histochemical and confocal laser scanning microscopical analysis

Re-absorbable dermal fillers of poly-hydroxyethyl-methacrylate suspended in hyaluronic acid are considered overall safe and well tolerable because of biocompatibility; nevertheless, rarely, late, or early adverse reactions may occur.

Three-Dimensional Computed Tomographic Study on the Periorbital Branches of the Ophthalmic Artery: Arterial Variations and Clinical Relevance

BACKGROUND

Filler injection is a popular cosmetic procedure, but it can entail vascular complications. Periorbital injections have the highest risk within the entire injection area.

OBJECTIVES

The authors sought to systematically screen for periorbital arterial variations prior to treatment.

METHODS

The external carotid arteries of 10 cadaveric heads were infused with adequate lead oxide contrast. The facial and superficial temporal arteries of another 11 cadaveric heads were injected with the contrast in sequential order. Computed tomography (CT) scanning was performed after injection of contrast, and 3-dimensional (3D) CT scans were reconstructed using validated algorithms.

RESULTS

Three types of periorbital blood vessels were found to derive from the ophthalmic artery, including 30% directly originating from the ophthalmic artery, 65% originating from its trochlear branch, and 5% originating from its supraorbital branch. In the forehead, the ophthalmic artery, originating from the internal carotid arteries, formed anastomoses between the frontal branch of the superficial temporal artery, originating from the external carotid artery, with the deep and superficial branches of the supratrochlear and supraorbital arteries, respectively. The lateral orbit and malar plexus can be classified into 4 types based on the trunk artery: the zygomatic orbital artery (27%), the transverse facial artery (23%), the premasseteric branch of the facial artery (19%), and all 3 contributing equally (31%).

CONCLUSIONS

Postmortem 3D CT can map periorbital arterial variations. The branching pattern of the ophthalmic artery, the ophthalmic angiosome in the forehead, and the distribution of the lateral orbit and malar plexus were identified at high resolution to guide clinical practice.

Determining a reliably visible and inexpensive surface fiducial marker for use in MRI: a research study in a busy Australian Radiology Department

OBJECTIVES

Single-use commercial surface fiducial markers are used in clinical imaging for a variety of applications. The current study sought to find a new, reliably visible, easily sourced and inexpensive fiducial marker alternative for use with MRI.

DESIGN

Five commonly requested MRI sequences were determined (three-dimensional (3D) T1-weighted, T1 coronal, 3D T2-weighted, T2 fat suppressed, proton density), to examine the visibility of 18 items (including a commercial fiducial marker).

SETTING

Clinical 3T MRI scanner in an Australian Tertiary Hospital and an Australian University Biomedical Engineering research group.

INTERVENTIONS

18 marker alternatives were scanned using five common MRI sequences. Images were reformatted to obtain both an image through the mid-height of each marker and a maximum intensity z-projection image over the volume of the marker. Variations in marker intensity were profiled across each visible marker and a visibility rating defined.

MAIN OUTCOME MEASURES

Outcome measures were based on quantitative assessment of a clear intensity contrast ratio between the marker and the adjacent tissue and a qualitative assessment of visibility via a 3-point scale.

RESULTS

The fish oil capsule, vitamin D capsule, paint ball pellet, soy sauce sushi tube and commercial markers were typically visible to a high quality on all the imaging sequences and demonstrated a clear differential in intensity contrast against the adjacent tissue. Other common items, such as plasticine 'play doh' and a soft 'Jelly baby' sweet, were surprise candidates, demonstrating high-quality visibility and intensity contrast for the 3D T1-weighted sequence.

CONCLUSIONS

Depending on the basis for referral and MRI sequence chosen, four alternative fiducial markers were determined to be inexpensive, easily sourced and consistently visible. Of these, the vitamin D capsule provided an excellent balance between availability, size, cost, usability and quality of the visualised marker for all the commonly used MRI sequences analysed.