Magnetic Resonance Imaging of Acute Head and Neck Infections

Infectious and Inflammatory Sinonasal Diseases

Rhinosinusitis is a commonly encountered disease. Imaging is not typically required in acute uncomplicated rhinosinusitis; however, it is integral in the evaluation of patients who present with prolonged or atypical symptoms or when acute intracranial complications or alternate diagnoses are suspected. Knowledge of the paranasal sinus anatomy is important to understand patterns of sinonasal opacification. Bacterial, viral, and fungal pathogens are responsible culprits and, with duration of symptoms, serve to categorize infectious sinonasal disease. Several systemic inflammatory and vasculitic processes have a predilection for the sinonasal region. Imaging, along with laboratory and histopathologic analysis, assist in arriving at these diagnoses.

Advanced imaging of head and neck infections

When head and neck infection is suspected, appropriate imaging contributes to treatment decisions and prognosis. While contrast-enhanced CT is the standard imaging modality for evaluating head and neck infections, MRI can better characterize the skull base, intracranial involvement, and osteomyelitis, implying that these are complementary techniques for a comprehensive assessment. Both CT and MRI are useful in the evaluation of abscesses and thrombophlebitis, while MRI is especially useful in the evaluation of intracranial inflammatory spread/abscess formation, differentiation of abscess from other conditions, evaluation of the presence and activity of inflammation and osteomyelitis, evaluation of mastoid extension in middle ear cholesteatoma, and evaluation of facial neuritis and labyrinthitis. Apparent diffusion coefficient derived from diffusion-weighted imaging is useful for differential diagnosis and treatment response of head and neck infections in various anatomical sites. Dynamic contrast-enhanced MRI perfusion may be useful in assessing the activity of skull base osteomyelitis. MR bone imaging may be of additional value in evaluating bony structures of the skull base and jaw. Dual-energy CT is helpful in reducing metal artifacts, evaluating deep neck abscess, and detecting salivary stones. Subtraction CT techniques are used to detect progressive bone-destructive changes and to reduce dental amalgam artifacts. This article provides a region-based approach to the imaging evaluation of head and neck infections, using both conventional and advanced imaging techniques.

Surgical management of lateral neck abscesses in children: a retrospective analysis of 100 cases

Cervical abscesses are relatively common infections in pediatric patients. There is an ongoing debate about the necessity and time point of surgical drainage. The identification of a focus of infection might play an important role in facilitating a therapeutic decision. In a retrospective study, 100 pediatric patients aged 1-18 years who underwent incision and drainage of a lateral cervical abscess at our institution were analyzed. Patients were divided into two groups based on whether a focus of infection could be identified or not. Data collection included patient characteristics, microbiological results, antibiotic regimen, and clinical course. A focus of infection was found in 29% (29/100) of the patients, most frequently in the tonsils. A causative microorganism was found in 75% (75/100) of all patients, with Staphylococcus aureus and Streptococcus pyogenes being the most common pathogens. All patients received an empiric antibiotic therapy in addition to surgery. Antibiotic medication was changed in 31% in both groups (9/29 with a focus of infection and 22/71 without a focus of infection) during therapy. Children without an identified focus of infection generally were younger and had more comorbidities reducing immune response while also showing differences in the pathogens involved. There were no complications associated to surgery or antibiotic therapy in any of the patients involved.

CONCLUSION

Children with an identified focus of infection show several differences compared to those with isolated lateral abscesses, especially regarding the microorganisms involved. But the focus of infection seems not to have an impact on patient's outcome.

WHAT IS KNOWN

• Neck abscesses are a relatively common disease in the pediatric population and may cause serious complications. • Therapy in general consists of intravenous antibiotics with or without surgery.

WHAT IS NEW

• The focus identification has no impact on patient's outcome. • Children with an identified focus of infection show several differences compared to those with isolated lateral abscesses, especially regarding their medical history, age, and the microorganisms involved.

Dental Emergencies: A Practical Guide

Dental disease is a frequent finding on head and neck images, especially in the context of emergencies, and can be a challenge for radiologists who are inexperienced with findings of dental trauma or disease. Dental abnormalities can be subtle and therefore must be included in the systematic approach to these images. Although dedicated dental images are not acquired in most emergency cases, the teeth are included on many different images of the head and neck, and their initial evaluation seldom requires a specific protocol. The high prevalence of craniofacial trauma, sinus infection, and maxillomandibular procedures, among other conditions, frequently requires interpretation of dental images in daily emergency practice. The imaging findings can be categorized into infection, trauma, and complications of procedures, although sometimes these categories can overlap. Such categories can help the radiologist decide which imaging protocol and dynamic maneuvers should be used and are also useful when reading images and proposing differential diagnoses. Familiarity with the imaging findings of dental emergencies improves the radiologist's diagnostic confidence and role in guiding patient care, avoiding progression to life-threatening conditions, and reducing aesthetic problems, dental loss, and related conditions. Information about the imaging protocols is provided, the relevant anatomy of the teeth and related structures is reviewed, and the key imaging findings of dental emergencies are presented.^©RSNA, 2019.

Wisdom Tooth's Revenge: Retropharyngeal Abscess and Mediastinitis after Molar Tooth Extraction

Retropharyngeal abscess is potentially associated with high morbidity and mortality as a result of its direct anatomical connection with the mediastinum. Therefore, knowledge of the relevant anatomy is essential for recognizing the presence and extent of disease in a timely manner. In this case report, we aim to review the pertinent anatomy and patterns of spread of infection from a full blown deep neck space infection to result in mediastinitis and empyema.