Imaging of Head and Neck Emergencies

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.

Imaging assessment of deep neck spaces infections: an anatomical approach

Despite the widespread use of antibiotics, deep neck infections are still a relevant clinical problem and can cause severe and potentially life-threatening complications. Imaging plays a pivotal role into the clinical management of deep neck infections, allowing identification of the source of infections, definition of the precise extension of the disease and early diagnosis of local or distant complications. The complex anatomy of deep neck spaces may hide the actual extent of disease: the knowledge of neck anatomy enables radiologists to rapidly evaluate expected routes of spread of infections and to effectively communicate crucial information to surgeons. Computed Tomography is the most used imaging modality for assessing primary site of infection, extent of disease and local complications. Magnetic resonance imaging may be used as a second level imaging modality for individuating intracranial or spinal complications. The present work aims to review the imaging of deep neck spaces infections, focusing on relevant anatomy and clinical scenarios, underlining practical teaching points for each of them. Familiarity with deep neck spaces anatomy and knowledge of most common routes of spread of infections allow the radiologist to make a prompt diagnosis and to look for early signs of potential complications.

Magnetic Resonance Imaging of Head and Neck Emergencies, a Symptom-Based Review, Part 1: General Considerations, Vision Loss, and Eye Pain

Use of magnetic resonance (MR) imaging in the emergency department continues to increase. Although computed tomography is the first-line imaging modality for most head and neck emergencies, MR is superior in some situations and imparts no ionizing radiation. This article provides a symptom-based approach to nontraumatic head and neck pathologic conditions most relevant to emergency head and neck MR imaging, emphasizing relevant anatomy, "do not miss" findings affecting clinical management, and features that may aid differentiation from potential mimics. Essential MR sequences and strategies for obtaining high-quality images when faced with patient motion and other technical challenges are also discussed.

ACR Appropriateness Criteria® Neck Mass-Adenopathy

A palpable neck mass may be the result of neoplastic, congenital, or inflammatory disease. Older age suggests neoplasia, and a congenital etiology is more prevalent in the pediatric population. The imaging approach is based on the patient age, mass location, and clinical pulsatility. Underlying human papillomavirus-related malignancy should be considered in all age groups. Although the imaging appearance of some processes in the head and neck overlap, choosing the appropriate imaging examination may allow a specific diagnosis, or a limited differential diagnosis. Tissue sampling is indicated to confirm suspected malignancy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

CT of the Neck: Image Analysis and Reporting in the Emergency Setting

Interpreting findings seen at CT of the neck is challenging owing to the complex and nuanced anatomy of the neck, which contains multiple organ systems in a relatively small area. In the emergency department setting, CT is performed to investigate acute infectious or inflammatory symptoms and chronic processes. With few exceptions, neck CT should be performed with intravenous contrast material, which accentuates abnormally enhancing phlegmonous and neoplastic tissues and can be used to delineate any abscesses or necrotic areas. As part of the evaluation, the vascular structures and aerodigestive tract must be scrutinized, particularly for patency. Furthermore, although the patient may present because of symptoms that suggest non-life-threatening conditions involving structures such as the teeth or salivary glands, there may be serious implications for other areas, such as the orbits, brain, and spinal cord, that also may be revealed at the examination. With a focus on the emergency setting, the authors propose using an approach to interpreting neck CT findings whereby 12 areas are systematically evaluated and reported on: the cutaneous and subcutaneous soft tissues, aerodigestive tract and adjacent soft tissues, teeth and periodontal tissues, thyroid gland, salivary glands, lymph nodes, vascular structures, bony airspaces, cervical spine, orbits and imaged brain, lung apices, and superior mediastinum. The use of a systematic approach to interpreting neck CT findings is essential for identifying all salient findings, recognizing and synthesizing the implications of these findings to formulate the correct diagnosis, and reporting the findings and impressions in a complete, clear, and logical manner.Online supplemental material is available for this article.^©RSNA, 2019.

Nontraumatic head and neck injuries: a clinical approach. Part 2

Nontraumatic emergencies of the head and neck represent a challenge in the field of neuroradiology for two reasons. As explained in the first part of this update, these entities affect an area where the thorax joins the cranial cavity and can thus compromise both structures; second, they are uncommon, so they are not well known. Maintaining the same approach as in the first part, focusing on the clinical presentations in the emergency department rather than on the anatomic regions affected, we will study the entities that present with two patterns: those that present with a combination of cervical numbness, dysphagia, and dyspnea and those that present with acute sensory deficits. In the latter group, we will specifically focus on visual deficits, because this is the most common symptom that calls for urgent imaging studies.

Nontraumatic head and neck emergencies: a clinical approach. Part 1: cervicofacial swelling, dysphagia, and dyspnea

Nontraumatic emergencies of the head and neck represent a challenge in the field of neuroradiology for two reasons: first, they affect an area where the thorax joins the cranial cavity and can thus compromise both structures; second, they are uncommon, so they are not well known. Various publications focus on nontraumatic emergencies of the head and neck from the viewpoints of anatomic location or of particular diseases. However, these are not the most helpful viewpoints for dealing with patients in the emergency department, who present with particular signs and symptoms. We propose an analysis starting from the four most common clinical presentations of patients who come to the emergency department for nontraumatic head and neck emergencies: cervical swelling, dysphagia, dyspnea, and loss of vision. Starting from these entities, we develop an approach to the radiologic management and diagnosis of these patients.

Indications and radiological findings of acute otitis media and its complications

Most cases of acute otitis media resolve with antibiotics and imaging is not required. When treatment fails or a complication is suspected, imaging plays a crucial role. Since the introduction of antibiotic treatment, the complication rate has decreased dramatically. Nevertheless, given the critical clinical relevance of complications, the importance of early diagnosis is vital. Our objective was to review the clinical and radiological features of acute otitis media and its complications. They were classified based on their location, as intratemporal or intracranial. Imaging makes it possible to diagnose the complications of acute otitis media and to institute appropriate treatment. Computed tomography is the initial technique of choice and, in most cases, the ultimate. Magnetic resonance is useful for evaluating the inner ear and when accurate evaluation of disease extent or better characterization of intracranial complications is required.