Imaging of the neck

The neck encloses a tremendous spectrum of tissues in a compact space. The normal and pathologic anatomy of the neck can be exquisitely displayed with high-resolution CT and MR imaging. Accurate assessment of the neck requires a thorough knowledge of both its complex anatomy and the scope of pathologic entities that may affect the various cervical compartments. We review the advances in the past year that serve to improve our ability to identify and characterize pathology of the cervical soft tissues.     

Imaging of lymphadenopathy in the neck

Imaging is playing a major role in the assessment of cervical lymphadenopathy. In infectious disease, the assessment of abscess formation and the relation of the abscess to surrounding vital structures is crucial for its management. In head and neck malignancies, imaging can be helpful for staging. Imaging of the neck for the assessment of nodal metastases can be used to detect occult metastases or to assess operability of palpable metastases. The detection of small occult metastases has limitations, as micrometastases cannot be depicted; however, imaging can fulfill a role in diminishing the risk of occult metastases, and thus influence management. For this purpose a very sensitive technique is necessary. The currently used radiological criteria are not sensitive enough to accomplish enough reduction of the risk of occult metastases; therefore, more sensitive CT and MRI criteria, but especially ultrasound-guided aspiration, should be employed to assess the clinically negative neck.     

Imaging of pediatric neck masses

Palpable neck masses are a common indication for pediatric imaging. Such lesions may be caused by infectious, inflammatory, tumoral, traumatic, lymphovascular, immunologic, or congenital etiologies. Radiological assessment of neck masses in young children should be tailored based on patient presentation and physical examination, as well as clinical suspicion. The goal of imaging should be to help arrive at a diagnosis or limited differential in an efficient manner while minimizing radiation exposure.     

Imaging findings of a hibernoma of the neck

Hibernoma is an uncommon benign fatty tumor that arises from the vestiges of fetal brown fat. We present a case report of a hibernoma of the neck in an asymptomatic 19-year-old girl and describe the important imaging findings. Computed tomography (CT) shows a well defined hypodense mass with septations. Magnetic resonance imaging (MRI) shows intermediate T1 and bright T2 signal of the mass and also demonstrates the characteristic marked contrast enhancement.     

Imaging of rhabdomyosarcomas of the head and neck

Rhabdomyosarcoma (RMS) is the most common childhood malignancy of the head and neck. The Intergroup Rhabdomyosarcoma Study now divides head and neck RMS into three categories by site of origin: orbital, parameningeal (middle ear, paranasal sinuses, and nasopharynx), and all other head and neck sites. CT is clinically applicable in the diagnosis of RMS of the head and neck, in treatment planning, and in the follow-up of patients with these tumors. Specific areas of applicability include determination of the presence/absence of intracranial and meningeal involvement, definition of tumor extent to guide radiation therapy planning, and demonstration of tumor regression or recurrence during and after treatment. CT has played an important role in the dramatically improved prognosis seen in RMS over the last 10 years. The role of MR in evaluating these patients is not yet defined, but it has promise because of the ease of obtaining multiple projections and the avoidance of ionizing radiation.     

Imaging of scleroma in the head and neck

We review the appearance of scleroma in the head and neck on imaging. Scleroma is a chronic granulomatous disease that primarily affects the nasal cavity, but the pharynx and larynx may also be involved. On imaging, nasal scleroma appears as bilateral or unilateral expanded homogeneous nasal masses that may exhibit hyperintense signal on T₁ weighted images. Pharyngeal scleroma commonly narrows the pharyngeal lumen and may involve the soft and hard palate. Imaging is essential to detect the extent of subglottic stenosis in patients with laryngeal scleroma. Rarely, scleroma may involve the orbit or the middle ear. Imaging is essential for the early diagnosis of scleroma and for differentiating it from other granulomatous and neoplastic lesions. Also, imaging is important for treatment planning and follow-up of patients after therapy.Scleroma is a chronic granulomatous disease affecting the upper respiratory airway. The causative organism is Klebsiella rhinoscleromatis, which is a Gram-negative bacterium. Rhinoscleroma is transmitted by means of direct inhalation of droplets or contaminated material. Scleroma usually begins at the nose and may progress to involve the larynx, pharynx or other regions of the neck. The term scleroma is preferred over the term rhinoscleroma because this disease affects not only the nose. Patients may present with non-specific rhinitis symptoms, signs of granulomatous proliferation or scarring. Scleroma tends to progress slowly over many years, and is characterised by periods of remission and relapse. When the disease progresses with proliferation, it may simulate a tumour. At a later stage, it may produce scarring of the respiratory tract. Early diagnosis of scleroma by differentiating it from other granulomatous or neoplastic lesions is critical to avoid recurrence and late sequelae [1-4].Scleroma is commonly seen in tropical and temperate zones, such as Africa, Asia, eastern Europe, South America and Central America. Scleroma primarily affects the nasal cavity (95–100%), but the nasopharynx (18–43%), oropharynx (13–35%), larynx (15–40%), trachea (12%) and bronchi (2–7%) can also be involved [4]. Scleroma is rarely seen in the orbit, middle ear and cervical lymph nodes. Nasal and pharyngeal scleroma is more common in males (male-to-female ratio, 2:1), and laryngotracheal scleroma is more common in females (female-to-male ratio, 4:1). It is commonly seen in the second to fourth decade of life. Scleroma occurs at the junction regions where two types of epithelium meet. Nasal scleroma starts where squamous epithelium of the vestibule meets the ciliary epithelium of the nose. Pharyngeal scleroma is usually located in the transition between the respiratory and squamous epithelium at the naso-oropharyngeal junction. Laryngeal scleroma is located below the true vocal cord, where the transitional epithelium of the true vocal cord merges with the columnar epithelium of the subglottic area [2-6].This article reviews the imaging of scleroma in the head and neck.     

Imaging of denervation in the head and neck

Denervation changes maybe the first sign of a cranial nerve injury. Recognition of denervation patterns can be used to determine the site and extent of a lesion and to tailor imaging studies according to the most likely location of an insult along the course of the affected cranial nerve(s). In addition, the extent of denervation can be used to predict functional recovery after treatment. On imaging, signs of denervation can be misleading as they often mimic recurrent neoplasm or inflammatory conditions. Imaging can both depict denervation related changes and establish its cause.This article briefly reviews the anatomy of the extracranial course of motor cranial nerves with particular emphasis on the muscles supplied by each nerve, the imaging features of the various stages of denervation, the different patterns of denervation that maybe helpful in the topographic diagnosis of nerve lesions and the most common causes of cranial nerve injuries leading to denervation.     

Imaging of granulomatous lesions of the neck in children

Cervical lymphadenopathy is the most common presentation of granulomatous inflammation of the neck in children and is usually caused by NTM infection. Although certain granulomatous infections have characteristic imaging features, there is considerable overlap in the imaging appearance of the various disorders. The diagnosis is usually based on a combination of clinical features, histopathologic examination, serologic tests, and culture results.     

Imaging manifestations of neck masses in the immunocompromised host

Human immunodeficiency virus (HIV) infection, haematological malignancy, and immunosuppression for transplantation and autoimmune disorders have led to a large increase in immunocompromised patients. Neck masses are relatively common in this patient group and include both opportunistic and severe manifestations of common infections, benign hyperplasia, and primary or secondary malignancies. Although biopsy may be necessary for definitive diagnosis, features on cross-sectional imaging may suggest a specific diagnosis or limit the differential diagnosis and facilitate optimal patient management. This article will review critical aspects of neck anatomy, illustrate the spectrum of imaging features, and discuss the interpretative pearls and pitfalls when evaluating neck masses in immunocompromised patients.     

Imaging of nodal metastases in the head and neck

Therapeutic outcome of head and neck cancer is influenced strongly by the presence of nodal metastases. Sensitivity and specificity of the physical examination for the diagnosis of nodal metastasis is unsatisfactory, resulting in both false negatives and false positives of 25 to 40%. Preoperative detection of nodal metastases therefore becomes one of the important goals of imaging studies of patients with head and neck cancer. Despite several advanced techniques and the wide clinical use of MR, MR has surprisingly added little to the diagnostic accuracy of contrast-enhanced CT. Although CT and MR allow detection of abnormally enlarged nodes or necrotic nodes, neither borderline-sized nodes without necrosis nor extracapsular spread are reliably differentiated from reactive or normal nodes in patients with head and neck cancer. Lack of definitive diagnostic methods of metastatic lymph nodes is a serious shortcoming in the preoperative workup for patients with head and neck cancer. To avoid missing small metastatic nodes, a large number of patients clinically staged as NO have undergone elective neck dissection to exclude metastases. With development of more tissue-specific imaging techniques, patients can be better characterized according to the status of nodal disease so that an appropriate therapeutic protocol can be designed for an individual case.     

Imaging evaluation of head and neck infections

Infections of the head and neck are frequent and usually have a good prognosis even though complications may sometimes be life threatening. In addition to airway compromise, intracranial and thoracic extension may occur. Diagnosis usually is made on clinical examination and imaging may play a significant role in assessing the extent of the disease, detecting complications and assist in surgical planning. The imaging protocol should be appropriate for the proposed diagnosis and suspected complications. CT of the soft tissues of the neck and chest is the imaging test of choice. Interpretation requires knowledge of the anatomy to understand the modalities of local and distant spread of the disease. Imaging evaluation is important but should not delay emergently needed treatment for entities such as epiglottitis and necrotizing fasciitis.     

Imaging of head and neck venous malformations

Venous malformations (VMs) are non proliferative lesions that consist of dysplastic venous channels. The aim of imaging is to characterise the lesion and define its anatomic extent. We will describe the plain film, ultrasound (US) (including colour and duplex Doppler), computed tomography (CT), magnetic resonance imaging (MRI), conventional angiographic and direct phlebographic appearances of venous malformations. They will be illustrated at a number of head and neck locations, including orbit, oral cavity, superficial and deep facial space, supraglottic and intramuscular. An understanding of the classification of such vascular anomalies is required to define the correct therapeutic procedure to employ. Image-guided sclerotherapy alone or in combination with surgery is now the first line treatment option in many cases of head and neck venous malformations, so the radiologist is now an integral part of the multidisciplinary management team.