Rohini N. Nadgir

Superior Semicircular Canal Dehiscence: Congenital or Acquired Condition?

BACKGROUND AND PURPOSE: It remains unclear whether SSCD syndrome, characterized by onset of vestibular symptoms in the setting of loud noises, is a congenital or acquired condition. The purpose of this investigation was to assess the prevalence of SSCD on imaging among multiple age groups to determine whether this condition is more likely to be congenital or acquired. MATERIALS AND METHODS: Following approval of the institutional review board, 306 consecutive temporal bone CT examinations performed between July 2005 and March 2007 were retrospectively reviewed. Of these, 2 patients were eliminated due to destructive processes in the inner ear. Patients ranged in age from 7 months to 89 years. Images were independently evaluated by 2 neuroradiologists, and the superior semicircular canal was characterized as normal, thin, or frankly dehiscent in each temporal bone. Any discrepancies were resolved by consensus. The patient list was then subcategorized into 5 age groups, and the prevalence of SSCD was calculated for each group. RESULTS: Twenty-four patients were identified with SSCD, of which 6 demonstrated dehiscence bilaterally. One hundred thirty-seven subjects were identified with thinning, of which 50 demonstrated thinning bilaterally. Each successively older age category experienced a 93% increase (95% CI, 30%–187%) in the prevalence of SSCD (P = .001) and a 9% increase (95% CI, −5%–25%) in the prevalence of thinning (P = .21). Neither crude nor age-adjusted models demonstrated a significant association between thinning and contralateral dehiscence or vice versa. CONCLUSIONS: The increased radiologic prevalence of SSCD among older age groups suggests that this is more commonly an acquired rather than congenital condition.

Clinical and Radiologic Manifestations of Sickle Cell Disease in the Head and Neck

Sickle cell disease is a common inherited blood disorder that is characterized by the presence of sickle-shaped red blood cells. The clinical manifestations of sickle cell disease vary, but they may be attributed to three mechanisms: vaso-occlusion, chronic hemolytic anemia, and infection. The imaging appearances of central nervous system and musculoskeletal involvement by sickle cell disease have been well documented; however, involvement in the head and neck often is underappreciated, although it is not uncommon. In the head and neck, sickle cell disease can involve the inner ears, orbits, paranasal sinuses, bones, lymph nodes, and vessels. Manifestations of inner ear involvement include labyrinthine hemorrhage and labyrinthitis ossificans. In the orbits, they include lacrimal gland swelling, orbital wall infarction, and subperiosteal hemorrhage or fluid. In the paranasal sinuses, extramedullary hematopoiesis is seen. When bone is involved, infarction, osteomyelitis, bone marrow hyperplasia, and deposition of iron in bone marrow are seen in the maxillofacial bone and skull base. When lymph nodes are involved, lymphadenopathy is seen, and when blood vessels are involved, arterial stenosis and ectasia are seen. An understanding of the pathophysiology of sickle cell disease and knowledge of the various clinical and radiologic manifestations are crucial for prompt diagnosis and appropriate treatment.

Posttreatment CT and MR imaging in head and neck cancer: what the radiologist needs to know.

In patients with head and neck cancer, posttreatment imaging can be complicated and difficult to interpret because of the complexity of the surgical procedures performed and the postirradiation changes, but such imaging is critical for the evaluation of (a) the response to therapy and (b) tumor control. Posttreatment changes are affected by the type of surgery performed, reconstruction, neck dissection, and radiation therapy. Three types of flaps are used for reconstruction in the head and neck region: (a) the local flap, with geometric repositioning of adjacent tissue; (b) the pedicle flap, with rotation of donor tissue and preservation of the original vascular system; and (c) the free flap, with transfer of tissue that is revascularized by using microvascular surgical techniques. The posttreatment imaging findings in patients with head and neck cancer can be divided into four groups: altered anatomy secondary to surgical reconstruction, tumor recurrence, potential postsurgical complications, and possible postirradiation changes. Potential postsurgical complications are wound infection, abscess, fistula, flap necrosis, hematoma, chylous fistula, and serous retention. Possible postirradiation changes include mucosal necrosis, osteoradionecrosis, radiation-induced vasculopathy, radiation pneumonitis, radiation lung fibrosis, radiation-induced brain necrosis, and radiation-induced secondary malignancies. A familiarity with the imaging characteristics of posttreatment changes and of the potential complications caused by surgery and irradiation and an ability to differentiate these findings from tumor recurrence are essential for posttreatment surveillance and follow-up management of patients with head and neck cancer.

MRI of Complicated Pouchitis

OBJECTIVE The purpose of this study is to assess the ability of MRI to identify the presence of inflammation related to the pouch reservoir in symptomatic patients with an ileal pouch-anal anastomosis who present with clinically suspected complicated pouchitis. CONCLUSION Initial results suggest that MRI should be considered in patients who have undergone ileal pouch-anal anastomosis and present a clinical impression of complicated pouchitis. MRI showed abnormalities consistent with complicated pouchitis in seven of nine examinations, with findings including pouch wall thickening, abnormal wall enhancement, peripouch fluid collection, sinus and fistula tract formation, lymphadenopathy, and peripouch stranding and fatty proliferation. MRI findings of complicated pouchitis should raise the suspicion of Crohns disease and should prompt further investigation.

Diagnostic Imaging in Nontraumatic Pediatric Head and Neck Emergencies

Evaluation of pediatric patients in the emergency setting is complicated by a limited history and physical examination, which often produce findings that overlap with multiple disease processes. Imaging therefore plays a critical role in achieving an accurate and timely diagnosis. Knowledge of the typical clinical and imaging manifestations of common pediatric head and neck emergencies and congenital abnormalities allows the interpreting radiologist to identify the primary cause of the condition as well as any associated complications that may warrant immediate surgical management. The specific imaging protocol depends on the patients clinical status. Radiography, ultrasonography, and contrast material-enhanced computed tomography all may be appropriate modalities for an initial examination. In especially difficult or complex cases, magnetic resonance imaging may offer additional detail with respect to the extent of disease.

Imaging of Cervical Lymphadenopathy in Children and Young Adults

OBJECTIVE This article describes the role of imaging in evaluating cervical lymphadenopathy in patients from birth to their mid-20s, illustrates imaging features of normal and abnormal lymph nodes, and highlights nodal imaging features and head and neck findings that assist in diagnosis. CONCLUSION Cervical lymph node abnormalities are commonly encountered clinically and on imaging in children and young adults. Although imaging findings can lack specificity, nodal characteristics and associated head and neck imaging findings can assist in determining the underlying cause.

Granulomatous Disease in the Head and Neck: Developing a Differential Diagnosis

Granulomatous diseases have a varied etiology that includes autoimmune, infectious, idiopathic, and hereditary causes. The unifying factor in these diseases is the formation of granulomas, which histologically are mononuclear inflammatory cells or macrophages surrounded by lymphocytes. Granulomatous diseases often have systemic manifestations that affect organs throughout the body. Granulomatous diseases with head and neck manifestations include granulomatosis with polyangiitis, Churg-Strauss syndrome, Behçet disease, chronic granulomatous disease, and sarcoidosis. Infectious causes include tuberculosis, cat-scratch disease, syphilis, leprosy, actinomycosis, rhinoscleroma, and fungal infections. In the head and neck, granulomatous disease may affect the orbits, sinonasal cavities, salivary glands, aerodigestive tract, temporal bone, or skull base. Imaging findings include sinonasal opacification, ocular and other soft-tissue masses, osseous erosion, airway narrowing, lymphadenopathy, and salivary gland infiltration. Vascular involvement may also be evident, with displacement, narrowing, or occlusion of arteries and veins. Some radiologic findings of granulomatous processes have a considerable overlap with findings of malignancy, and a radiologic differential diagnosis inclusive of both is critical to avoid incorrect clinical treatment. Without the benefit of a prior clinical diagnosis, laboratory findings, or suggestive clinical signs and symptoms, granulomatous diseases may be difficult to differentiate radiologically. Although individual granulomatous diseases may have overlapping findings at imaging, certain radiologic findings should prompt the inclusion of granulomatous diseases in the differential diagnosis, thus facilitating appropriate clinical management.

Clinical and Radiologic Findings of Inner Ear Involvement in Sickle Cell Disease

BACKGROUND AND PURPOSE: SCD has been reported to involve the inner ear and result in LH and LO. Our purpose was to examine the prevalence of inner ear involvement and to assess the relationship between clinical and imaging findings in patients with SCD. MATERIALS AND METHODS: Review of our institutions imaging data base for patients with SCD who underwent imaging of the brain or head and neck region or both by CT, MR, or both from 2004 to 2008 was performed. Presenting symptoms, type of SCD, sex, imaging studies performed, and imaging findings were documented. RESULTS: Among 89 patients with SCD identified (41 males, 48 females), 17 patients (14 males, 3 females; 10–48 years old) underwent imaging evaluation for inner ear complaints, including SNHL, dizziness, vertigo, and tinnitus. LH was identified in 3 patients (3 males) and LO was identified in another 3 patients (2 males, 1 female). All patients with LH had sickle-hemoglobin C disease, whereas those with LO consisted of 2 patients homozygous for HbS (2) and 1 with HbS/β-thalassemia. Patients with LH presented with vestibular symptoms (2 vertigo, 1 dizziness), whereas patients with LO presented with SNHL. LH was seen in the basal turn of cochlea and vestibule, whereas LO involved the lateral semicircular canal. CONCLUSIONS: LH and LO were found in approximately one-third of patients with SCD with inner ear symptoms and preferentially affected males.

Injuries of the Globe: What Can the Radiologist Offer?

Traumatic ocular injuries are a significant cause of blindness and visual deficits. In the setting of acute orbital trauma, urgent ophthalmologic evaluation and intervention are critical in preserving vision. However, in the acute trauma setting, clinical evaluation of the globe may be difficult in the presence of surrounding periorbital soft-tissue swelling and other associated injuries, and patient cooperation may be limited because of unresponsiveness, altered mentation, or sedation. Often, rapid access to imaging is part of the initial diagnostic evaluation, and radiologists may be the first to identify traumatic injuries of the globe. Because of this, radiologists should be familiar with normal orbital and globe anatomy at various imaging modalities and have a thorough understanding of the various patterns of ocular injury and their imaging appearances. Radiologists should also be familiar with the various mimics of ocular injury, including congenital and acquired conditions that may alter the shape of the globe, various types of ocular calcifications, and the different types of material used to treat retinal detachment. Such knowledge may help radiologists make accurate diagnoses, which facilitates prompt and appropriate patient care.

Periapical Lucency around the Tooth: Radiologic Evaluation and Differential Diagnosis

Periapical lucencies are often seen incidentally at head and neck imaging studies performed for indications not related to the teeth. These lesions are, however, occasionally manifestations of diseases that have a wide range of effects and may at times represent the source of symptoms that prompted the study. The vast majority of periapical lucencies are the result of apical periodontal or pulpal disease. If found in an advanced state or left untreated, disease related to the tooth may spread to adjacent tissues, including the sinuses, orbits, deep fascial spaces of the neck, and intracranial structures, and result in a significant increase in patient morbidity and mortality. Although the majority of periapical lucencies seen on radiographs and computed tomographic images occur secondary to apical periodontal or pulpal disease, not all lucencies near the tooth root are due to infection. Lucency near the tooth root may be seen in the setting of other diseases of odontogenic and non-odontogenic origin, including neoplasms. Although imaging findings for these lesions can include periapical lucent components, awareness of the varied secondary imaging features can aid the radiologist in developing an accurate differential diagnosis. Familiarity with the imaging features and differential diagnoses of diseases or conditions that cause lucency around the tooth root results in appropriate referral and prompt diagnosis, management, and treatment, and can prevent unnecessary additional imaging or intervention. In addition, early recognition and appropriate treatment of infectious processes will result in improved clinical outcomes and a decrease in morbidity and mortality.