The nasopharynx is located in the upper aerodigestive tract. Its roof is formed by the basisphenoid, basiocciput and the anterior aspect of the first two cervical vertebrae, in front of the clivus. The lateral walls are formed by the margins of the superior constrictor muscle and the pharyngobasilar fascia, pharyngeal recess, torus tubarius and pharyngeal opening of auditory tube. The inferior margin of the nasopharynx is a horizontal plane passing through the hard palate and palatopharyngeal muscle. Anteriorly, it is in direct continuity with the nasal cavity through the posterior choanae. It is approximately 2.0 cm in anteroposterior diameter and about 4.0 cm in craniocaudal extent. Squamous cell carcinoma accounts for about 70% to 98% of nasopharyngeal malignant lesions found in adults. This tumor presents a high incidence in Asians, most frequently in men, and is the third most frequent cancer in women. The clinical presentation of this disease depends on the size and site of the lesion, with small-sized lesions being asymptomatic. Computed tomography and magnetic resonance imaging play essential and complementary roles in the staging and treatment of patients with nasopharyngeal cancer.

Keywords: Computed tomography, Nasopharynx, Tumor, Carcinoma

OBJECTIVE: The aim of this study was to evaluate sonographic features of thyroid gland in patients with thyroiditis. MATERIALS AND METHODS: During a nine-month period, 38 patients previously diagnosed with thyroiditis by the Ultrasound Unit of "Instituto de Radiologia da Faculdade de Medicina da Universidade de São Paulo", São Paulo, SP, Brazil, were studied. Thirteen-six of these patients were women in the age range between 17 and 78 years. The following variables were observed and studied: thyroid volume, echogenicity, echotexture, and the presence of level VI chain lymph nodes (pre-tracheal, the preferential site of thyroid drainage), besides the gland dimensions. RESULTS: Thirteen patients had goiter; 37 of 38 thyroid glands presented heterogeneous echotexture and diffuse hypoechogenicity. Thyroiditis was diagnosed by laboratory tests in all patients. Level VI chain (pre-tracheal) lymph nodes were observed in 28 cases, all of them with reactional features. Of these cases, ten patients were submitted to fine needle aspiration biopsy, and the cytological result indicated inflammatory reaction. No case of nodule-simulating focal thyroiditis was found. CONCLUSION: The thyroid gland sonographic hypoechogenicity and heterogeneity, in association with the presence of cervical chain lymph nodes, constitute findings of great importance in the diagnosis of thyroiditis when correlated with clinical and laboratory tests findings.

Keywords: Ultrasound, Thyroid, Thyroiditis

OBJECTIVE: To describe the different presentations of craniofacial fibrous dysplasia in a revisional study of 14 computed tomography exams. MATERIALS AND METHODS: The authors have selected 14 cases of craniofacial fibrous dysplasia attended at the Head & Neck Surgery/Otorhinolaryngology Service and Diagnostic Imaging Service of "Hospital Heliópolis", São Paulo, SP, Brazil, between 1991 and 2002. Three of the following most relevant tomographic findings were analyzed: number of bones affected, predominant radiological presentation and the disease uni- or bilaterality. RESULTS: A predominance of a mixed pattern was observed in relation to the disease presentation. Also, contiguous involvement of two or more bones was observed as well as equivalence between cases of unilateral and bilateral craniofacial involvement, possibly due the fact that most patients presented the monostotic type of fibrous dysplasia. CONCLUSION: The knowledge of tomographic features of craniofacial fibrous dysplasia is of paramount importance for surgical planning and post-treatment follow-up.

Keywords: Fibrous dysplasia of bone, Skull, Face, Facial bones, X-ray computed tomography

OBJECTIVE: To evaluate the role, especially of computed tomography, in the staging of maxillary sinus carcinomas. MATERIALS AND METHODS: Ten cases of carcinoma treated in Hospital Heliópolis Department of Diagnostic Imaging and Head and Neck Surgery, São Paulo, SP, Brazil, in the period between 1988 and 2002, were evaluated. RESULTS: Nine patients presented with tumor extension to the cheek, eight to the masticator space, seven to the mouth floor and hard palate, five to the pterygoid fossa, five to the orbit, three to the ethmoid bone, and one to the skull base. Three of the patients were staged T3, and seven T4. Two patients had lymph nodes metastases at their initial presentation, and were staged T4. All of the cases were histopathologically confirmed. CONCLUSION: The accurate analysis of the tumor local extent and dissemination by means of computed tomography and magnetic resonance imaging plays a relevant role in the surgical planning, besides influencing the therapeutic conduct and prognosis.

Keywords: Squamous cell carcinoma, X-ray tomography, Cancer, Maxillary sinus

OBJECTIVE: The aim of this study is to evaluate the role of computed tomography and magnetic resonance imaging in the characterization of deep tissue extension of malignant tumors of the nasal cavity. MATERIALS AND METHODS: Twelve patients diagnosed with malignant tumors of the nasal cavity were retrospectively evaluated at the Departments of Diagnostic Imaging and Head and Neck Surgery of the "Complexo Hospitalar Heliópolis", São Paulo, Brazil, between 1990 and 2000. All cases were confirmed by histopathologic examination. RESULTS: Extension to the maxillary and ethmoid sinuses was identified in six patients, extension to contralateral nasal cavity, orbit and lamina cribosa in five patients, extension to nasal pharynx and masticator space in two patients, extension to cavernous sinus, anterior/middle cranial fossa, pterygomaxillary fossa, inferior/superior orbital fissure, frontal sinus, contralateral ethmoid sinus, contralateral lamina cribosa, hard palate and pterygopalatine fossa in one patient. CONCLUSION: It is important to precisely assess the local extension and spread of tumor by computed tomography and magnetic resonance imaging in order to plan the approach to treatment, which will influence the prognosis.

Keywords: Nasal cavity, Malignant neoplasm, Computed tomography, Magnetic resonance imaging