Non-nodal neck masses.

Planar imaging has made significant contributions to the evaluation of patients with non-nodal neck masses. The clinical history, physical examination, and imaging characteristics of these lesions are often complimentary. Yet, planar imaging much more accurately defines the size, location, and extent of these lesions than is revealed on physical examination. The CT and MR characteristics are often sufficiently specific to arrive at the correct preoperative diagnosis in these patients. We present the classical radiographic and clinical features of several non-nodal neck masses.

Inverted papilloma of the nasal vault and paranasal sinuses: spectrum of CT findings.

Inverted papilloma is a benign epithelial neoplasm that arises within the nasal vault and, less commonly, in the paranasal sinuses. It is relatively uncommon, accounting for less than 4% of mucosal tumors in this region. The tumor is characterized by a high recurrence rate (emphasizing the importance of accurate tumor mapping and total tumor extirpation), associated epithelial malignant tumors (5-8%), and bone destruction. The CT appearance of inverted papilloma is variable and non-specific. Nonetheless, inverted papilloma is the most likely diagnosis when a unilateral mass in the nasal vault, producing benign bony changes, extends centrifugally into the maxillary and ethmoidal sinuses and through the nasal choana into the nasopharynx in an elderly patient with chronic nasal obstruction. The purpose of this essay is to illustrate the CT features of inverted papilloma.

MR findings in oculocerebrorenal syndrome.

Oculocerebrorenal syndrome is an X-linked recessive disorder characterized by congenital ocular abnormalities, mental retardation, renal disease, and metabolic bone disease. We report a case of oculocerebrorenal syndrome and, using T1-, proton density-, and T2-weighted imaging sequences, are able to characterize two distinct white matter abnormalities: one lesion is punctate and has signal characteristics that parallel that of cerebrospinal fluid; a second lesion, found in association with the first, consists of patchy white matter abnormalities that are hypointense on T1-weighted images but hyperintense on proton density- and T2-weighted images.

Posterior fossa neoplasms: multiplanar imaging.

Multiplanar imaging capabilities and increased tissue contrast inherent to MR permit inimitable evaluation of the normal and abnormal structures of the posterior fossa. A review of common posterior fossa neoplasms in adults and children is presented with emphasis on the MR characteristics.

MR imaging of the sellar and juxtasellar regions.

Multiplanar capability and superior tissue contrast differentiation render magnetic resonance (MR) imaging the preferred method for examining patients with pituitary axis dysfunction or visual field deficits. In a review of 131 sellar or juxtasellar abnormalities, 76% were common lesions with distinctive features that helped establish their diagnosis: macroadenoma (n = 51), microadenoma (n = 20), meningioma (n = 14), craniopharyngioma (n = 10), and aneurysm (n = 5). On T1-weighted images, microadenomas were usually hypointense relative to normal pituitary gland, and macroadenomas and meningiomas were isointense relative to gray matter. Both microadenomas and meningiomas were more conspicuous immediately after contrast material administration. Craniopharyngiomas were the most heterogeneous of all the sellar lesions due to their cystic and solid components. MR images of aneurysms showed flow void and heterogeneous increased signal intensity in areas of slower turbulent flow. Other characteristics such as extrasellar versus intrasellar location, nature of contrast material enhancement, the presence of cystic components, and clinical findings permitted differentiation among less common lesions, including granulomatous disease, metastases, chiasmatic glioma, arachnoid cyst, hypothalamic glioma, schwannoma, germinoma, epidermoid, Rathke cyst, chordoma, chondrosarcoma, colloid cyst, and hamartoma.

Maxillary sinus hypoplasia: classification and description of associated uncinate process hypoplasia.

Maxillary sinus hypoplasia is an anomaly of the paranasal sinuses occasionally encountered by otolaryngologists. Although this entity has been previously reported, an association between maxillary sinus hypoplasia and anomalies of other paranasal sinus structures, such as the uncinate process, has not yet been described. Additionally, the literature lacks a system by which the various types of maxillary sinus hypoplasia can be classified using computerized tomographic (CT) imaging. Two hundred and two consecutive coronal sinus computerized tomographic scans from patients undergoing evaluation at our institution were analyzed to determine the prevalence of MSH and associated paranasal sinus anomalies. The overall prevalence of maxillary sinus hypoplasia was 10.4%. Three distinct patterns of hypoplasia were evident. Type I, characterized by a normal uncinate process, a well-defined infundibular passage, and mild sinus hypoplasia, occurred in 14 patients (6.9%). Type II, characterized by absence or hypoplasia of the uncinate process, an ill-defined infundibular passage, and soft-tissue density opacification of a significantly hypoplastic sinus occurred in 6 patients (3.0%). Type III, characterized by absence of the uncinate process and a profoundly hypoplastic, cleft-like sinus, occurred in 1 patient (0.5%). Recognition of associated anomalies of the uncinate process in patients with maxillary sinus hypoplasia undergoing sinus surgery is of utmost clinical significance because the uncinate process serves as a key landmark during functional endoscopic sinus surgery. Failure to recognize hypoplasia or absence of the uncinate process could lead to inadvertent intraoperative damage to the adjacent medial orbital wall.

Duplex Doppler ultrasound evaluation of calcified inferior vena cava thrombosis.

We describe the use of duplex Doppler ultrasound in the noninvasive assessment of inferior vena cava patency and abdominal venous flow dynamics in a four month old infant with calcified inferior vena cava thrombosis.

Intracerebral malignant melanoma: high-field-strength MR imaging.

Thirteen patients with intracerebral malignant melanoma underwent high-field-strength (1.5-T) magnetic resonance (MR) imaging. The images were correlated with computed tomography (CT) scans (n = 7) and surgical specimens (n = 7). Most commonly, these lesions were hyperintense to normal white matter on T1-weighted images and hypointense to normal white matter on T2-weighted images. Hemorrhage in the lesion may have a greater influence on this unique appearance than does melanin. The increased tissue sensitivity of MR imaging allowed for 22% greater lesion detection than did CT.

Angelchik antireflux device: computed tomography appearance.

The Angelchik antireflux prosthesis is a silicon gel-filled, doughnut-shaped device with a tantalum tie strap that wraps around the gastroesophageal junction after reduction of a hiatal hernia. If dislodged, this prosthesis may produce a confusing picture on computed tomography, as it is of soft tissue density and may mimic a mass lesion. The computed tomography appearance of a normally placed prosthesis is demonstrated, and a case of prosthesis dislodgment diagnosed by computed tomography is reported.

Hyperprolactinemia: an unusual manifestation of suprasellar cystic lesions.

Two patients with suprasellar cysts and hyperprolactinemia are described. These lesions were diagnosed by CT metrizamide cisternography. Suprasellar cysts are a rare cause of pathologic hyperprolactinemia, which most commonly results from pituitary adenomas. Tissue diagnosis revealed suprasellar arachnoid cysts in the first patient and Rathke's cleft cyst in the second. The differential diagnosis of suprasellar cysts is presented, and distinguishing radiographic characteristics are discussed.

Perineural tumor extension to the cavernous sinus from superficial facial carcinoma: CT manifestations.

The mechanism of cavernous sinus involvement by metastatic carcinoma from a facial primary tumor is poorly understood. The lack of lymphatic and obvious direct extension implicate either a vascular or perineural method of spread. The authors describe four patients who exhibited cavernous sinus metastases from facial carcinoma, all of whom experienced cranial nerve symptoms before the diagnosis of cavernous sinus involvement was made. Furthermore, the pathologic specimens from these patients exhibited extensive perineural involvement. The authors propose that the mechanism of metastasis in these patients is perineural extension.

Craniofacial mucormycosis: assessment with CT.

Computed tomographic (CT) scans of ten patients with rhinocerebral mucormycosis were reviewed. Early paranasal sinus involvement appeared as mucosal thickening on CT scans, usually without air/fluid levels. Recognition as mucormycosis was facilitated by knowledge of the clinical setting or by identification of invasive disease. Evidence of bone destruction on CT scans was seen in only two patients, was a late finding, and usually was absent despite deep extension of disease beyond the bony confines of the paranasal sinus. Five cases had intracranial involvement, either as fungal abscess or infarction. Intracranial mucormycosis usually involved the base of the brain and cerebellum following invasion of the infratemporal fossa or orbit. Intracerebral fungal abscess appeared as low-density masses on CT scans, with variable peripheral enhancement and little surrounding vasogenic edema. Identification of a rim of spared cortex was useful in distinguishing infection from bland infarct. Serial CT scans were also useful in assessing response to hyperbaric oxygen treatment, surgery, and chemotherapy.

Chronic pulmonary embolism in children.

Chronic pulmonary embolism with pulmonary hypertension in children is rarely diagnosed clinically; literature review yielded only 17 recorded cases. To demonstrate the radiographic features as well as to encourage the diagnostic consideration of chronic pulmonary embolism in children, this report focuses on three additional children with chronic pulmonary embolism. Of these 20 total cases, only two were not catheter-related; 17 patients had emboli as a complication of ventriculoatrial shunting, and one had emboli secondary to indwelling venous hyperalimentation. Analysis of the information available on the 20 cases revealed the following radiographic features: cardiomegaly (19 cases), large central pulmonary arteries with rapid distal tapering (15 cases), oligemia (five cases), "infiltrate" (three cases), and effusion (two cases). With increasing use of central catheterization as treatment for children with chronic illness, the incidence of chronic pulmonary embolism will likely increase; therefore, clinical diagnosis should reflect this increase. The radiologist in particular should be aware of the clinical and radiologic features of chronic pulmonary embolism in children.

Chronic tension pneumothorax presumably due to a "ball valve" bronchopleural fistula.

We have described an unusual variant of bronchopleural fistula whose ball valve characteristics led to a chronic tension pneumothorax without fluid collection in a postpneumonectomy space.