Significance of CT and MR findings in sphenoid sinus disease

Disorders of the paranasal sinuses, particularly the sphenoid sinus, can be associated with significant disorders of the optic and other cranial nerves. We examined 100 consecutive routine CT scans, 100 posterior fossa CT scans, and 100 MR scans to look for evidence of sinus disease, especially of the sphenoid sinus. The sphenoid sinus was abnormal in 7% of scans by all methods. Other sinuses were more frequently abnormal, including maxillary (23%), ethmoid (34%), and frontal (16%). Although MR was more sensitive in detecting sinus inflammation in the ethmoid and maxillary sinuses, the frequency of visible sphenoid sinus abnormalities detected by MR was not significantly greater when compared with CT. Of those patients with abnormal sphenoid sinuses, 24% had visual problems associated with the abnormality.     

自发性颈动脉海绵窦瘘CT表现1例报告

颈动脉海绵窦瘘发病率低，临床以外伤性多见，白发性更少见，现收集1例报道如下。 患者，女，47岁，因右眼渐进性突出伴上睑下垂复视3月左右而就诊。眼科检查：右眼矫正视力，光感（-13．00D）。睑组织红肿，上睑重度下垂，结膜水肿充血，血管明显迂曲扩张，角膜透明，视网膜静脉迂曲扩张，眼球向正前方突出，突出度为16—98—22，     

Brown tumor of the sphenoid sinus in a patient with secondary hyperparathyroidism: CT and MR imaging findings

We present a case of brown tumor of the sphenoid sinus in a patient with secondary hyperparathyroidism. CT showed an expansile soft-tissue attenuation mass centered in the sphenoid sinus. CT at bone window setting demonstrated expansile, lytic change and remodeling of the surrounding bone. On MR imaging, the lesion showed iso-intensity to gray matter on T1-weighted images and heterogeneous hyperintensity on T2-weighted images, and showed intense enhancement. The extent of the lesion and its relationship to the surrounding structures were best evaluated by CT and MR imaging.     

Orbital complications of functional endoscopic sinus surgery: MR and CT findings

AIM: To describe the radiological findings of ophthalmic complications during functional endoscopic sinus surgery (FESS) and correlate them with the clinical manifestations and mechanisms of injury. METHODS: This was a retrospective review of the clinical and cross-sectional imaging findings of 9 patients with orbital complications during FESS. RESULTS: The most common site of entry into the orbit during FESS was the lower medial orbital wall (7 of 9), followed by the inferior orbital wall, resulting in injury to the medial rectus (4 of 9) and, less frequently, the inferior rectus (2 of 9) or superior oblique muscles (1 of 9). Extensive scarring on imaging (3 of 9) was associated with global ocular motility dysfunction. In contrast, localized scarring (3 of 9) or extraocular muscle trauma (6 of 9) resulted in disturbance of eye movement in the direction of gaze from the injured site. CONCLUSIONS: Orbital magnetic resonance and computed tomography findings correlate very well with the abnormal eye movements clinically observed, and can assist in clarifying the cause of injury and guide surgical corrective management of patients suffering orbital complications from FESS. Radiologists should be familiar with the recent developments in FESS instrumentation as well as with the most commonly injured structures within the orbit.     

Sphenoid sinus mucocele causing third nerve paralysis: CT and MR findings

A 64-year-old woman presented with a 2 week history of ptosis and medial-gaze paralysis of her left eye. Computed tomography scanning of the paranasal sinuses revealed an expansile, homogeneous lesion with no contrast enhancement in the sphenoid sinus. The mass was hyperintense on all MR sequences and there was extension of the mass to the left cavernous sinus and optic canal. Operation revealed a large mucocele. Third nerve palsy disappeared 4 weeks after operation. Because the spread of mucoceles is variable, they may cause different symptoms. Radiological evaluation, especially computed tomography and magnetic resonance imaging, are useful in diagnosis of mucoceles and help to explain the clinical symptoms by showing the spread of the lesion.     

Adenoid cystic carcinoma of the maxillary sinus: CT and MR imaging findings

Objective

The purpose of this study was to determine whether adenoid cystic carcinomas (ACCs) of the maxillary sinus have features on CT and MR imaging.

Materials and methods

Nine patients with histopathologically proved maxillary sinus ACCs were included. The growth pattern was classified as expansile or destructive types on the basis of CT images. CT images were also reviewed for adjacent bony defects and MR images were reviewed for tumor extension. Fluid accumulation in the ipsilateral maxillary sinus was also assessed.

Results

The tumors had caused adjacent bony expansion with minimal bony defects in 4 patients whereas those in the remaining 5 patients had caused extensive destruction of adjacent bones comprising the maxillary sinus walls. Nasal cavity invasion was observed in 7 patients, retroantral fat pad invasion in 5, pterygopalatine fossa invasion in 4, and orbital invasion in 3. All 4 expansile ACCs were accompanied by accumulation of a small amount of fluid in the surroundings of the tumors, which was revealed as hyperintensity on T1-weighted images.

Conclusion

The growth pattern of maxillary sinus ACCs can be classified into an expansile type with minimal bony defects and a destructive type with extensive bony defects.     

Expansile organized maxillary sinus hematoma: MR and CT findings and review of literature

An organized hematoma is a chronic state of fibrotic tissue surrounding a hemorrhage. A mass lesion resulting from hematoma in the maxillary sinus was first reported in 1917, and the term, "blood boil," was clinically coined from such features as encapsulated blood and locally aggressive behavior. Subsequently, others have reported lesions with a similar appearance and clinical course, and now, in Japan, blood boil is used as a clinical term for such lesions. Factors that may predispose a patient to hematoma formation vary, and the pathogenesis of the mass is still uncertain. The lesions are mainly composed of an organized hematoma, regardless of their origin. We present 2 cases of organized maxillary sinus hematomas that have unusual radiologic findings and correlate these findings with the histopathologic findings.     

The petrosquamosal sinus: CT and MR findings of a rare emissary vein.

BACKGROUND AND PURPOSE: Morphologic changes in the dural sinuses and emissary veins of the posterior fossa relate closely to the development of the brain. We report characteristic findings of imaging in six patients with a rare and forgotten emissary vein called the petrosquamosal sinus (PSS). METHODS: From a larger group of patients with ear abnormalities, we selected six patients from three ENT imaging centers, because they had CT features suggestive of a PPS. This was the criterion for inclusion in this retrospective study. They were explored by high-resolution CT (HRCT) of the temporal bone. MR venography was performed in three patients to determine the presence and patency of the emissary vein. RESULTS: The PPS was bilateral in two patients and unilateral in the other four. It affected mainly the left side (left:right ratio, 5:3). Three patients had associated inner ear (n = 2) or middle ear malformations (n = 1). Five of six patients had jugular vein hypoplasia, with development of emissary mastoid veins in three patients. CONCLUSION: Petrosquamosal sinus can be identified on HRCT in a typical location. It is encountered more frequently in patients referred for congenital abnormalities of the skull base. This rare anatomic variant should be assessed before surgical treatment, because proper identification of these large venous channels would be of interest to the surgeon.     

Tributary venosinus occlusion and septic cavernous sinus thrombosis: CT and MR findings.

PURPOSEIn autopsy reports of patients who died of septic cavernous sinus thrombosis, tributary venosinus occlusion has been a common finding related to intracranial inflammatory complications. The purpose of this article is to illustrate the MR and CT appearance of septic cavernous sinus thrombosis and tributary venous occlusion.METHODSOver a period of 7 years, eight patients with septic cavernous sinus thrombosis were examined by contrast-enhanced thin-section CT. The CT scans of these eight patients and those of 30 healthy control subjects were assessed independently and subjectively by two blinded readers to ascertain the presence, size, and density of areas of nonopacification within the cavernous sinus and the presence of filling defects and dilation of tributary veins and venous sinuses. In six subjects, MR images supplemented by a contrast-enhanced spoiled gradient-recalled acquisition in the steady state (SPGR) sequence were assessed with respect to the presence of filling defects, expansion, and signal abnormalities within the cavernous sinus and tributary veins and sinuses. The MR and CT findings were compared.RESULTSThe CT studies of the eight patients were consistently differentiated from those of the control subjects by the two readers. Contrast-enhanced CT findings in patients included areas of nonopacification that were present within the cavernous sinus bilaterally in six cases and unilaterally in two. The size of the filling defects exceeded 7 mm in 76% of thrombosed cavernous sinuses compared with 9% of control subjects. The mean density of filling defects in patients differed significantly from those in control subjects. Comparison of the MR and CT findings in six cases showed the contrast-enhanced SPGR sequence to be equivalent to CT with respect to delineation of filling defects.CONCLUSIONContrast-enhanced high-resolution CT findings indicate that venosinus thrombosis associated with septic cavernous sinus thrombosis is not restricted to the superior ophthalmic vein and is more common than previously assumed. A contrast-enhanced SPGR MR sequence may be used as a reliable alternative to establish the diagnosis of cavernous sinus and tributary venosinus thrombosis.     

Elastofibroma: CT and MR findings

Two cases of elastofibroma of the chest wall are reported. Each patient was investigated with CT and, in 1 case, MR imaging was also performed. Elastofibroma appears like a mass in the subscapular region and often presents problems of differential diagnosis. The contribution of MR imaging is reported.     

Hypointense paranasal sinus foci: differential diagnosis with MR imaging and relation to CT findings

Despite the plethora of information provided by magnetic resonance (MR) imaging that allows differentiation of some substances that are indistinguishable at computed tomography (CT), there are diagnostic problems. In particular, there are several quite disparate substances that all appear as either low signal intensity or signal void on T1-weighted images and even lower signal intensity or signal void on T2-weighted images. These substances include air, desiccated secretion, mycetomas, acute hemorrhage, calcium, bone, and enamel. When they are surrounded by material that has long T1 and T2 relaxation times, a not uncommon MR appearance in the sinonasal cavities, they may be impossible to differentiate from one another. The current explanations for the low signal intensities are presented, the similarities in the MR appearance are illustrated, and the use of CT to resolve diagnostic problems is discussed. CT appears to be the best modality for initially examining patients with suspected routine inflammatory disease or fungal infection.     

Lead encephalopathy: CT and MR findings

Lead is toxic to many organ systems, among them bone marrow, muscles, kidneys, endocrine glands, joints, and nervous system. Encephalopathy is a rare but severe complication of lead poisoning. Lead toxicity is much less common in adults. Adult lead poisoning results primarily from exposure by inhalation in the workplace. In this report, two cases of adult toxic encephalopathy due to lead poisoning are presented with CT and MR findings.     

Lhermitte-Duclos disease: CT and MR findings

The typical CT findings of Lhermitte-Duclos disease (dysplastic gangliocytoma of the cerebellum) are a hypodense nonenhancing unilateral posterior fossa mass, with or without adjacent occipital thinning, hydrocephalus, and calcification. Magnetic resonance (MR) has been found to be very helpful, and superior to CT, in delineating the margins of the lesion for determining the extent of surgical resection. Since recurrence is known, MR is important in the follow-up of these patients. To our knowledge this is the first reported case that included MR examination with administration of gadolinium. There was no enhancement of the lesion, consistent with previous reports of no contrast enhancement on CT.     

Sinus pericranii: CT and MR findings

A case of sinus pericranii communicating with the right transverse sinus is reported. The radiographic findings on CT, angiography, and magnetic resonance imaging are presented.     

Marchiafava-Bignami disease: CT and MR findings

We describe characteristic findings in a patient with Marchiafava-Bignami disease who was serially imaged with CT and MR. Involvement of the entire corpus callosum was visualized with both types of imaging. Following administration of gadolinium-DTPA, the lesion was clearly enhanced in the subacute stage. Correspondence to: S. Otake     

Meningioangiomatosis: CT and MR findings.

Meningioangiomatosis (MA) is a rare hamartomatous lesion of the cerebral cortex; to date only 18 cases with imaging findings have been reported in the English literature. The origin of MA is probably malformative, with possible association with neurofibromatosis. These lesions frequently cause seizures in young patients. We report two new cases seen at our institution and present their CT and MR findings clearly illustrating MA cortex infiltration. Gd-DTPA used in one of the two cases failed to cause enhancement.     

Nasopharyngeal teratoma: CT and MR findings

Teratomas of the nasopharynx occur usually in neonates. We present a case of teratoma which was discovered in an adult, and which relapsed after 34 years. The conventional radiograms, CT, MR, and histologic appearances are described. Received 3 January 1996; Revision received 1 March 1996; Accepted 4 March 1996