Gas in the cavernous sinus.

PURPOSETo evaluate the significance of cavernous sinus gas identified on head CT scans.METHODSHead CT scans were viewed prospectively for a period of 3 years. The charts of patients who demonstrated cavernous sinus gas were reviewed.RESULTSSeventeen patients without head trauma and 10 patients with head trauma demonstrated gas in the cavernous sinus. None of the patients had symptoms or developed symptoms originating in the cavernous sinus. All of the patients without trauma had an intravenous line in place. Sphenoid fractures or basilar skull fractures were not a constant finding in trauma patients with cavernous sinus gas.CONCLUSIONSIn patients without symptoms referable to the cavernous sinus, gas in the cavernous sinus does not appear to be a significant finding. The gas is most likely the result of venous air emboli from intravenous lines or penetrating trauma.     

CT demonstration of cavernous sinus fat

CT demonstration of cavernous sinus fat deposits has been described as abnormal and potentially a specific sign of Cushing disease. CT scans of 100 patients without biochemical or clinical evidence of Cushing disease and of 10 patients with Cushing disease were studied retrospectively. Twenty-seven percent of the non-Cushing patients demonstrated fat in one or both cavernous sinuses. Forty percent of Cushing disease patients had detectable cavernous sinus fat. While fat deposits were more frequent in the Cushing disease group, this was not statistically significant (p = greater than .6). CT demonstration of cavernous sinus fat ordinarily should be regarded as a normal finding.     

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.     

Cavernous sinus invasion by pituitary adenomas

One hundred ninety-eight surgically explored pituitary adenomas were evaluated preoperatively by high-resolution computed tomography (CT). At surgery, evidence of direct cavernous sinus invasion was demonstrated in 19. CT findings in these cases included cavernous sinus expansion (17 patients) and visible encasement of the internal carotid artery (14 patients). The invasive tumor often enhanced to a lesser degree than the cavernous sinuses and ipsilateral internal carotid artery. Intracavernous cranial nerve compression, obliteration, or displacement (14 patients), invasion of the lateral wall of the cavernous sinus (seven patients), and diffuse bone destruction (seven cases) were other findings. Magnetic resonance imaging in three patients provided excellent demonstration of intracavernous internal carotid artery encasement, but displacement and obliteration of intracavernous cranial nerves was not shown as well as it was with CT. Histologically, only three patients showed anaplastic features and only one of them had distant metastases. There was no correlation between histologic features, hormone assays, and invasiveness. This experience indicates any type of pituitary adenoma, regardless of its endocrinologic activity, can invade the cavernous sinus. Cavernous sinus involvement makes complete surgical removal difficult. Preoperative recognition of invasive behavior of these tumors has prognostic value and aids in designing appropriate management. CT is the most useful technique generally available for evaluation and follow-up.     

Tolosa-Hunt syndrome revisited: not necessarily a diagnosis of exclusion

The Tolosa-Hunt syndrome (THS), a steroid-responsive painful ophthalmoplegia secondary to idiopathic granulomatous inflammation, historically has been categorized as a diagnosis of exclusion because of its nonspecific radiologic presentation. Five patients who satisfied the anatomic and clinical criteria of this syndrome underwent high-resolution CT of the orbital apex/cavernous sinus region. Two patients were diagnosed as having orbital apex pseudotumor, two as having cavernous sinus inflammation, and one as having a cavernous sinus epidermoid by the characteristic CT and clinical findings. Follow-up studies while the patients were asymptomatic demonstrated complete resolution of the CT abnormalities in four patients and clinical improvement in all five patients. Our data suggest that orbital apex pseudotumor and granulomatous inflammation of the cavernous sinus have similar clinical features and should be considered as part of the spectrum of THS. With the advent of high-resolution CT, THS may now be a diagnosis of inclusion. Symptomatic improvement after steroid therapy is an essential but not absolute proof of the syndrome, since lesions such as lymphomas may also respond to steroids. Resolution of the soft-tissue inflammation of CT is an additional criterion for diagnosis.     

Metastatic disease to the cavernous sinus: clinical syndrome and CT diagnosis

We analyzed the clinical constellation of signs and symptoms and the radiographic studies of 17 patients with histologic verification of cavernous sinus metastases. Although most patients presented with acute, unilateral, painful ophthalmoplegia, and with a rapidly progressive course, the clinical diagnosis of metastatic disease was often delayed. This was probably due to the fact that, in the majority of patients, cavernous sinus symptoms were either the first expression of an unknown malignancy or the first manifestation of metastatic disease in those with a known primary. Computed tomography was found to be an indispensable diagnostic aid. In 16 of the 17 patients CT established the presence of an enhancing mass in the cavernous sinus sometimes associated with bone erosion. Thin section, contrast enhanced high resolution CT in axial and coronal projections represents the imaging procedure of choice for metastatic disease to the cavernous sinus.     

Magnetic resonance imaging of the cavernous sinus

The magnetic resonance (MR) appearance of the cavernous sinus was studied by correlating the MR images of normal volunteers and cryomicrotomic sections from six cadavers. In addition, MR images of patients with parasellar masses were compared with corresponding intravenously enhanced computed tomographic (CT) scans. The MR appearance of the cranial nerves in the cavernous sinuses is demonstrated, as well as MR signs of a parasellar mass, including obliteration of intracavernous venous spaces, displacement of the intracavernous internal carotid artery, and bulging of the lateral wall of the cavernous sinus. MR proved to be more effective than CT in delineating the parts of the cavernous sinus.     

Comparison of MR imaging, CT, and angiography in the evaluation of the enlarged cavernous sinus

Twenty-one patients with enlargement of the cavernous sinus were studied with CT and MR imaging. Eighteen of the patients also had cerebral angiography. MR was superior to CT in differentiating parasellar aneurysms from neoplastic masses. MR was also superior to both CT and angiography in defining the relationships of cavernous sinus neoplasms to the internal carotid artery, pituitary gland, optic chiasm, infundibulum, and fifth cranial nerves. Only in the definition of bone erosion or hyperostosis was MR inferior to another method (CT). We conclude that MR should be the initial diagnostic study in patients with symptoms of a parasellar mass, with supplementation when necessary by CT and angiography.     

Septic thrombosis of the cavernous sinus: diagnosis with the aid of computed tomography

A case of septic cavernous sinus thrombosis is described which was observed with high resolution computed tomography (CT). The significant CT findings in cavernous sinus thrombosis (CST) include irregular filling defects within a widened enhancing cavernous sinus. Concomitant findings are unilateral or bilateral swelling of the orbital soft tissues and sinusitis.     

颈内动脉海绵窦段创伤性假性动脉瘤破入蝶窦的CT和MRI诊断

目的评价CT和MRI对颈内动脉海绵窦段创伤性假性动脉瘤（TPA）破入蝶窦的诊断价值.方法对经DSA证实的6例海绵窦段TPA破入蝶窦的CT和MRI资料进行回顾性分析.全部患者均行CT检查,5例行MR检查.结果6例颈内动脉海绵窦段TPA中,CT平扫均显示蝶窦侧壁骨折及其密度增高,2例CT增强扫描均可见蝶窦呈明显均匀强化,强化程度与正常血管一致,海绵窦扩大,1例CT血管成像（CTA）明确显示动脉瘤体与瘤颈.5例行MR SE序列平扫,患者均表现为分层状混杂长T1、混杂长T2信号的血栓,4例尚可见瘤腔内的流空现象;3例增强扫描示蝶窦呈明显均匀强化,强化程度与正常血管一致,其中1例在相位编码方向上流动伪影明显;2例MR血管成像均明确显示瘤体与瘤颈.结论CT和MRI是诊断颈内动脉海绵窦段TPA破入蝶窦的有效非创伤性检查,并可作为手术前后长期随访的良好检查方法.     

Gadolinium-DTPA and MR imaging of pituitary adenoma: a preliminary report

Gadolinium-DTPA MR imaging (Gd-MR), unenhanced MR imaging, and contrast-enhanced CT studies were compared prospectively in six patients with surgically confirmed pituitary adenomas and three patients without sellar pathology to determine the utility of Gd-MR in the diagnosis of pituitary adenoma. In normal patients, the pituitary gland, cavernous sinus, and infundibulum enhanced by T1 shortening after gadolinium. In adenoma patients, two of four focal lesions identified with contrast-enhanced CT were identified with Gd-MR, and one was identified with unenhanced MR. The earliest short repetition-time sequence performed after gadolinium injection was best for focal lesion detection. Normal cavernous sinus enhancement by gadolinium made identification of cavernous sinus extension of adenoma difficult. Infundibulum displacement was better seen with contrast-enhanced CT (two vs one); however, unenhanced and Gd-MR were better than contrast-enhanced CT for demonstrating chiasmal compression (four vs three). Contrast-enhanced CT, Gd-MR, and plain MR were equally able to identify gland enlargement, sellar floor erosion, and abnormalities of the diaphragma sellae. In this preliminary series, we found Gd-MR to be promising for imaging adenomas; however, modifications in Gd-MR technique including thinner slices and immediate scanning after gadolinium injection are necessary for the best detection of focal lesions.     

Fat in the normal cavernous sinus

Summary The cavernous sinuses of 17 patients examined by metrizamide CT cisternography with 1.5 mm-thick slices were reviewed. Most of the cavernous sinuses contained fatty components. Anterior lateral end and posterior end of the cavernous sinus are the common sites where the fat is visible.     

64层螺旋CT对颈内动脉海绵窦瘘的诊断价值

目的探讨64层螺旋CT在颈内动脉海绵窦瘘（ICCF）诊断中的价值。方法回顾性分析我院经血管内栓塞治疗成功的ICCF共16例,所有患者均经64层螺旋CT及DSA检查。结果 CT主要表现：所有患者患侧眼球突出、海绵窦扩大、眼上静脉扩张,部分患者眼下静脉、内眦静脉、面静脉、小脑半球上表面外侧脑膜静脉扩张,岩上、下窦扩张,眼外肌肿胀,眼球壁增厚。利用高级血管处理软件显示直接型瘘10例,间接型瘘6例。结论 64层螺旋CT克服了常规CT对颈动脉海绵窦瘘直接征象的显示并不满意的弱点,可清楚显示颈动脉海绵窦瘘瘘口的位置和大小,同时可以有效地评价Willis环的功能,可为颈动脉海绵窦瘘的诊断、治疗及疗效评价提供有价值的信息。     

颈动脉海绵窦瘘的CT诊断（附16例分析）

目的 分析颈动脉海绵窦瘘（CCF）的CT表现。材料与方法 回顾分析16例具有完整临床资料的CCF的CT表现有外伤史者12例,占75％,10例经DSA造影证实。结果 CT主要表现为：（1）眼球突出;（2）海绵窦扩大;（3）眼上静脉扩张。结果 眼眶CT扫描是一种无创的颈动脉海绵窦瘘的诊断方法,具有准确、方便、特异等特点,但应进行必要的鉴别诊断。     

Computed tomography of cavernous sinus diseases

Summary We retrospectively analyzed CT scans of 21 cavernous sinus lesions in an attempt to discover CT findings helpful to the differential diagnosis. With the integration of various CT observations it was possible to categorize the lesions into inflammatory, vascular, benign neoplastic and malignant metastatic lesions with few exceptions. Four of 5 cases of septic cavernous sinus thrombophlebitis revealed unilateral or bilateral multiple irregular filling defects in the enhancing cavernous sinus with or without orbital inflammatory change. Four of 5 cases of carotid-cavernous fistula demonstrated unilateral or bilateral diffuse bulging and homogeneous enhancement of the cavernous sinus with obliteration of normal low densities of cranial nerves and gasserian ganglion. Dilatation and tortuosity of superior ophthalmic vein were also associated. Four of 5 cases of benign neoplastic lesion showed well-circumscribed enhancing masses confined to the cavernous sinus with pressure erosion or hyperostosis of adjacent bone. Five of 6 cases of malignant metastatic lesion showed changes suggesting malignancy such as destruction of adjacent bone or associated manifestations of intracranial spread. As compared with the axial scan, coronal scans proved to be more sensitive in detection of subtle cavernous sinus expansion, and superior in evaluation of intracavernous neural structures, relationships with the pituitary gland and changes in the skull base. Axial scans, however, were superior in detection of associated orbital and intracranial abnormalities. Scans in both projections are needed in the evaluation of most cavernous sinus diseases.     

Sixth nerve neuroma in the cavernous sinus: CT features

A sixth nerve neuroma arising within the cavernous sinus is reported. This is the third sixth nerve neuroma cited in the world literature and the first to have CT demonstration. The unusual CT enhancement characteristics excluded the more common cavernous sinus masses and suggested the correct diagnosis preoperatively.     

Dynamic CT of the laterosellar extradural venous spaces

We evaluated the ability of dynamic CT scanning to accurately demonstrate the laterosellar extradural venous spaces. Careful examination of 680 consecutive patients with this technique has permitted us to describe four main venous groups: the veins of the lateral wall (present in 98% of cases), the vein of the inferolateral group located beneath cranial nerve VI (present in 92% of cases), the medial vein located between the internal carotid artery and the pituitary gland (present in 20-30% of cases), and the vein of the carotid sulcus located between the intracavernous internal carotid artery and the lateral wall of the sphenoid bone (present in 65% of cases). The vein of the carotid sulcus is absent only when the internal carotid artery lies close to the sphenoid bone. In 12 patients with suspected cavernous sinus invasion, dynamic CT scanning demonstrated obliteration of the vein of the carotid sulcus. In five patients with huge tumors of the temporal region, dynamic CT scanning of the cavernous sinus permitted demonstration of normal laterosellar extradural venous spaces, thus permitting exclusion of intracavernous sinus invasion. We believe dynamic CT is the imaging technique best suited for studying the laterosellar extradural venous spaces. Its spatial resolution and dynamic capacity make it superior to MR, and it should be the first procedure when invasion of the cavernous sinus by a pituitary tumor is suspected.     

Gallium scintigraphy in a case of septic cavernous sinus thrombosis

Septic cavernous sinus thrombosis, a relatively uncommon disease entity, frequently can be fatal. Early diagnosis is imperative in order that appropriate treatment be instituted. A 59-year-old woman who was admitted to our institution with complaints of diplopia, blurred vision and fevers that developed following a tooth extraction is presented. Initial CT and lumbar puncture on the day of admission were totally normal. A repeat CT performed 48 hours after admission, on the same day as gallium imaging, demonstrated findings consistent with cavernous sinus thrombosis. Gallium imaging demonstrated intense uptake in the left cavernous sinus and left orbit as well as moderately increased activity in the right cavernous sinus and orbit, confirming infection. The patient was treated with antibiotics, and repeat CT and gallium imaging were performed ten days later, both of which demonstrated near total resolution of the disease process. Conceivably, if gallium imaging had been initiated on the day of admission it may have been the first study to demonstrate an infectious process in the cavernous sinus. Gallium imaging should be considered as a diagnostic tool in the noninvasive workup of this entity.     

Dynamic CT scanning for the evaluation of pituitary tumor invasion to the cavernous sinus

A CT method for evaluating cavernous sinus invasion by pituitary adenomas or parasellar tumors is described. This technique is easily performed without special software. A persistent, isolated visualization of the internal carotid artery seems to indicate invasion of the cavernous sinus.     

脑血管畸形的MRI诊断：与CT,脑血管造影对比分析

报道了６４例脑动静脉畸型和８例脑海绵状血管瘤的ＭＲＩ表现，并对ＭＲＩ、ＣＴ及脑血管造影在脑血管畸形诊断中的应用价值进行了对比分析。６４例脑动静脉畸形的ＭＲＩ均见到典型征象──流空信号簇。２９例见到粗大的供应动脉或／和引流静脉，１４例见到扩大的静脉窦。结果表明，ＭＲＩ对于脑动静脉畸形及其并发症的诊断优于ＣＴ，并可弥补脑血管造影的不足。ＭＲＩ与ＣＴ的联合应用对脑海绵状血管瘤的定性诊断很有意义。