海绵窦侵袭型垂体瘤磁共振诊断系统及其相关因素分析

目的：探讨MR对海绵窦侵袭型垂体瘤的诊断价值，寻求建立一套海绵窦侵袭型垂体瘤的MR诊断系统。方法：选取手术中已经确诊的39例海绵窦侵袭型垂体瘤，同期162例非侵袭型垂体瘤做对照，应用计算机分析冠状位MR上肿瘤与海绵窦的关系。包括海绵窦形态的改变、窦内间隙的改变以及肿瘤与颈内动脉海绵窦段的关系等。将相关的各个类型均做为拟诊标准分别计算各自的灵敏度(Se)、特异度(Sp)、阳性预告值(PV )、阴性预告值(PV-)。依据医学统计学原理中的判别分析法进一步系统分析MR图像对于是否海绵窦侵袭型垂体瘤的诊断意义。结果：肿瘤包绕颈内动脉≥70％确诊侵袭的意义最大(PV ，100％)，肿瘤超过颈内动脉外侧连线的诊断意义也较高(PV ，86．1％)；如果肿瘤包绕颈内动脉的角度不到20％、肿瘤未超过颈内动脉内侧连线以及海绵窦内侧间隙未出现肿瘤则可以排除海绵窦侵袭的存在。同时应用判别分析法建立了一个海绵窦侵袭型垂体瘤及非海绵窦侵袭型垂体瘤的统计学判别计量数值表。从而完善了海绵窦侵袭型垂体瘤MR图像诊断系统。结论：通过系统分析垂体瘤加RI的表现，能够比较准确的确立海绵窦侵袭型垂体瘤的诊断。     

Diagnostic imaging and differential diagnosis of pathological processes of the sinus cavernosus

To describe the different imaging modalities for the evaluation of pathological changes in the cavernous sinus as well as to compile criteria for differential diagnosis. Imaging of the cavernous sinus comprises the primary use of tomographic modalities such as CT or MRI.The continuing development of multislice-CT (MSCT) allows the depiction of bony structures of the cavernous sinus with a high resolution.Secondary reconstructions of the acquired data set allow a reliable evaluation especially of the bony topography including the foraminae of nerves and vessels. Uni- or bilateral structures can be visualized using contrast-enhanced CT.CT-angiography is capable of demonstrating the course of the internal carotid artery and its involvement in pathologies of the cavernous sinus, this recent achievement has only been made available by use of the current short scanning times. Contrast-enhanced MRI in axial and coronal orientation, optionally using fat saturation techniques as well as arterial and venous MRI-angiography (MRA) are used to depict the soft parts of the cavernous sinus. Care must be taken to cover all topographic detail including different signal intensities, as multiple inborn, neoplastic, infectious or traumatic changes can be present hampering the radiologic diagnosis of the cavernous sinus. Uni- and bilateral infiltration of the cavernous sinus as well as vascular involvement represent additional criteria leading to the differential diagnosis.The advent of dynamic sequences as well as diffusion and perfusion weighted MRI have broadened the spectrum of diagnostic modalities. Digital subtraction angiography as an invasive technique is used during therapeutic procedures such as the local treatment of aneurysms or carotid-cavernous fistulas.     

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.     

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.     

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.     

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.     

Tentorial enhancement on MR images is a sign of cavernous sinus involvement in patients with sellar tumors

BACKGROUND AND PURPOSE: This study was undertaken to analyze enhancement patterns of the dura around sellar tumors and to compare the results with tumor invasion or compression of the cavernous sinuses. Postoperative enhancement patterns on MR images were compared with preoperative findings. METHODS: Contrast-enhanced coronal and sagittal MR images were examined prospectively in 96 patients with sellar tumors (65 macroadenomas, 15 microadenomas, 14 Rathke cleft cysts, and two chordomas at the sella). All patients underwent surgical treatment, and pre- and postsurgical features on MR images were compared. RESULTS: Presurgical MR images showed dural enhancement in 36.5% of the patients: asymmetric tentorial enhancement in 24 patients, symmetric tentorial enhancement in seven, and sphenoidal ridge or clivus enhancement in four. Asymmetric tentorial enhancement disappeared after surgical decompression in seven patients. For evaluation of cavernous sinus invasion ipsilateral to the enhancement, sensitivity and specificity of the asymmetric tentorial enhancement sign were 81.3% and 86.3%, respectively. Sensitivity and specificity of the sign were 42.9% and 93.6% for cavernous sinus involvement, including compression and invasion. CONCLUSION: Asymmetric tentorial enhancement is a useful sign in the diagnosis of invasion or severe compression of the cavernous sinus by sellar tumor. The sign may represent venous congestion or collateral flow in the tentorium due to obstructed flow in the medial portion of the cavernous sinus.     

鞍旁病变的MR诊断

目的　通过总结 5 9例鞍旁病变的MR表现 ,探讨鞍旁病变的MR诊断和鉴别诊断。方法　 5 9例鞍旁病变 ,均行MR平扫检查 ,41例行MR增强扫描。 3 5例经手术病理证实 ,2 4例经临床证实。结果　鞍旁脑膜瘤信号和强化表现与其他部位脑膜瘤类似 ,累及垂体时需要与垂体瘤侵犯海绵窦鉴别。肿瘤从桥小脑角延伸到鞍旁是三叉神经瘤的特点。转移瘤常见于鼻咽癌颅内侵犯。痛性眼肌麻痹表现为海绵窦增大和动眼神经强化。海绵状血管瘤可以呈长T1 长T2 信号 ,显著强化。动脉瘤呈流空低信号 ,可以有血栓形成。结论　多数鞍旁病变MR表现有特点 ,少数需要结合临床进行鉴别诊断     

Detailed imaging of abducens nerve anatomy using contrast-enhanced 3D-TOF MR angiography

PurposeCranial nerves (CNs), particularly CN IV and VI are difficult to visualize with conventional MRI techniques, particularly within the cavernous sinus region. The aim of this study was to evaluate the capacity of high-resolution contrast enhanced 3D time-of-flight (TOF) MR angiography using new generation 3 T imaging technology to provide detailed visualization of CN VI anatomy, particularly within the cavernous sinus and petroclival regions.MethodsTwo neuroradiologists conducted bilateral evaluation of CN VI visibility in 23 patients for nerve segments located in the petroclival segment (dural cave and Dorello's canal), and three divisions of the cavernous sinus. All images were collected using contrast enhanced TOF MR angiography using a new generation 3 T machine.ResultsOf the CN VI segments assessed, average visibility of CN VI was best achieved in Dorello's canal. Overall visibility of CN VI within the regions inspected was best achieved in the axial view, with the exception of the dural cave, which was best assessed using the coronal view.We also identified strong agreement in assessment of nerve visibility between the two reviewers.We also identified a putative CN6 duplication and a small schwannoma, highlighting the fidelity of our approach.ConclusionContrast enhanced 3D TOF MR angiography can visualize CN VI anatomy, particularly within the petrocavernosal region and cavernous sinus with simultaneous visualization of arterial and venous structures. This cannot be easily achieved using traditional MRI techniques. This imaging technique might be used with new generation machines to evaluate CN VI anatomy and pathologies within the petrocavernosal region and cavernous sinus, especially relating to vascular pathologies.     

The imaging of conditions affecting the cavernous sinus

The cavernous sinus can be affected by a wide range of conditions including tumours, infection, inflammation, and trauma. Disease in the cavernous sinus can produce characteristic signs and symptoms, which relate to the numerous crucial structures traversing and surrounding the cavernous sinus. Imaging, with the use of different techniques, plays a crucial role in diagnosis and management. The anatomy and imaging of the different disease entities in the cavernous sinus will be reviewed.     

海绵窦海绵状血管瘤的MRI表现(2例及文献复习)

目的:探讨海绵窦海绵状血管瘤(cavernous sinus hemangiomas,CSHAs)的MRI表现特征。方法:回顾性分析经手术病理证实的2例CSHAs的MRI表现,并复习文献资料。结果:海绵状血管瘤位于左、右侧海绵窦各1例,MRI呈分叶状,边缘清晰,呈长T1长T2信号,信号均匀,未见出血及钙化。增强扫描病变明显强化,强化程度高于垂体,并表现出渐进性、向心性强化的特点。结论:CSHAs的MR表现具有特征性,MR检查有助于作出正确的定位和定性诊断。     

MR imaging of cavernous sinus involvement by pituitary adenomas

The ability of high-resolution MR imaging (1.5 T) to detect invasion of the cavernous sinuses by pituitary adenoma was determined through a retrospective review of 74 patients. These patients were divided into three groups: 25 normal subjects, 24 subjects with invasive pituitary adenomas, and 25 subjects with noninvasive pituitary adenomas. A fourth group of 30 patients, who subsequently underwent surgery for pituitary adenoma, was evaluated prospectively by MR for the presence or absence of cavernous sinus invasion. Several features were analyzed: (1) the detectability of the medial and lateral dural margins of the cavernous sinus (2) the size and variation in intensity of compartments within the cavernous sinus (3) the relationship of endocrine function to the surgical and MR appearance of the cavernous sinus and (4) carotid artery displacement or encasement by tumor. The normal cavernous sinuses were usually symmetric, but their sizes varied. The lateral dural margin of the cavernous sinus was always recognized on MR as a linear, discrete, low-intensity area. The medial dural margin (pituitary capsule) was seen on MR in only two of the 25 normal patients. In all 24 patients with cavernous sinus invasion involvement was unilateral and was most common with laterally positioned prolactin or adrenocorticotropic hormone secretory adenomas. Invasion of the cavernous sinus was suspected by MR in only two of the 13 invasive microadenomas and was questionable in three. In 10 of the 11 macroadenomas with surgically proved dural invasion, MR demonstrated an asymmetric increase in size and intensity of the superior and inferior cavernous sinus compartments. Noninvasive macroadenomas compressed and displaced the cavernous sinus bilaterally. The prospective MR evaluation of 30 patients undergoing surgery for pituitary tumor revealed a sensitivity for predicting cavernous sinus invasion of 55%, a specificity of 85.7%, a positive predictive value of 62.5%, and a negative predictive value of 81.8%. No feature permitted certain distinction between invasive and noninvasive microadenomas, as the medial dural wall of the cavernous sinus could not be reliably identified. The most specific sign of cavernous sinus invasion was carotid artery encasement.     

The value of paramagnetic contrast agent gadolinium-DTPA in the diagnosis of pituitary adenomas

Summary The purpose of this study was to assess the role of MR imaging and the paramagnetic contrast agent Gadolinium-DTPA(Gd-DTPA) in the diagnosis of pituitary macroadenomas. 44 macroadenomas were examined with MRI before and after intravenous application of Gd-DTPA. Gd-DTPA produced excellent enhancement of solid adenoma. The best contrast between adenoma and surrounding structures could be gained on post-Gd T1-weighted images. Post-Gd images were equivalent to pre-Gd images in the evaluation of supra-and infrasellar extensions of macroadenomas. Post-Gd images had advantages in the evaluation of cavernous sinus invasion by adenoma. The difference in degree of contrast enhancement between adenoma and cavernous sinus facilitated the exact evaluation of lateral extension by adenoma in 18 cases. Almost equal degree of enhancement of both structures impaired tumor-sinus contrast in 2 cases. In the other 24 cases the tumor filled the cavernous sinus completely. It is our opinion that Gd-DTPA can be used on a widespread basis because of its excellent capability to highlight and delineate pituitary adenomas.     

Investigation of fat in the dural sinus

Detection of fat in the cranium usually indicates the presence of a fat-containing tumor such as lipoma, dermoid cyst or teratoma. However, since 1982, Hasso et al demonstrated with CT the presence of normal adipose tissue in the cavernous sinus, the mere existence of fat in the cranium does not necessarily mean the presence of a fatty tumor. The author first described fat deposition in the superior sagittal sinus and torcular Herophili following a CT study performed in 1986. The purpose of this study was to investigate the distribution, frequency, and anatomical correlations of fat in the dural sinus as demonstrated on CT. Fat was detected in the cavernous sinus in 20% of all cases (492/2408), and occurred more frequently (25%) in those older than 50 years. Fat was less frequent in the other dural sinuses (3%; 75/2296). The most common location was the torcular Herophili, followed in decreasing order of frequency by the straight sinus, inferior sagittal sinus, superior sagittal sinus and transverse sinus. Pathological examination was performed in three cases. Fat deposition was composed of normal adipose tissue and was devoid of fibrous encapsulation or infiltration. In one case, the fat seemed to be partly exposed to the subarachnoid space on CT, whereas on autopsy, thin dura mater covering the fat nodule was confirmed. Fat in the dural sinus must be differentiated from cavernous nodule or sinus thrombosis. The Hounsfield unit may be helpful in making a definitive diagnosis.     

MR imaging of Tolosa-Hunt syndrome

The Tolosa-Hunt syndrome consists of painful ophthalmoplegia caused by cavernous sinus inflammation, which is responsive to steroid therapy. The MR features of 11 patients with the clinical diagnosis of Tolosa-Hunt syndrome were studied. Two patients had normal MR studies of the orbit and cavernous sinuses. In nine patients, abnormal signal and/or mass lesions were seen in the cavernous sinuses; in eight cases, the abnormality was hypointense relative to fat and isointense with muscle on short TR/TE images and isointense with fat on long TR/TE scans. Extension into the orbital apex was seen in eight cases. In six of nine cases the affected cavernous sinus was enlarged; in five of nine it had a convex outer margin. One patient had a thrombosed cavernous sinus and superior ophthalmic vein in addition to a cavernous sinus soft-tissue mass. The signal intensity of Tolosa-Hunt syndrome in this limited series was similar to that of orbital pseudotumor and is confined to a limited differential diagnosis, which includes meningioma, lymphoma, and sarcoidosis.     

Cavernous sinus invasion by pituitary adenoma: MR imaging

PURPOSE: To define magnetic resonance (MR) imaging criteria for the diagnosis of cavernous sinus invasion by pituitary adenoma. MATERIALS AND METHODS: The MR images obtained in 106 patients (86 female, 20 male; age range, 16-71 years) were reviewed retrospectively by two physicians. The standard-of-reference criteria for invasion were the surgical findings. A chi(2) analysis was performed, and the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for nine groups of MR imaging signs were computed. RESULTS: Invasion of the cavernous sinus was certain (PPV, 100%) if the percentage of encasement of the internal carotid artery (ICA) by tumor was 67% or greater. It was highly probable if the carotid sulcus venous compartment was not depicted (PPV, 95%) or the line joining the lateral wall of the intracavernous and supracavernous ICAs was passed by the tumor (PPV, 85%). It was definitely not invaded (NPV, 100%) if the percentage of encasement of the intracavernous ICA was lower than 25% or the line joining the medial wall of the intracavernous and supracavernous ICAs was not passed by the tumor. CONCLUSION: The radiologic diagnosis of cavernous sinus invasion by pituitary adenoma remains difficult, but the above-mentioned criteria may be of assistance.     

MRI of infarction of a cavernous sinus tumor in Nelson's syndrome

We report the MRI appearances of an infarcted cavernous sinus tumor in a patient with Nelson's syndrome. Invasive tumors of the pituitary extending to the cavernous sinus are discussed and the role of MRI in preoperative investigation is highlighted.     

Rare and challenging extra-axial brain lesions: CT and MRI findings with clinico-radiological differential diagnosis and pathological correlation

There are many kinds of extra-axial brain tumors and tumor-like lesions, and definitive diagnosis is complicated in some cases. In this pictorial essay, we present rare and challenging extra-axial brain lesions including neuroenteric cyst, primary leptomeningeal melanomatosis, isolated dural neurosarcoidosis, intradiploic epidermoid cyst, ruptured dermoid cyst, intraventricular cavernoma, and cavernous hemangioma of the skull with imaging findings and clinico-radiological differential diagnosis, including the pathologic correlation. Familiarity with these entities may improve diagnostic accuracy and patient management.Intracranial extra-axial pathologies arise from tissues other than brain parenchyma, such as meninges, dura, calvarium, ventricles, choroid plexus, pineal gland, or pituitary gland. There are many kinds of extra-axial tumors and tumor-like lesions, and their definitive diagnosis can often be made easily via imaging studies. However, conditions such as rarity, atypical localization or overlapping symptomatology may complicate the diagnosis.In this pictorial essay, we present a few examples of rare and challenging extra-axial brain lesions from our archive with a brief review of clinico-radiological differential diagnosis, including the pathologic correlation. It should be noted that there are many other rare extra-axial brain lesions that are not mentioned in this text, such as solitary fibrous tumor, hemangiopericytoma, leiomyosarcoma, plasmacytoma, Rosai-Dorfman disease, and inflammatory myofibroblastic tumor.     

Cranial nerve assessment in cavernous sinus tumors with contrast-enhanced 3D fast-imaging employing steady-state acquisition MR imaging

Introduction  The purpose of this study is to apply contrast-enhanced 3D fast-imaging employing steady-state acquisition (3D-FIESTA) imaging to the evaluation of cranial nerves (CN) in patients with cavernous sinus tumors. Methods  Contrast-enhanced 3D-FIESTA images were acquired from ten patients with cavernous sinus tumors with a 3-T unit. Results  In all cases, the trigeminal nerve with tumor involvement was easily identified in the cavernous portions. Although oculomotor and abducens nerves were clearly visualized against the tumor area with intense contrast enhancement, they were hardly identifiable within the area lacking contrast enhancement. The trochlear nerve was visualized in part, but not delineated as a linear structure outside of the lesion. Conclusions  Contrast-enhanced 3D-FIESTA can be useful in the assessment of cranial nerves in and around the cavernous sinus with tumor involvement.     

海绵窦内海绵状血管瘤的影像学诊断(附4例报告)

目的:探讨海绵窦海绵状血管瘤影像学特点,以提高其诊断水平。方法:回顾性分析经手术后病理证实的4例海绵窦海绵状血管瘤,均有CT和MRI检查资料,1例行DSA检查。结果:4例海绵窦海绵状血管瘤均位于左侧,CT表现为均匀的稍高密度影,伴蝶骨轻度骨质侵蚀,未见钙化。MRI检查见T1WI呈较脑灰质低的均匀信号,T2WI呈较脑灰质高的均匀信号,静脉注射钆喷酸葡甲胺后T1WI显示明显强化的均匀高信号,形态特点呈内小外大的哑铃状结构,边缘清晰。1例DSA检查见颈内动脉受压移位明显,但无管腔狭窄征象,于毛细血管期和窦期有浅淡的肿瘤染色。结论:MRI是术前诊断海绵窦海绵状血管瘤最具价值的检查手段,而CT、DSA可作为鉴别诊断工具。