海绵窦区病变

• Cranial nerves III and IV and the first and second divisions of the cranial nerve V (from superior to inferior) are located in the lateral dural wall of the CS (called the oculomotor trigone) • 动眼神经、滑车神经、三叉神经的第1、2分支（眼神经和上颌神经）位于 海绵窦的侧壁（称为动眼神经三角） • Cranial nerve V courses in the central part of the CS inferolateral to the ICA • 三叉神经走行与海绵窦的中部，位于颈内动脉的下方 • The CS is a multiseptate space, which shows intense contrast enhancement of the slower flowing venous blood • 海绵窦是一个多分隔的空间，由于慢流速的静脉血而增强后能明显强化 • The ICA appears as a signal-intensity void structure • 颈内动脉则表现为血管流空信号
• Transverse diameter is 5–7 mm 左右径5–7 mm • Vertical diameter is 5–8mm 上下径5–8mm • Anteroposterior diameter is 10–15mm 前后径10–15mm • The CS is composed of a network of small venous channels that may arbitrarily be divided into different compartments • 内有小静脉通道组成的网，能任意分成不同的间隔
Anatomy 解剖
• The CS is composed of 2 layers of dura that split to form a septate venous channel • 海绵窦是有2层硬脑膜分隔形成的静脉通道 • Each dural wall contains an outer layer apposed to bone and an inner layer in contact with blood or CSF • 每层硬脑膜由靠近颅骨的外层和临近血液/脑脊液的内层 组成
• Meckel腔
– Meckel腔（Meckel cave，MC）为颅中窝中后份的硬脑膜陷窝，区域狭小、 空间结构复杂并与许多重要神经、血管结构相毗邻 – 三叉神经根由桥脑发出后,从岩上窦下方穿小脑幕的三叉神经孔至三叉神经 节，在这段距离之前，三叉神经根与脑膜的关系酷似脊神经根与脊膜鞘的 关系，其外覆盖着硬脑膜和蛛网膜，并形成一腔隙，称为Meckel 腔 – Meckel 腔为由颅后窝向颅中窝后内侧部分突入的硬脑膜陷凹，分为上、下、 前、后壁及内、外侧壁
• Epidermoid and Dermoid Cysts 表皮或皮样囊肿
• Disorders of Histiocyte Proliferation 组织细胞增生症
• Schwannoma 神经鞘瘤
– A trigeminal nerve schwannoma commonly involves the CS and, in 50% of instances, has a typical dumbbell-shape with bulky tumor in the Meckel cave and the prepontine cistern with a waist at the porous trigeminus – 三叉神经鞘瘤在最常见，发病率约50%，典型的哑铃样形状， Meckel腔和桥前池的肿块+腰部位于三叉神经孔 – Conversely, it may be found only involving the Meckel cave – 也可以仅仅累及Meckel腔 – It may be solid or have variable cystic or hemorrhagic components with occasional fluid levels – 肿瘤可以是实性的，也可以有多样的囊变或出血，偶见液平 – Small tumors tend to be homogeneous, whereas large ones are frequently heterogeneous in appearance – 肿瘤体积小则多质地均匀，体积大的肿瘤多为非均质性表现
• 前壁和上壁与海绵窦后部静脉间隙相邻；外侧壁与颅中窝内侧壁硬脑膜相邻，内 侧壁前部与颈内动脉海绵窦段后升部相邻，并夹第四对颅神经，也有少量结缔组 织相连；内侧壁后部与颞骨岩尖部的骨膜相贴 • 三叉神经节位于Meckel 腔内，呈半月形或三角形，其表面覆盖蛛网膜，后者包 绕三叉神经形成蛛网膜下腔的三叉池 • 半月神经节位于中颅凹的后内侧，由关系密切的三种间隙围绕: 三叉神经池、 Meckel 腔和海绵窦硬膜外间隙 • 蛛网膜包裹三叉神经节，与三叉神经节之间有一定的间隙，松散的三叉神经节纤 维之间也有一定的间隙，共同构成三叉池 • 三叉神经池与邻近蛛网膜间隙相连，脑池造影时可被充盈 • 海绵窦间隙位于形成中颅凹内侧壁的固有硬膜和蝶骨骨膜和岩骨尖之间
• Routine T2, FLAIR, and precontrast T1WI of the entire brain • Post-contrast T1WI 3-mm-thick images of the axial and coronal planes with at least 1 plane imaged with a fat-saturation technique • Thin-section 3D heavily T2-weighted images may allow visualization of individual cranial nerves in the CS and adjacent cisterns • 全脑的常规T2WI、FLAIR、平扫T1WI • 轴位和冠状位的增强扫描，3mm层厚，至少一个切面为压脂像 • 薄层3D重T2WI成像，可使每一根颅神经和临近的脑池显像 • CT is best performed by using a multidetector scanner after intravenous administration of iodinated contrast medium. • Acquisitions in axial or coronal planes by using 1-mm-thick sections may be obtained and then reformatted in other planes • CT扫描最好使用多探测器仪器的增强扫描 • 采集1mm层厚的轴位或冠状位信息，并可其他方位重建
• Patients with CS syndrome usually present with paresis of 1 or more cranial nerves (III-VI), which may be associated with painful ophthalmoplegia • The clinician needs to know the type of CS lesion, its relationship to crucial neurovascular structures, and its extension into the surrounding tissues • These findings are essential for deciding therapeutic modalities such as microsurgery, radiation therapy, or medical treatment as well as for appropriate planning of surgery or radiation therapy
• 偶尔，海绵窦可见脂肪沉积，这是正常表现
– 这些脂肪沉积的区域更常见于肥胖患者、库欣综合征患者、接受 外源性甾类激素治疗的患者
Normal fat deposits 正常的脂肪沉积 Axial noncontrast CT scan shows normal and incidentally found deposits of fat (arrowheads) in the posterior CSs CT平扫可见海绵窦后部的脂肪沉积，少见 但为正常
Imaging Lesions of the Cavernous Sinus 海绵窦区病变
白洁 2011-08-31
• The cavernous sinus (CS) contains vital neurovascular structures that may be affected by vascular, neoplastic, infective, and infiltrative lesions arising in the CS proper or via extension from adjacent intra- and extracranial regions • 海绵窦有重要的神经血管结构， 可发生海绵窦本身固有的 或由临近的颅内外结构延伸 至海绵窦的血管、肿瘤、 感染或浸润性病变
• Occasionally, the CS may contain fatty deposits that are normal
– These fatty zones may be more prominent in obese patients or those with Cushing syndrome or receiving exogenous steroid therapy