SWI在颅内肿瘤中的应用ppt课件

The application of SWI in cerebral tumor SWI在颅内肿瘤中的应用 Zhao Shanshan Introduction Susceptibility-weighted imaging (SWI) is a novel magnetic resonance (MR) technique that exploits the magnetic susceptibility differences of various tissues, such as blood, iron and calcification. 磁敏感加权成像（ SWI ）是一种利用组织磁敏感性差 异产生图像的磁共振新技术，例如出血、铁和钙化 Introduction SWI consists of using both magnitude and phase images from a high-resolution, three-dimensional fully velocity- compensated gradient echo sequence. SWI 包括强度图和相位图，分辨率高且是三维高速补偿梯度回波 Magnitude images increase the conspicuity of the smaller veins and other sources of susceptibility effects,which is depicted using minimal intensity projection(minIP) 应用最小强度投影 (minIP)技术对强度图像进行后处理，可以使静脉及其 它磁敏感物质显示更清楚 Introduction Susceptibility-weighted imaging is better able to define the internal architecture of the lesion in comparison to conventional MR sequences as well as to CE T1-weighted images 磁敏感加权成像较常规 MR序列如 CE-T1加权成像，更好的显示病灶 内部结构 The internal architecture of tumors varies significantly between SWI and CE T1 imaging. SWI 上和 CET1图像显示肿瘤内的结构明显不同 Diversity Internal architecture in CE T1: determined by the presence of necrosis, cysts, and tumor boundaries CE T1可显示的内部结构：坏死、囊变和肿瘤边缘 Internal architecture in SWI : determined mostly by blood products either from venous vascular content and micro- hemorrhage in a tumor SWI 可显示的内部结构：主要由其内部的血液成分决定，脉管系统 和瘤内微出血 Figure 1. SWI (right) shows regions of venous vascular content and hemorrhage in a tumor,which are not seen in the conventional postcontrast T1-weighted image (left). 图 1. SWI(右 )能显示常规 T1 增强图像 (左 )不能显示的瘤内微量出血和脉 管系统 Fig. 2 Glioblastoma multiformae.a CE fat-suppressed axial T1-weighted images showing the necrotic heterogeneously enhancing mass in the right frontal lobe. b Axial 2D GRE. c minIP SWI. Note that the tumor neovascularity and hemorrhages are better shown in SWI3.SWI illustrates the hemoglobin breakdown products within the tumor not detected in conventional images 图 2. 多形性恶性胶质瘤 . a. CE 压脂轴位 T1加权图像，右侧额叶可见含坏死的不均匀强 化肿瘤； b. 轴位 2D GRE. c. minIP SWI. SWI 可显示常规序列不能显示的血红蛋白降 解产物 Value This difference in image appearance can allow recurrent tumor to be distinguished from postsurgical trauma. 由于显示的图像不同，可区分术后出血和复发肿瘤 While necrosis is also a factor that determines the internal architecture in SWI sequences and T1 sequences, late enhancement on T1 sequences shows homogenization of signal between necrotic andparenchymal tumor regions. 其中 T1和 SWI 上显示的瘤内坏死结构也是另一个影响因素，增强 T1 上肿瘤坏死和实质区域显示信号均匀 On CE SWI images, necrotic regions become high in signal compared to the low signal tumor parenchyma CE SWI 上坏死区域显示高信号，而肿瘤实质区域显示低信号 Figure 3. Metastasis of lung adenocarcinoma in the left fronto-parietal area.CE T1 imaging (b), in comparison with precontrast T1 imaging (a), shows two areas that did not enhance and likely correspond to necrosis. The same areas appear bright on T2 (not shown), supporting that hypothesis. CE SWI (d), in comparison with SWI (c), shows an enhancement of the same areas, suggesting late enhancement due a leakage of contrast agent because CE SWI was performed at least seven minutes after the CE T1 imaging. The dark margins of the tumor keep the same hypointense signal after contrast, suggesting venous vasculature a b c d Figure 3.额顶叶肺腺癌转瘤。 CE T1(b)与常规 T1(a)对比，两个没有强化的区域 是相应的坏死区域，在 T2上信号显示更亮些 (无图像 )，能够证实这个假设。 CE- SWI(d)与 SWI(c)对比，同样的区域出现强化；由于 CE SWI是在 CE T1图像后至 少几分钟后采集，故延迟强化是因为造影剂泄露造成。增强后肿瘤低信号区仍显 示低信号，考虑是静脉脉管系统 Value Susceptibility-weighted imaging also provides FLAIR-like contrast because the CSF is suppressed while edema is enhanced relative to the normal tissue . This unique contrast combination of T2* effects and edema within a single image allows for improved detection of space-occupying lesions. 磁敏感加权图像可以显示液体反转序列显示的对比信号；因为与 正常脑组织对比水肿信号被强化时， CSF信号被抑制。这种独特 的对比结合单幅图像中 T2*效应和水肿能够增加占位效应明显病灶 的检出 Fig. 4 Primary central nervous system (CNS) lymphoma. a CE fat- suppressed axial T1-weighted images. Note the intensely enhanced splenial lesion. b Axial FLAIR. c minIP SWI, showing areas of hemorrhage and perilesiona edema well 图 4. 原发性中枢神经淋巴瘤。 a.轴位 CE-压脂 T1加权图像。胼胝体压部病灶明显强 化。 b. 轴位 FLAIR； c. minIP SWI，能很好显示出血和 病灶周围水肿区域 Value Phase images of SWI are needed to differentiate tumor vasculature from calcifications since both show hypointensity on minIP images. 由于脉管系统和钙化在 minIP图上均显示低信号， SWI 相位图可用于 鉴别两者 Calcium, being diamagnetic, shows negative phase (in left- hand MR systems) and is thereby hypointense in phase images. 钙化是逆磁性物质显示负相位 (左手 MR系统 )，因此在相位 图上显示低信号 Tumor vasculature due to the presence of increased deoxy-Hb shows a paramagnetic effect with a resultant positive phase on phase SWI images 瘤血管内存在大量脱氧血红蛋白可产生顺磁性效应，在 SWI 相位上呈 正相位 Fig. 5 Right frontal oligodendroglioma.a NECT. Note the calcified cortical based lesion (thick arrow). b Axial 2D GRE showing the calcification (thick arrow). c SWI minIP showing the calcification (thick arrow)and the peripheral vessel (thin arrow), both of which are hypointense. d CE fatsuppressed axial T1-weighted image showing the enhancing peripheral vein (thin arrow).e SWI phase showing the calcification (thick arrow) and the deoxy-Hb in the peripheral vein (thin arrow) showing opposite phase information;consequently, the two will be differentiated 图 5. 右侧额叶少突胶质细胞 瘤。 a. NECT.显示皮层钙化 ( 粗箭头 )； b.轴位 GRE序列显 示钙化 (细箭头 )； c. SWI minIP图上显示钙化 (粗箭头 ) 和外周血管影 (细箭头 )； d. CE 压脂轴位 T1图像，显示周 边血管强化影 (细箭头 )； e. SWI相位图显示钙化 (粗箭头 ) 和周边含脱氧血红蛋白的血 管影 (细箭头 )，给出相反的信 息，可对两者进行鉴别 Value The tumor growth depend on the patho-vasifaction. It exisited a feature which include vessel structure with tachygrowth and multiple microhemorrage, so SWI can conduct to make grade of tumor. 由于肿瘤生长依赖病理血管形成，恶性肿瘤通常具有快速增长的血管 结构和多发微量出血，因此应用 SWI 有助于肿瘤的分级 High-grade tumors often have a hemorrhagic component, which may be useful for staging Bloodproducts (deoxyhemoglobin, methemoglobin, ferritin,and hemosiderin) are well recognized by the SWI sequence. 高级别肿瘤往往含有出血成分 (脱氧血红蛋白、高铁血红蛋白、铁蛋白 和含铁血黄素 ) ，而 SWI 能很好的显示不同阶段的成分； 图 6. 男， 49岁，右侧顶枕叶星形细胞瘤 .a. T1FLAIR，可 见右顶叶病灶内小血管数量少并且清晰度差； b和 c. T2WI及 T2FLAIR，显示病灶内小血管略增多； d. CE-T1WI，清晰显 示了肿瘤实性强化部分，但其肿瘤血管与肿瘤实质无法区分 ； e. SWI-MinIP，显示小血管清晰，边界清晰，走行连续、 迂曲； f. CE-SWI-MinIP，除了显示病灶内的小血管，还显示 例肿瘤强化部分，低信号血管在高信号的肿瘤实质中尤为明 显 Figure 6 Male, 49 years old, the right parietal and occipital astrocytoma . a. T1-FLAIR, the right parietal lobe lesion is noted of less blood vessels within poor resolution; b and c. T2WI and T2FLAIR, small blood vessel in the tumor slightly increased; d. CE-T1WI, clearly showed the enhanced part of the solid tumor, but it is difficult to distinguished the tumor blood vessels from parenchyma of tumor; e. SWI-MinIP, clearly demonstrated small blood vessels, clear boundaries, running continuously, tortuous; f. CE- SWI-MinIP, in addition to revealing the small blood vessels within the lesion, also showed enhanced portion of tumor, tumor blood vessels with low-signal is particularly evident compared with parenchyma with high signal Figure 7 female, 27 years old, the right frontal lobe astrocytoma grade ； a-d, T1FLAIR, T2WI, T2FLAIR, CE-T1WI, conventional serial can not showed the signs of tumor hemorrhage and small blood vessels; e-g. SWI-MinIP, CE -SWI -MinIP and CE-SWI-MaxIP, small veins and also can not demonstrated signs of small vein and bleeding 图 7. 女， 27岁，右侧额叶星形细胞瘤 级 a-d， T1FLAIR,T2WI,T2FLAIR,CE-T1WI，常规序列未见肿瘤内出血 和小血管征象； e-g. SWI-MinIP， CE- SWI-MinIP和 CE- SWI- MaxIP,同样未见小静脉和出血征象 Value Susceptibility-weighted imaging can also differentiate intraaxial tumors from extraaxial tumors by demonstrating the shift of vessels around the mass 磁敏感加权成像鉴别轴内和轴外肿瘤，主要观察对瘤周 血管的受压移位情况 Fig. 8 Interhemispheric epidermoid. a Axial 2D GRE, b SWI minIP. SWI provides more information as the left thalamostriate and the septal veins (thin arrow) are being shifted laterally by the mass 图 8. 两半球间的表皮样囊肿 a. 轴位 2DGRE， b. SWI minIP图 SWI可显示肿瘤压迫左侧丘脑纹状体和脑中隔静脉向一侧移位 Value SWI can also be used to differentiate acoustic schwanommas from cerebellopontine angle meningiomas with the improved detection of microhemorrhages within schwanommas, which are not observed in the meningiomas SWI 可用于鉴别听神经鞘瘤和桥小脑较脑膜瘤，听神 经鞘瘤可显示微出血，而脑膜瘤不出现 Fig. 9 Right acoustic schwannoma. a Axial 2D GRE, b SWI minIP. Both show the microhemorrhages within the tumor, but SWI shows them better. Note also the widened right internal auditory meatus (arrow) 图 9. 右侧听神经鞘瘤 .a. 轴位 2DGRE； b. b SWI minIP 两者均可见瘤内微出血影，但是 SWI显示更好。可见右侧内耳道增宽 Conclusion 1. In the terms of showing the small veins, SWI T2WI and FLAIR T1WI and CE-T1WI 在小静脉方面， SWI T2WI及 FLAIR T1WI及 CE-T1WI 2.In the terns of revealing hemorrage, SWI shows up, followed by T2WI and FLAIR, T1WI and CE-T1WI shows the worst. On SWI, bleeding within the tumor showed patchy low signal, a clear boundary, which is superior to conventional sequence, 在出血方