呼吸系统影像解读2015

呼吸系统影像解读,李惠民,1.叶和野Lobe,右肺 左肺 S上叶 尖段 1后段 2前段 3中叶 舌段外侧段 上舌段 4 内侧段 下舌段 5下叶背段 6内基底段 7前 8外 9后 10,尖后段,内前基底段,肺野Lung field,横向纵向间隙,第2，4肋骨前端下缘划水平线 3等分 第1肋以上为第1肋骨圈,上中下野 内中外带 1、2肋间为第1肋间隙，依此类推,报告中最好不要写“左上肺或左下肺”，而应该是“左肺上叶或左肺下叶”，左肺上叶还可以分为固有上叶和上下舌段,肺门,2，肺纹理和支气管血管束,肺纹理，Lung markings：由肺门向肺野分出的树枝状阴影，由肺血管、支气管、淋巴管以及结缔组织支架构成与“支气管血管束”对应，是一个平片概念描述肺纹理清晰，粗细、分布未见异常；肺纹理增多增粗，模糊，紊乱肺纹理稀少，细小,2，肺纹理和支气管血管束,支气管血管束，Bronchovascular bundles，BVB：支气管肺血管及其支撑组织构成的管网线状结构。与肺纹理对应，是CT概念。因为在CT上支气管和血管是可以分辨的，因此称BVB描述支气管中心性和血管中心性的大体表现相似，都是BVB为中心，很多时候可能不易区分通常写“支气管血管束增粗/模糊/分布”等，一般不写增多。,CR平片,CR 边缘强化片,肺纹理对应CT三维重建表现,过度充气,3，淋巴结，Lymph node,常态：直径不超过3mm-5mm偏态：隆凸下可达2cm病态对于肿瘤病人，淋巴结短轴径大于10mm具有较好的转移诊断的敏感性和特异性；不常见位置时该指标可以降为8mm；隆凸下该指标增至15mm；对于直径5-8mm之间、数量中等这种状态，可以称为亚临床或不确定,4，主肺动脉窗， aortopulmonary window,解剖AP window代表一个纵隔间隙，胸片上表达为一个界面；位于AP带(AP Stripe)的后面，上缘是主动脉弓内侧壁，下缘是左肺动脉上壁，前缘是升主动脉后壁，后缘是降主动脉前壁，内缘是气管前部，左主支气管外壁，后缘是食管。是炎症和肿瘤性淋巴结病的好发部位,胸片和 CT 表现正位胸片上显示为主动脉下、左肺动脉上的纵隔左缘局部凹口，可以因为主动脉迂曲而有改变。 胸片上通过其外缘构成的界面确定AP window，由左肺、胸膜与肺动脉和主动脉弓缘相贴并正切而形成左肺突入主动脉弓与左肺动脉间隙，构成一个正常的凹面折返 (reflection B)。AP窗呈凸面外形时为异常AP窗呈直线外形时可正常可异常，动态显示以往凹面现在直线则考虑异常。,胸片局部放大,正常胸片的凹面AP窗 (*) ，箭头显示正常AP线(aortic-pulmonary stripe),主-肺动脉窗异常意味着其包含的结构发生病变：左侧喉返神经、左侧迷走神经、动脉韧带、脂肪、淋巴结以及支气管动脉等。主-肺动脉窗外凸可能性：突出的纵隔脂肪、淋巴结增大、支气管动脉瘤、神经鞘瘤等。左侧声带或膈肌麻痹应想到APW的异常。,64岁肺癌,5，奇食窝， azygoesophageal recess,不属于纵隔线范畴，但却是重要的纵隔-肺界面Anatomy右后纵隔隐窝，右肺下叶突入其内。上缘为奇静脉弓，后缘为奇静脉和椎前胸膜，内缘为食管及其邻近结构，下至主动脉裂孔,胸片和CT表现右侧奇静脉下胸膜食管线也可以勾画出该窝，当食管内有气体衬托时上方与隆突下间隙相连，稍向左凸；中1/3变异最大，典型是直线，或稍左凸；下1/3典型呈直线右上部分外凸可见于部分儿童或青少年，但出现在年长者视为异常异常的病因有淋巴结肿大、 主动脉裂孔、支气管肺-前肠畸形、食管肿瘤、胸膜病变以及左房增大等,正常奇食窝上部稍左凸，下部直线状,CT显示奇食窝(箭头),食管裂孔疝。正位胸片显示奇食窝下部1/3右侧凸表现；CT显示疝囊。,纵隔与附属结构,纵隔及其线lines和带stripes叶裂 Fissure胸膜腔 cavity,6，右气管旁线，Right Paratracheal Stripe，R-PTS,右上叶脏壁层胸膜与气管右侧壁紧密相贴(也包括其间的脂肪)，两侧的气体(肺和气管)勾画出的中间结构构成右气管旁线正常厚度不超过4 mm.上下约3-4cm，自锁骨向下，于奇静脉弓水平达气管支气管角可能是最常见到的纵隔线， Woodring and Daniel 报道其显示率为PA位上97%；纵隔内脂肪较多时显示不好,放大片显示右气管旁带stripe (arrows).,CT显示右气管旁带stripe (arrow)由右上叶与气管之间的气管壁、右上叶胸膜及其间的软组织共同构成,多种疾病disease entities可以造成该线的增宽或外形改变，如气管旁淋巴结肿大、甲状(旁)腺肿瘤、气管肿瘤或狭窄等最常见的异常情况是淋巴结肿大胸膜疾病如积液或增厚也是造成其增宽的最常见病因之一,M52，以为甲状旁腺瘤。胸片显示RPTS增宽，CT证实是气管右旁肿块伴弥漫性骨质疏松(primary hyperparathyroidism),7，Aortic-Pulmonary Stripe,Keats首先描述，其实际反映一种纵隔折返或界面(mediastinal reflection or interface)，由左肺前部胸膜与肺动脉和主动脉弓缘相贴并正切而形成该线较直，或轻度膨凸，在主动脉弓和肺动脉干外缘走行,CT显示 正常主肺带 stripe (arrows)，由左肺缘与肺动脉和主动脉弓缘之间构成,前纵隔疾病如甲状腺或胸腺肿块或血管前淋巴结肿大可改变其外形，表现为外凸,42岁淋巴瘤。 (a) 胸片显示主肺动脉带外凸 (arrows). (b) CT 显示血管前间隙内淋巴结增大 (arrows),8，叶裂内脂肪，Intrafissural Fat,表现为侧位胸片上斜裂下部三角形密度增高增宽区，容易与中叶不张混淆。,斜裂脂肪 (arrows) ，很象中叶不张,几个征像,剪影征，Silhouette sign,胸片解剖性软组织界面的缺如称为剪影征(The silhouette sign is the absence of depiction of an anatomic soft-tissue border)由于邻近的肺组织实变、不张甚至肿块或液体充盈，从而导致界面丧失造成；剪影征是由于相似密度结构邻接导致。剪影征也见于漏斗胸甚至一些正常人不一定都是疾病的。,剪影征，右心缘模糊 (arrows).,肺血再分布，Pulmonary blood flow redistribution,病生由于肺血管床的肺血管阻力增加而导致。 胸片和CT一些肺区的血管变少变细，另一些肺区则显示增多增粗，称为再分布二尖瓣疾病时上下叶血流分布倒置是典型再分布例子。,胸片显示血流再分布到上肺区,马赛克现象，mosaic attenuation pattern,CT 高低密度区交织分布提示 (a) 局灶间质性疾病patchy interstitial disease, (b) 闭塞性小气道疾病 obliterative small-airways disease, or (c)血管闭塞性疾病 occlusive vascular disease. 马赛克现象Mosaic attenuation pattern 比马赛克缺血mosaic oligemia 和马赛克灌注 perfusion概念范围更广。小气道空气捕捉征造成的马赛克现象可以通过呼气相扫描确定，低密度区是异常的。间质性疾病造成的马赛克则是高密度区是异常的,mosaic attenuation pattern ，闭塞性小气道疾病,mosaic oligemia, perfusion,PathophysiologyOligemia反映肺血流下降，多数局灶性，通常反映该区域缺血状态。 Radiographs and CT scans表现为局灶区域肺血管变细变少，提示血流下降。,oligemia (arrows),空气捕捉征，air trapping,Pathophysiology气体在气道闭塞远端的潴留CT scans呼气相上局灶肺实质密度低于周围肺实质而容积也不缩小，称为AT，呼吸气相对比容易观察。需要与血管性低灌注鉴别。,air trapping.,气道异物,盘状或线状不张，platelike / linear atelectasis,Radiographs and CT scans盘状或线状不张指的是局灶节段性不张呈线状表现，常指向胸膜(连接)，水平线状多见，也可以斜行或垂直，厚度从几mm到1cm不等。,linear atelectasis.,树芽征，tree-in-bud pattern,CT scans表示小叶中心性分枝状结构，类似发芽的树枝。反映了细支气管腔内和周围疾病谱，包括黏液嵌塞、炎症以及纤维化。多见于肺部周边，通常伴有较大支气管异常。尤其多见于弥漫性泛细支气管炎 (diffuse panbronchiolitis)、结核支气管扩散,tree-in-bud pattern (arrows).,肺结构扭曲变形，architectural distortion,Pathology由于肺疾病尤其是肺纤维化导致支气管、血管、叶裂或小叶间隔等的异常移位，称为Architectural distortion CT scans提示肺纤维化，伴肺容积丧失。,纤维化导致肺结构扭曲,胸膜下(曲)线，subpleural curvilinear line,CT scans表现为13 mm厚的薄层曲线，距离胸膜一般不超过10mm，平行于胸膜如果见于仰卧位肺后部，常对应于正常肺组织的不张(坠积)，俯卧位消失可以确诊也见于肺水肿、纤维化，以及石棉肺患者,胸膜下线,蜂窝，Honeycombing,Pathology即终末肺，表示肺结构破坏和纤维化组织。 Radiographs and CT scans,honeycombing.,胸膜斑， pleural plaque,Transverse CT scan shows pleural plaque (arrow) anteriorly in right hemithorax.,Pseudoplaque,CT scans肺结节与脏层胸膜融合构成的肺部阴影，类似胸膜斑。多见于结节病、矽肺、煤工尘肺等。,结节病，假性胸膜斑,apical cap，肺尖帽,Pathology肺尖部慢性缺血透明样变导致局部肺-胸膜纤维化，牵拉局部胸膜致胸膜外脂肪层突入，最终形成帽样结构，称为肺尖帽。这与年龄相关。 Radiographs and CT scans肺尖区均匀软组织密度的帽样结构单侧或双侧，下缘锐利或不规则最厚可达30 mm，但一般在5mm以内 。,Magnified chest radiograph shows apical cap (arrow).,Bulla，肺大泡,Pathology直径1 cm以上、边缘锐利、薄壁1mm以内的含气腔。 Radiographs and CT scans圆形低密度透亮区，1 cm 以上，薄壁或无壁，伴肺气肿 。,Coronal CT scan shows large bulla in left lower lung zone.,Bleb，肺大疱,Anatomy脏层胸膜内或胸膜下区肺内的小(1cm以内)的含气腔隙。CT scans薄壁小囊，与胸膜相连。,Cyst，囊肿,Pathology有上皮层覆盖，或不同厚度的纤维壁 A cyst is any round circumscribed space that is surrounded by an epithelial or fibrous wall of variable thickness. Radiographs and CT scans通常壁厚小于2mm，不伴肺气肿。多含气，也可以液体等。囊性肺疾病常包括淋巴管平滑肌瘤病、朗格汉斯组织细胞增生症等,Coronal CT scan shows a cyst.,淋巴管平滑肌瘤病,Emphysema，肺气肿,PathologyEmphysema is characterized by permanently enlarged airspaces distal to the terminal bronchiole with destruction of alveolar walls. Absence of obvious fibrosis was historically regarded as an additional criterion, but the validity of that criterion has been questioned because some interstitial fibrosis may be present in emphysema secondary to cigarette smoking. Emphysema is usually classified in terms of the part of the acinus predominantly affected: proximal (centriacinar, more commonly termed centrilobular, emphysema), distal (paraseptal emphysema), or whole acinus (panacinar or, less commonly, panlobular emphysema). CT scansThe CT appearance of emphysema consists of focal areas or regions of low attenuation, usually without visible walls. In the case of panacinar emphysema, decreased attenuation is more diffuse.,Bullous emphysema，泡性气肿,PathologyBullous emphysema is bullous destruction of the lung parenchyma, usually on a background of paraseptal or panacinar emphysema.,Centrilobular emphysema，小叶中心性肺气肿,PathologyCentrilobular emphysema is characterized by destroyed centrilobular alveolar walls and enlargement of respiratory bronchioles and associated alveoli. This is the commonest form of emphysema in cigarette smokers. CT scansCT findings are centrilobular areas of decreased attenuation, usually without visible walls, of nonuniform distribution and predominantly located in upper lung zones. The term centriacinar emphysema is synonymous.,Transverse CT scan shows centrilobular emphysema.,Panacinar emphysema，全腺泡性肺气肿,PathologyPanacinar emphysema involves all portions of the acinus and secondary pulmonary lobule more or less uniformly. It predominates in the lower lobes and is the form of emphysema associated with 1-antitrypsin deficiency. CT scansPanacinar emphysema manifests as a generalized decrease of the lung parenchyma with a decrease in the caliber of blood vessels in the affected lung. Severe panacinar emphysema may coexist and merge with severe centrilobular emphysema. The appearance of featureless decreased attenuation may be indistinguishable from severe constrictive obliterative bronchiolitis. The term panlobular emphysema is synonymous.,Transverse CT scan shows panacinar emphysema.,Paraseptal emphysema，间隔旁肺气肿,PathologyParaseptal emphysema is characterized by predominant involvement of the distal alveoli and their ducts and sacs. It is characteristically bounded by any pleural surface and the interlobular septa. CT scansThis emphysema is characterized by subpleural and peribronchovascular regions of low attenuation separated by intact interlobular septa, sometimes associated with bullae. The term distal acinar emphysema is synonymous.,Transverse CT scan shows paraseptal emphysema.,Interstitial emphysema，间质性肺气肿,PathologyInterstitial emphysema is characterized by air dissecting within the interstitium of the lung, typically in the peribronchovascular sheaths, interlobular septa, and visceral pleura. It is most commonly seen in neonates receiving mechanical ventilation. Radiographs and CT scansInterstitial emphysema is rarely recognized radiographically in adults and is infrequently seen on CT scans. It appears as perivascular lucent or low-attenuating halos and small cysts.,Transverse CT scan shows interstitial emphysema (arrow).,皮下气肿，纵隔气肿，间质气肿,报