课件：呼吸次常见病诊断.ppt

1,Respiratory disease,放射学院 刘林祥 6222136 ,2,肺隔离症,Pulmonary sequestration 一部分肺与正常肺分离，且不接受肺动脉供血，而仅接受来自体循环异常血管的供血 肺叶内型肺隔离症：隔离肺与邻近正常肺位于同一脏层胸膜内，供血动脉多来自降主动脉或其分支，静脉回流多经过肺静脉 肺叶外型肺隔离症：有单独的脏层胸膜包裹，90%位于左下叶后基底段，也可位于膈下或纵隔内，供血动脉来自腹主动脉，静脉回流通过下腔静脉、奇静脉或半奇静脉回流到体循环。30%合并膈疝,3,4,Pulmonary sequestration,5,6,Pulmonary sequestration,7,Pulmonary sequestration,8,9,肺真菌病,肺霉菌病，因人体抵抗力低下而真菌侵入引起 真菌种类多，但对人体能致病者只有十余种，按其致病的部位可分为浅部真菌和深部真菌 深部真菌的多数可引起肺部病变。常见的有曲菌、念珠菌、奴卡菌、放线菌、新型隐球菌等。这些真菌有的广泛存在于自然界中，为腐物寄生菌，有的寄生于正常人体内 正常人体对真菌有较强的抵抗力，肺真菌病少见,10,可能引发肺真菌病的因素,机体抵抗力降低 口腔卫生不佳 生活和职业中接触较多被真菌孢子污染的物质 抗生素的大量应用，人体对抗生素敏感和不敏感的致病菌之间的相互拮抗作用产生紊乱，敏感者被抑制，有利于不敏感者的繁殖 长期应用激素使机体的免疫功能低下 恶性肿瘤、严重烧伤或大手术后，免疫功能低下,11,感染途径与病理变化,内源性感染：口腔和上呼吸道内寄生的真菌，如放线菌和念珠菌，由于口腔卫生不佳或身体抵抗力降低时，侵入肺部引起感染 外源性感染：带有真菌孢子的尘土吸入肺内，如奴卡菌病、曲菌病和隐球菌病 继发性感染：体内其他部位的真菌病变经血行或淋巴播散到肺部，或膈下病变直接侵犯蔓延到肺部 病理变化：过敏、急性炎症、化脓性病变、肉芽肿形成、空洞、纤维化和钙化 扩散方式：直接侵犯、淋巴播散和血行播散,12,肺真菌病的影像学表现,散在性小结节：大小不一，密度均匀、边缘较清楚的圆形阴影 斑片状影：多在两肺中下部，形态大小不一，边缘清楚或模糊，病灶可融合呈地图状，伴有肺纹理增多增强 肺段或肺叶实变：斑片状影可发展融合为密度高、范围大的实变影，侵犯一个肺段或肺叶，似肺段性或大肺叶炎表现,13,肺真菌病的影像学表现,肿块及空洞：肿块常为多发，密度较高，其内可有多处透亮区。部分单发肿块周围可见晕轮样改变，称为晕轮征，为曲菌感染的早期表现 真菌球：多见于曲菌病。空洞或空腔内边缘光整的球形致密影，其大小因所在空洞或空腔的大小和病变发展程度而不同。曲菌球与洞壁或腔壁之间可见新月状空隙，为空气半月征 其他：纵隔或肺门淋巴结肿大、胸腔积液或脓胸，胸膜肥厚粘连。侵犯纵隔及心包，形成纵隔脓肿或心包炎。病程长者有纤维性病灶和钙化灶,14,影像诊断与鉴别诊断,肺曲菌病的曲菌球和晕轮征具特征性，其他肺真菌病影像学表现缺乏特征性 以下几点有助于提示肺真菌病的诊断 肺部病灶影存在时间长，又缺乏某些常见疾病的特征，且在鉴别中也无其他疾病应有的临床症状时，提示肺真菌病的可能 经较长时间的动态观察，病灶变化不大，或虽有所变化，但不符合一般炎症、结核等病的发病规律时，提示本病的可能 病人有长期应用大量抗生素、激素、免疫抑制剂等类药物的病史，提示本病的可能,15,肺曲菌病,Aspergillosis 又称肺笰状菌病，肺部最常见的真菌病 曲菌广泛存在于自然界，孢子在空气中到处皆有，吸入其孢子不一定致病，大量吸入可引起急性气管、支气管炎或肺炎 常寄生在人体上呼吸道，痰培养中常可发现，很少使健康人致病 慢性病病人免疫功能低下时，入侵肺部发生肺曲菌病,16,肺曲菌病 病理,发于肺内空洞或空腔，繁殖过程中，菌丝、纤维素、细胞碎屑及粘液混合形成曲菌球 发生于支气管者则因过敏反应，分泌物增多，曲菌菌丝又使粘液变稠而不易排出，滞留于支气管内，在支气管内形成粘液嵌塞 侵袭型为曲菌引起的肺部炎症、化脓及肉芽肿性病变，病变范围可较广泛,17,肺曲菌病 临床,与吸入曲菌量有关，也与机体对曲菌发生的变态反应有关 无症状 有的起病急，有发热、咳嗽、咳痰、咯血等症状，酷似急性肺炎 有的起病缓慢，有低热、夜间盗汗、咳嗽、咳脓痰带血，病情时好时坏，颇似肺结核,18,X线表现,肺空洞或空腔内的圆形或类圆形致密阴影 34cm，密度较均匀，边缘较光整 可有钙化，呈斑点钙化或边缘钙化 不侵及空洞壁，体积小于空洞内腔，立位与卧位比较，位置可有改变，且总是处于近地位。曲菌球与空洞壁间可见新月形空隙，为空气半月征 曲菌球易发于肺结核空洞，两上肺尖后段多见，洞壁多较薄 侵袭型曲菌病表现为一侧或两侧肺野的单发或多发斑片状影，也可为肺叶或肺段的实变影，病灶坏死可形成脓肿，少数见空洞形成,19,CT表现,薄壁空洞或空腔内的孤立球形灶，边缘光滑锐利，大小不等，常见空气半月征 曲菌球处于近地位，呈软组织密度，有时见钙化，无强化 支气管粘液嵌塞表现为柱状致密影 侵袭型曲菌病感染早期，肺部出现结节或肿块状实变影，周围出现晕轮征，即在结节或肿块状病灶周围可见环绕的较低密度区域，其密度介于结节与正常肺组织间，形似晕轮，为周围出血所致 小叶性实变或小叶融合性影，多发球形病灶伴空洞形成及肺门淋巴结肿大,20,Microscopic features of A fumigatus,High-power photomicrograph conidiophores with the characteristic head appearance and minute spores,Medium-power photomicrograph septate hyphae branching at an angle of approximately 45,21,Bilateral aspergillomas,M71, with residual tuberculosis large cavities bilaterally in the upper lobes containing fungus balls of different sizes,22,Radiography,Mycetomas: a solid, round or oval mass with soft-tissue opacity within a lung cavity Separated from the wall of the cavity by an airspace of variable size and shape, resulting in the “air crescent“ sign Moves with the patient changes position,23,Mobile aspergilloma within a pulmonary cystic cavity,M43 Supine and prone A change in the position A fumigatus was discovered at bronchoscopy,24,Aspergillomas,Often associated with thickening of the cavity wall and adjacent pleura 10% of mycetomas resolve spontaneously Thickening of the cavity wall and pleura is due to a hypersensitivity reaction Reversibility of the pleural thickening corresponding to the resolution of intracavitary fungal material,25,Parasites（寄生虫病）,Organisms obtain nourishment and shelter from other organisms Host may either be unaffected or suffer harmful consequences Vary widely in size and complexity, from relatively simple unicellular protozoans (amebae) to more complex multicellular organisms ( worms, flukes) Distributed worldwide, a higher prevalence in developing countries, inadequate sanitation,26,Common human infection throughout the world Epidemics of parasitic diseases (malaria) have devastated large populations and pose a serious barrier to progress in many developing countries Economic and social changes over the past decades are stimulating rural-to-urban migration in most endemic areas, parasitic diseases that are more common in rural areas are no longer entirely absent in the urban population In industrialized countries, risk groups for parasitic diseases includes travelers, recent immigrants, and patients with AIDS,Parasites,27,Hydatid Disease（包虫病）,A worldwide zoonosis produced by the larval stage of the Echinococcus tapeworm Two main types of hydatid disease are caused by E granulosus and E multilocularis The former is commonly seen in the great grazing regions of the world the Mediterranean region, Africa, South America, the Middle East, Australia, and New Zealand, and is the most frequently encountered type of hydatid disease in humans,28,Geographic distribution of hydatid disease endemic due to the transmission of E granulosus by means of the dog-sheep cycle (solid red areas). Red stripes indicate areas where transmission occurs by means of alternative life cycles in which carnivores such as wolves and foxes serve as definitive hosts and goats, camels, and horses serve as intermediate hosts,29,肺包虫病,肺棘球蚴病，为细粒棘球绦虫或多房棘球绦虫之幼虫（即棘球蚴）感染人体所致，在人体寄生的棘球蚴病称为包虫囊肿 传染源多为狗，寄生于狗肠内的细粒棘球绦虫虫卵随粪便排出污染牲畜皮毛、水源及牧草等，病人多因食入污染的食物或水而感染，虫卵也可经呼吸道吸入而发生感染,30,发病过程,棘球蚴虫卵在十二指肠内孵化为六钩蚴，进入肠壁的毛细血管，并经门脉至肝脏，再经肝静脉、下腔静脉、右心、肺动脉到达肺 六钩蚴周围有大单核细胞和嗜酸性粒细胞浸润，并逐渐长成棘球蚴的囊状体，有的可形成巨大的囊肿 包虫囊肿的壁分为两层，外层为角质层，较坚韧，起保护和营养胚层的作用；内层为胚层（或称为生发层），能分泌液体，具有繁殖作用，液体内有毛钩和头节，头节脱落则形成子囊 囊肿破裂，囊液溢出，头节可在邻近形成新的囊肿 肺包虫囊肿可破入支气管及继发感染,31,症状,咳嗽、咯血、胸痛及发热 破入胸腔引起气胸和胸腔积液 破入支气管时咳出大量囊液 较小的包虫囊肿可无症状 嗜酸性粒细胞增多 皮试及血清学试验有助诊断,32,X线,单发或多发的圆形或类圆形影，110cm 密度均匀，囊状，边缘光滑清楚，可环形钙化 外囊破裂，并与支气管相通，少量气体进入内外囊之间，在囊肿上部形成新月形透亮影 内外囊同时破裂，并与支气管相通，部分囊内的内容物咳出，空气进入囊内形成气液平面 内外囊同时破裂后，若内囊塌陷，漂浮于液平面上形成凹凸不平的形态，称为“水上浮莲”征 肺表面的囊肿破裂可形成气胸或液气胸,33,CT,囊肿1cm以下时，边缘模糊的片状影。2cm，轮廓清楚的类圆形囊性影，分叶状。边缘光整，密度均匀，CT值为液体密度 囊壁薄厚不一，囊肿与胸膜或纵隔相邻处变平 囊肿衰老呈不规则状，似实质性肿瘤，但密度仍较低 合并感染时边缘模糊，类似肺脓肿 破裂可形成支气管瘘，咳出部分囊液且空气进入囊内后出现气液面 破入支气管后，若外囊有细小裂口而内囊未破，可有少量气体进入内外囊之间，呈现新月形或镰刀状气体影 空气进入外囊内，内囊塌陷并漂浮于液面，“水上浮莲征”,34,Life Cycle of E granulosus,The definitive host is usually a dog (or other carnivore) The adult worm lives in the proximal small bowel of the definitive host, attached by hooklets to the mucosa Eggs are released into the hosts intestine and excreted in the feces Sheep are the most common intermediate hosts. They ingest the ovum while grazing on contaminated ground The ovum loses its protective chitinous layer as it is digested in the duodenum The released hexacanth embryo, or oncosphere, passes through the intestinal wall into the portal circulation and develops into a cyst within the liver,35,Life Cycle of E granulosus,When the definitive host eats the viscera of the intermediate host, the cycle is completed Humans may become intermediate hosts through contact with a definitive host (usually a domesticated dog) or ingestion of contaminated water or vegetables Once in the human liver, cysts grow to 1 cm during the first 6 months and 23 cm annually thereafter, depending on host tissue resistance,36,Life cycle (dog-sheep cycle) of E granulosus,Diagram shows the most prevalent life cycle of E granulosus, in which a dog and sheep serve as the definitive and intermediate hosts, respectively,37,Three layers,Outer pericyst, composed of modified host cells that form a dense and fibrous protective zone Middle laminated membrane, is acellular and allows the passage of nutrients Inner germinal layer, the scolices (the larval stage of the parasite) and the laminated membrane are produced Middle laminated membrane and the germinal layer form the true wall of the cyst,38,Hydatid Cyst Structure,Daughter vesicles (brood capsules) are small spheres that contain the protoscolices and are formed from rests of the germinal layer Before becoming daughter cysts, these daughter vesicles are attached by a pedicle to the germinal layer of the mother cyst At gross examination, the vesicles resemble a bunch of grapes Daughter cysts may grow through the wall of the mother cyst, particularly in bone disease,39,Multivesicular cyst,Photograph of a human kidney be sectioned along the midcoronal plane A large cyst with the typical “bunch of grapes“ appearance due to daughter cysts () ureter,40,Hydatid Cyst,Cyst fluid is clear or pale yellow, has a neutral pH, and contains sodium chloride, proteins, glucose, ions, lipids, and polysaccharides The fluid is antigenic and may also contain scolices and hooklets When vesicles rupture within the cyst, scolices pass into the cyst fluid and form a white sediment known as hydatid sand,41,Hydatid Disease in humans,Once the parasite passes through the intestinal wall to reach the portal venous system or lymphatic system, the liver acts as the first line of defense and is therefore the most frequently involved organ Hydatid disease involves the liver in 75% of cases, the lung in 15%, and other organs in 10% The lungs are the second most frequent site of hematogenous spread in adults and probably the most common site in children,42,Hematogenous Dissemination,Compressible organs such as the lung or brain facilitate the growth of the cyst Most cysts are acquired in childhood, remain asymptomatic for a long period of time, and are later diagnosed incidentally at chest radiography Cysts are multiple in 30% of cases, bilateral in 20%, and located in the lower lobes in 60% Calcification in pulmonary cysts is very rare, although it may be seen in pericardial, pleural, and mediastinal cysts,43,Pulmonary hydatid cyst,M3 A well-circumscribed, masslike lesion with a polycyclic configuration in the left lower lobe There is obliteration of the left costophrenic angle,44,Pulmonary hydatid cyst,Sudden coughing attacks, hemoptysis, and chest pain are the most common symptoms After cyst rupture, expectoration of cyst fluid, membranes, and scolices may occur Rupture into the pleural cavity may occur Bacterial infection of the cyst is the most serious complication commonly seen after rupture,45,Pulmonary hydatid cyst,Well-defined masses, usually round, peripheral cysts may be oval or polycyclic Air collection appears as a thin, radiolucent crescent in the upper part of the cyst and is known as the crescent sign or meniscus sign As air continues to enter this space, the two layers separate completely and the cyst shrinks and ruptures, allowing the passage of air into the endocyst,46,Pulmonary hydatid cyst,An air-fluid level inside the endocyst and air between the pericyst and the endocyst with an “onion peel“ appearance constitute the Cumbo sign After partial expectoration of the cyst fluid and scolices, the cyst empties and the collapsed membranes can be seen inside the cyst (serpent sign). When it has completely collapsed, the crumpled endocyst floats freely in the cyst fluid (water lily sign) If the fluid is entirely evacuated by expectoration, the remaining solid components will fall to the most dependent part of the cavity (“mass within a cavity“),47,Open cysts,A child with fever, cough, and expectoration Left lateral decubitus position A large cavitary lesion with an air-fluid level in the inferior left lung Air is seen between the pericyst and the laminated membrane of the cyst Pulmonary infiltrate adjacent to the cyst Pleural effusion due to superimposed bacterial infection,48,A child with previous episodes of cough and expectoration,Lateral chest radiograph An intracystic serpentine structure representing collapsed membranes,49,Open lung cyst,M20, experienced a sudden coughing attack followed by expectoration of clear fluid left lateral decubitus position A cavitary lesion in the right upper lobe with solid contents that have settled in the most dependent part of the cavity The solid component represents the detached, crumpled endocyst,50,Pulmonary hydatid disease, E granulosus,M43, A large cyst in the right lower lung,F32, A hypoattenuating crescent sign (meniscus sign),51,Alveolar Echinococcosis and Polycystic Echinococcosis,Caused by E multilocularis and E vogeli Have a similar clinicopathologic course and are acquired through the same mechanism, similar to that described for E granulosus The parasite grows from the metacestode (larva) in the liver and, resembling a neoplasm Lung involvement is less frequent than in unilocular cystic echinococcosis, results from metastatic dissemination or direct extension,52,Alveolar and Polycystic Echinococcosis,Infection becomes symptomatic after 515 years secondary to local compression or dysfunction of the affected organ, usually the liver Nonspecific symptoms such as fatigue, weight loss, cough, and hemoptysis can be present A mass of fibrous tissue containing several scattered cavities of widely varying diameters with necrotic areas is frequently seen, as calcifications,53,Alveolar and Polycystic Echinococcosis,Diagnosis can be made with immunohistochemical and histologic analysis, serologic tests CT and MRI are the imaging modalities of choice for better defining the location and extent of pulmonary disease Calcifications may develop as the disease progresses (33%100% of cases) Secondary lung compromise by direct extension may mimic a lung cancer,54,Polycystic echinococcosis,M25 Chest radiograph Multiple peripheral round areas of soft-tissue opacity,55,Polycystic echinococcosis,CT clearly defined capsule with a relatively hypoattenuating center, a finding that reflects the cystic nature of the lesions E vogeli was identified at pathologic analysis as the etiologic agent,56,Polycystic echinococcosis of the chest wall from E vogeli,M13 Cystic thickening of the pleura with chest wall involvement.,57,Schistosomiasis（血吸虫病）,S hematobium, S mansoni, and S japonicum S mansoni is endemic to Africa, Saudi Arabia, Brazil, Madagascar, Venezuela, and Puerto Rico S japonicum is more frequently seen in east Asia Infection is acquired through exposure of the skin to water contaminated with cercariae excreted by snails, which have the ability to penetrate the skin or the intestinal wall, then migrate to the lung and afterward to the liver, where the parasite continues its life cycle The second most common cause of mortality among parasitic infections after malaria, affecting 150200 million people and causing 500,000 deaths each year,58,life cycle of Schistosoma species,59,Geographic distribution of Schistosoma species,60,Pulmonary schistosomiasis,Early pulmonary schistosomiasis (38 weeks after parasitic penetration) results from immunologic reaction, in which eosinophils are sequestered in the lungs Symptoms：shortness of breath, wheezing, and dry cough,61,Early pulmonary schistosomiasis,The diagnosis is suggested in patients who live in or have traveled to endemic areas and who present with eosinophilia May have both clinical and radiologic manifestations after the onset of symptoms Associated urticaria, arthralgia, hepatosplenomegaly, hepatitis, eosinophilia,62,Early pulmonary schistosomiasis,Small nodular lesions with ill-defined borders or, less commonly, a reticulonodular pattern or bilateral diffuse areas of ground-glass increased opacity or hyperattenuation at radiography and CT Asymptomatic cases that manifest with abnormal radiologic findings may also be seen Sensitivity is low for the examination of stool and urine for eggs in this stage of infection,63,Early pulmonary schistosomiasis,M28 had traveled to Mali Initially, had fever and urticaria, after which experienced dry cough, predominantly at night CT shows multiple nodular lesions with ill-defined borders in the lower lobes. Histologic analysis revealed S mansoni,64,Results from granulomatous reaction to eggs deposited in the pulmonary vasculature, which leads to intimal fibrosis, pulmonary hypertension, and cor pulmonale Often preceded by liver involvement by portal hypertension, which allows the eggs to shunt from the portal system into the pulmonary vasculature Dyspnea, chest pain, fatigue, palpitations, cough, and, lately, right-sided heart failure,Chronic pulmonary disease,65,Chronic pulmonary disease,Radiographic and CT findings are also consistent with these clinical findings and include cardiomegaly and pulmonary arterial enlargement Diagnosis is made by identifying eggs in stool or urine samples or at rectal biopsy Serologic tests are not very helpful because they cannot help differentiate a former infection from current disease,66,七律二首 送瘟神 1958.07.01,绿水青山枉自多，华佗无奈小虫何！ 千村薜荔人遗矢，万户萧疏鬼唱歌。 坐地日行八万里，巡天遥看一千河。 牛郎欲问瘟神事，一样悲欢逐逝波。 春风杨柳万千条，六亿神州尽舜尧。 红雨随心翻作浪，青山着意化为桥。 天连五岭银锄落，地动三河铁臂摇。 借问瘟君欲何往，纸船明烛照天烧,67,毛泽东诗词送瘟神鉴赏,1958年7月1日，读6月30日人民日报，余江县消灭了血吸虫。浮想联翩，夜不能寐。微风拂煦，旭日临窗。遥望南天，欣然命笔 当毛泽东得知江西余江县消灭了为害极广的的血吸虫病时，作为共和国的缔造者，一个时刻系念着人民的领袖，他激动不已，彻夜难眠，感慨和热忱化作了这两首七律 领袖的爱国爱民之情，闪射出了灿烂的艺术光辉,68,第一首，诗人回顾过去，描述了瘟神给中国带来的无穷灾难。首联“绿水青山枉自多，华佗无奈小虫何”，抒发了诗人的悲愤心情 祖国的南方，向来以鱼米之乡著称，这里青山绿水、风景秀丽。可是，一个小小的血吸虫竟使大好河山萧杀黯淡，就连华佗这样的名医奈之不何 “绿水青山”与“枉自多”对举，“华佗”与“无奈”相联，强烈的反差、对比，寄寓了诗人多么深厚的感情，又饱含了人民大众多少苦楚！ “千村薜荔人遗矢，万户萧疏鬼唱歌”，“千村”“万户”极言受灾地域之广，受灾人数之多,鉴 赏2,69,“坐地日行八万里，巡天遥看一千河”道出人民寻求解脱灾祸的强烈呼声 随着地球的自转和公转，人们寻遍长天，看过无数的星河 然而，年年岁岁惨况依然，苦难依旧，人们到哪里去寻求帮助他们解脱疾病、消灭瘟君的救星呢？,鉴 赏3,70,鉴 赏4,通过“坐地”“巡天”的超凡想象，诗的尾联引出了神话传说中天河边的牛郎：“牛郎欲问瘟神事，一样悲欢逐逝波” 牛郎是劳动人民的化身神，他当然关心着人民的疾苦，要问“瘟神”肆虐之“事”。如何回答呢？诗人的答词是：一切悲欢离合都随着时光的流逝而成为过去了 这样，人间天上浑然一体，极大地开拓了诗词包容的时空和思想蕴含，写出了旧中国带给人民的灾祸，那是天怒人怨，世所难容,71,第二首情绪热烈、语调高亢，与第一首感情抑郁、语义哽咽形成了鲜明的对比 首连“春风杨柳万千条”二句即是一幅意气飞扬的画面。在经历了冰封雪裹的严冬之后，新忠告大地万物复苏，一片欣欣向荣。如今的南方春天，千万条杨柳随风飘拂，景象格外优美。孟子说“人皆可以为尧舜。”但在封建社会，这对于地位极其低下的民众来说，只不过是一种幻想。即使是那些认识到“民可载舟，民可覆舟”的明君圣主，也仍是站在历史的对立面，把民众当成负载自己功业的工具,鉴 赏5,72,集领袖与诗人与一身的毛泽东，从历史唯物主义的高度，认识到人民的力量及其创造历史的作用，因而写出了“六亿神州尽舜尧”的诗句。表达了毛泽东对人民群众的期待与歌颂，也表达了毛泽东真正民主的人本思想。解放了的人民，确定了社会主人的地位，本质力量得到了淋漓的发挥，让高山地头，令河水让路，将扼住人们命运的瘟神彻底消灭，这样的人民是真正的神、真正的舜尧。诗人用一颗热爱人民、服务人民的心，唱出了热情澎湃的心声，表达了无产阶级革命领袖对人民的关怀、推崇,73,鉴 赏6,“红雨随心翻作浪，青山着意化为桥”景物完全化为了情思，自然景物变得通人心、随人意，人与美丽的景色交融一体。暮春的落花飘入水中，随人的心意翻着锦浪，一座座青山相互连同，就象专为人们搭起的凌波之桥，整个中国呈现出一派兴盛的气象 此时的水和山，仍然是从前的“绿水青山”，可在旧时代，山河被瘟神糟蹋，虽多亦枉然。到了新时代，人人成为舜尧，山水也焕发青春，大地在日新月异地改变着面貌,74,鉴 赏7,“天连五岭银锄落，地动山河铁臂摇”，歌颂了人民群众改天换地的威力。“五岭”绵延在南方，“三河”奔腾于北国，这两个地名，代表了整个中国。祖国到处皆是银锄齐挥、铁臂同摇，人民群众的凌云之志，山河动容 诗人以高妙的艺术手笔，概括了当时社会主义建设的雄伟场面，令人叹服。同时，诗句中还滲透了诗人“力拔山兮”的伟岸精神和自力更生的进取意识。诗人“人定胜天”的思想，化成美妙的诗句，闪射出了动人心魄的魅力,75,鉴 赏8,全诗名为“送瘟神”，但第二首的前六句却不见瘟神的影子，只在