肺病影像解剖基礎(chǔ)00匯總課件

1、HRCT : Key findings in Interstitial Lung Diseases Secondary Lobule The basic anatomic unit of pulmonary structure and function.The smallest lung unit that is surrounded by connective tissue septa.It measures about 1-2 cm and is made up of 5-15 pulmonary acini, that contain the alveoli.Secondary Lobu

2、leSupplied by a small bronchiole (terminal bronchiole) in the center, that is parallelled by the centrilobular artery. Veins and lymphatics run in the periphery within the interlobular septa.Two lymphatic systems: Central network, runs along the bronchovascular bundle towards the centre of the lobul

3、e ; Peripheral network, located within the interlobular septa and along the pleural linings.Secondary LobuleSecondary LobuleCentrilobular area Usually the site of diseases, that enter the lung through the airways ( i.e. hypersensitivity pneumonitis, respiratory bronchiolitis, centrilobular emphysema

4、 ).Perilymphatic area Usually the site of diseases, that are located in the lymphatics of in the interlobular septa ( i.e. sarcoid, lymphangitic carcinomatosis, pulmonary edema). These diseases are usually also located in the central network of lymphatics that surround the bronchovascular bundle.Sec

5、ondary LobuleCentrilobular area in blue (left) and perilymphatic area in yellow (right)Secondary LobuleThere are too many lines, either as a result of thickening of the interlobular septa or as a result of fibrosis as in honeycombing . Septal thickening Thickening of the lung interstitium by fluid,

6、fibrous tissue, or infiltration by cells results in a pattern of reticular opacities due to thickening of the interlobular septa.Reticular pattern Reticular patternSmooth septal thickening Usually seen in interstitial pulmonary edema (Kerley B lines); lymphangitic spread of carcinoma or lymphoma and

7、 alveolar proteinosis.Nodular or irregular septal Thickening occurs in lymphangitic spread of carcinoma or lymphoma; sarcoidosis and silicosis. Reticular patternFocal irregular septal thickening in the right upper lobe.This is typical for lymphangitic carcinomatosis.Reticular patternPulmonary lympha

8、ngitic carcinomatosis (PLC) In 50% of patients the septal thickening is focal or unilateral. This finding is helpful in distinguishing PLC from other causes of interlobular septal thickening like Sarcoidosis or cardiogenic pulmonary edema. Hilar lymphadenopathy is visible in 50% and usually there is

9、 a history of (adeno)carcinoma. Identical findings can be seen in patients with Lymphoma and in children with HIV infection, who develop Lymphocytic interstitial pneumonitis (LIP), a rare benign infiltrative lymphocytic disease.Reticular patternA combination of smooth septal thickening and ground-gl

10、ass opacity with a gravitational distribution.The diagnosis was cardiogenic pulmonary edema.Reticular patternCardiogenic pulmonary edema Generally results in a combination of septal thickening and ground-glass opacity. There is a tendency for hydrostatic edema to show a perihilar and gravitational d

11、istribution. Thickening of the peribronchovascular interstitium, which is called peribronchial cuffing, and fissural thickening are also common.Reticular patternBoth septal thickening and ground glass opacity in a patchy distribution.Some lobules are affected and others are not.This combination of f

12、indings is called crazy paving.Reticular patternCrazy paving was thought to be specific for alveolar proteinosis, but is also seen in many other diseases ： PCP, bronchoalveolar carcinoma, sarcoidosis, nonspecific interstitial pneumonia(NSIP), organizing pneumonia (COP), adult respiratory distress sy

13、ndrome， pulmonary hemorrhage. Reticular pattern- HoneycombingRepresents the second reticular pattern recognizable on HRCT.Small cystic spaces lined by bronchiolar epithelium with thickened walls composed of dense fibrous tissue.Typical feature of (UIP). Nodular patternPerilymphatic distribution Nodu

14、les are seen in relation to pleural surfaces, interlobular septa and the peribronchovascular interstitium. Almost always visible in a subpleural location, particularly in relation to the fissures.Nodular patternCentrilobular distribution Nodules are limited to the centrilobular region. Unlike perily

15、mphatic and random nodules, centrilobular nodules spare the pleural surfaces. The most peripheral nodules are centered 5-10mm from fissures or the pleural surface. Nodular patternRandom distribution Nodules are randomly distributed relative to structures of the lung and secondary lobule. Nodules can

16、 usually be seen to involve the pleural surfaces and fissures, but lack the subpleural predominance often seen in patients with a perilymphatic distribution. Nodular patternAlgorithm for nodular pattern Look for the presence of pleural nodules. These are often easiest to see along the fissures.If pl

17、eural nodules are absent or few in number, the distribution is likely centrilobular. If pleural nodules are visible, the pattern is either random (miliary) or perilymphatic. If there are pleural nodules and also nodules along the central bronchovascular interstitium and along interlobular septa, you

18、 are dealing with a periplymphatic distribution. If the nodules are diffuse and uniformly distributed, it is likely a random distribution. Algorithm for nodular patternPerilymphatic distribution Most commonly seen in sarcoidosis. Aalso occur in silicosis, coal-workers pneumoconiosis and lymphangitic

19、 spread of carcinoma. Notice the overlap in differential diagnosis of perilymphatic nodules and the nodular septal thickening in the reticular pattern. Sometimes the term reticulonodular is used.Perilymphatic distributionThis is a typical case of sarcoidosis.Notice the nodules along the fissures ind

20、icating a perilymphatic distribution (red arrows).Always look carefully for these nodules in the subpleural region and along the fissures, because this finding is very specific for sarcoidosis.Typically in sarcoidosis is an upper lobe and perihilar predominance and in this case we see the majority o

21、f nodules located along the bronchovascular bundle (yellow arrow).Perilymphatic distributionAnother typical case of sarcoidosis.Perilymphatic nodules, and multiple enlarged lymph nodes.In end stage sarcoidosis we will see fibrosis, which is also predominantly located in the upper lobes and perihilar

22、.Centrilobular distributionCentrilobular nodules are seen in: Hypersensitivity pneumonitis Respiratory bronchiolitis in smokers Infectious airways diseases (endobronchial spread of tuberculosis or nontuberculous mycobacteria, bronchopneumonia) Uncommon in bronchioloalveolar carcinoma, pulmonary edem

23、a, vasculitis .In many cases centrilobular nodules are of ground glass density and ill defined (figure).They are called acinair nodules.Ill defined centrilobular nodules of ground glass density in a patient with hypersensitivity pneumonitisCentrilobular distributionTree-in-bud Tree-in-bud is of valu

24、e for narrowing the differential diagnosis.Describes the appearance of an irregular and often nodular branching structure, most easily identified in the lung periphery. Represents dilated and impacted (mucus or pus-filled) centrilobular bronchioles. Tree-in-budAlmost always indicates the presence of

25、: Endobronchial spread of infection (TB, MAC, any bacterial bronchopneumonia) Airway disease associated with infection (cystic fibrosis, bronchiectasis) less often, an airway disease associated primarily with mucus retention (allergic bronchopulmonary aspergillosis, asthma).Tree-in-budOn the right ，

26、 active endobronchial spread of TB，a tree-in-bud is seen.In most patients with active tuberculosis, the HRCT shows evidence of bronchogenic spread of disease even before bacteriologic results are available. Random distributionA patient with random nodules as a result of miliary TB.The random distrib

27、ution is a result of the hematogenous spread of the infection.Small random nodules are seen in: Hematogenous metastases Miliary tuberculosis Miliary fungal infections Sarcoidosis may mimick this pattern, when very extensive Langerhans cell histiocytosis (early nodular stage) .Sarcoidosis usually has

28、 a perilymphatic distribution, but when it is very extensive, it spreads along the bronchovascular bundle to the periphery of the lung and may reache the centrilobular area.Random distributionLangerhans cell histiocytosis is an uncommon disease characterised by multiple cysts in patients with nicoti

29、ne abuse.In a very early stage, these patients show only nodules, that later on cavitate and become cysts (figure).As in all smoking related diseases, there is an upper lobe predominance.High Attenuation patternGround-glass-opacity (GGO): a hazy increase in lung opacity without obscuration of underl

30、ying vessels ; Consolidation :the increase in lung opacity obscures the vessels.The increase in lung density is the result of replacement of air in the alveoli by fluid, cells or fibrosis. dark bronchus sign In GGO the density of the intrabronchial air appears darker as the air in the surrounding al

31、veoli. air bronchogram In consolidation, there is exclusively air left intrabronchial.Ground-glass opacityGround-glass opacity (GGO) represents: Filling of the alveolar spaces with pus, edema, hemorrhage, inflammation or tumor cells. Thickening of the interstitium or alveolar walls below the spatial

32、 resolution of the HRCT as seen in fibrosis. The location of the abnormalities in ground glass pattern : Upper zone predominance: Respiratory bronchiolitis, PCP. Lower zone predominance: UIP, NSIP, DIP. Centrilobular distribution: Hypersensitivity pneumonitis, Respiratory bronchiolitis Thus ground g

33、lass in itself is very unspecific. Ground-glass opacityGround-glass opacityOn the right we see consolidation and ground-glass opacity with persistent chest abnormalities. Histology revealed broncho-alveolar cell (BAC) carcinoma BAC may present as: solitary nodule or mass (40% of patients) focal or d

34、iffuse consolidation (30%) as in this case. diffuse ill-defined centrilobular nodules (30%) due to endobronchial spread. Mosaic attenuationThe term is used to describe density differences between affected and non-affected lung areas.There are patchy areas of black and white lung.The role is to deter

35、mine which part is abnormal: the black or the white lung.When ground glass opacity presents as mosaic attenuation consider: Infiltrative process adjacent to normal lung Normal lung appearing relatively dense adjacent to lung with air-trapping Hyperperfused lung adjacent to oligemic lung due to chron

36、ic thromboembolic disease It can be difficult to distinguish these three entities.Mosaic attenuation There are two diagnostic hints for further differentiation: Look at expiratory scans for air trapping Look at the vesselsIf the vesses are difficult to see in the black lung as compared to the white

37、lung, than it is likely that the black lung is abnormal. Then there are two possibilities: obstructive bronchiolitis or chronic pulmonary embolism.Sometimes these can be differentiated with an expiratory scan.If the vessels are the same in the black lung and white lung, then you are looking at a pat

38、ient with infiltrative lung disease, like pulmonary hemmorrhage.Temporary bronchiolitis with air trapping is seen in: (post) infection Inhalation of toxin Rheumatoid arthritis, Sjgren Post transplant Drug reaction (penicillamine) Mosaic attenuationMosaic attenuationHypersensitivity pneumonitis (HP)

39、An allergic lung disease caused by the inhalation of antigens contained in a variety of organic dusts.Farmers lung is the best-known HP syndrome.HP usually presents in two forms either as ground glass in a mosaic distribution as in this case or as centrilobular nodules of ground glass density (acina

40、r nodules).Mosaic pattern in a patient with hypersensitivity pneumonitisMosaic attenuationOn the right a patient with ground glass pattern in a mosaic distribution.The clue here is the enlargement of pulmonary arteries (arrow) in the areas of ground glass.The ground glass appearance is the result of

41、 hyperperfused lung adjacent to oligemic lung with reduced vessel caliber due to chronic thromboembolic disease.Mosaic attenuationAnother patient with ground glass pattern in a mosaic distribution.Again the ground glass appearance is the result of hyperperfused lung with large vessels adjacent to ol

42、igemic lung with small vessels due to chronic thromboembolic disease.Emboli adherent to the wall and intravascular septa are typical for chronic thromboemboli in which partial recanalization took place.Crazy PavingA combination of ground glass opacity with superimposed septal thickening .Crazy Pavin

43、 can be seen in: Alveolar proteinosis Sarcoid NSIP Organizing pneumonia (COP/BOOP) Infection (PCP, viral, Mycoplasma, bacterial) Neoplasm (Bronchoalveolarca (BAC) Pulmonary hemorrhage Edema (heart failure, ARDS, AIP) Crazy Pavin in a patient with Alveolar proteinosis.Consolidation Acute consolidatio

44、n is seen in: Pneumonias (bacterial, mycoplasma, PCP) Pulmonary edema due to heart failure or ARDS Hemorrhage Acute eosinophilic pneumoniaChronic consolidation is seen in: Organizing Pneumonia Chronic eosinophilic pneumonia Fibrosis in UIP and NSIP Bronchoalveolar carcinoma or lymphomaConsolidationT

45、wo cases with chronic consolidation. There are patchy non-segmental consolidations in a subpleural and peripheral distribution.The differential diagnosis: The final diagnosis was cryptogenic organizing pneumonia (COP). In chronic eosinophilic pneumonia the HRCT findings will be the same, but there w

46、ill be eosinophilia. In fibrosis there will be other signs of fibrosis like honeycombing or traction bronchiectasis. Bronchoalveolar carcinoma can also look like this.ConsolidationOrganizing pneumonia (OP)Organizing pneumonia represents an inflammatory process in which the healing process is charact

47、erized by organization and cicatrization of the exudate rather than by resolution and resorption. It is also described as unresolved pneumonia. If no cause can be identified it is called cryptogenic organizing pneumonia (COP).It was described in earlier years as Bronchiolitis-obliterans-organizing p

48、neumonia (BOOP). Patients with COP typically present with a several-month history of nonproductive cough. Many cases are idiopathic, but OP may also be seen in patients with pulmonary infection, drug reactions, collagen vascular disease, Wegeners granulomatosis and after toxic-fume inhalation.Consol

49、idationChronic eosinophilic pneumonia An idiopathic condition characterized by extensive filling of alveoli by an infiltrate consisting primarily of eosinophils. Like in COP , patchy non-segmental consolidations in a subpleural distribution. Low Attenuation patternThe fourth pattern : Emphysema Lung

50、 cysts (LAM, LIP, Langerhans cell histiocytosis) Bronchiectasis Honeycombing EmphysemaCentrilobular emphysema Most common type Irreversible destruction of alveolar walls in the centrilobular portion of the lobule Upper lobe predominance and uneven distribution Strongly associated with smoking.Panlob

51、ular emphysema Affects the whole secondary lobule Lower lobe predominance In alpha-1-antitrypsin deficiency, but also seen in smokers with advanced emphysemaParaseptal emphysema Adjacent to the pleura and interlobar fissures Can be isolated phenomenon in young adults, or in older patients with centr

52、ilobular emphysema In young adults often associated with spontaneous pneumothorax Emphysema Centrilobular emphysema due to smoking. The periphery of the lung is spared (blue arrows). Centrilobular artery (yellow arrows) is seen in the center of the hypodense area.EmphysemaParaseptal emphysemaLocaliz

53、ed near fissures and pleura and is frequently associated with bullae formation (emphysema larger than 1 cm).EmphysemaPanlobularl emphysema Uniform destruction of the underlying architecture of the secondary pulmonary lobules, leading to widespread areas of abnormally. Pulmonary vessels in the affect

54、ed lung appear fewer and smaller. Panlobular emphysema is diffuse and is most severe in the lower lobes. Mild and even moderately severe panlobular emphysema can be very subtle and difficult to detect on HRCT.Cystic lung disease Lung cysts wall thickness less than 4mm. Cavities wall thickness more t

55、han 4mm and are seen in infection (TB, Staph, fungal, hydatid), septic emboli, squamous cell carcinoma and Wegeners disease.Cystic lung diseaseLangerhans cell histiocytosisBronchiectasisThe diagnosis : bronchial dilatation (signet-ring sign) bronchial wall thickening lack of normal tapering with vis

56、ibility of airways in the peripheral lung mucus retention in the broncial lumen associated atelectasis and sometimes air trappingThe most common cause of bronchiectasis is prior infection, usually viral, at an early age. It also occurs in patients with chronic bronchitis, COPD and cystic fibrosis.Br

57、onchiectasisThe chest film with a typical finger-in-glove shadow.The HRCT shows focal bronchiectasis with extensive mucoid impaction, which is typical for ABPA. Allergic bronchopulmonary aspergillosis occurring in patients with asthma or cystic fibrosis.It characteristically presents with the findin

58、gs of central bronchiectasis, mucoid impaction and atelectasis.ABPA: glove-finger shadow due to mucoid impaction in central bronchiectasis in a patient with asthma.HoneycombingDefined by the presence of small cystic spaces with irregularly thickened walls composed of fibrous tissue.Often predominate

59、 in the peripheral and subpleural lung regions regardless of their cause.Subpleural honeycomb cysts typically occur in several contiguous layers.This finding can be distinguished from paraseptal emphysema in which subpleural cysts usually occur in a single layer.HoneycombingUsual Interstitial Pneumo

60、nia (UIP) The case shows subpleural honeycomb cysts in several contiguous layers.There is also a lower lobe predominance and widespread traction bronchiectasis.These findings are typical for Usual Interstitial Pneumonia (UIP).Distribution within the lungUpper lung zone preference : Inhaled particles