G孤立性肺結(jié)節(jié)的診斷現(xiàn)狀

孤立性肺結(jié)節(jié)的診斷現(xiàn)狀長(zhǎng)海醫(yī)院呼吸內(nèi)科孫沁瑩SolitaryPulmonaryNodule(SPN)定義：（coinleision)任何肺內(nèi)或胸膜的病灶，在X線(xiàn)上表現(xiàn)直徑在2-30mm，邊緣清晰或不清晰的圓形或類(lèi)圓形陰影。

FleischerSocietyGlossary肺實(shí)質(zhì)內(nèi)直徑《3cm圓形或類(lèi)圓形的病灶，不伴有淋巴結(jié)腫大，阻塞性肺炎或肺不張。

Chest2003；123：89-96

概況0.09%-0.20％所有胸片150，000/年（預(yù)計(jì)）病因：肉芽腫性疾病、肺癌、錯(cuò)構(gòu)瘤

惡性結(jié)節(jié)：10－70％占手術(shù)切除肺結(jié)節(jié)的60-80%IA期肺癌術(shù)后5年生存率61-75％

良性結(jié)節(jié)：感染性肉芽腫80％錯(cuò)構(gòu)瘤10％病因Figure1a.

Ribfractureina50-year-oldwomanwithmultiplemyeloma.(a)Close-upposteroanteriorradiographoftherightupperlungshowsapoorlymarginatednodularareaofincreasedopacityoverlyingtheanterioraspectoftherightsecondrib(arrow).(b)CTscanshowsahealedfractureoftherightsecondrib(arrow).Notethelyticlesionsinthevertebralbodysecondarytomultiplemyeloma.Figure2a.

Pseudonoduleina50-year-oldman.(a)Close-upposteroanteriorradiographoftherightlungshowsasmoothlymarginatednodularareaofincreasedopacityprojectingoverthelung(arrow).Notetheadjacentelectrocardiographicleadattachmentpad(arrowhead).Onafollow-upradiographobtainedafterremovaloftheattachmentpad(notshown),nonodulewasobserved.(b)Frontandbackviewsoftheelectrocardiographicleadattachmentpadshowaneccentricallylocatedsilvernitratepad,whichexplainsthecontiguousnodularareaofincreasedopacityonthechestradiograph.Figure4a.

Osteophyteoftheleftfirstribina60-year-oldwoman.(a)Posteroanteriorchestradiographshowsapoorlydefinednodularareaofincreasedopacityoverlyingtheanterioraspectoftheleftfirstrib(arrow).(b)Posteroanteriorchestradiographobtained2yearsearliershowsthatintervalgrowthhasoccurred(cfa).Thisintervalgrowthraisedsuspicionformalignancy.(c)ContiguouschestCTscans(imageonrightobtainedatalowerlevel)revealthattheareaofincreasedopacityisalargeosteophyteofthefirstrib.Hadfluoroscopybeenperformed,costlyCTcouldhavebeenavoided.Figure5a.

Cutaneousnodulesina51-year-oldmanwithneurofibromatosisandprostaticadenocarcinoma.(a)Posteroanteriorradiographshowsnumerouswell-marginatednodularareasofincreasedopacityprojectingovertheloweraspectofthethoraxandapoorlymarginatednoduleoverlyingtheupperaspectofthelefthemithorax(arrow).Becausethelocationoftheuppernodulewasuncertain,CTwasperformed.(b)CTscanhelpsconfirmtheintraparenchymallocationofthenoduleintheleftupperlobe.(c)CTscandemonstratesmultiplecutaneousnodules.Figure6a.

Segmentalbronchialatresiaina17-year-oldgirl.(a)Close-upposteroanteriorradiographoftherightlowerlungshowsanodularareaofincreasedopacityinthelowerlobe(arrow).(b)ChestCTscans(imageonleftobtainedatalowerlevel)showabranchingtubularareaofincreasedattenuationintherightlowerlobeaswellaspulmonaryparenchymawithlowerthanexpectedattenuation.Thesefindingsarecharacteristicofsegmentalbronchialatresiaandobviatedfurtherwork-up.Figure7a.

Multiplearteriovenousmalformationsina23-year-oldwomanwithhereditaryhemorrhagictelangiectasia.ContiguouschestCTscansrevealmultiplesmallnodularareasofincreasedattenuationbilaterallywithenlargedfeedinganddrainingvessels,findingsthatarediagnosticforarteriovenousmalformations.Achestradiographobtainedearlier(notshown)demonstratedapossiblesmallsolitarypulmonarynoduleintherightlowerlobe.Figure2a:

(a)Chestradiographshowsanincidentalsmallnodule(arrow)attheleftcostophrenicangle.(b)Thin-sectionCTscanshowscentralfatattenuation(–43HU)inthenodule.Hamartomawasdiagnosed.Figure4:CTscanina90-year-oldwomanwithchroniccongestiveheartfailureshowsatinynoduleadjacenttotherightmajorfissurethatislikelytorepresentacongestedintrapulmonarylymphnode(arrow).Follow-upCTwasnotperformedbecauseofthepatient'sadvancedage.胸部CT檢測(cè)情況病灶敏感性大小≤５mm74％＞5mm82％性質(zhì)毛玻璃樣65％實(shí)性83％部位外周80%中央61%Radiology2003;228:70-75SPN惡性危險(xiǎn)因素SPN

大小常規(guī)胸片僅能辨別直徑9mm以上結(jié)節(jié)80％良性結(jié)節(jié)直徑小于2cm42％惡性結(jié)節(jié)直徑小于2cm，15％惡性結(jié)節(jié)直徑小于1cm,直徑8mm左右結(jié)節(jié)經(jīng)隨訪(fǎng)惡性發(fā)生率10-20%,直徑<4mm結(jié)節(jié)惡性發(fā)生率<1%非鈣化直徑小于1cm結(jié)節(jié)，42-92%為良性Radiology2006;239:34-49.Radiographics.2000;20:43-58.Radiology2005;237:395-400.SPN部位良性結(jié)節(jié)分布無(wú)規(guī)律性肺癌：右肺/左肺1.5，上葉占70％IPF患者合并肺癌好發(fā)于下葉外周或發(fā)生纖維化部位50％腺癌位于外周，鱗癌多為中央型Radiology2006;239:34-49.TransverseCTscanina75-year-oldmanwithidiopathicpulmonaryfibrosisshowsasolidleftlowerlobenodule(arrow).FNABofthenodulerevealedsquamouscellcarcinoma.SPN邊緣光滑：21％惡性結(jié)節(jié)邊界清，多見(jiàn)于轉(zhuǎn)移瘤分葉：25％良性結(jié)節(jié)有分葉，惡性組織生長(zhǎng)非均質(zhì)性不規(guī)整：傾向于惡性，可見(jiàn)于肉芽腫性疾病、類(lèi)脂性肺炎等毛刺：Figure8a.

LungnodulecausedbyDirofilaria(canineheartworm)inanasymptomatic70-year-oldman.(a)Close-upCTscanoftherightlungshowsaperipheral,smoothlymarginated,noncalcifiedlungnodule.(b)Photographofaspecimenobtainedwithwedgeresectionshowsawell-circumscribed,2-cmnodulewithyellowareasofgeographicnecrosis.(c)High-powerphotomicrograph(originalmagnification,x175;hematoxylin-eosinstain)showsintravascularDirofilaria.Mostinfectionsmanifestaslungnodulesfromembolicinfarctioncausedbyintravascularworms.光滑F(xiàn)igure9.

Solitarymetastasisfrombladdercancerina45-year-oldwoman.ChestCTscanshowsasmoothlymarginated,1-cmperipheralnodule.Metastaticdiseasewasconfirmedatresection.Solitarymetastasesaccountfor3%-5%ofallresectedsolitarypulmonarynodules.分葉Figure10.

Non-smallcelllungcancerina63-year-oldwoman.Close-upchestCTscanoftherightlungshowsalobulatedandspiculatednoduleinthelowerlobe.Figure11a.

Arteriovenousmalformationina34-year-oldmanwithhereditaryhemorrhagictelangiectasia.(a)Close-upposteroanteriorradiographoftherightlungshowsalobulated,well-marginatednoduleinthelowerlobe(arrows).(b)ChestCTscandemonstratesafeedingartery(arrow)andanenlargeddrainingvein(arrowhead).(c)CTscanshowsthenidusofthemalformation.(d)Pulmonaryangiogramhelpsconfirmarteriovenousmalformation.Notetheearlydrainingvein(arrows).Figure12.

Intralobarsequestrationina14-year-oldboy.ChestCTscanshowsalobulated,well-marginatednodulewithhomogeneousattenuationintherightlowerlobe.Intrapulmonarysequestrationwasconfirmedatresection.邊緣不規(guī)整或細(xì)毛刺Figure13.

Bronchioloalveolarcellcarcinomaina65-year-oldman.ChestCTscanshowsanirregularnoduleabuttingthemajorfissure.Notetheindentationoftheadjacentportionofthemajorfissureowingtodesmoplasticreactionaroundthetumor.Figure14.

Non-smallcelllungcancerina61-year-oldwoman.Close-upchestCTscanoftherightlungshowsaspiculatednodulewitheccentriccavitationintheupperlobe.SPN內(nèi)部特征鈣化脂肪密度結(jié)節(jié)衰減空洞空泡征支氣管充氣征鈣化55％良性結(jié)節(jié)有鈣化結(jié)節(jié)直徑小于3cm，有下列鈣化形式之一考慮良性：中心性，分層，彌漫性，爆米花樣，超過(guò)結(jié)節(jié)面積10％13％肺癌有不同程度的鈣化－偏心樣鈣化類(lèi)癌、轉(zhuǎn)移性骨肉瘤、軟骨肉瘤、結(jié)腸癌、卵巢癌也可表現(xiàn)為良性鈣化Figure21.

Granulomainanasymptomatic64-year-oldman.Close-upchestCTscanoftheleftlungshowsasoft-tissuenodulewithcentralcalcificationintheupperlobe.Notetheeccentriccavitationwithinthenodule.Figure23.

Pulmonarychondrohamartomaina40-year-oldman.Close-upchestCTscanoftherightlungshowsalobulatednodulewithcentralpopcornlikecalcificationintheupperlobe.Figure22a.

Histoplasmomainanasymptomatic50-year-oldman.(a)Close-uptomogramoftheleftlungdemonstratesasmooth,well-marginatednodule.(b)Photographofaresectedspecimenhelpsconfirmcentralcalcificationandlaminatedfibroustissue.Figure28a.

Granulomatousdiseaseina48-year-oldwoman.(a)ChestCTscan(10-mmcollimation)showsanodulewithperipheralcalcificationandacalcifiedrighthilarnode.(b)Thin-sectionCTscan(3-mmcollimation)betterdemonstratesthediffusesolidcalcificationinthenodule,afindingthatistypicalofabenigncauseFigure8:TransverseCTscanshowsa1-cm-diameterleftlowerlobenodulewithcentralniduscalcification.Thisfindingisindicativeofbenigndisease.Figure9a:

(a)Chestradiographshowsarightupperlobenodulewithcentralcalcification.Themarginsareirregular.(b)CTscanshowsarightupperlobenodulewithirregularmarginsthatrepresentspulmonarycarcinoma(blackarrow).Thecalcificationseenontheradiographiscausedbyacalcifiedgranulomaanteriortothetumor(whitearrow).Figure10:CTscaninan80-year-oldmanshowsa2.2-cm-diameternoduleintheleftupperlobewitheccentriccalcification.FNABofthenodulerevealedadenocarcinoma.Figure11:CTscanshowseccentricdensecalcificationinarightlowerlobecarcinoidtumorFigure12:CTscanshowscalcifiedrightlowerlobenodulethatresemblesabenigngranuloma(arrow).Thepatienthadahistoryofosteosarcoma.Openlungbiopsyrevealedmetastaticdisease.Figure24.

Typicalpulmonarycarcinoidtumorina68-year-oldwoman.ChestCTscanshowsalobulatedlesionwithscatteredpunctatecalcificationsintheleftlowerlobe.Figure25a.

Non-smallcelllungcancerina45-year-oldwoman.(a)Close-upchestradiographoftherightlungshowsalobulated,sharplymarginatednoduleintheupperlobe.Notethepresenceofemphysemaandupperlobebullae.(b)Close-upchestCTscanoftherightlungrevealsamorphouscalcificationinthenodule,apatternthatistypicalofmalignancy.Adenocarcinomawasconfirmedatresection.Figure26.

Lungcancerina72-year-oldman.Close-upchestCTscanoftherightlungshowsalobularlesionwithperipheralpunctatecalcificationintheupperlobe,afindingthatisconsistentwith"engulfed"granuloma.Unlikethatincalcifiedgranulomas,calcificationinengulfedgranulomaistypicallyperipheralandconstitutesonlyasmallpartofthenodule.Figure27a.

Metastaticosteosarcomaina21-year-oldman.(a)Close-upchestCTscanoftheleftlungshowsasmall,high-attenuationnoduleinthelowerlobe(arrow).Thisfindingwassuggestiveofabenigncause.(b)ChestCTscanobtained8monthslaterrevealsintervalgrowthofthenodule,whichhashighattenuationandalobulatedcontour.Resectionrevealedmetastaticosteosarcoma.脂肪密度良性：錯(cuò)構(gòu)瘤、脂肪瘤惡性：脂肉瘤、腎透明細(xì)胞癌Figure19a.

Hamartomainanasymptomaticman.(a)ChestCTscanshowsaheterogeneous,sharplymarginatedlesionwithsmallfocalareasofcalcificationandfat.Thesefindingsaretypicalfeaturesofhamartoma.(b)Photographofaresectedspecimendemonstratesayellowish,glistening,lobularcutsurface,afindingthatisconsistentwithfat.(c)Photomicrograph(originalmagnification,x100;hematoxylin-eosinstain)helpsconfirmthepresenceofadiposetissue(arrow)andshowsepithelialtissuecontaininganislandofbasophiliccartilage(arrowhead).Thismixtureofepithelialandmesenchymaltissueisdiagnosticforhamartoma.Figure20a.

Pulmonaryhamartomaina74-year-oldwoman.(a)ChestCTscanobtainedwith10-mmcollimationdemonstratesanodule(arrow),butitsinternalmorphologicfeaturesarepoorlyvisualized.(b)Thin-sectionCTscanobtainedwith1-mmcollimationbetterdemonstratesapunctateareaoffatwithinthenodule(arrow),afindingthatisdiagnosticforhamartoma.結(jié)節(jié)衰減非實(shí)性（毛玻璃樣）：34％為惡性，直徑大于1.5cm圓形惡性風(fēng)險(xiǎn)度增加（多見(jiàn)于BAC、腺癌有BAC特征）良性：炎癥性病變，癌前病變（不典型腺瘤樣增生，支氣管肺泡過(guò)度增生）部分實(shí)性：40-50%直徑小于1.5cm結(jié)節(jié)為惡性，實(shí)性成分位于中央?yún)^(qū)提示侵襲性腺癌實(shí)性：15％直徑小于1cm病灶為惡性，轉(zhuǎn)移性病灶多為實(shí)性Figure14:CTscaninan81-year-oldmanshowsa2.8-cmirregular,partlysolidleftupperlobenodulewithpleuraltags.FNABrevealedbronchioloalveolarcellcarcinoma.Figure13:CTscanina64-year-oldmanshowsanoval2.1-cmleftlowerlobenonsolidnodule(arrow).FNABrevealedadenocarcinoma.空洞(>5mm)良性空洞：壁光滑、薄(<4mm)惡性空洞：偏心、壁不規(guī)整、厚(>16mm)15%肺癌有空洞（病灶直徑>3cm）Figure16.

Aspergillusinfectionina48-year-oldmanwithleukemia.Close-upchestCTscanoftherightlungshowsathin-walledcavitarynodule.Figure17.

Squamouscelllungcancerina60-year-oldwoman.Close-upposteroanteriorradiographoftherightlungshowsasmoothlymarginatednoduleinthelowerlobe.Notetheeccentriccavitationandthickwalls.Figure18:CTscaninan83-year-oldmanshowsa2.3-cmleftupperlobecavitarynodule.Thewallisvariableandthecavitywallisasthickas8mm.FNABrevealedsquamouscellcarcinoma.Figure19:CTscaninan80-year-oldmanshowsarightupperlobe2.9-cmcavitarynodulewithasmooth,uniform2.5-mm-thickcavitywall.FNABrevealednon–smallcelllungcancer.Figure18.

Bullettrackfromagunshotwoundina20-year-oldman.Close-upposteroanteriorradiographoftherightlungshowsasmoothlymarginated,thick-wallednodulewitheccentriclucencyinthemidlung.Notethebulletfragmentsoverlyingtherightlung.Thesefindingsareconsistentwithparenchymalhematomaandabullettrack.空泡征：空泡征為腫瘤內(nèi)小的低密度影，多為2～3mm大小，1個(gè)或多個(gè)，CT掃描僅限于1～2個(gè)層面見(jiàn)到?？张菡魇俏撮]塞的小支氣管或肺泡，主要原因同支氣管空氣征一樣，為癌細(xì)胞呈伏壁生長(zhǎng)，部分肺泡腔和細(xì)支氣管未被腫瘤組織填充，腫瘤內(nèi)的纖維組織或瘢痕組織的牽拉而擴(kuò)張。多見(jiàn)于BAC或腺癌支氣管充氣征是指結(jié)節(jié)內(nèi)見(jiàn)到充氣的支氣管，CT表現(xiàn)為氣體密度小管影。此征多見(jiàn)于中高分化的腺癌，癌細(xì)胞沿著支氣管呈伏壁生長(zhǎng)，肺的支架結(jié)構(gòu)未被破壞，腫瘤內(nèi)的支氣管結(jié)構(gòu)仍保存。有此征象的腫瘤與無(wú)此征象的腫瘤相比，具有相對(duì)低度惡性的生物學(xué)行為。在惡性SPN的發(fā)生率為26．9％～65．0％而在良性SPN，其發(fā)生率僅為0．0％～5．9％

SPN與支氣管的關(guān)系I型：支氣管被SPN截?cái)郔I型：支氣管進(jìn)入SPN呈錐狀中斷Ⅲ型：支氣管在SPN內(nèi)呈長(zhǎng)段開(kāi)放狀，并可進(jìn)一步分叉Ⅳ型：支氣管緊貼SPN邊緣走行，管腔形態(tài)正常V型：支氣管緊貼SPN邊緣走行，管腔受壓變扁ClinicalRadiology(2004)59,1121–1127I型：支氣管被SPN截?cái)郔I型：支氣管進(jìn)入SPN呈錐狀中斷Ⅲ型：支氣管在SPN內(nèi)呈長(zhǎng)段開(kāi)放狀，并可進(jìn)一步分叉Ⅲ型：支氣管在SPN內(nèi)呈長(zhǎng)段開(kāi)放狀，并可進(jìn)一步分叉Ⅳ型：支氣管緊貼SPN邊緣走行，管腔形態(tài)正常V型：支氣管緊貼SPN邊緣走行，管腔受壓變扁I型：支氣管被SPN截?cái)郔I型：支氣管進(jìn)入SPN呈錐狀中斷Ⅲ型：支氣管在SPN內(nèi)呈長(zhǎng)段開(kāi)放狀，并可進(jìn)一步分叉Ⅳ型：支氣管緊貼SPN邊緣走行，管腔形態(tài)正常V型：支氣管緊貼SPN邊緣走行，管腔受壓變扁ClinicalRadiology(2004)59,1121–1127惡性結(jié)節(jié)最常見(jiàn)的腫瘤一支氣管關(guān)系是I型，其次為Ⅳ型，V型最少見(jiàn)；良性結(jié)節(jié)最常見(jiàn)的是V型，其次為I型，未見(jiàn)到Ⅱ型。就腫瘤一支氣管關(guān)系類(lèi)型而言，I型惡性SPN多于良性SPN，后者主要見(jiàn)于結(jié)核球；Ⅱ型僅見(jiàn)于惡性SPN；Ⅲ型可見(jiàn)于惡性和良性SPN，但前者的支氣管形態(tài)僵硬，管腔保持通暢甚或輕度擴(kuò)張；后者支氣管形態(tài)柔軟，走向自然，管腔擴(kuò)張度不如惡性腫瘤，并常見(jiàn)支氣管有多個(gè)樹(shù)枝狀分又及支氣管呈斷續(xù)狀表現(xiàn)；IV型以惡性SPN占絕大多數(shù)V型則以良性SPN多見(jiàn)。SPN一支氣管關(guān)系類(lèi)型的病理基礎(chǔ)膨脹性生長(zhǎng)：瘤細(xì)胞增殖、堆積，呈實(shí)性壓迫、推移鄰近肺組織，由于腫瘤為支氣管源性，故導(dǎo)致支氣管在腫瘤邊緣截?cái)?。伏壁性生長(zhǎng)：以肺結(jié)構(gòu)為支架，瘤細(xì)胞沿肺泡壁和肺泡隔爬行，經(jīng)肺泡孔擴(kuò)展，同時(shí)可經(jīng)淋巴道、小氣道或以直接浸潤(rùn)的方式從1個(gè)肺小葉擴(kuò)展到另1個(gè)肺小葉，而支氣管仍保持通暢，形成支氣管充氣征。支氣管管壁由外向內(nèi)的腫瘤浸潤(rùn)、管壁產(chǎn)生的纖維性增殖性反應(yīng)使支氣管管壁增厚、僵硬，加上瘤內(nèi)成纖維化反應(yīng)的牽拉，使瘤內(nèi)的支氣管不僅未被腫瘤壓扁，反而保持高度的通暢，甚至有所擴(kuò)張，形成惡性腫瘤的含氣支氣管征特有的表現(xiàn)。良性結(jié)節(jié)邊緣的支氣管未受腫瘤侵犯和成纖維化反應(yīng)的影響，管壁仍很柔軟，易受膨脹性生長(zhǎng)的結(jié)節(jié)壓迫，導(dǎo)致管腔變扁甚至閉塞。結(jié)核球引起支氣管截?cái)嗍怯捎诤笳邊⑴c形成包膜。炎性假瘤的含氣支氣管征由肺實(shí)質(zhì)的滲出、實(shí)變、機(jī)化襯托引起，支氣管形態(tài)自然，常見(jiàn)樹(shù)枝狀分叉，管腔內(nèi)可有分泌物、出血或血栓，使支氣管表現(xiàn)為斷續(xù)狀。SPN血管特征惡性結(jié)節(jié)增強(qiáng)超過(guò)良性結(jié)節(jié)CT增強(qiáng)值低于15HU傾向于良性CT凈增值超過(guò)25HU，清除值5-31HU傾向惡性AJR2007;188:57-68Graphoffourdifferenttypesoftime-attenuationcurveofnodulehemodynamicsinconsiderationofbothwash-inandwashoutphasesofdynamicCT.Radiology2005;237:675-683PatternsofNoduleEnhancementatEarlyandDelayedEnhancementCT

PatternsofNoduleEnhancementaccordingtoHistologicDiagnosisFig.4A

—Metastaticadenocarcinomain57-year-oldmanwithrectalcancershowsnetenhancementof25Handwashoutof5-31HondynamichelicalCTandpositiveuptakeonintegratedPET/CT.Lungwindowoftransversethin-section(2.5-mmcollimation)CTscanshows9-mmnodule(arrow)inleftupperlobe.Fig.3A

—Adenocarcinomain67-year-oldmanshowsnetenhancementof25Handwashoutof5-31HatdynamichelicalCTandpositiveuptakeatintegratedPET/CT.Lungwindowoftransversethin-section(2.5-mmcollimation)CTscanshows16-mmnodule(arrow)inleftupperlobehaslobulatedandspiculatedmargin.Figure3a.CTscansoftuberculomawithtypeIIenhancement(<25HUwash-in)ina58-year-oldman.(a)Transversethin-section(2.5-mmcollimation)scanobtainedwithlungwindowattheleveloftherightmainbronchusshows21-mmnodulewithlobulatedandspiculatedmarginintherightupperlobe.(b)Serialimageswithdynamicenhancementcurveforthenodule.Peakenhancementis49HU;netenhancement,3HU;andabsolutelossofenhancement(washout),1HU.Figure4a.CTscansoforganizingpneumonia(focalpneumoniawithoutspecificmicroorganism)withtypeIIIenhancement(25HUwash-inwithpersistentenhancement)ina58-year-oldwoman.(a)Transversethin-section(2.5-mmcollimation)scanobtainedwithlungwindowatthelevelofthehepaticdomeshows14-mmnodule(arrow)inrightlowerlobe.Bronchiectasisisalsoseeninbothlowerlobes.(b)Serialimageswithdynamicenhancementcurveforthenodule.Peakenhancementis118HU;netenhancement,69HU.Thisnoduleshowedpersistentenhancementwithoutabsolutelossofenhancement.Figure5.CTscansofleiomyomawithtypeIVenhancement(25HUwash-in,>31HUwashout)ina45-year-oldwoman.Serialimageswithdynamicenhancementcurvefortheleftlowerlobenoduleshowpeakenhancementis165HU;netenhancement,133HU;absolutelossofenhancement(washout),90HU;andtimetopeakenhancement,1minute.病理學(xué)基礎(chǔ)：周?chē)头伟┑难┰从谥夤軇?dòng)脈，腫瘤間質(zhì)內(nèi)血管豐富，且分化不成熟，血管分布紊亂，基底膜不完整，管壁通透性高，有利于大分子造影劑滲入細(xì)胞間隙，部分肺癌微血管擴(kuò)張，利于造影劑在血管內(nèi)停留。結(jié)核球是中央的干酪壞死區(qū)為纖維包膜所包裹，干酪壞死因乏血管而無(wú)強(qiáng)化。周?chē)头伟┟黠@高于結(jié)核球。從時(shí)間—密度曲線(xiàn)觀察，兩者截然不同，結(jié)核球的曲線(xiàn)低平，無(wú)明顯峰值。而周?chē)头伟﹦?dòng)態(tài)增強(qiáng)后2min內(nèi)達(dá)到高峰，周?chē)头伟┑闹饕獜?qiáng)化形態(tài)是完全強(qiáng)化，少部分周?chē)詮?qiáng)化。結(jié)核球的主要強(qiáng)化形態(tài)是無(wú)強(qiáng)化及包膜樣強(qiáng)化，結(jié)核球的不同強(qiáng)化形態(tài)取決于包膜的富血管、完整度及厚度。炎性結(jié)節(jié)形成過(guò)程中，肺動(dòng)脈水平上發(fā)生彌漫性血栓，血供直接源于支氣管動(dòng)脈，造影劑通過(guò)相對(duì)較直的、結(jié)構(gòu)正常的血管進(jìn)入間質(zhì)，進(jìn)入血管周?chē)g質(zhì)的造影劑因淋巴管的通暢加快了引流。部分惡性及良性病灶持續(xù)強(qiáng)化無(wú)清除可能與局部組織纖維化的程度數(shù)量相關(guān)。SPN生長(zhǎng)速度評(píng)價(jià)大部分惡性結(jié)節(jié)倍增時(shí)間30-400天2年隨訪(fǎng)病灶穩(wěn)定，倍增時(shí)間至少730天傾向良性疾病倍增時(shí)間小于7天，超過(guò)465天傾向良性直徑小于1cm病灶較難評(píng)價(jià)Radiographics.2000;20:59-66Td=Ti·log2/3·log(Di/Do)

Ti=intervaltimeDi=initialdiameterDo=finaldiameterFigure1.

Effectofinitialnodulesizeonperceptionofgrowth.Schematicillustratestwovolumedoublingsofa4-mmnoduleanda3-cmnodule.Becausetheeyeperceivesthearithmeticincreaseindiameterratherthanthechangeinvolume,thesmallernoduleappearstobegrowingmoreslowlythanthelargerone,eventhoughbotharedoublinginvolumeatthesamerate.Figure21a:

(a)CTscaninan80-year-oldmanshowsa2.5-cmrightupperlobenoduleattheposteriorsegment.(b)RepeatCTscanobtainedpriortotreatmentperformed2monthslatershowsrapidintervalenlargement.Thevolumetricdoublingtimewas26days.FNABrevealedmixedsmallcellandnon–smallcellcarcinoma.BayesianAnalysis

臨床、影像學(xué)資料EffectofageandsmokinghistoryonpCainanindeterminatepulmonarynodule.Close-upchestCTscanoftherightlungshowsa7-mm,smoothlymarginated,noncalcifiednoduleinthemiddlelobe.Onthebasisofdecisionanalysis,observationwouldbethemostcost-effectivemanagementstrategyina35-year-oldnonsmoker(pCa=0.01)orcurrentsmoker(pCa=0.05),andbiopsywouldbethemostcost-effectivemanagementstrategyina70-year-oldnonsmoker(pCa=0.07)orcurrentsmoker(pCa=0.50)其他輔助檢查對(duì)于SPN診斷價(jià)值PET核素顯像PET直徑1-3cm實(shí)性結(jié)節(jié)，敏感性94％特異性83％SUV值超過(guò)2.5即為陽(yáng)性假陽(yáng)性：局部感染，炎癥，肉芽腫性疾病假陰性：病灶直徑小于1cm，類(lèi)癌，BACFigure7a.

Non-smallcelllungcancerina65-year-oldman.(a)