05 chest x-ray interpretation

8/7/2019 05 chest x-ray interpretation

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Hff:;::interPretationThc cmphasisof this chaptcris rhc X ray appcaranceof common con-clit ionsthat you wil l se ewhen on call. As the majority of patientsrcquir ing cmergencyphysiotherapyare short of breathor havc sub-optimal gas exchange,only abnormalit iesof the lungs an d pleuralsp:rccsarc demonstratcd.Only frontal X-rays (posteroantcrior(PA)and anteropostcrior(AP)) arc uscdes thesear cthc oncsthat yo u wil lbc rcquireclto intcrprct .Rcmcnrbcrtheta pcrfcctchcstX rer,(CXR; Fig.5.1)requircscorrccrpet icnrposi t ioningand rhc corrccr X r. ry dosc.I )cf icicrrcyin any of

Figure 5.1 Normal chestX-ray.Ke/:1 trachea;2horizontalfissure;3costophrenicangle:4ritht hemidiaphragm;5 left hemidiaphraSm;6hearrshadow7 aorticarch;8riShthilum;9lefthilum..E

5 CHESTX{AY INTERPNFTANONthcsc results in a subopt;mal X-ray and may produce appearanccsthatsinrulatelung pathology.

NORMAL LOAARANATOMY. Th e right lung containsthreelobes,upper(RUL), middle(RML) an d

lowcr (RLL) (Fig. s.2A-B).. On the right sidc,thc obliquc fissuresepararesthe RUL from the RLI-abovc thc horizontal fissureand thc RML from the RLL bclow it.. The horizontal f issurcscparatcsthc RUL from rh c RML.

Remember:When lookinSat a frontal CXR:. RUL is at the top abovethe horizontal fissure. RML is at the baseanteriorly below the horizo ntal fisslre. RLL is posterior.

Horizontal n\Fiture 5.2AFrontalplane.Figure5.2BRightlun8,lateral.


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I

Figure 5,2Clunt,lateral.

Lowerzone Figure 5.2D Lungfleld zones.

. The left lung cons ists of two lobcs, uppcr (LUL) arld lowcr(l . t . l -) ( l ig.5.2C). Th e l ingula is the most infcrior part ofthe LUL.. 'l hc obl iqucf issureon the left sideseparatcsthc LUL and LLL.

Remember:The LUL is anterior and t}|e LLL isposterior.

For dcscript ivc purposcs,th e lungs on the CXR are dividcd intothi rds or zones(Fig.5.2D):. uPperzonc. mid-zone

Thcscarc NOT ANATOMICAL divisions.For example,the apexofthe lower lobe on eachsideis in thc mid-zonc.

HOWTO INTERPRETABNORMALITIESINTHE LUNGFIELDSONTHE CXREssentially,theseareasareabnormalbecausetheyappeareither:. too whiteor. too black.

Too \A/hiteLe't Th c r'.rsrrnajorityof abnormalit icsin thc on callse$ingar carcasthatar ctoo whitcan dthc commonestcausesarc:

CH'' X.MYINTXT.PRSTATION

. col lapseor.itelec(asis. consol;dation. plcural cffusionr pulrronary oedcma.Too Black\ fhen there are arcaswhich appcar. Pncumothorax. c()Pl).L.achof thcscis dcscribcdbelow.

ATELECTASIS/COLLAPSEAtelcctasisor col lapscrefcrsto an areaof lung which is airlcssand thelung col lapscsin this reg;on.A!clcctasismav involvc an ent;rclobc orcvcn an cnt i rc lung.' l 'hc cbcstX-ray wil l show a lossof lung volume.This meansthatthc lung field wil l bc smallcr than expccted.OdTer structurcsma vmovc to f i l l up the space,so thcrc may bc:. shift of the rnediastinalstructurcssuchas the heartor t rachc; l. eleuationof rhc hcmidiaphragmconpared ro rhc othcr sidc.Th e arcaof collapscdlung appcarses a whi tc or'dcnsc'area and thisrcprcscntsair lesslung rissuc.\f lhen this affectsa small volumc of thclung, thc appcaranceis of a white l ine and this is often seenat thc lungbascsin postoperat ivcplt icnts. Whcn a wlrole lobe col lapscs,cachproducesa spcci f icappcarance(Tablc5.1):

too black, the most important

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@X"RAYINTERPRETATION5 CHEST

Figure5.3 Rightupperlobecol lapse.Th ehorizonralf issureis no worientatedobliquely.Th etracheais deviatedto the rightwhichis evidenceof mediastinalshift.

5 CHESTX.RAYINTERPRETATION

Fi8ure 5. 4 Ri tht middle lobe co lapse.Th e r i8ht hear t border is indis t inc tand there is a vaguewhi te appearanceto rhe adjacentlun8.

Figure 5.5 Rightlowerlobecol lapse.Thereis abnormalwhitenesswitha straightouterborder(arrow)low in the rightlun8.The riShtheartborderis sti l lvisible.

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Table 5.1 Appearanceof lobe col lapsePresentation. There is increaseddensity high in the riSht l!n8 down tothe hor izontal fssure. This fissureswingsupwards and can adopt an almostvertical position (Fig.5.3). The Rl"lL collapsesdown againstthe right heart borderwhich becomesindistinct (Fig.5.4). The right hetrrt borde s clearlyseen on a normal CXRbcauseit lis adjacentto the air-filledmiddle lobe. There is a trianSulardnsity low i n the right lung but theriShtheart borde r can still be clarly seen(Fig.5.5). The left lunSis slightlywhiter than the right. The LUL is antrior and so collapsesagainstthe anteriorchestwal l .Thus,youse et r i rin the LLLthroughth edensecol lapsedLU L (F i8.5.6). A t r ianSulardens i tyis seenbehindthe hear t(F ig.5.7). The part of the heart sh:dow to the left of the spine iswhiter rhan thar to th e right of che spine

Lob collapseRU Lcol lapse

Rl '11col lapse

RLL collapseLU L col lapse

LL Lcol lapse


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Figure5.6 Lef tupperlobecol lapse.Therets a hazyincreasedwh tenessoverthe lefthemithorax.The lefrhearrborderis indistinct.

Figure 5.7 Lef t lower lobe col lapse. Increasedwhi tenessis seenbehrndthe heart with a straight outer edge (arrows).

5 CHESTX-RAYINTERPRETATION

Figure 5.8 Lef tlunScol lapse.Thereis abnormalwhirenessoverrh elefthemithorax.The heart is shifredto the left within the abnormalarea.Vhen a rvholclung col lepscsthcrc is incrersed(lensitvof rhc cnri rchcrni thor-ex(l; igs 5. l l ud 5.9).This.rppcrrenccis sonrct inrcscal lerl.r' rvhi tc out ' , r l though thcrc. l rc ()therci luscsfor dris. A pncunrorc.torrrr is in eflcct an cxtrcmc fornr o[ cornplctc lung col l i rpsc.rnrlsou il l look thc s.rmcon (lXR but vou nral sc erib i rrcgul . rr i tr nrerl ' inqtl lc sitc() f !he thorrcotornv.

Remember:When you see complete collapseof the left lungassociaredwirh RULcollapsein a v entilated patienralwayscheck rhe position of theendotrachealtube. lf the tube has been advanceddown the right mainbronchusthen only the RMLand RLLwil l be aerated(Fi9.5.10).

CONSOLIDATIONConsolid.rt ionoccursrvhcn.rir in lung is rcpleccdbt f luid. l hc distribution of th is consolidit;orr rner bc patchv or nr. rv. rf fect:rn cntirc

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Figure 5.9 Pneumonectomy.Abnormal whi tenessis seen in th e lef themithorax. The trachea and heart are shifted to the left.

Figure5.10 Collapseof the leftlunt andrightupperlobe.Note thet ip ofth eETrubewhichliesin the rishtinte.lobarbronchus.

5 CHESTX.RAYINTERPRETATIONsciamcntor lobc.'fhe composirionof this f luid dcpcndson thc c,rusc:. infccte'clf luicl,as in pncumonia(the corl rnloncstceuscthrt \ ' ()u

rvi l l scc). srl ivaor l i istric contcnts,sccnin cescsof rspiretion. l '1, , , ,J,i l c. r.c. , , l rr. rurr. rr i .Lrrro(i ,nlu\ i , ,n. scloustransutl l tc,sccnin alvrolarpulmonarvocdcmx.Although thc distribution nray hc' lpto cl icit thc ceusc,th e ricl iologi-cl l lppcaranceof consol id,rr ionis thc s.rrnefor r l l of thcsc:Radiological Appearance. The whi teness or shadowing in thc lung is poorly defined. It is

cl i ff icult to scc the edgcsof thcsc arcrs.The shadowinghas bccndcscribedas'f lufff in appcirr: rncc.o lhcrc is no loss of volunTe,unlikc atclcctasis,es drcrc is no lungcolhpsc'(Fig.5. 1l) .

Figure 5,'l ' l Traumaticconsolidationof the rishtupperlobe.Thereisabnormalwhitenessin the right upperlobe.The horizontalfissureis in itsnormalposit ion,so thereis no volumeloss.Note the shraPnelin the

@CHESTX-RAYINTERPRETATION

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f @X.RAYINTERPRETATION. An air bronchogram mav tre sc'en,part icularlv when thcrc iscrrcnsiveconsolidation.This is causcd[rl consolidationof lung t is

suc:rdjaccntto an ai t -f i l lcd brorrchuswhich thus st i rndsout es rbl . rcktube anid thc consol idrt ivcshadorving(Irig.5.t2).Krrorvlcdgeof lobaranatomvhclpsto locelizcconsol idat ionesit clocsrvi th etclcctasis(Fig. S.13).lt is important in tcrrnsof how vou t rcatvour paticrlt; rndnral alsoprovide clucs:r sto thc causc:. Aspirerion rcnclsto particulerly ir{fectthc r ight lowcr lobc rvhcn

thc pet icnt is crcct asthc right nrainrnd lorvcrlobc bronchi i rc thcrrost vcr! icxl(Fig.5.1,+).Aspir: rt ionis part icularlvsccr,in thc apicalscgrncntso| thc lower-lobcswhcn thc paticn t is supincas thescbronchi arc di rccrcdpos-tcriorlv and erc thus thc nrostdcpcnclcntin l patientlving fl i t .l .urrg contusion tcnds to occur in thc sct t ing of t raunra so thcremal bc skin bruising.rncl\ { )u nrrv scerib f rrcturcs on thc CXR( tr is.s. l5).

Figure 5.t2 RiShtlowerlobeconsolidation.The abnormalwhitenessin therightlower andmid-zonesis poorlydefinedand'cloudy. Thereis a trident-shapedlucencywhichis an air bronchogram(arrows).The righthean borderremainsvisible.

5 CHESTX-MY INTERPRTATION

Figure 5.13 Middlelobeconsolidation.Th epoorlydeflned'f luffy'increasedwhitenessabutsthe horizontalfissureand rhere is no volumeloss.

Figure 5.14 Rightlowerlobeco nsolidation.The upperl imitof thisabnormalwhitenessshowsthe locationof the apicalsetmentof the rightlowerlobe.whichis in the mid-zone.


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wX.MY INTERPR$ATION5 CHEST

Figure 5.15 Traumaticrighrlowerlobeconsolidation.Note the ribfractures(arrows).

. In alvcolarpulmonaryocdcma,thc consolidatio nappcarenccrcndsto bc situatedin thc mid-zoncsaround thc hila.ln children,infcct ivc consol iderionis of tcn ci rcular in shapc.This istLrnrcd,1r^und pncum,,nia{Ft ts.5. lo).Remember:In real life,consolidationand atelectasiscommonly occur together,but by analysingthe abnormalwhite areasoo the CXR you will findthat one of these tends to predominareand thus is probably themost important when it comes to treating the patient.

PLEURAL EFFUSIONThis rcfersto fluid in thc plcuralspacc.It occupicsthc dcpendentpartof thc plcuralspaccdue to gravi tv so whcn th e paticnt is crcctor scmi-crcc! ; t occupiesthc lowcr zone on CXR init ial ly. However, i f thcpat icntis supinc,;r occupicsthc postcriorsurfaceo{ thc plcuralspace.

5 CHESTX.MYINTRPRFTATION

Figure 5. i6 Roundpneumonia.Theroundedparchywhiteareain theritht lower zone representsconsolidation.

Radiological AppearanceThc characrcrist icfeatureof tbe abnormal whitcnessin plcural ef{usion is that it is uniform throughout.It is not patchy.Most paticntsthat vo u wil l sccwil l havcrhcir X rar'srakenerccrorscri i crect :. A smal lcf fusion prcscntsas blunting of the costophrcnicanglc,th crcgionon thc CXR betwecnthc hcmidixphrag men drhc chestrvi r l l .. In a modcratc-sizcdcffusion, rhe top of thc f luid is sccnas : r hori -zontl l l ine and therc is a mcniscusar thc poinr where $e f luidtouchesthc chcstwall. Thc hcmidiaphra gmis obscured(Fig.5.17).. Virh a very large ef fusionthcrc miy bc shifr of the mediastinu,newavfrom thc sideof the ef{usion.A largccffusion is anothcrcausc1o r a'whi tc out 'appcaranccbut thc posit ion of the mediastinurntcl ls vou if ir is due to atelectasisor effusion(I ig. 5.18).If thc paticnt is supinc thc f luid adopts a posterior locat ion. Thustherc rvi l l bc a general izcdincrcascdwhitcnessof the lung field.Th clung can sti l l bc secnln d is cf fcct ivclv bcing vicwcd through a rhinlayerof f luid.


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Figure 5.17 Ritht pleuraleffusion.There is uniformwhitenessat the baseofthe right hemithoraxwith a horizontaluppersurfaceanda meniscusseenat the chestwall.

PULMONARY OEDEMAThe majoriryofcasesaredueto left ventricularfailure.Thefcaturesare:. The heartis usuallyenlarged.. There may be consolidationaround thc hila as dcscribcdabovc(Fig.5.1e).. Thcrc may bc tiny, thin horizontallineswhichareseenin the lowerzonesvrherethe lung touchesthe chestwall. Thcse are due toocdcmain the lungsubstanceor interstitiumratherrhanthe alveoliand areknown asKerley B lines(Figs5.20and 5.21).r Thcrc arc largc distended veins seen in the upper zones

(Fig.s.20).. Theremay bepleuraleffusions.

Figure 5.18 Leftpleuraleffusion.Thereis uniformwhitenessoverthe lefthemithoraxandthe heartandmediastinumare displacedto the ritht. Thusthere is'too muchvolume'on the leftdue to a massavepleuralefirsion.

Figure 5.19 Heart failureandalveolarpuhonary oedema.The heart isenlargedandthere is bilateralconsolidationaroundthe hila,theso-called'bat! wing'appearance.Note the smallleft pleuraleffusion..E


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L!r ry5 CHsfX,RYlNft$[FtAnON

Figure 5.20 Interstitialpulmonaryoedema.The heart is enlarged.Thereis prominenceof the upper lobe veins(arrow),representinglpper lobeblood diversion.KerleyB linesare seenat the riShtbaseandthere is a smallriSht-sidedpleuraleffusion.

PNEUMOTHORAX'Ihis is an important causcof a lung ficld appearingtoo black andrcfcrs to air in the pleural space.Thc fcatures on thc CXR are:. Ih c lung cdgc is sccn as a whire Jine parallelro the chesr wall( | ig.5.22).. Lung markingsdo not cxtcnd out beyond thiswhite line.o I hc arcaoutsidethislung cdgcis blackcrthanth eareainsidethe linc.A pncumothorlx may involve the entire hemithoraxand in this caserlrclc will bc no lung markings visible ar all. In a rensionpneumo-tlrorrrr thc irir in th c plcural spaccstcadily incrcascsan d can buildrr p rignil ic.rnrprcssurc,pushing the mediastinumxway towards thcd

Figure S,21 KerleyB lines.Thin horizontalwhite linesare seenreachintthe pleuralsurfaceat the costophrenicangle.

oppositc side (Fig.5.2l). This can causecardiacarrcsrand is rhus asurgicalemcrgency.

Hazard:Youshouldnot usepositivepressurventilation(e.g.CpABlppBorNlV) in a patientwith a pneumothoraxasyou mayturn it into atensionDneumothorax.

Occasionally, the air in the pleural caviry may be locatcdparticularly when the parienr is supine. This makes it moresc cas therc may not bc a visiblelung edge.Bc suspicious

anteriorly,dif{icult toif the CXRr )


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@5 CHESTX.MYINTERPRETATION

LungmarkinSsdo not extendinto this blackarea.

of r vcntilatcdpatient shows onc lung to be blackcr than thc odrer,particularlyin the lowcr zonc,an d is ass.rciatcdwith otherwiseuncx-plainedsuboptimalga sexchangc.

COPDThc lungs appcarhypcrinflated ar,d blacker in cmphyscmaduc tcrth e dcstruction of lung rissuc. Thin wrllecl sacs or bullae n,avdc"clop and appcar as particularly bleck arcas,often at thc top ofth c lung. ln thcse cases,unlikc pneumothorax, thcrc is no visiblelung cdge and lung markings are seen rceching the chest wall( I r ig.5.2a).. E

5 CHSTX-RAYINTERPRETATION

Figure 5.23 Lefi tension pneumothorax.The left hemithorax containsnolung markinSsat a l l .The hear r and mediastinumare sh i f tedro the r ight .

@

bILFigure5.22 Rightpneumothorax.A blackareain theriShtlung,whoseedgeis clearlyseenasa

a. Icl{ |

-ritht hemithoraxwhite line(arrows).

nnI4 COPDs.No lunt

lunSsis visi

Bothedterthe> lungway ro

Figure5.24uPPerzones.reachinSallt

arlyin th emarkingsside.

particuiarlyvs lungmarn eachside

normal,pato nshowstt wallon

r than no lInsPectone. Close in

I lunSsareis v is ib le . ,Preurarsu

../r


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5 CHESTX.RAYINTERPRETATION

Hazard:lf you use positive pressureventilation in these patients,be aware lhatthere is a risk of creatinga pneumothorax by burstinSone of thethin-walled bullae.Usuallyrhe benefitsto the patien! outweigh thissmall risk but it is important to discussthis with a doctor.

This ch.rptcris e guidc to hclp r ou irrtcrprctrbrrormel(lXlls whcn onc,r l l .I lorvcvcr' ,i t is import.rnt to clcvclop.r svstcnrrric,lppr or.h iorcacling:r CX R so esto ,rbt.rinl l l thc infor mation ar.ri lrbleto r ou.ArknowledsernPnfs

I .rrr gr:rtc lulto Dr D.l. Dcl.rnr .rndI)r L\\ i l lrorvl for thc uscol thcircxtcrrsircfi lnr collccti,rnand to I) r .f. l). Arqcnt 1orsu;)phing thc i i lnrof rouncipncunronie.Further readinp

CorncJ, C;rrrol lM, BrorvnI, Delanr D (2002)(lhcstX rrv nrclct.rr.. lnLlcJn.I oncl,n:Churchil lI- ir inqsronc.

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05 chest x-ray interpretation

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