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! Eberhard!KE,!Sørensen!EM! !! ©!SATS!Copenhagen!⎟ !!emss15.sats;kbh.dk! !! ! !

CHEST&X(RAY&ALGORHITHM&!Remember!to!go!through!all!the!steps!of!the!algorithm!to!avoid!overlooking!any!pathology!!!1) Identify&patient&!Start!by!checking!that!the!chest!X;ray!belongs!to!the!patient!you!are!examining.!!!

FRONTAL!VIEW!!2) View&and&quality&!To!interpret!the!image!correctly!you!need!to!know!how!the!chest!X;ray!has!been!taken:!!!

a) Has&the&patient&been&standing&or&lying&(supine&position)?!Standing!is!the!golden!standard.!If!the!patient!has!been!lying,!the!quality!of!the!chest!X;ray!is!not!as!good,!and!you!have!to!be!careful!when!interpreting;!the!heart!might!look!larger,!the!lung!structure!more!rough!and!it’s!hard!to!ensure!maximal!inspiration.!!!!!!!!

b) Is&it&a&posterior(anterior&(PA)&view&or&an&anterior(posterior&(AP)&view?!A!PA!view!is!the!standard.!It!means!that!the!X;ray!beam!passes!through!the!patient!from!posterior!to!ante;rior.!A!supine!chest!X;ray!is!always!AP.!If!the!image!is!AP!the!mediastinum!and!the!heart!will!seem!enlarged.!!!

!c) Identify&the&right&and&left&side.!The!patient’s!right!hand!side!needs!to!be!on!the!left!side!of!

the!image.!!!It!will!be!written!on!the!image!how!it!is!taken.!!!

d) Is&the&image&rotated?&The!spinous!processes!must!be!centered!on!the!vertebrae!and!ster;num!right!in!front.!The!clavicles!need!to!be!levelled.!&&

e) Was&the&image&taken&under&full&inspiration?&You!should!be!able!to!identify!the!10!upper!posterior!ribs.!&

&Now!you!are!ready!to!interpret!the!chest!X;ray.!We!start!by!interpreting!the!frontal!plane:!!3) Mediastinum&(trachea)&&Locate!the!trachea,!which!you!will!find!in!front!of!the!spine!as!an!air;filled!tube.!It!needs!to!be!in!the!center!of!the!picture!and!might!diverge!slightly!to!the!right!because!of!the!aortic!arch.!When!assessing!mediastinum,!check!for!clear!boarder!lines.!The!important!and!recognizable!structures!of!the!mediastinum!on!x;ray!are!the!heart,!ascending!and!descending!aorta,!the!aortic!arch!and!lymph!nodes.!Displacement!or!loss!of!definition!of!the!boarder!lines!or!abnormal!densities!might!indicate!disease.!

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! Eberhard!KE,!Sørensen!EM! !! ©!SATS!Copenhagen!⎟ !!emss15.sats;kbh.dk! !! ! !

4) Heart&&Again!look!for!clear!contours!of!the!heart.!Abnormalities!in!the!lungs!can!cover!up!the!edges!of!the!heart.!Next!look!for!the!cardio;thoracic!ratio!=!cardiac!width/thoracic!width.!The!cardiac!width!should!be!between!1/3!and!1/2!of!the!thoracic!width!on!a!PA!projection.!Remember!that!you!can’t!rely!on!the!heart!size!on!an!AP!projection.!!

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5) Diaphragm&(subdiaphrama)&&Check!if!each!hemi;diaphragm!appears!as!a!well!defined,!rounded,!domed!structure.!The!right!hemi;diaphragm!is!slightly!higher!than!the!left!due!to!the!liver.!The!left!hemi;diaphragm!should!be!visible!behind!the!heart.!If!air;filled!you!will!find!the!gastric!ventricle!just!below!the!left!hemi;diaphragm.!Be!aware!that!a!rim!of!air!underneath!the!diaphragm!is!a!sign!of!abdominal!pathology;!pneumoperitoneum.!!6) &Costophrenic&angle&&&Locate!the!costophrenic!angle!where!the!diaphragm!and!the!chest!wall!meets.!It!should!be!clear!and!sharp!on!both!sides!and!forms!an!acute!angle.!&7) Hilar&region&&

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! Eberhard!KE,!Sørensen!EM! !! ©!SATS!Copenhagen!⎟ !!emss15.sats;kbh.dk! !! ! !

Assess!the!hilar!regions!by!checking!the!position,!density!and!size.!The!left!hilum!is!usually!higher!than!the!right.!The!density!and!size!should!be!similar!on!each!side.!Differences!in!size!and!density!is!a!good!indication!of!an!underlying!pathology!e.g!enlarged!lymph!nodes.!!!!!!8) Lung&fields&To!assess!the!lung!fields,!divide!the!lungs!into!three!zones;!an!upper,!middle!and!lower!zone.!Be!aware!that!these!zones!do!not!equate!the!lung!lobes!!Compare!the!right!and!left!of!each!zone!and!look!for!any!asymmetry!that!is!not!explained!by!the!normal!structures.!Check!if!an!area!of!the!lung!is!either!too!black!or!too!white,!or!if!the!structure!of!the!tissue!looks!different!compared!to!the!opposite!or!sur;rounding!lung!tissue.!Remember!that!some!pathologies!might!affect!both!lungs!symmetrically,!and!have!in!mind!the!look!of!a!normal!chest!X;ray.!Here!are!some!impor;tant!things!to!look!out!for:!

a) Pneumothorax:&1)!Follow!the!chest!wall!from!the!costophrenic!angle!and!to!the!apices.!Does!the!lung!tissue!reach!the!wall!all!the!way,!or!du!you!find!any!black!areas?!A!pneumothrorax!can!be!anything!from!a!thin!black!rim!to!an!entire!blanck!lung!field.!2)!Is!the!mediastinum!pushed!towards!the!opposite!site!as!a!sign!of!a!tension!pneumot;horax?!

b) Consolidation&and&atelectasis:&Both!of!these!conditions!make!the!lung!tissue!more!dense!why!it!appears!whiter.!Atelectasis!is!collapsed!lung!tissue.!In!a!consolidation,!lung!tissue!and!small!airways!are!filled!with!material/liquid,!e.g.!infec;tion!or!edema.!It!can!be!hard!to!differ!the!two!but!look!for!the!air!bronchogram!characteristic!for!consolidation.!In!addition,!the!atelectasis!might!pull!the!surrounding!structure!such!as!the!mediastinum!and!diaphragm,!whereas!a!consoli;dation!pushes!them!away.!!

c) Pleural&effusion:&a!pleural!effusion!is!an!excess!of!fluids!in!the!pleural!cavity.!It!accumulates!at!the!bottom!part!of!the!cavity!due!to!gravity,!and!shows!meniscus!signs!along!the!chest!wall!and!mediastinum.!A!pleura!effusion!might!push!the!surroundings!like!the!consolidation.!!

d) Lung&stasis&and&edema:&Lung!stasis!is!character;ized!by!enlarged!vessels!visible!all!the!way!to!the!chest!wall.!Look!for!apical!flow!shift!–normally!the!vessels!are!more!apparent!in!the!lower!lung!zones.!Edema!is!the!next!step!when!the!fluid!fills!the!lung!tissue!as!well!giving!the!lung!fields!a!cloudy!appearance.!

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! Eberhard!KE,!Sørensen!EM! !! ©!SATS!Copenhagen!⎟ !!emss15.sats;kbh.dk! !! ! !

e) Emphysema:&Due!to!destruction!of!the!lung!tissue,!the!lungs!will!look!darker.!To!compen;sate,!you!will!often!find!a!barrel;shaped!thorax!and!the!diaphragm!flattened!with!a!less!acute!costophrenic!angle.!

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9) Ribs&!Follow!the!edges!of!each!rib,!looking!for!signs!of!fractures!or!any!dark!areas!in!the!bones.!!&!

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LATERAL!VIEW!&

1) Diaphragm:&&!Identify!the!right!and!left!hemi;diaphragm.!The!right!hemi;diaphragm!is!situated!higher!than!the!left!due!to!the!liver.!&

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2) Costophrenic&angle&!As!in!the!frontal!plane!the!costophrenic!angles!should!be!clear!and!sharp.!Re;member!to!look!at!both!the!anterior!and!posterior!angle.!The!posterior!angle!is!lower!than!the!anterior!and!effusions!will!often!accumulate!here!first.!!&!

3) Retrosternal&region&!Look!at!the!area!between!the!sternum!and!the!heart.!It!should!be!a!slim!rim.!A!larger!dark!area!indicates!emphysema!while!a!white!area!indicates!a!consolidation.&!

4) Hilar&region&!Check!the!density.&!

5) Lung&fields&&!Compare!the!lung!fields!in!front!and!above!the!heart!with!the!ones!behind!the!heart.!They!should!have!equal!density.!&!

6) Vertebrae&!The!vertebrae!should!get!darker!as!you!follow!the!spine!caudally.!Look!for!the!shape,!size,!col;lapsed!vertebras!and!areas!that!are!darker!or!lighter!than!the!surrounding!bone.!!!

&One&last&thing:&remember&the&patient!&Don’t&get&lost&in&the&X(ray&☺&