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8/13/2019 Jurnal Radiologi Lobar Atelektasis Imaging
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Lobar Atelectasis Imaging Author: Sat Sharma, MD, FRCPC; Chief Editor: Eugene C Lin, MD
Overview
The term atelectasis, hich is defined as diminished lung !olume, is deri!ed from the "ree#ords atelesand ektasis,hich mean incom$lete e%$ansion &see the image 'elo() Atelectasis
ma* affect all or $art of a lung, and it is one of the most common radiogra$hic a'normalities)
Recogni+ing atelectasis on a chest radiogra$h is im$ortant 'ecause a sinister underl*ing$atholog* ma* 'e $resent)-, ., /, 0, 1, 23 Se!eral t*$es of atelectasis ha!e 'een descri'ed; each has a
uni4ue radiogra$hic $attern) Atelectasis can 'e categori+ed as o'structi!e or nono'structi!e)
Gross anatomic specimen showing airless lungs, or atelectasis. Atelectasis refers to either
incomplete expansion of the lungs or the collapse of previously inflated lungs, which produces
areas of relatively airless pulmonary parenchyma.
Obstructive atelectasis
An o'struction 'eteen the al!eoli and trachea causes rea'sor$tion of al!eolar gas, leading to an
o'structi!e atelectasis) The o'struction can occur at the le!el of the larger or smaller 'ronchus,and it ma* 'e secondar* to a foreign 'od*, 'enign or malignant tumor, mucus $lug, and 'lood
clot, as ell as 'ronchial transection, fi'rotic stenosis from granulomas or inflammation,
$ol*chondritis, $ost 'rach*thera$* or radiothera$* stenosis, and other o'structi!e lesions)53
The de!elo$ment of atelectasis de$ends on se!eral factors, including the e%tent of collateral!entilation and the com$osition of ins$ired gas) 6'struction of a larger 'ronchus is li#el* to
$roduce lo'ar atelectasis, hereas the o'struction of a smaller 'ronchus causes segmental
atelectasis) The $attern of atelectasis often de$ends on collateral !entilation, hich is $ro!ided'* the $ores of 7ohn and the canals of Lam'ert)
Right middle lo'e &RML( s*ndrome, a form of chronic atelectasis, usuall* results from 'ronchial
com$ression and o'struction '* surrounding l*m$h nodes or 'ronchial scarring) Partial 'ronchial
o'struction and recurrent infection ma* also lead to chronic atelectasis and acute or chronic$neumonitis)
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Nonobstructive atelectasis
Loss of contact 'eteen the $arietal and !isceral $leurae causes nono'structi!e atelectasis) The
etiologies ma* 'e lung com$ression, the loss of surfactant, and scarring or infiltrati!e disease ofthe lung) Se!eral t*$es of nono'structi!e atelectasis are #non to occur from a !ariet* of causes)
A $leural effusion or a $neumothora% eliminates contact 'eteen the $arietal and !isceral
$leurae, and rela%ation or $assi!e atelectasis results) The uniform elasticit* of a normal lung
$reser!es the sha$e, e!en after atelectasis is $resent) The middle and loer lo'es colla$se morethan the u$$er lo'es in the $resence of a $leural effusion, hereas the u$$er lo'es are more
affected '* a $neumothora%)
Com$ression atelectasis occurs hen an* s$ace8occu$*ing lesion of the thora% com$resses the
lung and forces air out of the al!eoli) The mechanism is similar to rela%ation atelectasis)
Adhesi!e atelectasis results from surfactant deficienc*)Surfactant loers the surface tension of
the al!eoli and therefore $la*s an im$ortant role in $re!enting the al!eoli from colla$sing)Decreased $roduction or inacti!ation of surfactant, as o'ser!ed in acute res$irator* distress
s*ndrome &ARDS( and similar disorders, leads to al!eolar insta'ilit* and atelectasis)
Cicatri+ation atelectasis results as a se4uela of se!ere $arench*mal scarring and is usuall* caused'* granulomatous disease or necroti+ing $neumonia) The lo'ar colla$se from cicatri+ation ma*
'e either o'structi!e if the 'ronchi are in!ol!ed or nono'structi!e 'ecause of the fi'rotic $rocess
in the lung $arench*ma) Re$lacement atelectasis occurs hen the al!eoli of an entire lo'e arefilled '* tumor &eg, 'ronchioal!eolar cell carcinoma(, resulting in a loss of !olume)
Rounded atelectasis, also called folded8lung s*ndrome or 9leso!s#* s*ndrome, occurs as the
lung colla$ses and folds secondar* to fi'rous 'ands and adhesions to the !isceral $leura)3
Theincidence is high in as'estos or#ers &2185< of cases() Patients are t*$icall* as*m$tomatic,and the mean age at $resentation is 2 *ears) Rounded atelectasis is a 'enign disorder)
Preferred examination
Chest radiogra$hs are generall* sufficient to diagnose lo'ar atelectasis and to identif* the
colla$sed lo'e) Chest radiogra$hs are also useful in diagnosing $lateli#e atelectasis,
$osto$erati!e atelectasis, and rounded atelectasis, as ell as for folloing the course of theatelectasis) For e%am$le, chest radiogra$hs can 'e used to determine hether an inter!ention,
such as chest $h*siothera$*, has resulted in im$ro!ement)=, -3
>oe!er, in some situations, chest radiogra$hic findings ma* not 'e diagnostic) This generall*
occurs hen a concomitant $leural fluid or large $ulmonar* masses are $resent) ?n such cases,com$uted tomogra$h* &CT( scanning is a useful ne%t imaging stud*) CT scanning should 'e
used to assess o'structi!e atelectasis; this modalit* is also hel$ful in e!aluating the mediastinum,
chest all, hilum, $leura, and ad@acent lung)--, -., -/, -0, -1, -23
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Magnetic resonance imaging &MR?( has no $articular !alue in the diagnosis of lo'ar atelectasis,
e%ce$t for distinguishing o'structi!e from nono'structi!e atelectasis)-53
Limitations of techniques
A concomitant $leural effusion, $leural mass, or large lung mass ma* limit the usefulness ofchest radiogra$h* in the diagnosis of atelectasis)
hen a 'asal o$acit*, an o$acit* of the hemithora%, and other signs of atelectasis are not
o'!ious, determining hether the o$acit* is a $leural effusion or a lo'ar colla$se ma* 'e
difficult) ?n those situations, a CT scan can 'e of immense hel$) ?ntra!enous contrastenhancement is often re4uired for a$$ro$riate imaging and for differentiating among !arious
causes of atelectasis)
The limitation of CT scanning ma* 'e in differentiating 'eteen o'structi!e and nono'structi!e
causes of atelectasis) Furthermore, a CT scan ma* not 'e useful in determining hether the
o'structing lesion is a tumor, mucus $lug, nono$a4ue foreign 'od*, or 'lood clot)
Radiography
Chest radiogra$hs and CT scans sho direct and indirect signs of lo'ar colla$se) Direct signsinclude dis$lacement of fissures and o$acification of the colla$sed lo'e) ?ndirect signs include
the folloing:
Displacement of the hilum
Mediastinal shift toward the side of collapse
Loss of volume in the ipsilateral hemithorax
Elevation of the ipsilateral diaphragm
Crowding of the ris
Compensatory hyperlucency of the remaining loes
!ilhouetting of the diaphragm or heart order
Complete atelectasis
Com$lete atelectasis of an entire lung is characteri+ed '* a com$lete colla$se of a lung, hichleads to o$acification of the entire hemithora% and an i$silateral shift of the mediastinum) The
mediastinal shift se$arates atelectasis from a massi!e $leural effusion) &See the images 'elo)(
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Chest radiograph demonstrating complete atelectasis of the left lung
Chest radiograph depicting complete right lung atelectasis.
Right upper lobe collapse
The colla$sed right u$$er lo'e &RBL( shifts mediall* and su$eriorl*, resulting in ele!ation of the
right hilum and the minor fissure) The RBL ma* also colla$se laterall*, $roducing a $leural8'ased o$acit* that ma* loo# li#e a loculated $leural effusion)
The minor fissure in an RBL colla$se is usuall* con!e% at its su$erior as$ect, 'ut it ma* a$$ear
conca!e 'ecause of an underl*ing mass lesion) This is called the "olden sign of S &also #non as
the "olden S sign and the S sign of "olden()
Tenting of the dia$hragmatic $leura, called the @u%ta$hrenic $ea# sign, is another hel$ful sign of
RBL atelectasis) &See the images 'elo)(-3
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"mage depicting a right upper loe collapsing posteriorly and inferiorly.
#ight upper loe collapse. $his chest radiograph shows volume loss in the upper loe, upward
shifting of the hori%ontal fissure, and elevation of the right side of the diaphragm.
Lateral chest radiograph demonstrating a right upper loe collapsing anteriorly and superiorly.
$he opacity is seen in the anterior and superior locations.
Right middle lobe collapse
RML colla$se o'scures the right heart 'order on a $osteroanterior &PA( image) The lateral !ie
shos a triangular o$acit* o!erl*ing the heart 'ecause the ma@or fissure shifts u$ard and the
minor fissure shifts donard) ith orsening colla$se, the o$acit* diminishes in si+e, and itma* 'e 'arel* $erce$ti'le) &See the images 'elo)(
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"mage depicting a right middle loe collapsing medially.
&osteroanterior '&A( 'left( and lateral chest 'right( radiographs. A right middle loe collapse
oliterates the right heart order on the &A image and pro)ects as a wedge*shaped opacity on
the lateral view.
Right lower lobe collapse
The colla$sed right loer lo'e &RLL( shifts $osteriorl* and inferiorl*, resulting in a triangular
o$acit* that o'scures the RLL $ulmonar* arter*) The ma@or fissure, normall* not !isi'le on a PAradiogra$h, is e!ident ith an RLL colla$se) The su$erior mediastinal structure shifts to the
right, causing a su$erior triangle sign) Laterall*, the colla$sed RLL o'literates the $osterior one
third of the right hemidia$hragm and $ro@ects as an o$acit* o!er the normall* lucent area) &Seethe images 'elo)(
"mage depicting a right lower loe collapsing anteriorly and superiorly.
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"mage depicting a right lower loe collapsing anteriorly and superiorly.
"mage depicting the lingula collapsing medially.
Left upper loe collapse. $his radiograph shows an opacity that is contiguous with the aortic
+no, a smaller left hemithorax, and a mediastinal shift. $he luftsichel sign involves
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hyperextension of the superior segment of the left lower loe, which then occupies the left apex.
Chest radiograph demonstrating a left upper loe collapse, resulting in a veil*li+e opacity that
extends upward and outward from the hilum. Additional signs of loss of volume in the left
hemithorax and crowding of the ris are also evident on this radiograph.
Lateral chest radiograph demonstrating a left upper loe collapsing anteriorly.
Left lower lobe collapse
6n frontal !ies, an increased retrocardiac o$acit* o'literates the LLL $ulmonar* arter* and the
left hemidia$hragm) The hilar structures shift donard, and the rotation of the heart $roducesflattening of the cardiac aist, hich is #non as the flat8aist sign) The su$erior mediastinum
ma* shift and o'literate the aortic arch; this is the to$8of8the8aortic8#no' sign)
6n the lateral radiogra$hs, an o$acit* silhouettes the $osterior third of the left dia$hragm, and ano$acit* is $ro@ected o!er the normall* lucent area) &See the images 'elo)(
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"mage depicting a left upper loe collapsing superiorly and anteriorly.
Left lower loe collapse. $his chest radiograph shows volume loss on the left side, an elevated
and silhouetted left diaphragm, and an opacity ehind the heart 'ie, sail sign(.
Rounded atelectasis
?n cases of rounded atelectasis, segmental or su'segmental atelectasis occurs secondar* to
!isceral $leural thic#ening and entra$ment of the lung tissue)
Rounded atelectasis manifests as a su'$leural mass, and 'roncho!ascular structures radiate out
of the mass toard the hilum) An associated $arietal $leural $la4ue ma* 'e $resent) The sirl
a$$earance of the 'roncho!ascular shados is called the comet8tail sign and esta'lishes thediagnosis)-=3
Degree of confidence
Chest radiogra$h* has the highest sensiti!it* hen direct signs of atelectasis can 'e detected)More s$ecificall*, the identification of a dis$laced fissure is of significant ad!antage in
diagnosing lo'ar colla$se) The $resence of se!eral indirect signs further corro'orates the direct
signs in the diagnosis of atelectasis)
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False positivesnegatives
Modest loss of !olume ma* occur secondar* to lo'ar consolidation; this ma* lead to the
erroneous diagnosis of lo'ar colla$se)
A loculated $leural effusion or $leural effusion ith $assi!e colla$se ma* 'e mista#enl*identified as a colla$se secondar* to an endo'ronchial lesion) False8negati!e results ma* occur if
the colla$se does not in!ol!e the hole lo'e; this situation ma* 'e secondar* to an incom$letel*
o'structi!e 'ronchial lesion or $artial !entilation of the lo'e)
Plateli#e atelectasis or $osto$erati!e atelectasis ma* often 'e missed on chest radiogra$hs'ecause it ma* 'e o'scured '* other thoracic structures) A false8negati!e diagnosis ma* also
occur if the $atient cannot ta#e a full 'reath or if the antero$osterior or lateral chest radiogra$h is
not a!aila'le)
Computed Tomography
Radiogra$hic changes of lo'ar colla$se are more o'!ious on CT scans than on $lain radiogra$hs)
CT scans are additionall* hel$ful in identif*ing and locali+ing an o'structing 'ronchial lesion)Correlation ith a chest radiogra$h hel$s in the e!aluation, as does careful e%amination of the
mediastinum, hilum, and $leura)
The $rimar* changes of lo'ar colla$se seen on CT scan are as follos:
"rregular narrowing or occlusion of a ronchus, indicating an ostructive loar collapse
Loe ecoming pie shaped rather than hemispherical on cross*section.
&ossile pro)ection of the loe as a *shaped structure where the apex is situated at theorigin of the affected ronchus
-verall increased opacity of the loe
&ossile ulge in the ad)acent fissure 'ie, the Golden sign of !(, caused y a mass
&attern of collapse affected y previous pleural adhesions and fluid or air in the pleural
space
&ossile infiltration of the entire loe y the tumor, giving it a loular, rather than wedge*
shaped, appearance
Right upper lobe collapse
The RBL is 'ordered mediall* '* the mediastinum, su$eriorl* '* the chest all, inferiorl* '* the
minor fissure, and $osteroinferiorl* '* the su$erior $ortion of the o'li4ue fissure)
6n CT scanning, RBL colla$se a$$ears as a right $aratracheal o$acit*, and the minor fissure
a$$ears conca!e laterall*) The RBL colla$ses against the mediastinum, and this is identified as a
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edge of uniform attenuation e%tending along the mediastinum to the anterior chest all)
Concomitant h*$erinflation of the middle and loer lo'es is $resent) A 'ulge in the contour of
the colla$sed RBL occurs secondar* to an endo'ronchial tumor and gi!es an S8sha$edconfiguration) Endo'ronchial o'struction is readil* identifia'le on the CT scan) &See the image
'elo)(
$his computed tomography scan shows a right upper loe collapse secondary to a right hilarmass. -n ronchoscopy, an endoronchial lesion that occluded the right upper loe ronchus
was seen.
Right middle lobe collapse
The RML is 'ounded mediall* '* the right heart 'order; anteriorl* and laterall* '* the chest
all; $osteriorl* '* the ma@or fissure; and su$eriorl*, the minor fissure)
As the RML colla$ses, the minor fissure shifts donard and the o'li4ue fissure is dis$laced
forard) ith a $rogressi!e loss of !olume, the middle lo'e colla$ses mediall* against the right
heart 'order) The colla$sed middle lo'e is a edge8sha$ed o$acit* that e%tends laterall* from thehilum toard the lateral chest all) ?t is 'ounded $osteriorl* '* the RLL and anteriorl* '* the
h*$erinflated RBL)
6n CT scans, a triangular o$acit* along the right heart 'order, ith the a$e% $ointing laterall*, isa characteristic finding) This a$$earance resem'les a tilted ice8cream cone)
Right lower lobe collapse
The RLL is 'ordered inferiorl* '* the hemidia$hragm, $osteriorl* and laterall* '* the chest all,
mediall* '* the heart and mediastinum, and anteriorl* '* the ma@or fissure)
The RLL generall* colla$ses in a $osteromedial direction against the $osterior mediastinum ands$ine) An endo'ronchial lesion ma* result in a con!e% lateral contour of the colla$sed RLL) The
ma@or fissure is dis$laced $osteromediall*)
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Left upper lobe collapse
The LBL is 'ounded mediall* '* the mediastinum, inferiorl* '* the left heart 'order, su$eriorl*
and laterall* '* the chest all, and $osteriorl* '* the ma@or fissure)
CT scanning shos the inferior location of the colla$sed lo'e and the shift of the RBL across themidline) LBL colla$se occurs anterosu$eriorl*) As o$$osed to the RBL, the colla$sed LBL
maintains more contact ith the anterior and lateral chest all) >*$eraeration of the su$erior
segment of the LLL ma* cause dis$lacement and su$erior mo!ement; these changes ma*account for $eriaortic lucenc* or the luftsichelsign on PA images) The LBL maintains its contact
ith the mediastinum and remains attached to the left hilum '* a edge of colla$sed tissue) The
anterosu$erior direction of the colla$se $ro@ects a edge8sha$ed triangular o$acit*, ith the a$e%
$ointing $osteriorl*) Endo'ronchial o'struction is easil* identified on CT scans)
Left lower lobe collapse
The LLL is 'ordered inferiorl* '* the hemidia$hragm, $osteriorl* and laterall* '* the chest all,mediall* '* the heart and mediastinum, and anteriorl* '* the ma@or fissure) The LLL colla$ses
mediall* toard the mediastinum and maintains contact ith the hemidia$hragms) The ma@or
fissure mo!es $osteriorl*) The LLL has an o$acit* situated against the $osterior mediastinum)CT scanning shos the atelectatic LLL in the inferior $osterior location) &See the image 'elo)(
Computed tomography scan shows a left lower loe collapse with a small pleural effusion.
Passive atelectasis
Passi!e atelectasis is li#el* the most common form of atelectasis) ?t occurs secondar* to the
$resence of air or fluid in the $leural s$ace) The CT scan easil* de$icts $leural effusion and theunderl*ing colla$sed lung) Differentiation ma* 'e made easier ith the use of contrast medium)
The $attern of colla$se secondar* to an endo'ronchial lesion is distorted in the $resence of$leural fluid) CT scanning ma* 'e of some hel$ in distinguishing 'enign causes from malignant
causes of $leural effusion) An irregular or nodular $leural surface ma* indicate an underl*ing
malignanc*)
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Cicatri!ation atelectasis
Scarring or fi'rosis from an inflammator* disease ma* lead to cicatri+ation colla$se, the most
common e%am$le 'eing $re!ious tu'erculosis)
?n cicatri+ation atelectasis, an endo'ronchial lesion is not seen and the 'ronchial tree in thecolla$sed lo'e is hidden) Mar#ed !olume loss is $resent, and 'ronchiectatic changes fre4uentl*
occur in the in!ol!ed lo'e)
Chronic middle8lo'e s*ndrome results in a $atent 'ronchus) Significant 'ronchiectasis and
scarring ma* 'e o'ser!ed in the colla$sed lo'e)
"dhesive atelectasis
Adhesi!e atelectasis occurs secondar* to the loss of surfactant) A common cause is lung colla$sedue to radiation $neumonitis) The CT scan a$$earance is a shar$ line demarcating the normal
$ulmonar* $arench*ma from the irradiated lung, hich is generall* $aramediastinal)
Replacement atelectasis
Re$lacement atelectasis is a form of !olume loss in hich the $ulmonar* $arench*ma is re$laced
'* tumor infiltration) ?n this situation, the CT scan shos uniform attenuation throughout thein!ol!ed lo'e) This finding generall* mimics consolidation) The tumor ma* gro into the edges
and structures, such as the chest all or mediastinum)
Rounded atelectasis
Rounded atelectasis is a form of chronic atelectasis that ma* a$$ear as a mass lesion on chest
radiogra$hs) Although this form is most commonl* associated ith as'estos e%$osure, other'enign conditions ma* also 'e $resent) These conditions include tu'erculosis, uremic $leuritis,
$ulmonar* infarction, and other causes of $leuritis) 9ecause of adhesions 'eteen the !isceral
$leura and $arietal $leura, the atelectatic lung 'ecomes tra$$ed and folds onto itself)
?n cases of rounded atelectasis, the CT scan results are diagnostic and definiti!e; therefore,further in!estigations to e%clude lung cancer are not re4uired) The CT scan findings are a
$eri$heral o!al or edge8sha$ed attenuating area ith smooth lateral edges and a medial
irregular or ill8defined 'order that $oints to the hilum) Distortion and dis$lacement of the 'lood
!essels and 'ronchi a$$ear in a characteristic cur!ilinear configuration that leads to the roundedatelectasis &ie, comet8tail sign() ?n most cases, 'ronchograms are seen on the CT scan, and
calcification is also common) &See the image 'elo)(
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Computed tomography scan demonstrating rounded atelectasis in a patient exposed to
asestos. $his image shows a peripheral pleural*ased opacity with crowding of the
ronchovascular structures in the comet*tail sign.
Degree of confidence
The common etiologies of lo'ar colla$se include central endo'ronchial tumor, long8standinginfection, $leural disease, and $re!ious irradiation) CT scanning ma* $la* an im$ortant role in
differentiating o'structi!e endo'ronchial lesions from other forms of colla$se) 9* identif*ing the
e%act location of an endo'ronchial lesion and the $resence of $eri'ronchial s$read, CT scans
ma* 'e hel$ful in $lanning 'ronchosco$* and trans'ronchial 'io$s*) E!aluation of themediastinum, $leura, chest all, and adrenal glands $la*s a role in the staging $rocess)
?n e!aluating $atients ith radiogra$hicall* at*$ical forms of colla$se, CT scans further hel$ in
accuratel* delineating the colla$se and in identif*ing an* additional $atholog*) ., .-3 CT scans are
$articularl* hel$ful in $atients ho ha!e a $leural effusion associated ith atelectasis, and theseimages ha!e a significant ad!antage o!er $lain radiogra$hs in the assessment of $leural
malignanc*) Finall*, CT scans are es$eciall* useful in e!aluating $atients ith cicatri+ationatelectasis) These $atients ha!e underl*ing 'ronchiectasis and $resent ith at*$ical $lainradiogra$hic findings)
False positivesnegatives
Determining the cause of an endo'ronchial o'struction on the 'asis of CT scans alone ma* 'e
difficult) CT scans ma* not 'e useful in distinguishing among an endo'ronchial malignanc*, a
'enign tumor, mucus $lug, 'lood clot, and another nono$a4ue foreign 'od*) Significant lungcolla$se associated ith $leural effusion ma* not ha!e the characteristic findings of lo'ar
colla$se; therefore, discerning hether an endo'ronchial lesion is $resent ma* 'e difficult)
CT scans ma* not 'e accurate in identif*ing 'enign and malignant causes of $leural effusion) CT
scanning is also limited in differentiating a consolidation secondar* to an infectious cause from are$lacement colla$se in hich a tumor has infiltrated the entire lo'e)
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CT scans do not o'!iate 'ronchosco$*, hich is a mandator* $rocedure to accuratel* locali+e an
endo'ronchial lesion and to characteri+e its nature) 9ronchosco$* ma* also ser!e a thera$eutic
role)
Magnetic Resonance Imaging
The role of MR? in differentiating a central o'structing tumor from a $eri$heral colla$sed lung
has 'een e!aluated) T.8eighted se4uences are useful in identif*ing an endo'ronchial lesion)-5,..3 9ecause li$id8laden macro$hages accumulate in the su'acute $hase of lo'ar colla$se,
$rogressi!e l*m$hoc*tic infiltration and collagen de$osition occur ithin the $ulmonar*
interstitium) ?n these situations in hich the ratio of lung to fat in the colla$sed lung is greaterthan -, T.8eighted MR?s are most useful in differentiating a tumor from lung colla$se)
MR? ma* ha!e a role in the e!aluation of adhesi!e atelectasis) T.8eighted se4uences ma* hel$
in differentiating fi'rosis secondar* to an endo'ronchial o'struction from radiation8induced
$neumonitis) Furthermore, MR? ma* ha!e a role in diagnosing rounded atelectasis 'ecause MR?s
ma* more accuratel* de$ict cur!ilinear !essels in the folded lung)./3
Degree of confidence
MR? is an e%cellent imaging modalit* in situations in hich intra!enous contrast material cannot
'e administered) MR?s ma* delineate the e%tent and the location of a tumor; this modalit* ma*
also ha!e a role hen CT scans are not hel$ful in differentiating 'eteen a tumor and acolla$sed lung)
?n a stud* of - $atients, MR? as useful in identif*ing a tumor due to a colla$sed lung in 1
&1
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Lobar Atelektasis Imaging
Penulis:Sat Sharma.MD,frcpc;Chief Editor:Eugene C Lin,MD
Gambaran singkat
7eadaan atele#tasis didiefinisi#an se'agai 'er#urangn*a !olume $aru, 'erasal dari
'ahasa *unani ateles dan e#tasis, *ang 'erarti adan*a e#s$ansi *ang tida# sem$urna) Atele#tasis
mem$egaruhi semua 'agian atau se'agian dari $aru, dan meru$a#an #asus radiologis *ang sering
ter@adi) Mengenal atele#atsis dari gam'aran radiologis sangat $enting #arena #emung#inan
adan*a #elainan lain *ang mengi#uti) 9e'era$a @enis atele#tasis a#an di@elas#an, setia$ @enis
memili#i 'entu# radiogra$hi#) Atele#tasis di#ategori#an men@adi o'stru#tif dan nono'tru#tif)
Obstruktif Atelektasis
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Adan*a o'stru#tif diantara al!eoli dan trachea menga#i'at#an adan*a rea'so$si dari gas
al!eolar, *ang men*e'a'#an te@adin*a atele#tasis o'stru#tif) 7eadaan o'stru#tif ini 'isa ter@adi
$ada 'ron#us #ecil dan 'esar, dan hal ini 'isa ter@adi #arena adan*a secondary dan 'enda asing,
Tumor @ina# mau$un tumor ganas, mucus plug, atau clot dari darah, ronchial transecion
firotic stenosis, dari granuloma atau inflamasi, ploychondritis, post rachytherapy atau
radiotherahy stenosisdan lesi o'stru#tif lain*a
Per#em'angan dari atele#tasis 'er#aitan dengan 'e'era$a factor, termasu#
$engem'angan dari collateral !entilasi dan #om$osisi dari gas ins$irasi) 6'stru#si dari 'ron#us
'esar men*e'a'#an ter@adin*a lo'ar atele#tasis, dan o'stru#tif dari 'ron#us #ecil men*e'a'#an
segmental atele#tasis) "am'aran dari atele#tasis tergantung $ada !entilasi #ontralateral, *ang
dise'a'#an oleh $ori #ohn dan #anal dari lam'ert
!ight middle loe "!ML# sydrome, meru$a#an 'entu# dari atele#tasis #roni#, 'iasan*a
ter@adi #om$resi dari 'ronchial dan o'stru#si *ang di#elilingi dari limfenodi dan @aringan $arut
'ronchial) 6'stru#si $artial dari 'ron#us dan adan*a infe#si *ang 'erulang men*e'a'#an
ter@adin*a atele#tasis #ronis dan $neumonitis a#ut atau #roni#)
Nonobstruktif Atelekatasis
Terle$asn*a $leura !isceralis dan $arientalis men*e'a'#an ter@adin*a atele#tasis non
o'stru#tif) Etiologin*a #emung#inan dise'a'#an #arena ada*a #om$resi dari $aru, hilangn*a
surfa#tan, ter@adin*a @aringan $arut atau infiltrati!e $ulmonar* disease) 9e'era$a @enis atela#tasis
non o'stru#tif di#etahui muncul dari 'e'era$a macam $en*e'a')
Ter@adin*a pleural effusion atau $nemothora#s men*e'a'#an terle$asn*a i#atan dari
$leura $arientalis dan !iseralis, dan men*e'a'#an rela#sasi atau atelectasis $asif) "a'ungan
elasitas dari $aru normal a#an mem$ertahan#an 'entu#, alau setelah ter@adin*a atele#tasis)
7ola$s lo'us tengah dan 'aah le'ih 'an*a# ter@adi dari$ada lo'us atas dengan adan*a efusi$leura sedang#an $ada lo'us atas le'ih sering ter#ena $nemothora#s)
7om$resi atele#tasis ter@adi #eti#a setia$ ruang *ang mengisi lesi rongga thora#s mene#an
$aru8$aru dan mema#sa udara #eluar dari al!eoli) Me#anisme ini miri$ dengan rela%ation
atelectasis)
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Adhesi!e atele#tasis meru$a#an hasil dari #e#urangan dari surfa#tan) Surfactant
menurun#an tegangan $ermu#aan al!eoli dan #arena itu memain#an $eran $enting dalam
mencegah ter@adin*a #ola$sn*a al!eoli) Penurunan $rodu#si atau ina#ti!asi surfa#tan, se$erti
*ang ter@adi dalam sindrom gangguan $erna$asan a#ut &$!DS( dan gangguan *ang sama,
men*e'a'#an #etida#sta'ilan al!eolar dan atele#tasis)
>asil $en*em'uhan atele#tasis meru$a#an se4uele @aringan $arut $aren#im $arah dan
'iasan*a dise'a'#an oleh $en*a#it granulomatosa atau necroti%ing pneumonia) 7ola$sn*a lo'ar
dari fase $en*em'uhan da$at 'eru$a o'stru#tif @i#a meli'at#an 'ron#us atau nono'stru#tif
#arena $roses fi'rosis $ada $aren#im $aru) Penggantian atele#tasis ter@adi #eti#a al!eoli dari
seluruh lo'us disi oleh tumor &misaln*a, #arsinoma sel 'ronchioal!eolar(, menga#i'at#an
hilangn*a !olume)
!ound atelaktasis, @uga dise'utfolded&lung syndromeatausindrom 'leso(sky, ter@adi dengan
#ola$sn*a $aru8$aru *ang disertai li$atan se#under hingga fi'rous 'and dan $erleng#etan $leura
!isceral) 7e@adian ini 'an*a# ter@adi $ada $e#er@a as'es &2185 < #asus() 7eluhan 'iasan*a
asim$tomati#, dan usia rata8rata munculn*a $en*a#it ini adalah 2 tahun) !ound $telektasis
meru$a#an $en*a#it *ang @ina#)
Pemeriksaan yang dipilih
Pemeri#saan radiografi dada umumn*a cu#u$ untu# mendiagnosa lo'ar atele#tasis dan
untu# identifi#asi ter@adin*a #ola$s lo'us) Radiografi dada @uga 'erguna dalam mendiagnosis
$lateli#e atele#tasis, atele#tasis $asca o$erasi, dan round atelektasis, serta untu# mengo'ser!asi
$er@alanan atele#tasis terse'ut) Se'agai contoh, radiografi dada da$at diguna#an untu#
menentu#an a$a#ah inter!ensi, se$erti fisiotera$i dada, telah menghasil#an $er'ai#an)
amun, dalam 'e'era$a situasi, temuan foto tora#s tida# 'isa diguna#an dalam diagnosti#)
>al ini umumn*a ter@adi #eti#a terda$atn*a cairan $ada $leura atau massa $ada $aru) Dalam
#asus terse'ut, Computer tomography "C)# scanning adalah studi $encitraan 'erguna untu#
'eri#utn*a) CT scan da$at diguna#an untu# menilai atele#tasis o'stru#tif, modalitas ini @uga
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mem'antu dalam menge!aluasi mediastinum, dinding dada, hilus, $leura, dan $aru8$aru *ang
'erde#atan)
Magnetic resonance imaging "M!*#tida# memili#i ma#na tertentu dalam diagnosis lo'ar
atele#tasis, #ecuali untu# mem'eda#an o'stru#tif dari atele#tasis nono'stru#tif)
Keterbatasan pemeriksaan
Se'uah efusi $leura *ang ter@adi 'ersamaan, massa $leura, atau massa $aru 'esar da$at
mem'atasi #emam$uan $emeri#saan radiografi dada dalam diagnosis atele#tasis)
7eti#a opacity asal, opacity hemitoraks, dan tanda8tanda lain dari atele#tasis tida# @elas,
untu# menentu#an a$a#ah o$acit* terse'ut efusi $leura atau #ola$s lo'us mung#in sulit) Dalam
situasi itu, CT scan da$at 'ermanfaat 'esar) Pening#atan #ontras intra!ena sering di$erlu#an
untu# $encitraan *ang te$at dan untu# mem'eda#an antara 'er'agai $en*e'a' atele#tasis)
7eter'atasan CT scan mung#in dalam mem'eda#an antara $en*e'a' o'stru#tif dan
nonostruktif atelektasis) Selain itu, CT scan tida# memili#i #emam$uan dalam menentu#an
a$a#ah lesi *ang mengham'at adalah tumor, mucus $lug, 'enda asing nono$a4ue, atau 'e#uan
darah)
Radiografi
Tanda8tanda langsung termasu# $emindahan celah dan #e#eruhan dari #ola$sn*a lo'us)
Tanda8tanda tida# langsung meli$uti:
Per$indahan dari hilus
Pergeseran mediastinum #e arah sisi *ang #ola$s
>ilangn*a !olume di hemitora#s i$silateral
Pening#atan diafragma i$silateral
Tulang rusu# *ang @ara#n*a sema#in de#at
7om$ensasi hi$erlucen dari lo'us *ang tersisa
Silhouettingdiafragma atau 'atas @antung
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Atelektasis Total
Atele#tasis total seluruh $aru8$aru ditandai dengan #ola$sn*a seluruh 'agian dari $aru8
$aru, *ang men*e'a'#an o$acifi#asi dari seluruh hemitora#s dan $ergeseran mediastinum
i$silateral) Pergeseran mediastinal memisah#an atele#tasis dari efusi $leura masif) &Lihat gam'ar
di 'aah)(
+amaran radiografi yang menunukkan adanya atelektasis komplet pada paru kiri
+amaran radiografi menunukkan adanya atelektasis komplit dari paru&paru kanan
Kolapsnya lobus bagian kanan atas
7ola$sn*a 'agian #anan atas lo'us &RBL( a#an 'ergeser #e medial dan su$erior, sehingga
ter@di ele!asi hilus #anan dan fisura minor) RBL @uga da$at ter@adi #ola$s secara lateral,menghasil#an o$acit* 'er'asis $leura *ang mung#in terlihat se$erti efusi $leura loculated)
Fisura minor dalam #ola$sn*a RBL 'iasan*a cem'ung $ada as$e# su$erior, teta$i
mung#in @uga muncul 'entu# ce#ung #arena adan*a lesi massa *ang mendasarin*a) ?ni dise'ut
+olden s sign&@uga di#enal se'agaigolden s signataus sign of the golden(
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Tenting dari $leura diafragma, dise'ut u-taphrenic peak sign, adalah tanda lain *ang
mem'antu diahnosis atele#tasis RBL) &Lihat gam'ar di 'aah)(
+amaran yang menunukkan lous kanan atas yang kolaps pada agian posterior dan inferior
olaps paru lous kanan atas. /oto thora- ini menunukkan hilangnya (olume paru pada lous atas,
pergeseran fisura hori%ontal ke atas, dan adanya ele(asi pada sisi kanan diafragma
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/oto thora- Lateral memperlihatkan kolaps pada lous kanan atas anterior dan superior. +amaran
radiopa0ue terlihat di anterior dan superior.
Kolaps lobus kanan tengah
7ola$s $ada lo'us #anan tengah $aru menga'ur#an 'atas #anan @antung $ada Foto thora%
PA &$osteroanterior() Pada foto thora% lateral mem$erlihat#an adan*a gam'aran triangular
radiopa0uemenutu$i @antung #arena $ergeseran fisura ma*or #eatas dan $ergeseran fisura minor
#e'aah) Pada #ola$s *ang 'erat, u#uran radio$a4ue 'er#urang dan #emung#inan gam'aran
*ang tam$a# tida# @elas) &lihat gam'ar di'aah(
Pada gamar menunukkan kolaps lous kanan tengah
/oto )hora- Posteroanterior "kiri# dan foto thora- lateral "kanan#. olaps lous kanan tengah
mengaurkan atas kanan antung pada /oto P$ dan tampak gamaran radiopa0ue yang terepit padafoto lateral.
Kolaps lobus kanan baah
7ola$s $ada lo'us #anan 'aah $aru a#an menggeser sisi $osterior dan inferior,
menghasil#an gam'aran triangular radiopa0ue*ang menga'ur#an arteri $ulmonalis $ada lo'us
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#anan 'aah) Adan*a Fisura ma*or, normaln*a tida# terlihat $ada foto thora% PA, men@elas#an
adan*a #ola$s lo'us #anan 'aah) Stru#tur mediastinum su$erior a#an 'ergeser #e #anan,
mem'entu# tanda segitiga $ada sisi su$erior) Pada sisi lateral, #ola$s lo'us #anan 'aah
menga'ur#an se$ertiga $osterior hemidiafragma #anan dan menun@u##an adan*a gam'aran
radio$a4ue *ang seharusn*a radiolusen $ada daerah terse'ut) &lihat gam'ar di'aah(
+amar menunukkan kolaps lous kanan a1ah sisi anterior dan superior
+amar memperlihatkan kolaps medial lingular
/oto )hora- lateral memperlihatkan kolaps lous kanan a1ah yang menyeakan hilangnya (olume
paru, mengaurkan sisi kanan diafragma dan tampak gamaran radiopa0ue pada agian posterior.
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Atelectasis lo'us #anan tengah dan lo'us #anan 'aah *ang ter@adi 'ersamaan da$at
terlihat se'agai ele!asi hemidiafragma #anan atau efusi su'$ulmoni#) Dengan mengidentifi#asi
adan*a fisura da$at mem'im'ing menu@u diagnosis *ang a#urat) &lihat gam'ar di'aah(
/oto thora- memperlihatkan kolaps lous kanan a1ah dan lous kanan tengah. Paru kiri
hypere-panded.
Kolaps lobus kiri atas
Pada atelectasis lo'us #iri atas a#an menggeser sisi anterior dan su$erior) $ada se'agian
#asus, segmen su$erior *ang mengalami hypere-panded$ada lo'us #iri 'aah a#an menem$ati
ruang diantara atelectasis lo'us atas dan arcus aorta) >al terse'ut a#an mem'eri#an gam'aran
'ulan sa'it $ada $aru *ang 'an*a# terisi udara &aerated(, dise'ut dengan luftsichel sign)
Pada Foto Thora% PA, atelectasis lo'us #iri atas menun@u##an gam'aran sedi#it
radio$a4ue $ada hemithora% #iri atas dan menga'ur#an 'atas #iri @antung) Pada Foto Thora%
lateral, fisura ma*or a#an 'ergeser $ada sisi anterior di'ela#ang sternum)&lihat gam'ar di'aah(
+amar menunukkan adanya kolaps lous kiri atas agian superior dan anterior
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olaps lous kiri atas. /oto thora- menunukkan adanya gamaran radiopa0ue yang erada dekat aortic
kno, hemithora- kiri yang leih kecil, dan pergeseran mediastinal. $danya tanda luftsichel dan
hypere-tension pada segmen superior lous kiri a1ah, yang kemudian menempati apeks kiri.
+amaran radiografi yang menunukkan adanya kolaps lous atas,yang menghasilkan opacity yang
meluas keatas dan keluar dari hilus.)anda tamahan yang menunukkan adanya kehilangan (olume dari
hemithoraks kiri dan adanya penyempitan dari rusuk yang merupakan ukti dari gamaran radiografi ini
$danya gamaran radiolograph yang menunukkan adanya kolaps agian lous kiri anterior
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Kolaps lobus kiri baah
Pada gam'aran Frontal, adan*a $ening#atan gam'aran radio$a4ue $ada 'agian
retro#ardia *ang menga'ur#an arteri $ulmonalis lo'us #iri 'aah dan hemidiafragma #iri)
Stru#tur hilus a#an 'ergeser #e 'aah, dan rotasi @antung men*e'a'#an lurusn*a $inggang
@antung, *ang mana di#etahui se'agai tanda flat&1aist) Mediastinum su$erior mung#in a#an
'ergeser dan menga'ur#an gam'aran arcus aorta; hal ini adalah tanda top&of&the&aortic&kno)
Pada Foto thora% lateral, tam$a# 'a*angan radio$a4ue $ada se$ertiga $osterior diafragma
#iri, dan adan*a gam'aran radio$a4ue a'normal $ada 'agian *ang seharusn*a radiolusent) &lihat
gam'ar di'aah(
olaps pada lous kiri a1ah. pada foto thora- menunukkkan erkurangnya (olume paru pada sisi kiri,
ele(asi dan adanya ayangan pada diafragma kiri dan gamaran radiopa0ue di elakang antung "sail&
sign#
Rounded Atelektasis
Pada #asus rounded atelectasis, atelectasis segmental atau su'segmental a#an ter@adi
$ene'alan $leura !isceral se#under dan @aringan $aru a#an terdesa#)
Manifestasi !ounded $telektasis adalah adan*a massa su'$leura, dan stru#tur
'ron#o!as#uler *ang men*e'ar #eluar dari massa menu@u #e hillus) 7emung#inan a#an tam$a#
@uga $la# $leura $arietal) Tam$a#n*a 'a*angan 'ron#o!as#uler se$erti $usaran, dise'ut tanda
e#or #omet dan a#an menun@ang diagnosis)
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Tingkat Kepercayaan
Foto thora% memili#i sensiti!itas *ang tinggi @i#a tanda langsung dari Atele#tasis da$at
ditemu#an) Pemeri#saan *ang le'ih s$esifi# adalah identifi#asi dari fisura *ang 'er$indah tem$at
#arena da$at mem'eri#an manfaat *ang signifi#an dalam mendiagnosis lo'us *ang #ola$s)
Terlihatn*a tanda8tanda *ang tida# langsung i#ut mem$er#uat tanda8tanda langsung untu#
mendiagnosis atelectasis)
False positive atau negative
9er#urangn*a !olume $aru dera@at sedang memung#inan ter@adin*a #onsolidasi lo'us
se#under; hal ini da$at mengarah $ada diagnosis *ang salah untu# lo'us *ang #ola$s)
Efusi $leura terlo#alisasi atau efusi $leura dengan #ola$s *ang $asif memung#in#an
ter@adi salah identifi#asi se'agai #ola$s se#under dari lesi endo'ron#ial) >asil false negati(e
mung#in ter@adi @i#a #ola$s tida# dii#uti seluruh 'agian lo'us; #eadaan ini #emung#inan adalah
$roses se#under dari o'stru#si in#om$lit lesi 'ron#ial atau adan*a $arsal !entilasi $ada lo'us)
Platelike atelectasisatau atelectasis postoperati(esering tida# tam$a# $ada foto thora%
#arena #emung#inan di#a'ur#an oleh stru#tur thora% *ang lain)false negati(e@uga da$at ter@adi
@i#a $asien tida# 'isa menari# nafas ma#simal atau @i#a foto thora% antero$osterior atau lateral
tida# da$at dila#u#an)
!omputer tomografi
"am'aran radiografi untu# lo'us *ang #ola$s le'ih @elas dengan mengguna#an C) scans
di'anding#an dengan foto $olos) C) scans@uga 'ermanfaat untu# identifi#asi dan mencari tahu
lo#asi dari o'stru#si lesi 'ron#ial. C) scans'er#orelasi dengan Foto Thora% dalam mem'antu
menge!aluasi, se$erti haln*a $emeri#saan *ang teliti $ada mediastinum, hillus dan $leura)
"am'aran $rimer lo'us #ola$s *ang terlihat $ada C) scans:
Pen*em$itan irregular atau o#lusi 'ron#us, menun@u##an lo'us #ola$s o'stru#tif
Lo'us 'er'entu# se$erti $ie di'anding#an hemis$eris $ada 'agian 'erlaanan
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7emung#inan tam$a# gam'aran stru#tur 'er'entu# $ada lo'us dimana $unca#n*a
'erasal dari 'ron#us *ang ter#ena
Secara #eseluruhan ter@adi $ening#atan radio$a4ue $ada lo'us
7emung#inan ter@adi $enon@olan $ada fisura *ang 'erde#atan &+olden sign of S(*ang dise'a'#an oleh Massa
Adan*a Pola #ola$s oleh adan*a adhesi $leura se'elumn*a dan cairan atau udara
$ada ruang $leura
#emung#inan adan*a infiltrasi dari seluruh lo'us oleh #arena tumor, mem'eri#an
gam'aran lo'us *ang terdesa#
Kolaps lobus kanan atas
RBL ini 'er'atasan dengan mediastinum $ada sisi medial, sisi su$erior oleh dinding
dada, sisi inferior oleh fissure minor, dan sisi $osterioinferior oleh 'agian su$erior o'li4ue)
Pada CT scan, Colaps !2Lterlihat se'agai o$asitas $aratra#eal #anan dan fisura minor
a#an muncul ce#ung #e arah lateral) RBL *ang #ola$s a#an 'erlaanan dengan mediastinum,
dan ini diidentifi#asi se'agai irisan atenuasi merata *ang mem'entang se$an@ang mediastinum #e
dinding dada anterior) Terda$at hi$erinflasi secara 'ersamaan dari lo'us tengah dan 'aah)
Se'uah ton@olan di #ontur RBL *ang #ola$s ter@adi secara se#under a#i'at tumor endo'ron#ial
dan mem'eri#an gam'aran S&shaped) 6'stru#si endo'ron#ial ini mudah diidentifi#asi $ada CT
scan) &Lihat gam'ar di 'aah()
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Computed tomography scan ini menunukkan lous kanan atas dari kolaps sekunder ke arah massa hilus
kanan. Pada ronkoskopi, lesi endoronkial yang tersumat lous kanan atas ronkus akan terlihat.
Kolaps lobus medial kanan
RML di'atasi #e medial oleh 'atas @antung #anan, anterior dan lateral oleh dinding dada,
$osterior oleh fisura ma*or, dan su$erior oleh fisura minor)
7arena RML #ola$s, fisura minor 'ergeser #e 'aah dan fisura o'li4ue 'er$indah #e
de$an) Dengan hilangn*a !olume *ang $rogresif, lo'us tengah *ang #ola$s a#an #earah medial
menu@u 'atas @antung #anan) Lo'us tengah *ang #ola$s mem'eri#an gam'aran o$acit*
'er'entu# 'a@i *ang meman@ang #e lateral dari hilus menu@u dinding dada lateral) >al ini di'atasi
di $osterior oleh RLL dan anterior oleh h*$erinflasi dari RBL)
Pada CT scan, terda$at o$acitas 'er'entu# segitiga se$an@ang $er'atasan @antung #anan,
dengan menun@u# a$e% #e lateral, ini adalah $enemuan *ang #has) Penam$a#ann*a men*eru$ai
es #rim cone)
Kolaps lobus kanan baah
RLL 'er'atasan dengan hemidia$hragm $ada 'agian inferior, $osterior dan lateral oleh
dinding dada, di medial oleh @antung dan mediastinum, dan anterior oleh fisura ma*or)
7ola$s RLL umumn*a #e arah $osteromedial terhada$ mediastinum $osterior dan
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Computed tomography scan dapat memperlihatkan lous kiri a1ah yang kolaps dengan efusi
pleura minimal
Atelektasis pasif
Atele#tasis $asif #emung#inan 'entu# $aling umum dari atele#tasis) >al ini meru$a#an
se#under terhada$ adan*a udara atau cairan di rongga $leura) CT scan dengan mudah
menggam'ar#an efusi $leura dan $aru8$aru #ola$s *ang mendasari) Diferensiasi da$at dila#u#an
le'ih mudah dengan mengguna#an media #ontras) Pola dari #ola$s se#under lesi endo'ron#ial
terdistorsi dengan adan*a cairan $leura) CT scan mung#in ada manfaatn*a dalam mem'eda#an
$en*e'a' @ina# dari $en*e'a' ganas efusi $leura) Se'uah $ermu#aan $leura tida# teratur atau
nodular mung#in menun@u##an #eganasan)
"ikatriks atelektasis
aringan $arut atau fi'rosis dari $en*a#it radang da$at men@adi sem'uh #em'ali, contoh *ang
$aling umum adalah T9 lama
Pada si#atri#s atele#tasis, lesi endo'ron#ial tida# terlihat dan 'ron#ial $ada lo'us *ang #ola$s
a#an tersem'un*i) Tanda #ehilangan !olume muncul, dan $eru'ahan 'ronchie#tati# sering
ter@adi dilo'us *ang terli'at
>asil dari sindrom #roni# lo'us tengah8 terlihat $ada $atent 'ronchus) 9ron#ie#tasis *ang
signifi#an dan @aringan $arut da$at diamati di lo'us *ang #ola$s )
Adesif atelektasis
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Atele#tasis Adhesi!e muncul se#under terhada$ hilangn*a surfa#tan) Pen*e'a' umum
adalah #ola$s $aru #arena $neumonitis radiasi) CT scan menam$il#an garis ta@am *ang
mem'atasi $aren#im $aru *ang normal dari $aru8$aru iradiasi, *ang umumn*a terleta# di
$aramediastinal) Atele#tasis Adhesi!e muncul se#under terhada$ hilangn*a surfa#tan) Pen*e'a'
umum adalah #ola$s $aru #arena $neumonitis radiasi) CT scan menam$il#an garis ta@am *ang
mem'atasi $aren#im $aru *ang normal dari $aru8$aru iradiasi, *ang umumn*a terleta# di
$aramediastinal)
Replacement atelectasis
!eplacement atelektasis adalah 'entu# #ehilangan !olume di mana $aren#im $aru
diganti#an oleh infiltrasi tumor) Pada situasi ini, CT scan menun@u##an atenuasi seragam di
seluruh lo'us *ang terli'at ) Temuan ini umumn*a men*eru$ai #onsolidasi) Tumor da$at
'er#em'ang men@adi 'agian te$i dan stru#tur, se$erti dinding dada atau mediastinum)
Rounded atelectasis
!ounded atelectasisadalah 'entu# atele#tasis #ronis *ang mung#in muncul se'agai lesi
massa $ada radiografi dada) Mes#i$un ini adalah 'entu# *ang $aling sering di#ait#an dengan
$a$aran as'es, #ondisi @ina# lainn*a mung#in @uga muncul) 7ondisi ini termasu# T9C, $leuritis
uremi#, infar# $aru, dan $en*e'a' lain dari $leuritis) 7arena adhesi antara !isceral $leura
$arietal dan $leura, $aru8$aru *ang atele#tasis men@adi ter$erang#a$ dan terli$at #e dirin*a
sendiri)
Pada #asus rounded atelectasis, hasil dari CT scan adalah diagnosti# dan definitif,
sehingga $en*elidi#an le'ih lan@ut untu# men*ing#ir#an #an#er $aru8$aru tida# di$erlu#an)
Temuan dari CT Scan adalah o!al $erifer atau daerah attenuating 'er'entu# 'a@i dengan te$i
lateral *ang halus dan 'atas medial *ang tida# teratur atau tida# @elas *ang mengarah $ada hilus)
Distorsi dan $ergeseran dari $em'uluh darah dan 'ron#us muncul dalam #onfigurasi leng#ung
#has *ang mengarah #e rounded atelectasis &*aitu, comet8tail sign () Dalam #e'an*a#an #asus,
'ronchograms terlihat $ada CT scan, dan #alsifi#asi @uga sering ter@adi) &Lihat gam'ar di 'aah)(
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Computed tomography scan mem$erlihat#an rounded atelectasis $ada $asien *ang
ter$a$ar as'es) "am'ar ini menun@u##an $leura $eri$heral dengan 'asis o$asitas dengan
cro1dingstru#tur 'roncho!ascular dalam comet&tail sign8)
Tingkat kepercayaan
Etiologi ter@adin*a #ola$s umumn*a adalah tumor endo'ron#ial sentral, infe#si lama,
$en*a#it $leura dan radiasi se'elumn*a)CT scan memili#i $eranan $enting dalam mem'eda#an
o'stru#si lesi endo'ron#ial dengan 'entu# lesi #ola$s lain) Dengan menentu#an lo#asi *ang te$at
dari lesi endo'ron#ial dan adan*a $en*e'aran $eri'ron#ial, CT Scan mung#in da$at mem'antu
dalam $erancanaan 'ron#os#o$i dan 'io$s* trans'ron#ial) E!aluasi mediastinum, $leura, dindingdada dan #elen@ar adrenal 'er$eran dalam $roses $en*em'uhan)
Dalam menge!aluasi $asien dengan 'entu# radiografi ati$i#al #ola$s, CT Scan
mem'antu le'ih lan@ut untu# melihat #ola$s dengan a#urat dan mengindentifi#asi $atologi
tam'ahan) CT Scan sangat mem'antu $asien dengan efusi $leura *ang 'erhu'ungan dengan
atele#tasis, dan gam'aran ini memili#i #euntungan *ang signifi#an di'anding#an radiografi
$olos dalam $enilaian #eganasan $leura) A#hirn*a, CT Scan sangat 'erguna dalam menge!aluasi
$asien dengan atele#tasis men@adi sem'uh #em'ali) Pasien ini memili#i 'ron#ie#tasis danmuncul dengan gam'aran radiografi ati$i#al $lain)
False positif / negative
Menentu#an $en*e'a' o'stru#si endo'ron#ial 'erdasar#an CT scan sa@a mung#in sulit)
CT scan mung#in tida# 'erguna dalam mem'eda#an antara #eganasan endo'ron#ial, tumor
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@ina#, sum'atan lendir, 'e#uan darah, dan 'enda asing lain nono$a4ue) 7ola$s $aru *ang
signifi#an ter#ait dengan efusi $leura mung#in tida# ditemu#an #ara#teristi# #ola$s lo'us, oleh
se'a' itu mem'eda#an a$a#ah lesi endo'ron#ial ini ada mung#in a#an sulit)
CT scan mung#in tida# a#urat dalam mengidentifi#asi $en*e'a' @ina# dan ganas dari
efusi $leura) CT scan @uga ter'atas dalam mem'eda#an #onsolidasi se#under $en*e'a' infe#si
dari #ola$s dimana tumor telah masu# #e seluruh lo'us)
CT Scan tida# men*ing#ir#an 'ron#os#o$i, *ang meru$a#an $rosedur a@i' secara
a#urat mengetahui lesi endo'ron#ial serta ciri dan sifatn*a) 9ron#os#o$i @uga da$at 'er$eran
tera$euti#)
Magnetic Resonance Imaging
Peran MR? dalam mem'eda#an tumor sentral *ang mengham'at #ola$sn*a $aru8$aru di
$erifer telah diteliti) MR? T.8eighted 'erguna dalam mengidentifi#asi lesi endo'ron#ial)
#arena magrofag 'ermuatan li$id tera#umulasi dalam fase su'a#ut #ola$sn*a lu'us, infiltrasi
limfositi# $rogresif dan de$osisi #olagen ter@adi dalam interstitium $aru) Dalam #eadaan dimana
rasio lema# $aru #ola$s le'ih 'esar dari -. M!* )3&1eighted *ang $aling 'erguna dalam
mem'eda#an tumor dengan #ola$s $aru)
MR? mung#in memili#i $eran dalam menge!aluasi atele#tasis adhesi!e) M!* )3&
1eightedda$at mem'antu dalam mem'eda#an fi'rosis se#under a#i'at o'stru#si endo'ron#ial
dari radiasi $neumonitis) Selain itu, MR? memili#i $eran dalam mendiagnosa atele#tasis *ang
luas #arena MR? da$at le'ih a#urat menggam'ar#an $em'uluh darah di $aru8$aru)
Tingkat kepercayaan
MR? adalah modalitas imaging *ang sangat 'ai# dimana 'ahan #ontras intra!ena tida#
$erlu di'eri#an) MR? da$at menggam'ar#an luas dan lo#asi tumor) Modalitas ini @uga memili#i
$eran #eti#a CT scan tida# mem'antu dalam mem'eda#an antara tumor dengan #ola$s $aru)
Dalam suatu $enelitian terhada$ - $asien, MR? 'erfungsi dalam mengidentifi#asi tumor
a#i'at #ola$s $aru 1 &1
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'erhasil mem'eda#an antara tumor dengan #ola$s $aru &