ct applications in chest pathology
TRANSCRIPT
-
8/17/2019 CT Applications in Chest Pathology
1/16
CT Applications in Chest Pathology
Objectives are as follows,
• List the types of CT
• List the indications of chest CT
• Understand the applications of chest CT
• Identify the radiological signs of common chest diseases on CT
Basics of CT
• Two dimensional representation of a three dimensional slice
• Internal structure of the organ can be reconstructed from multiple slices
•
Image display settings can be varied by adjusting WW & WL
Lung window
Mediastinal window soft tissue window!
"one window
Types of CT Scans are,
-
8/17/2019 CT Applications in Chest Pathology
2/16
• Conventional CT
• #igh resolution CT
Conventional CT Vs HRCT
• Conventional$ % to ' mm thic( slices are obtained contiguously) imaging''* of the lung
• HRCT$ $+,mm thin slices of lung are obtained at non$contiguous intervals)
usually to - cm apart) throughout the whole lung+ + .nly , to '* of the
lung is sampled
Indications of Chest CT
• /valuation of an abnormality identi0ed on conventional radiographs $ 1olitary
pulmonary nodule2 lung tumour2mediastinal mass
• 3iagnosing & 1taging of Lung Cancer
• 3etection of occult pulmonary metastases
• 3etection of mediastinal nodes 2masses
• 3istinction of empyema from peripheral lung abscess
• 3etection and evaluation of aortic disease
• 4ulmonary embolism
• #aemoptysis
Applications of CT
1 !etection of "#n$ T#%o#rs-+ 3iagnosis%+ 5natomic e6tent of disease $Intra and2or e6tra thoracic disease e6tent ) T7M
descriptors8+ 3ecision of therapeutic strategy $1urgery $vs$ Chemotherapy $vs$ 4alliative
Care 9esectability 2 Irresectability,+ Image guided biopsies
Lung tumours
-
8/17/2019 CT Applications in Chest Pathology
3/16
"enign tumours $ #armatoma) 5denoma) 5: Malformation
Malignant tumours$ 4rimary "ronchial Ca) 5lveolar cell Ca!) 1econdary
Beni$n t#%o#rs& Har%ato%a
• '( of all solitary p#l%onary nod#les are har%ato%as
• It is the %ost co%%on beni$n l#n$ t#%o#r
• They are %ostly asy%pto%atic
Har%ato%a
• 9ound) smooth mass $ increase in si;e slowly
• Calci0cation in ,* $ pathognomonic if popcorn type
•
-
8/17/2019 CT Applications in Chest Pathology
4/16
+ 5ssess the primary tumour
-+ 5ssess the secondary e>ect 2complications
%+ 5ssess the nodal2 other metastasis
CT appearances in pri%ary %ali$nant t#%o#r
+ 3ense irregular hilar opacity
-+ 3ense peripheral opacity
%+ 3ense irregularly cavitating lesion
8+ #ilar opacity with collapse of a segment 2whole lung
*ali$nant t#%o#r&Secondary e+ects
+ 4leural e>usion
-+ Mediastinal widening
%+ .steolytic lesions of the rib
8+ 3iaphragmatic paralysis
!etection of "#n$ Cancer lain Radio$raphy vs CT
• Contrast resolution of CT is superior to plain chest radiography
• 1igni0cantly more nodules detected on CT
The Stages of Lung Cancer
•
1tage I -o nodal %etastases and s#r$ically re%ovable
-
8/17/2019 CT Applications in Chest Pathology
5/16
• 1tage II )dds hilar ly%ph node involve%ent .II)/ or resectable chest
wall0%ediastinal involve%ent .IIB/
• 1tage III 5 2tensive b#t resectable disease
• 1tage III " 2tensive b#t irresectable by conventional criteria b#t still
con3ned to chest, therefore consider radical radiotherapy
• 1tage I: !istant %etastases
The Staging of Lung Cancer: International Staging System
PRIMARY TUMUR !T"
• T !ia%eter ≤ 4c%s, s#rro#nded by l#n$ 0visceral ple#ra -o involve%ent of
lobar bronchi
•
T-54c% dia%eter6 involves %ain bronch#s b#t≥
7c% distal to carina6 invadesvisceral ple#ra6 associated with atelectasis or obstr#ctive pne#%onitis e2tendin$ to
hila b#t not involvin$ entire l#n$
• T#T#%o#r of any si8e b#t with invasion of9 chest wall,diaphra$%, %ediastinal ple#ra
parietal ple#ra, parietal pericardi#%, or t#%o#r in %ain bronch#s :7c% fro% carina
b#t not involvin$ carina6 or atelectasis 0 obstr#ctive pne#%onitis of entire l#n$
-
8/17/2019 CT Applications in Chest Pathology
6/16
T2T
1
• T$T#%o#r of any si8e b#t with invasion of9 heart, $reat vessels, trachea,
oesopha$#s, vertebral body, carina6 t#%o#r with %ali$nant ple#ral 0 pericardial
e+#sion6 or with satellite t#%o#r nod#le.s/ in ipsilateral pri%ary&t#%o#r lobe
The CT Staging of Lung Cancer? T1 vers#s T7 lesions
The CT Staging of Lung Cancer? T1 0 T7 lesions
-
8/17/2019 CT Applications in Chest Pathology
7/16
The CT Staging of Lung Cancer? T4 0 T; lesions
T%
S#perior s#lc#s t#%o#rs
The CT Staging of Lung Cancer? -odal Sta$in$
• 7. -one
• 7 Ipsilateral hilar
• 7- Ipsilateral %ediastinal .incl s#bcarinal/
• 7% Contralateral %ediastinal 0 hilar or s#praclavic#lar
%etection of Lung Cancer& BIOS
-
8/17/2019 CT Applications in Chest Pathology
8/16
*etastases in "#n$ Cancer
"iver %%$%*
)drenals -'$%%*
Brain D$-D*
Bone ,$-*
Key point
CT remains the mainstay in the non$invasive staging of lung cancerE
Mediastinal masses
• 57T/9I.9 M/3I51TI7UM
T#FM.M5
T/95T.M5
I7T95T#.95CIC T#F9.I3 /7L59G/M/7T
LFM4#.M5 !# T's an( an L"
-
8/17/2019 CT Applications in Chest Pathology
9/16
.T#/9 $ LFM4#57GI.M5
57/U9F1M .< 51C/73I7G 5.9T5
*iddle %ediastini#% = *asses
• Merge with hilae and cardiac borders
• Lymphadenopathy
• "ronchogenic cyst
• 5ortic aneurysm
• Most middle mediastinal masses are due to enlarged nodes+
osterior %ediastinal %asses
•
7eurogenic tumour
• /6tramedullary haemopoeisis
• 9eticulosis) myeloma
• 4aravertebral abscess
• /nlarged paravertebral lymph nodes
• #aematoma following injury to the spine
• 5ortic aneurysm
• #iatus hernia
• 3ilated oesophagus in achalasia
Thy%o%a = CT
-
8/17/2019 CT Applications in Chest Pathology
10/16
Retrosternal $oiter
Commonest pleural masses
• Mesothelio)a: It is a di>use or localised pleural mass+ Large pleural e>usions are
common+ May have associated pleural pla=ues
• Pleural )etastases $ often obscured by the accompanying e>usion
-
8/17/2019 CT Applications in Chest Pathology
11/16
*ali$nant %esothelio%a
"#n$ )bscess
)ortic ane#rys%
-
8/17/2019 CT Applications in Chest Pathology
12/16
#l%onary e%bolis%
In(ications of Chest HRCT
• 3etection of lung disease in patient with pulmonary signs and symptoms or
abnormal pulm function test but normal or e=uivocal CH9
– /mphysema) /6trinisic allergic alveolitis) small airway disease)
immunocompromised patient
• /valuation of di>usely abnormal CH9
– Cystic 0brosis) 1arcoidosis) interstitial lung disease #istocytosis H) 5931
-
8/17/2019 CT Applications in Chest Pathology
13/16
HRCT -or%al l#n$
Basic HRCT Patterns
• Lines
• 7odules
• Consolidation
• Ground$glass .pacity
• Cysts
Linear a*nor)alities
a! thic(ened interlobular septa
b! bronchovascular interstitial thic(ening
c! reticular change
e+g
-
8/17/2019 CT Applications in Chest Pathology
14/16
>ibrosin$ alveolitis
"y%phan$itic t#%o#r
-od#les
• 5 nodule is a rounded density that does not correspond to a vessel+
• The anatomic distribution of nodules$$centrilo*ular) ran(o)) or interstitial$$helps
to identify potential causes
e+g$ bronchopneumonia gives nodules in a centrilobular distribution
-
8/17/2019 CT Applications in Chest Pathology
15/16
-od#les = Infective
?ro#nd $lass opacity
• 5 ha;y opacity that does not obscure the associated pulmonary vessels+ This
appearance results from parenchymal abnormalities that are below the spatial
resolution of #9CT+
• /+g+ alveolar wall inammation or thic(ening) with partial air$space 0lling) or with
some combination of the two+
?ro#nd $lass& In@#en8a pne#%onia
-
8/17/2019 CT Applications in Chest Pathology
16/16
Cysts
• 9ounded structure that is 0lled with air and usually has a thin wall+
• The cyst contents are as dar( as air surrounding the patient
• /+g+Cystic bronchiectasis
Chronic interstitial 0brosis subpleural honeycombing!
LangerhanJs cell #istiocytosis
Lymphangioleiomyomatosis
Cystic Bronchiectasis
Consolidation