X Ray Chest in CAP

Dr G R Sethi

Questions Does it confirm pneumonia? Is it necessary for diagnosis of CAP? What are the radiological patterns in CAP? Can we differentiate Viral from Bacterial? Can we identify individual/specific

organism? What are the mimickers of pneumonia?

Does it confirm pneumonia?

CAP is a clinical diagnosis. X Ray Chest may be normal in some.

Is it necessary for diagnosis of CAP?

RTI guidelines suggest that It is not necessary in all cases

particularly non severe cases It should be done if

If diagnosis is ambiguous It is a complicated pneumonia If child does not improve/deteriorates in 48

hours

What are the radiological patterns in CAP?

Airways

Air Spaces

Interstitium

Hyperaeration Br wall thickening Atelectasis Irregular aeration

Parenchymal opacity Acinar opacity Airbronchogram

Fine linear markings Interlobular septal

thickening Small nodular opacities

Can we differentiate Viral from Bacterial?

Radiographic – pathologic correlation is imperfect.

Alveolar airspace pneumonia is more likely to be bacterial

Hyperinflation with interstitial could mean viral

We can narrow down the etiologic possibilities by adding clinical and lab

Using combination of criteria

Total no. of cases of LRTI:80

Probable Viral etiology of LRTI : 65

Probable Bacterial etiology of LRTI : 05

Antibiotic added later during the course of treatment

: 10

Hb : 10.9 gm/dl TLC : 9800 DLC : P56L40M2E2

PC : 1.80 lakh CRP : -VE

Sadia, 6mo F Fever, cough, Wheeze- 4

weeks Treated with antibiotics

because of infiltrates

Hb : 9.7 gm/dl TLC : 17200 DLC : P78L22M0E0

PC : 1.76 lakh CRP : +VE

Hb : 10.1 gm/dl TLC : 12400 DLC : P56L42M2E0 PC : 1.76 lakh CRP : -VE

DAY 4

Hb : 9.6 gm/dlTLC : 17900DLC : P81L16M1E2PC : 2.5 lakhsCRP : +VE

Localization

Position of opacity in AP/PA view Silhouette sign Lateral X Ray

Hb : 10.7 gm/dl TLC : 18600 DLC : P87L12M1E1

PC : 2.2 lakh CRP : +VE

Hb : 10.8 gm/dl TLC : 16800 DLC : P80L17M1E2

PC : 2.2 lakh CRP : +VE

Specific Bacterial Etiology S Pneumoniae & Kliebsella

Mycoplasma S Aureus Gram –ve bacteria

Airspace, lobar

Bronchopneumonia, lobular

Additiona findings in Kliebsella and Staph

Mimickers

Thank you very much