1 - CXR Interpretation

patient positions for x-ray

• posterior-anterior (PA)

best x-ray position

• patient upright

• full inspiration (diaphragm to rib 6 in front, to ribs 9-11 in back)

• can see fluid easier

• scapulae out of way

• less magnification than AP

patient positions for x-ray

• lateral

x-ray position

• can see behind heart and diaphragmatic dome

• can locate organs/densities in 3 dimensions

• left side to reduce heart magnification

• right hemidiaphragm higher than left

patient positions for x-ray

• anterior-posterior (AP)

x-ray position

• usually for bed-bound patients

• cardiac shadow magnified

• scapulae seen

• poor inflation

patient positions for x-ray

• lateral decubitus

x-ray position

• patient stands on right/left side

• can diagnose pleural effusion

patient positions for x-ray

• lateral neck

x-ray position

• can diagnose upper airway obstruction

thumb sign

positive sign for epiglottitis

steeple sign

positive sign for croup

steps of CXR interpretation

• step 1

administrative

• patient name

• exam date

• position and markers

• quality of film

steps of CXR interpretation

• step 2

initial survey

• body size, shape, and symmetry

• sex

• relative age

steps of CXR interpretation

• step 3 (PA/AP)

anatomy

• hemidiaphragms

• costophrenic angles

• left ventricle

• right atrium

• right and left hilum

• aortic arch

• superior vena cava

• trachea

• carina

• clavicles

• ribs

• vertebrae

• scapulae

• cardiothoracic ratio

  • < 50% (adults)

  • < 60% (children)

steps of CXR interpretation

• step 3 (lateral)

anatomy

• sternum

• heart

• aortic arch

• trachea

• left bronchus

• scapulae

• retrosternal air space

• vertebrae

• hemidiaphragms

• costophrenic angle

steps of CXR interpretation

• step 4

film evaluation

• correct position

  • vertebral column between clavicles

  • costophrenic angles equidistant to spine

• exposure

  • spinous vertebrae seen to T5/T6

  • relative densities

• extent of inspiration (9-11 ribs posteriorly)

steps of CXR interpretation

• step 5

survey for foreign material

• medical: tubes, lines, EKG, drains, prostheses

• non-medical: bullets, shrapnel, aspirates, etc.

internal line placement

• ET tube

3-5 cm above carina (adults)

• 18-23 cm at teeth

internal line placement

• central catheter (triple lumen)

distal tip in superior vena cava or right atrium

internal line placement

• PICC line

tip in subclavian or superior vena cava junction

internal line placement

• NG/OG tube

tip below diaphragm

internal line placement

• Swan Ganz catheter

loop shape through great vessels and myocardium

internal line placement

• chest tube

• enters through 2nd or 3rd intercostal space

• distal tip through adipose tissue into thorax

causes of volume loss on CXR

• atelectasis

• simple pneumothorax

• pneumonectomy

• lobectomy

• wedge resection

causes of volume gain on CXR

• tension pneumothorax

• pleural effusion

• hyperinflation

CXR signs

• absorptive atelectasis

type of atelectasis

• obstructive lesion on bronchus

• CXR signs

  • density of segment/lobe

  • volume loss

  • hyperinflation of normal lung

CXR signs

• relaxation atelectasis

type of atelectasis

• lung close to center of chest due to negative pressure in pleura

• CXR sign

  • compressed lung due to pneumothorax or pleural effusion

CXR signs

• adhesive atelectasis

type of atelectasis

• alveoli collapse due to loss of surfactant

• CXR sign

  • collapsed alveoli

CXR signs

• COPD: emphysema

• lungs darker than normal

• volume gain

  • flat diaphragm

  • increased intercostal spaces

  • barrel chest

  • increased retrosternal air space (lateral)

• decreased total heart space

• increase in observable pulmonary vessels

CXR signs

• COPD: bronchitis

hyperinflated lungs

CXR signs

• COPD: bronchiectasis

• cystic fibrosis

• hyperinflated lungs with cystic parenchymal anatomy

• recurrent pneumonia

CXR signs

• asthma

bilateral volume gain with normal parenchymal anatomy

CXR signs

• CHF

• pulmonary edema

• pulmonary vessels swollen with fluid

• meniscus sign

• cardiomegaly

other diagnostic imaging

• dyes: barium, angiograms, bronchograms

• CT

• MRI

silhouette sign

normal border between 2 adjacent structures becomes invisible due to consolidation or fluid

Kurley lines

linear opacities which indicate pulmonary edema or lymph engorgement

meniscus sign

concave costophrenic angle indicating fluid in pleural space

radiolucent

dark area on x-ray

radiodense / radiopaque

white area on x-ray

infiltrate

abnormal substance in lungs

consolidation

replacement of air in lungs with fluid, blood, pus, etc.

hyperlucency

lung area that is darker (less dense) than normal due to emphysema or pneumothorax

cephalization of vascular markings

blood vessels of upper lobes are dilated in a similar fashion to lower lobes

• indicates increased pulmonary pressure

diffuse

spread out over an area

opaque

white or light gray area on x-ray indicating blocked radiation

fluffy infiltrates in butterfly or bat wing pattern

opacity pattern in lungs that indicates pulmonary edema, pneumonia, aspiration, or pulmonary bleed

patchy or plate-like infiltrates

increased lung density due to infection, cancer, fibrosis, atelectasis, etc.

ground glass appearance

hazy gray areas in lungs due to infection, inflammation, ILD, edema, bleeding, or cancer

honeycomb pattern

air-filled cysts due to fibrosis or ILD

air bronchograms

air-filled airways in consolidated lung region due to alveolar fluid

wedge shaped infiltrate

triangular opacity in section of lung due to pulmonary infarction

nodule

white area in x-ray due to infection, inflammation, fibrosis, or cancer

AP shadow effect

abnormal opaque area due to pneumonia, hernia, fluid, etc.

overexposed

x-ray is excessively dark caused by too much radiation

underexposed

x-ray is excessively white caused by not enough radiation

bibasilar infiltrates

fluid buildup in bases of both lungs