Transcript Reading Chest Radiographs - University of Washington

Reading Chest
Radiographs
Basics
Anterior-Posterior vs. Posterior-Anterior
AP exaggerates cardiac size
PA requires pt to stand
Look at the whole radiograph
Learn a system - do it the same EVERY time
System
A-B-C-D-E-F
A - Airway/lung fields
B - Bones/soft tissue
C - Cardiac/mediastinum
D - Diaphragm
E - Examine Technique
F - Foreign bodies
Lung Parenchyma
Classify disease into 3 categories
Airspace: alveolar filling
fluffy, opacities, air-bronchograms
Interstitial: lines and small dots
reticulonodular, reticular, nodular
Nodule: single or multiple, vary in size, w/
or w/o cavitation/calcification, smooth or
irregular
Consolidation
Filling or loss of air spaces
Pus - Pneumonia
Fluid - Pulmonary edema
Blood - infarct, hemorrhage
Foreign body - aspiration
Tumor - bronchoalveolar carcinoma
Volume loss - atelectasis
RML atelectasis
Consolidation
Radiographic signs
Opacity, air bronchograms, silhouetting
Silhouette sign: intrathoracic lesion
touching border of heart, aorta, diaphragm
obliterating that border
Helps to identify location of consolidation
Left Heart
Silhouette sign
Consolidation
Silhouette sign:
What structure is silhouetted on PA?
R heart = RML
L heart = lingula
Aorta, diaphragm = Lower lobe
Lateral view: which diaphragm is
silhouetted?
Fissure sign: abrupt edge @ margin
Increased density of vert. just above
diaphragm on lateral
Collapse
Atelectasis - volume loss
Extrinsic compression (effusion, tumor, etc)
Airway obstruction
Extraluminal - tumor, LAD
Intraluminal - tumor, foreign body
Lobar collapse: mediatstinal shift to affected
side, displacement of hilum/fissures, fewer
vessels on affected side
Interstitial Pattern
Acute process:
Pneumonia - viral, fungal, Tb, PCP
Edema - CHF, Renal failure w/ overload
Drug/Transfusion reaction
Chronic: many etiologies
Normal/low lung volumes
Interstitial Pattern
Upper lobe predominant
Tb, pneumoconioses, fibrosis from
ankylosing spondylitis
Mid lung predominant
sarcoid, berylliosis, allergic alveolitis,
eosinophilic granulomatosis
Lower lung predominant
IPF, lymphangitic tumor spread, CVD
fibrosis, chronic edema, drug rxn
Interstitial Pattern
Large Lung volumes: indicates air trapping
Cystic fibrosis
Eosinophilic granulomatosis
Lymhangioleiomyomatosis
Tuberous sclerosis
Pulmonary Nodule(s)
Solitary Nodule: many etiologies
Primary lung tumor, mets, granuloma,
septic emboli, pulmonary AVM, hamartoma,
Wegener’s vasculitis, bronchiectasis,
fungal infection, etc
Important features
Change over time: growing is worrisome
Calcification: eccentric is worrisome
Size: > 3cm more worrisome
Pulmonary Nodule(s)
Multiple Nodules
Metastatic until proven otherwise
septic/bland emboli
vasculitides, CVD
pneumoconioses
Eosinophilic granulomatosis
Fungi, viral, Tb PNA
Wegener’s
Lymphoma
Cardiac Anatomy
Frontal view
Right atrium
SVC
Aortic knob
Left atrial
appendage
Left ventricle
Lateral view
Right atrium/Ventricle
Left ventricle
Left atrium
Aortic arch
Main Pulm. Artery
Descending Thoracic Aorta
Cardiac Anatomy
On frontal CXR - 45% or less than largest
diameter from inner aspect of rib to rib
laterally
Right heart border - mostly RA
Left Border - Aortic arch, MPA, LAA, LV
Atrial/Ventricular
Hypertropy
Right Atrium - Right border >4cm from center
of spine
Right Ventricle - fills retrosternal space >1/3
distance between diaphragm &
sternomanubrial joint
Left Atrium - subcarinal angle >90 degrees,
posterior deviation of left main stem bronchus
Left Ventricle - LV reaches spine prior to
diaphragm
Pulmonary Vasculature
Many potential patterns to help narrow
differential for cardiac disease
3 you need to know
Normal - lower lobe vessels larger due to
gravity, taper smoothly to periphery,
interlobar arterial size (11-16mm M, 914mm F)
Pulmonary Vasculature
Pulmonary venous hypertension: upper lobe
vessels larger “cephalization” result of hypoxic
vasoconstriction; dependent edema
LV failure (ASCHD, valvular), atrial
myxoma, PVOD
Pulmonary arterial hypertension: “pruning” or
rapid tapering of peripheral vessels from large
central arteries
Chronic venous HTN, COPD, Chronic PE,
vasculitides, Primary PHTN, L-to-R shunt
Kerley A line
Mediastinum
Several compartments
Anterior: ant. = sternum, post. =
pericardium
Middle: ant. = pericardium, post. = trachea
Posterior: ant. = trachea, post. = ribs
Don’t miss a widened mediastinum = could be
an aortic aneurysm
Mediastinum
Masses by compartment
Anterior: “4T’s”
Teratoma
Thymoma
Terrible tumor (lymphoma, mets)
Thyroid - goiter
Middle:
Aortic aneurysm
Mediastinum
Lymph nodes - Lymphoma/Mets
Pericardial/bronchogenic cyst
Posterior:
Aneurysm
Lymph nodes
Neurogenic tumors - ganglion tumor
Spine - osteophyte
Esophagus - paraesophageal hernia
Substernal Thyroid
Pleural Abnormalities
Effusions: fluid
300-500cc to blunt CP angle on frontal
150cc posterior to blunt CP angle on lateral
Free flowing or not?: obtain bilateral
decubital films
Subpulmonic: lateral peaking of diaphragm,
loss lung parenchyma below diaphragm
Pleural Abnormalities
Pneumothorax: air in pleural space
Apical or “deep sulcus”
Tension: flattened ipsilateral lung on
mediastinum
Masses
Angle w/ chest wall is obtuse
Center of Mass
Well defined margin only on 1 side
Pleural Abnormalities
Thickening
Focal: unilateral
usually from infection/hemorrhage
Plaque from asbestosis - near
diaphragms
Diffuse: unilateral
Smooth: Old Tb, empyem, hemothorax,
mesothelioma, mets, lymphoma
Nodular: same except Tb