Chest (lateral decubitus view)
The lateral decubitus view of the chest is a specialized projection rarely utilized with the commonality of CT. It is chiefly used in the pediatric population.
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Indication
Undertaken to demonstrate small pleural effusions, or for the investigation of pneumothorax and air trapping due to inhaled foreign bodies.
Patient position
- the patient is laying either left lateral or right lateral on a trolley on top of a radiolucent sponge
- note: when investigating pneumothorax the side of interest should be up; when investigating pleural effusions the side of interest should be down
- the detector is placed landscape posterior to the patient running parallel with the long axis of the thorax
- patient's hands should be raised to avoid superimposing on the region of interest, legs may be flexed for balance
- rotation of shoulders or pelvis should be minimized
- patients should be changed into a hospital gown, with radiopaque items (e.g. belts, zippers) removed
- x-ray is taken in full inspiration
Technical factors
- lateral decubitus
-
centering point
- midsagittal place (xiphisternum) at the level of T7
-
collimation
- laterally to include both lungs
- superior to the apex
- inferior to the costodiaphragmatic recess
-
orientation
- portrait (relative to the patient)
-
detector size
- 35 cm x 43 cm
-
exposure
- 100 - 125 kVp
- 3 - 10 mAs
-
SID
- 100 cm
-
grid
- yes
Image technical evaluation
A marker annotating 'horizontal beam decubitus" should always be present, with the side of interest clearly labeled.
The entire lung fields should be visible from the apices down to the lateral costophrenic angles.
- the chin should not be superimposing any structures
- minimal to no superimposition of the scapulae borders on the lung fields
- sternoclavicular joints are equal distant apart
- the clavicle is in the same horizontal plane
- a minimum of ten posterior ribs is visualized above the diaphragm
- the ribs and thoracic cage are seen only faintly over the heart
- clear vascular markings of the lungs should be visible
Practical points
- in the context of inhaled foreign bodies, bilateral decubitus lateral views should be performed, allowing for adequate assessment of any air trapping
- patients with obstructive foreign bodies will not have a collapsed lung, however, will manifest hyperlucency of the dependent lung
- ensure the patient is carefully rested against the wall detector and at no risk of falling
- rotation of a chest radiograph can simulate common pathology processes and make it hard to produce an appropriate diagnosis
- the sternoclavicular joints are a sound indicator for positional rotation, if one sternoclavicular joint is notably wider than the other, that respected side needs to be rotated toward the image receptor to correct rotation
- patients with a longstanding history of emphysema or COPD will have abnormally long lungs compared to the general population, remember this when collimating superior to inferior
- side marker placement is imperative; patients can have congenital conditions that mimic a mirrored image
- remember to explain to your patient what you are about to do; that is ask them to take a breath in and hold it; many times this gives the patient time to prepare and results in a better breath hold and therefore a higher quality radiograph
- always remember to tell your patient to breathe again
Related Radiopaedia articles
Radiographic views
- imaging in practice
- paediatric radiography
- general radiography (adult)
- shunt series
- chest radiography
- abdominal radiography
-
upper limb radiography
-
shoulder girdle radiography
- scapula series
-
shoulder series
- AP view
- internal rotation view
- external rotation view
- superoinferior axial view
- inferosuperior axial view
- modified trauma axial
- supine lateral
- modified supine lateral
- Y lateral view
- AP glenoid view (Grashey view)
- apical oblique view (Garth view)
- humerus (neck) AP view
- humerus axial (bicipital groove) view (Fisk view)
- outlet view (Neer view)
- Stryker notch view
- acromioclavicular joint series
- clavicle series
- sternoclavicular joint series
- arm and forearm radiography
- wrist and hand radiography
-
shoulder girdle radiography
-
lower limb radiography
- pelvic girdle radiography
- thigh and leg radiography
- ankle and foot radiography
- skull radiography
-
paranasal sinuses and facial bones radiography
- facial bones
- Caldwell view (angled skull PA view)
- nasal bones
- zygomatic arches
- orbits
- paranasal sinuses
- temporal bones
- dental radiography
- orthopantomography (OPG)
- mandible
- temporomandibular joints
- spine radiography
Chest
- imaging techniques
-
chest x-ray
-
approach
- adult
- pediatric
- neonatal
-
airspace opacification
- differential diagnoses of airspace opacification
- lobar consolidation
-
atelectasis
- mechanism-based
- morphology-based
- lobar lung collapse
- chest x-ray in the exam setting
- cardiomediastinal contour
- chest radiograph zones
- tracheal air column
- fissures
- normal chest x-ray appearance of the diaphragm
- nipple shadow
-
lines and stripes
- anterior junction line
- posterior junction line
- right paratracheal stripe
- left paratracheal stripe
- posterior tracheal stripe/tracheo-esophageal stripe
- posterior wall of bronchus intermedius
- right paraspinal line
- left paraspinal line
- aortic-pulmonary stripe
- aortopulmonary window
- azygo-esophageal recess
- spaces
- signs
- air bronchogram
- big rib sign
- Chang sign
- Chen sign
- coin lesion
- continuous diaphragm sign
- dense hilum sign
- double contour sign
- egg-on-a-string sign
- extrapleural sign
- finger in glove sign
- flat waist sign
- Fleischner sign
- ginkgo leaf sign
- Golden S sign
- Hampton hump
- haystack sign
- hilum convergence sign
- hilum overlay sign
- Hoffman-Rigler sign
- holly leaf sign
- incomplete border sign
- juxtaphrenic peak sign
- Kirklin sign
- medial stripe sign
- melting ice cube sign
- more black sign
- Naclerio V sign
- Palla sign
- pericardial fat tag sign
- Shmoo sign
- silhouette sign
- snowman sign
- spinnaker sign
- steeple sign
- straight left heart border sign
- third mogul sign
- tram-track sign
- walking man sign
- water bottle sign
- wave sign
- Westermark sign
-
approach
- HRCT
-
chest x-ray
- airways
- bronchitis
- small airways disease
-
bronchiectasis
- broncho-arterial ratio
- related conditions
- differentials by distribution
- narrowing
-
tracheal stenosis
- diffuse tracheal narrowing (differential)
-
bronchial stenosis
- diffuse airway narrowing (differential)
-
tracheal stenosis
- diverticula
- pulmonary edema
-
interstitial lung disease (ILD)
- drug-induced interstitial lung disease
-
hypersensitivity pneumonitis
- acute hypersensitivity pneumonitis
- subacute hypersensitivity pneumonitis
- chronic hypersensitivity pneumonitis
- etiology
- bird fancier's lung: pigeon fancier's lung
- farmer's lung
- cheese workers' lung
- bagassosis
- mushroom worker’s lung
- malt worker’s lung
- maple bark disease
- hot tub lung
- wine maker’s lung
- woodsman’s disease
- thatched roof lung
- tobacco grower’s lung
- potato riddler’s lung
- summer-type pneumonitis
- dry rot lung
- machine operator’s lung
- humidifier lung
- shower curtain disease
- furrier’s lung
- miller’s lung
- lycoperdonosis
- saxophone lung
-
idiopathic interstitial pneumonia (mnemonic)
- acute interstitial pneumonia (AIP)
- cryptogenic organizing pneumonia (COP)
- desquamative interstitial pneumonia (DIP)
- non-specific interstitial pneumonia (NSIP)
- idiopathic pleuroparenchymal fibroelastosis
- lymphoid interstitial pneumonia (LIP)
- respiratory bronchiolitis–associated interstitial lung disease (RB-ILD)
- usual interstitial pneumonia / idiopathic pulmonary fibrosis (UIP/IPF)
-
pneumoconioses
- fibrotic
- non-fibrotic
-
lung cancer
-
non-small-cell lung cancer
-
adenocarcinoma
- pre-invasive tumors
- minimally invasive tumors
- invasive tumors
- variants of invasive carcinoma
- described imaging features
- adenosquamous carcinoma
- large cell carcinoma
- primary sarcomatoid carcinoma of the lung
- squamous cell carcinoma
- salivary gland-type tumors
-
adenocarcinoma
- pulmonary neuroendocrine tumors
- preinvasive lesions
-
lung cancer invasion patterns
- tumor spread through air spaces (STAS)
- presence of non-lepidic patterns such as acinar, papillary, solid, or micropapillary
- myofibroblastic stroma associated with invasive tumor cells
- pleural invasion
- vascular invasion
- tumors by location
- benign neoplasms
- pulmonary metastases
- lung cancer screening
- lung cancer staging
-
non-small-cell lung cancer