Imaging the chest in Imaging the chest in traumatrauma

Chest traumaChest traumaBlunt

Penetrating

Trauma Chest RadiographTrauma Chest Radiograph

Usually AP, often supine, frequently in poor inspiration.

CT ChestCT Chest

Fractures and DislocationsFractures and DislocationsSpineRibsClaviclesSternumShoulders

Spine InjuriesSpine Injuries

Loss of alignment, fractures and paraspinal hematoma.

Rib FracturesRib Fractures

Indicator of underlying pleura, lung, liver, spleen, kidney injuries.

Flail ChestFlail Chest

Multiple rib fractures, especially if individual ribs fractured more than once, may cause paradoxical motion.

Associated pulmonary contusion.

Clavicle InjuriesClavicle Injuries

Sterno-clavicle joint Sterno-clavicle joint dislocationdislocation

Sterno-clavicle dislocation: Sterno-clavicle dislocation: CTCT

Shoulder InjuriesShoulder Injuries

dislocations and scapula fractures

CT Needed if Scapula Fracture CT Needed if Scapula Fracture SeenSeen

Sternum FracturesSternum Fractures

AIR where it shouldnAIR where it shouldn’’t bet bePneumothoraxPneumomediastinumSubcutaneous emphysemaSystemic venous air embolismPneumopericardiumPneumoperitoneum/

retroperitoneum

pnxpnx

PNEUMOTHORAX: CTPNEUMOTHORAX: CTMuch more sensitive

Even a small traumatic pneumothorax is important, especially if patient mechanically ventilated or going to OR: A simple pneumothorax can be converted into a life- threatening tension pneumothorax.

PNEUMOTHORAX: CTPNEUMOTHORAX: CT

Pneumothorax: SimplePneumothorax: SimpleErect AP/PA view bestVisceral pleural lineNo vessels or markingsVariable degree of lung collapseNo shift

PNEUMOTHORAX: SimplePNEUMOTHORAX: Simple

PNEUMOTHORAX: TensionPNEUMOTHORAX: TensionErect AP/PA view bestShift of

mediastinum/heart/trachea away from PTX side

Depressed hemidiaphragmDegree of lung collapse is

variable

PNEUMOTHORAX: TensionPNEUMOTHORAX: Tension

PNEUMOTHORAX: SupinePNEUMOTHORAX: SupineSupine AP view has limited sensitivity:

50%Deep sulcus signToo sharp heart

border/hemidiaphragm signIncreased lucency over lower chest

Cant see vessels

PNEUMOTHORAX: OpenPNEUMOTHORAX: Open

A large hole in the chest caused by a large low velocity missile.

Air enters the hole rather than the trachea causing hypoxia.

PNEUMOMEDIASTIUMPNEUMOMEDIASTIUMUsually from ruptured alveoli.Can also be from trachea,

bronchi, esophagus, bowel and neck injuries.

SignsSigns

Linear paratracheal lucencies

Air along heart border

“V ” sign at aortic-diaphragm junction

Continuous diaphragm sign

Continuous diaphragm signContinuous diaphragm sign

V sign of naclerioV sign of naclerio

PNEUMOMEDIASTINUM: CTPNEUMOMEDIASTINUM: CT

Trachea/bronchi injuriesTrachea/bronchi injuries

Tears occur within 2cm of carina

Persistant pneumothorax

Large pneumomediastinum

“Fallen lung”

Subcutaneous EmphysemaSubcutaneous Emphysema

Causes: Same as pneumomediastinum

PneumopericardiumPneumopericardium

PneumoperitoneumPneumoperitoneum

Pneumoperitoneum and sometimes pneumo-

retroperitoneum are seen on upright chest film, but occasionally are visible on supine chest radiograph.

HEMOTHORAXHEMOTHORAXVenous or arterial bleedingCan miss hundreds of cc’s on

supine film

HEMOTHORAXHEMOTHORAX

CT: HEMOTHORAXCT: HEMOTHORAX

PULMONARY CONTUSION PULMONARY CONTUSION and LACERATIONand LACERATIONContusion: Blood in intact lung

parenchymaLaceration: Blood in torn lung

parenchymaCan’t tell difference on chest film.

Contusions peak in 2-3 days, begin to resolve in a week; lacerations take much longer to resolve and may leave scars

Pulmonary Contusion and Pulmonary Contusion and LacerationLaceration

Marked contusionsMarked contusions

ContusionsContusions

CT: Pulmonary ContusionCT: Pulmonary Contusion

DIAPHRAGM InjuriesDIAPHRAGM Injuries5% of major blunt

trauma, also thoraco-abdominal penetrating trauma

Left clinically injured more than right 60/40

Sensitivity of Chest film 40%. CT better, but still misses some

Hard signs: NGT through g.e. junction then up into chest, and hollow viscus above diaphragm

Soft signs: Indistinct diaphragm, effusion, atelectasis

Position of NG TubePosition of NG Tube

Gut in ChestGut in Chest

Vascular InjuryVascular Injury

Signs of mediastinal haematoma:widened mediastinumindistinct or abnormal aortic contourdeviation of trachea or NGT to the rightdepression of left main bronchuswidened paraspinal stripe

CTCTIndirect signs of aortic injury:mediastinal haematomaperiaortic fat stranding

CTA : sensitivity 100%; specificity 100%.Signs of mediastinal haematoma:abnormal soft tissue density around mediastinal structuresLocation – periaortic haematoma than isolated mediastinal haematoma remote from the aorta.

Signs of aortic injury:intraluminal filling defect (intimal flap or clot)abnormal aortic contour (mural haematoma)Pseudoaneurysm & extravasation of contrast