1. Imaging: Thoracic Trauma
Tony Tiemesmann
Diagnostic Radiology
Bloemfontein Hospital Complex

2. Heart, Great Vessels, Esophagus, Tracheobronchial Tree, & Lungs
Introduction
Vital Structures
Heart, Great Vessels, Esophagus, Tracheobronchial Tree, & Lungs
25% of MVC deaths are due to thoracic trauma
12,000 annually in US
Abdominal injuries are common with chest trauma.
Prevention Focus
Gun Control Legislation
Improved motor vehicle restraint systems
Passive Restraint Systems
Airbags

3. Thoracic Skeleton Anatomy 1 12 Pair of C-shaped ribs Sternum Manubrium
Ribs 1-7: Join at sternum with cartilage end-points
Ribs 8-10: Join sternum with combined cartilage at 7th rib
Ribs 11-12: No anterior attachment
Sternum
Manubrium
Joins to clavicle and 1st rib
Jugular Notch
Body
Sternal angle (Angle of Louis)
Junction of the manubrium with the sternal body
Attachment of 2nd rib
Xiphoid process
Distal portion of sternum

4. Anatomy 2
3 weeks of gestation in humans

5. Anatomy 3
Neural
crest
Step 1: Neural groove forms.

6. Anatomy 4 Mediastinum Central space within thoracic cavity Boundaries
Lateral: Mediastinal pleura
Inferior: Diaphragm
Superior: Thoracic inlet
Posterior: Thoracic spine
Anterior: Sternum & costal cartilages
Superior & Inferior mediastinum
Inferior mediastinum
Anterior
Middle
Posterior

7. Anatomy 5 Structures (superior) Structures (inferior) Great Vessels
Oesophagus
Trachea
Nerves
Vagus
Phrenic
Thoracic Duct
Structures (inferior)
Anterior – fat, lymph nodes
Middle – heart, aorta, lower SVC, Trachea & main bronchi, lymph nodes, pulmonary veins & arteries, phrenic nerve
Posterior – Aorta, oesophagus, azygous & hemiazygous, thoracic duct, vagus

8. Heart Heart General Structure Pericardium Epicardium Myocardium
Surrounds heart
Visceral
Parietal
Serous
35-50 ml fluid
Epicardium
Outer Layer
Myocardium
Muscular layer
Endocardium
Innermost layer
4 weeks
6 weeks

9. Great Vessels Great Vessels Aorta Superior Vena Cava
Fixed at three sites
Annulus
Attaches to heart
Ligamentum Arteriosum
Near bifurcation of pulmonary artery
Aortic hiatus
Passes through diaphragm
Superior Vena Cava
Inferior Vena Cava
Pulmonary Arteries
Pulmonary Veins

10. Oesophagus Esophagus Enters at thoracic inlet Posterior to trachea
Exits at esophageal hiatus

11. Pathophysiology Blunt & Penetrating Trauma
Results from kinetic energy forces
Subdivision Mechanisms
Blast
Pressure wave causes tissue disruption
Tear blood vessels & disrupt alveolar tissue
Disruption of tracheobronchial tree
Traumatic diaphragm rupture
Crush (Compression)
Body is compressed between an object and a hard surface
Direct injury of chest wall and internal structures
Deceleration
Body in motion strikes a fixed object
Blunt trauma to chest wall
Internal structures continue in motion
Age Factors
Pediatric Thorax: More cartilage = Absorbs forces
Geriatric Thorax: Calcification & osteoporosis = More fractures

12. Cardiovascular 1 Myocardial Contusion
Occurs in 76% of patients with severe blunt chest trauma
Right Atrium and Ventricle is commonly injured
Injury may reduce strength of cardiac contractions
Reduced cardiac output
Electrical Disturbances due to irritability of damaged myocardial cells

13. Pericardial Tamponade
Cardiovascular 2
Pericardial Tamponade
Restriction to cardiac filling caused by blood or other fluid within the pericardium
Occurs in <2% of all serious chest trauma
However, very high mortality
Results from tear in the coronary artery or penetration of myocardium
Blood seeps into pericardium and is unable to escape
ml of blood can restrict effectiveness of cardiac contractions
Removing as little as 20 ml can provide relief

14. Myocardial Aneurysm or Rupture
Cardiovascular 3
Myocardial Aneurysm or Rupture
Occurs almost exclusively with extreme blunt thoracic trauma
Secondary due to necrosis resulting from MI
Signs & Symptoms
Severe rib or sternal fracture
Possible signs and symptoms of cardiac tamponade
If affects valves only
Signs & symptoms of right or left heart failure
Absence of vital signs

15. Traumatic Aneurysm or Aortic Rupture
Cardiovascular 4
Traumatic Aneurysm or Aortic Rupture
Aorta most commonly injured in severe blunt or penetrating trauma
85-95% mortality
Typically patients will survive the initial injury insult
30% mortality in 6 hrs
50% mortality in 24 hrs
70% mortality in 1 week
Injury may be confined to areas of aorta attachment
Signs & Symptoms
Rapid and deterioration of vitals
Pulse deficit between right and left upper or lower extremities

16. Other Vascular Injuries
Cardiovascular 5
Other Vascular Injuries
Rupture or laceration
Superior Vena Cava
Inferior Vena Cava
General Thoracic Vasculature
Blood Localizing in Mediastinum
Compression of:
Great vessels
Myocardium
Esophagus

17. Traumatic Esophageal Rupture
Oesophagus
Traumatic Esophageal Rupture
Rare complication of blunt thoracic trauma
30% mortality
Contents in esophagus/stomach may move into mediastinum
Serious Infection occurs
Chemical irritation
Damage to mediastinal structures
Air enters mediastinum
Subcutaneous emphysema and penetrating trauma present

18. Imaging: Radiography
NB NB
Delay only in life-threatening conditions
Haemo/Pneumothorax
Fractures (ribs - flail chest)
Mediastinum – widened, air
Diaphragmatic rupture
Foreign bodies

19. Imaging: Computed tomography
Blunt lung trauma – blood in bronchi, interstitial blood
Cardiac & major vessel trauma (with or without angio)
critical area to evaluate on CT scans is the aorta at the level of the left main pulmonary artery (90% of all CT-detected aortic injuries begin at or just above this level and that 85% of aortic injuries end at or just below it)
CTA
Bony elements & surrounding tissue

20. Imaging: MRI
Stable patients
CT unequivocal
NB: vascular and spinal injuries

21. Imaging: Ultrasound
Quick & non-invasive
FAST (focussed assessment for sonographic evaluation of the trauma patient)
Percardiac – percardiocentesis
Sternum
Pleural
Pulmonary contusion
Diaphragm
NB: Degree of confidence

22. Imaging: Echocardiography
Acute blunt cardiac injury – chamber disruption, valvular incompetence, coronary artery thrombosis, ventricular aneurysm formation, myocardial contusion
Detectable functional changes – cardiac function, motion abnormalities of the cardiac wall, pericardial effusions, valvular injury

23. Imaging: Angiography
Widened mediastinum on CXR (3% aortic injury)
Aortogram – rupture/pseudoaneurysm

24. Imaging: Nuclear medicine
Continuing symptoms with no radiological signs
Skeletal - technetium-99m diphosphonate
Cardiac - thallium-201 chloride

25. Trauma Imaging 1

26. Trauma Imaging 2

27. Trauma Imaging 3

28. Trauma Imaging 4

29. Trauma Imaging 5

30. Trauma Imaging 6

31. Trauma Imaging 7

32. Trauma Imaging 8

33. Trauma Imaging 9

34. Trauma Imaging 10

35. References
Kaewlai R, Avery L, Asrani A, Novelline R. Multidetector CT of Blunt Thoracic Trauma. RadioGraphics 2008; 28:1555–1570.
Jin W, Yang DM, Kim HC, Ryu KN. Diagnostic values of sonography for assessment of sternal fractures compared with conventional radiography and bone scans. J Ultrasound Med. Oct 2006;25(10):1263-8; quiz
Gavelli G, Canini R, Bertaccini P. Traumatic injuries: imaging of thoracic injuries. Eur Radiol. Jun 2002;12(6):
Khan AL et al. Trauma thoracic imaging. Medscape Oct 2011.
DiMaio VJM, Dana SE. Handbook of forensic pathology 2nd ed. CRC Press