What are the expected findings in a post-mortem computed tomography (PMCT) scan of a young to middle-aged adult blast trauma victim with no significant past medical history?

Expected PMCT Findings in Blast Trauma Victims

In a young to middle-aged adult blast trauma victim, post-mortem CT (PMCT) should demonstrate a characteristic multidimensional injury pattern including primary blast injuries to gas-containing organs (lungs, bowel, ears), secondary injuries from projectile fragments with unpredictable trajectories, tertiary blunt trauma from bodily displacement, and quaternary thermal injuries—with whole-body CT being essential as blast victims typically sustain injuries to three or more body regions in 47% of cases. 1

Primary Blast Injuries (Direct Overpressure Effects)

Pulmonary findings are the hallmark of primary blast injury and should be actively sought on PMCT:

• "Peribronchovascular" or "batwing/butterfly" pattern of central lung opacities, which is the characteristic imaging appearance of primary blast lung injury on CT 2
• Crescentic ground-glass opacities and areas of consolidation that do not respect anatomic lobar boundaries 2
• Pulmonary lacerations may appear 48-72 hours post-injury due to elastic recoil, presenting as cavitary lesions that can be missed on initial radiographs 2
• Sub-pleural sparing may be present in smaller contusions, helping distinguish blast injury from pneumonia 2

Hollow viscus injuries occur in 14-43.6% of blast victims in enclosed spaces:

• Bowel perforations, particularly when the explosion occurs in a confined space where blast overpressure reaches 3.8-5.2 atmospheres 3
• These injuries may be occult and require careful CT evaluation of bowel wall integrity and free fluid 3

Air embolism-induced injuries should be considered, as primary blast can cause acute arterial occlusion 4

Secondary Blast Injuries (Projectile/Fragment Trauma)

Secondary injuries are the most common extremity blast injuries and create the most unpredictable CT findings: 4

• Multiple metallic foreign bodies with unpredictable trajectories throughout the body—liberal whole-body imaging is mandatory because terminal ballistics of fragments are erratic 5
• Radiodense markers at entry/exit wounds help determine trajectory on CT 5
• Severe soft-tissue contamination with foreign material requiring identification of all penetrating tracts 4
• Fractures, traumatic amputations, and vascular injuries (pseudoaneurysms, occlusions, arteriovenous fistulas) best demonstrated on CTA 5

Tertiary Blast Injuries (Bodily Displacement)

Blunt trauma patterns from the victim being thrown by the blast wave: 6

• Traumatic amputations 4
• Multiple fractures, particularly skull fractures and long bone fractures 4, 6
• Blunt head trauma with intracranial hemorrhage 6
• Blunt torso trauma including solid organ injuries (liver, spleen lacerations) best seen on contrast-enhanced CT 5
• Flail chest occurs four times more frequently in combat blast casualties compared to civilian populations 2

Quaternary Blast Injuries (Miscellaneous)

• Burns occur in 12.7% of blast victims 1
• Thermal inhalation injury 6
• Crush injuries and compartment syndrome from structural collapse 6

Critical PMCT Protocol Considerations

Whole-body CT with IV contrast (if feasible in post-mortem setting) is the imaging standard:

• Single-acquisition whole-torso imaging is preferred over segmental imaging to follow projectile tracts 5
• Blast victims have significantly higher Injury Severity Scores (median 20.54) and involvement of three or more body regions (47.22%) compared to gunshot injuries 1
• Head (27.27%), facial (20%), and extremity injuries (85.45%) occur at significantly higher frequencies in blast trauma 1

Multi-detector CT with multi-planar reconstructions is the most sensitive modality for evaluating combat-related thoracic trauma 2

Common Pitfalls to Avoid

• Failing to image the entire body—the multidimensional nature of blast injury means isolated regional imaging will miss critical injuries 1
• Overlooking delayed pulmonary lacerations that may not appear until 48-72 hours post-injury 2
• Missing occult bowel perforations from primary blast injury, particularly in enclosed space explosions 3
• Underestimating the extent of secondary fragment injuries—liberal use of radiography in areas of skin punctures identifies foreign bodies requiring documentation 6
• Not recognizing the peribronchovascular pattern as specific for primary blast lung injury versus other causes of pulmonary trauma 2