In unstable patients with suspected thoracoabdominal injury, which imaging modality is preferred for rapid evaluation?

• A. CT first in unstable
• B. FAST for rapid evaluation
• C. MRI
• D. X-ray

Answer: (B)

In the unstable patient with suspected thoracoabdominal injury, the priority is rapid, bedside information to guide immediate management. Focused Assessment with Sonography for Trauma (FAST) provides quick, real-time checks for free intraperitoneal fluid that signals hemorrhage and can reveal pericardial effusion suggesting tamponade. When extended to the FAST exam (EFAST), it also screens for pneumothorax and hemothorax, which are common life-threatening injuries in chest trauma. The strength of FAST is its speed, portability, and repeatability at the bedside, with no radiation exposure, making it ideal during ongoing resuscitation. CT scanning, while more detailed, requires patient stabilization and transport to the scanner, which can delay critical decisions in someone who is unstable. X-ray and MRI have limitations in this context: X-ray may miss intraperitoneal bleeding, and MRI is not feasible for a hemodynamically compromised patient.